summaryrefslogtreecommitdiff
path: root/gcc/stmt.c
blob: 0baeb8ce27281183aabf57a3b2a95654c663a65e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
5501
5502
5503
5504
5505
5506
5507
5508
5509
5510
5511
5512
5513
5514
5515
5516
5517
5518
5519
5520
5521
5522
5523
5524
5525
5526
5527
5528
5529
5530
5531
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
5547
5548
5549
5550
5551
5552
5553
5554
5555
5556
5557
5558
5559
5560
5561
5562
5563
5564
5565
5566
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
5586
5587
5588
5589
5590
5591
5592
5593
5594
5595
5596
5597
5598
5599
5600
5601
5602
5603
5604
5605
5606
5607
5608
5609
5610
5611
5612
5613
5614
5615
5616
5617
5618
5619
5620
5621
5622
5623
5624
5625
5626
5627
5628
5629
5630
5631
5632
5633
5634
5635
5636
5637
5638
5639
5640
5641
5642
5643
5644
5645
5646
5647
5648
5649
5650
5651
5652
5653
5654
5655
5656
5657
5658
5659
5660
5661
5662
5663
5664
5665
5666
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
5681
5682
5683
5684
5685
5686
5687
5688
5689
5690
5691
5692
5693
5694
5695
5696
5697
5698
5699
5700
5701
5702
5703
5704
5705
5706
5707
5708
5709
5710
5711
5712
5713
5714
5715
5716
5717
5718
5719
5720
5721
5722
5723
5724
5725
5726
5727
5728
5729
5730
5731
5732
5733
5734
5735
5736
5737
5738
5739
5740
5741
5742
5743
5744
5745
5746
5747
5748
5749
5750
5751
5752
5753
5754
5755
5756
5757
5758
5759
5760
5761
5762
5763
5764
5765
5766
5767
5768
5769
5770
5771
5772
5773
5774
5775
5776
5777
5778
5779
5780
5781
5782
5783
5784
5785
5786
5787
5788
5789
5790
5791
5792
5793
5794
5795
5796
5797
5798
5799
5800
5801
5802
5803
5804
5805
5806
5807
5808
5809
5810
5811
5812
5813
5814
5815
5816
5817
5818
5819
5820
5821
5822
5823
5824
5825
5826
5827
5828
5829
5830
5831
5832
5833
5834
5835
5836
5837
5838
5839
5840
5841
5842
5843
5844
5845
5846
5847
5848
5849
5850
5851
5852
5853
5854
5855
5856
5857
5858
5859
5860
5861
5862
5863
5864
5865
5866
5867
5868
5869
5870
5871
5872
5873
5874
5875
5876
5877
5878
5879
5880
5881
5882
5883
5884
5885
5886
5887
5888
5889
5890
5891
5892
5893
5894
5895
5896
5897
5898
5899
5900
5901
5902
5903
5904
5905
5906
5907
5908
5909
5910
5911
5912
5913
5914
5915
5916
5917
5918
5919
5920
5921
5922
5923
5924
5925
5926
5927
5928
5929
5930
5931
5932
5933
5934
5935
5936
5937
5938
5939
5940
5941
5942
5943
5944
5945
5946
5947
5948
5949
5950
5951
5952
5953
5954
5955
5956
5957
5958
5959
5960
5961
5962
5963
5964
5965
5966
5967
5968
5969
5970
5971
5972
5973
5974
5975
5976
5977
5978
5979
5980
5981
5982
5983
5984
5985
5986
5987
5988
5989
5990
5991
5992
5993
5994
5995
5996
5997
5998
5999
6000
6001
6002
6003
6004
6005
6006
6007
6008
6009
6010
6011
6012
6013
6014
6015
6016
6017
6018
6019
6020
6021
6022
6023
6024
6025
6026
6027
6028
6029
6030
6031
6032
6033
6034
6035
6036
6037
6038
6039
6040
6041
6042
6043
6044
6045
6046
6047
6048
6049
6050
6051
6052
6053
6054
6055
6056
6057
6058
6059
6060
6061
6062
6063
6064
6065
6066
6067
6068
6069
6070
6071
6072
6073
6074
6075
6076
6077
6078
6079
6080
6081
6082
6083
6084
6085
6086
6087
6088
6089
6090
6091
6092
6093
6094
6095
6096
6097
6098
6099
6100
6101
6102
6103
6104
6105
6106
6107
6108
6109
6110
6111
6112
6113
6114
6115
6116
6117
6118
6119
6120
6121
6122
6123
6124
6125
6126
6127
6128
6129
6130
6131
6132
6133
6134
6135
6136
6137
/* Expands front end tree to back end RTL for GCC
   Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
   1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING.  If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.  */

/* This file handles the generation of rtl code from tree structure
   above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
   It also creates the rtl expressions for parameters and auto variables
   and has full responsibility for allocating stack slots.

   The functions whose names start with `expand_' are called by the
   parser to generate RTL instructions for various kinds of constructs.

   Some control and binding constructs require calling several such
   functions at different times.  For example, a simple if-then
   is expanded by calling `expand_start_cond' (with the condition-expression
   as argument) before parsing the then-clause and calling `expand_end_cond'
   after parsing the then-clause.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"

#include "rtl.h"
#include "tree.h"
#include "tm_p.h"
#include "flags.h"
#include "except.h"
#include "function.h"
#include "insn-config.h"
#include "expr.h"
#include "libfuncs.h"
#include "hard-reg-set.h"
#include "loop.h"
#include "recog.h"
#include "machmode.h"
#include "toplev.h"
#include "output.h"
#include "ggc.h"
#include "langhooks.h"
#include "predict.h"
#include "optabs.h"
#include "target.h"
#include "regs.h"

/* Functions and data structures for expanding case statements.  */

/* Case label structure, used to hold info on labels within case
   statements.  We handle "range" labels; for a single-value label
   as in C, the high and low limits are the same.

   An AVL tree of case nodes is initially created, and later transformed
   to a list linked via the RIGHT fields in the nodes.  Nodes with
   higher case values are later in the list.

   Switch statements can be output in one of two forms.  A branch table
   is used if there are more than a few labels and the labels are dense
   within the range between the smallest and largest case value.  If a
   branch table is used, no further manipulations are done with the case
   node chain.

   The alternative to the use of a branch table is to generate a series
   of compare and jump insns.  When that is done, we use the LEFT, RIGHT,
   and PARENT fields to hold a binary tree.  Initially the tree is
   totally unbalanced, with everything on the right.  We balance the tree
   with nodes on the left having lower case values than the parent
   and nodes on the right having higher values.  We then output the tree
   in order.  */

struct case_node GTY(())
{
  struct case_node	*left;	/* Left son in binary tree */
  struct case_node	*right;	/* Right son in binary tree; also node chain */
  struct case_node	*parent; /* Parent of node in binary tree */
  tree			low;	/* Lowest index value for this label */
  tree			high;	/* Highest index value for this label */
  tree			code_label; /* Label to jump to when node matches */
  int			balance;
};

typedef struct case_node case_node;
typedef struct case_node *case_node_ptr;

/* These are used by estimate_case_costs and balance_case_nodes.  */

/* This must be a signed type, and non-ANSI compilers lack signed char.  */
static short cost_table_[129];
static int use_cost_table;
static int cost_table_initialized;

/* Special care is needed because we allow -1, but TREE_INT_CST_LOW
   is unsigned.  */
#define COST_TABLE(I)  cost_table_[(unsigned HOST_WIDE_INT) ((I) + 1)]

/* Stack of control and binding constructs we are currently inside.

   These constructs begin when you call `expand_start_WHATEVER'
   and end when you call `expand_end_WHATEVER'.  This stack records
   info about how the construct began that tells the end-function
   what to do.  It also may provide information about the construct
   to alter the behavior of other constructs within the body.
   For example, they may affect the behavior of C `break' and `continue'.

   Each construct gets one `struct nesting' object.
   All of these objects are chained through the `all' field.
   `nesting_stack' points to the first object (innermost construct).
   The position of an entry on `nesting_stack' is in its `depth' field.

   Each type of construct has its own individual stack.
   For example, loops have `loop_stack'.  Each object points to the
   next object of the same type through the `next' field.

   Some constructs are visible to `break' exit-statements and others
   are not.  Which constructs are visible depends on the language.
   Therefore, the data structure allows each construct to be visible
   or not, according to the args given when the construct is started.
   The construct is visible if the `exit_label' field is non-null.
   In that case, the value should be a CODE_LABEL rtx.  */

struct nesting GTY(())
{
  struct nesting *all;
  struct nesting *next;
  int depth;
  rtx exit_label;
  enum nesting_desc {
    COND_NESTING,
    LOOP_NESTING,
    BLOCK_NESTING,
    CASE_NESTING
  } desc;
  union nesting_u
    {
      /* For conds (if-then and if-then-else statements).  */
      struct nesting_cond
	{
	  /* Label for the end of the if construct.
	     There is none if EXITFLAG was not set
	     and no `else' has been seen yet.  */
	  rtx endif_label;
	  /* Label for the end of this alternative.
	     This may be the end of the if or the next else/elseif.  */
	  rtx next_label;
	} GTY ((tag ("COND_NESTING"))) cond;
      /* For loops.  */
      struct nesting_loop
	{
	  /* Label at the top of the loop; place to loop back to.  */
	  rtx start_label;
	  /* Label at the end of the whole construct.  */
	  rtx end_label;
	  /* Label for `continue' statement to jump to;
	     this is in front of the stepper of the loop.  */
	  rtx continue_label;
	} GTY ((tag ("LOOP_NESTING"))) loop;
      /* For variable binding contours.  */
      struct nesting_block
	{
	  /* Sequence number of this binding contour within the function,
	     in order of entry.  */
	  int block_start_count;
	  /* Nonzero => value to restore stack to on exit.  */
	  rtx stack_level;
	  /* The NOTE that starts this contour.
	     Used by expand_goto to check whether the destination
	     is within each contour or not.  */
	  rtx first_insn;
	  /* Innermost containing binding contour that has a stack level.  */
	  struct nesting *innermost_stack_block;
	  /* List of cleanups to be run on exit from this contour.
	     This is a list of expressions to be evaluated.
	     The TREE_PURPOSE of each link is the ..._DECL node
	     which the cleanup pertains to.  */
	  tree cleanups;
	  /* List of cleanup-lists of blocks containing this block,
	     as they were at the locus where this block appears.
	     There is an element for each containing block,
	     ordered innermost containing block first.
	     The tail of this list can be 0,
	     if all remaining elements would be empty lists.
	     The element's TREE_VALUE is the cleanup-list of that block,
	     which may be null.  */
	  tree outer_cleanups;
	  /* Chain of labels defined inside this binding contour.
	     For contours that have stack levels or cleanups.  */
	  struct label_chain *label_chain;
	  /* Nonzero if this is associated with an EH region.  */
	  int exception_region;
	  /* The saved target_temp_slot_level from our outer block.
	     We may reset target_temp_slot_level to be the level of
	     this block, if that is done, target_temp_slot_level
	     reverts to the saved target_temp_slot_level at the very
	     end of the block.  */
	  int block_target_temp_slot_level;
	  /* True if we are currently emitting insns in an area of
	     output code that is controlled by a conditional
	     expression.  This is used by the cleanup handling code to
	     generate conditional cleanup actions.  */
	  int conditional_code;
	  /* A place to move the start of the exception region for any
	     of the conditional cleanups, must be at the end or after
	     the start of the last unconditional cleanup, and before any
	     conditional branch points.  */
	  rtx last_unconditional_cleanup;
	} GTY ((tag ("BLOCK_NESTING"))) block;
      /* For switch (C) or case (Pascal) statements.  */
      struct nesting_case
	{
	  /* The insn after which the case dispatch should finally
	     be emitted.  Zero for a dummy.  */
	  rtx start;
	  /* A list of case labels; it is first built as an AVL tree.
	     During expand_end_case, this is converted to a list, and may be
	     rearranged into a nearly balanced binary tree.  */
	  struct case_node *case_list;
	  /* Label to jump to if no case matches.  */
	  tree default_label;
	  /* The expression to be dispatched on.  */
	  tree index_expr;
	  /* Type that INDEX_EXPR should be converted to.  */
	  tree nominal_type;
	  /* Name of this kind of statement, for warnings.  */
	  const char *printname;
	  /* Used to save no_line_numbers till we see the first case label.
	     We set this to -1 when we see the first case label in this
	     case statement.  */
	  int line_number_status;
	} GTY ((tag ("CASE_NESTING"))) case_stmt;
    } GTY ((desc ("%1.desc"))) data;
};

/* Allocate and return a new `struct nesting'.  */

#define ALLOC_NESTING() ggc_alloc (sizeof (struct nesting))

/* Pop the nesting stack element by element until we pop off
   the element which is at the top of STACK.
   Update all the other stacks, popping off elements from them
   as we pop them from nesting_stack.  */

#define POPSTACK(STACK)					\
do { struct nesting *target = STACK;			\
     struct nesting *this;				\
     do { this = nesting_stack;				\
	  if (loop_stack == this)			\
	    loop_stack = loop_stack->next;		\
	  if (cond_stack == this)			\
	    cond_stack = cond_stack->next;		\
	  if (block_stack == this)			\
	    block_stack = block_stack->next;		\
	  if (stack_block_stack == this)		\
	    stack_block_stack = stack_block_stack->next; \
	  if (case_stack == this)			\
	    case_stack = case_stack->next;		\
	  nesting_depth = nesting_stack->depth - 1;	\
	  nesting_stack = this->all; }			\
     while (this != target); } while (0)

/* In some cases it is impossible to generate code for a forward goto
   until the label definition is seen.  This happens when it may be necessary
   for the goto to reset the stack pointer: we don't yet know how to do that.
   So expand_goto puts an entry on this fixup list.
   Each time a binding contour that resets the stack is exited,
   we check each fixup.
   If the target label has now been defined, we can insert the proper code.  */

struct goto_fixup GTY(())
{
  /* Points to following fixup.  */
  struct goto_fixup *next;
  /* Points to the insn before the jump insn.
     If more code must be inserted, it goes after this insn.  */
  rtx before_jump;
  /* The LABEL_DECL that this jump is jumping to, or 0
     for break, continue or return.  */
  tree target;
  /* The BLOCK for the place where this goto was found.  */
  tree context;
  /* The CODE_LABEL rtx that this is jumping to.  */
  rtx target_rtl;
  /* Number of binding contours started in current function
     before the label reference.  */
  int block_start_count;
  /* The outermost stack level that should be restored for this jump.
     Each time a binding contour that resets the stack is exited,
     if the target label is *not* yet defined, this slot is updated.  */
  rtx stack_level;
  /* List of lists of cleanup expressions to be run by this goto.
     There is one element for each block that this goto is within.
     The tail of this list can be 0,
     if all remaining elements would be empty.
     The TREE_VALUE contains the cleanup list of that block as of the
     time this goto was seen.
     The TREE_ADDRESSABLE flag is 1 for a block that has been exited.  */
  tree cleanup_list_list;
};

/* Within any binding contour that must restore a stack level,
   all labels are recorded with a chain of these structures.  */

struct label_chain GTY(())
{
  /* Points to following fixup.  */
  struct label_chain *next;
  tree label;
};

struct stmt_status GTY(())
{
  /* Chain of all pending binding contours.  */
  struct nesting * x_block_stack;

  /* If any new stacks are added here, add them to POPSTACKS too.  */

  /* Chain of all pending binding contours that restore stack levels
     or have cleanups.  */
  struct nesting * x_stack_block_stack;

  /* Chain of all pending conditional statements.  */
  struct nesting * x_cond_stack;

  /* Chain of all pending loops.  */
  struct nesting * x_loop_stack;

  /* Chain of all pending case or switch statements.  */
  struct nesting * x_case_stack;

  /* Separate chain including all of the above,
     chained through the `all' field.  */
  struct nesting * x_nesting_stack;

  /* Number of entries on nesting_stack now.  */
  int x_nesting_depth;

  /* Number of binding contours started so far in this function.  */
  int x_block_start_count;

  /* Each time we expand an expression-statement,
     record the expr's type and its RTL value here.  */
  tree x_last_expr_type;
  rtx x_last_expr_value;
  rtx x_last_expr_alt_rtl;

  /* Nonzero if within a ({...}) grouping, in which case we must
     always compute a value for each expr-stmt in case it is the last one.  */
  int x_expr_stmts_for_value;

  /* Location of last line-number note, whether we actually
     emitted it or not.  */
  location_t x_emit_locus;

  struct goto_fixup *x_goto_fixup_chain;
};

#define block_stack (cfun->stmt->x_block_stack)
#define stack_block_stack (cfun->stmt->x_stack_block_stack)
#define cond_stack (cfun->stmt->x_cond_stack)
#define loop_stack (cfun->stmt->x_loop_stack)
#define case_stack (cfun->stmt->x_case_stack)
#define nesting_stack (cfun->stmt->x_nesting_stack)
#define nesting_depth (cfun->stmt->x_nesting_depth)
#define current_block_start_count (cfun->stmt->x_block_start_count)
#define last_expr_type (cfun->stmt->x_last_expr_type)
#define last_expr_value (cfun->stmt->x_last_expr_value)
#define last_expr_alt_rtl (cfun->stmt->x_last_expr_alt_rtl)
#define expr_stmts_for_value (cfun->stmt->x_expr_stmts_for_value)
#define emit_locus (cfun->stmt->x_emit_locus)
#define goto_fixup_chain (cfun->stmt->x_goto_fixup_chain)

/* Nonzero if we are using EH to handle cleanups.  */
int using_eh_for_cleanups_p = 0;

static int n_occurrences (int, const char *);
static bool decl_conflicts_with_clobbers_p (tree, const HARD_REG_SET);
static void expand_goto_internal (tree, rtx, rtx);
static int expand_fixup (tree, rtx, rtx);
static void expand_nl_goto_receiver (void);
static void fixup_gotos (struct nesting *, rtx, tree, rtx, int);
static bool check_operand_nalternatives (tree, tree);
static bool check_unique_operand_names (tree, tree);
static char *resolve_operand_name_1 (char *, tree, tree);
static void expand_null_return_1 (rtx);
static enum br_predictor return_prediction (rtx);
static rtx shift_return_value (rtx);
static void expand_value_return (rtx);
static int tail_recursion_args (tree, tree);
static void expand_cleanups (tree, int, int);
static void check_seenlabel (void);
static void do_jump_if_equal (rtx, rtx, rtx, int);
static int estimate_case_costs (case_node_ptr);
static bool same_case_target_p (rtx, rtx);
static void strip_default_case_nodes (case_node_ptr *, rtx);
static bool lshift_cheap_p (void);
static int case_bit_test_cmp (const void *, const void *);
static void emit_case_bit_tests (tree, tree, tree, tree, case_node_ptr, rtx);
static void group_case_nodes (case_node_ptr);
static void balance_case_nodes (case_node_ptr *, case_node_ptr);
static int node_has_low_bound (case_node_ptr, tree);
static int node_has_high_bound (case_node_ptr, tree);
static int node_is_bounded (case_node_ptr, tree);
static void emit_jump_if_reachable (rtx);
static void emit_case_nodes (rtx, case_node_ptr, rtx, tree);
static struct case_node *case_tree2list (case_node *, case_node *);

void
using_eh_for_cleanups (void)
{
  using_eh_for_cleanups_p = 1;
}

void
init_stmt_for_function (void)
{
  cfun->stmt = ggc_alloc_cleared (sizeof (struct stmt_status));
}

/* Record the current file and line.  Called from emit_line_note.  */

void
set_file_and_line_for_stmt (location_t location)
{
  /* If we're outputting an inline function, and we add a line note,
     there may be no CFUN->STMT information.  So, there's no need to
     update it.  */
  if (cfun->stmt)
    emit_locus = location;
}

/* Emit a no-op instruction.  */

void
emit_nop (void)
{
  rtx last_insn;

  last_insn = get_last_insn ();
  if (!optimize
      && (GET_CODE (last_insn) == CODE_LABEL
	  || (GET_CODE (last_insn) == NOTE
	      && prev_real_insn (last_insn) == 0)))
    emit_insn (gen_nop ());
}

/* Return the rtx-label that corresponds to a LABEL_DECL,
   creating it if necessary.  */

rtx
label_rtx (tree label)
{
  if (TREE_CODE (label) != LABEL_DECL)
    abort ();

  if (!DECL_RTL_SET_P (label))
    {
      rtx r = gen_label_rtx ();
      SET_DECL_RTL (label, r);
      if (FORCED_LABEL (label) || DECL_NONLOCAL (label))
	LABEL_PRESERVE_P (r) = 1;
    }

  return DECL_RTL (label);
}

/* As above, but also put it on the forced-reference list of the
   function that contains it.  */
rtx
force_label_rtx (tree label)
{
  rtx ref = label_rtx (label);
  tree function = decl_function_context (label);
  struct function *p;

  if (!function)
    abort ();

  if (function != current_function_decl)
    p = find_function_data (function);
  else
    p = cfun;

  p->expr->x_forced_labels = gen_rtx_EXPR_LIST (VOIDmode, ref,
						p->expr->x_forced_labels);
  return ref;
}

/* Add an unconditional jump to LABEL as the next sequential instruction.  */

void
emit_jump (rtx label)
{
  do_pending_stack_adjust ();
  emit_jump_insn (gen_jump (label));
  emit_barrier ();
}

/* Emit code to jump to the address
   specified by the pointer expression EXP.  */

void
expand_computed_goto (tree exp)
{
  rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0);

  x = convert_memory_address (Pmode, x);

  emit_queue ();

  if (! cfun->computed_goto_common_label)
    {
      cfun->computed_goto_common_reg = copy_to_mode_reg (Pmode, x);
      cfun->computed_goto_common_label = gen_label_rtx ();

      do_pending_stack_adjust ();
      emit_label (cfun->computed_goto_common_label);
      emit_indirect_jump (cfun->computed_goto_common_reg);

      current_function_has_computed_jump = 1;
    }
  else
    {
      emit_move_insn (cfun->computed_goto_common_reg, x);
      emit_jump (cfun->computed_goto_common_label);
    }
}

/* Handle goto statements and the labels that they can go to.  */

/* Specify the location in the RTL code of a label LABEL,
   which is a LABEL_DECL tree node.

   This is used for the kind of label that the user can jump to with a
   goto statement, and for alternatives of a switch or case statement.
   RTL labels generated for loops and conditionals don't go through here;
   they are generated directly at the RTL level, by other functions below.

   Note that this has nothing to do with defining label *names*.
   Languages vary in how they do that and what that even means.  */

void
expand_label (tree label)
{
  struct label_chain *p;
  rtx label_r = label_rtx (label);

  do_pending_stack_adjust ();
  emit_label (label_r);
  if (DECL_NAME (label))
    LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label));

  if (DECL_NONLOCAL (label))
    {
      expand_nl_goto_receiver ();
      nonlocal_goto_handler_labels
	= gen_rtx_EXPR_LIST (VOIDmode, label_r,
			     nonlocal_goto_handler_labels);
    }

  if (FORCED_LABEL (label))
    forced_labels = gen_rtx_EXPR_LIST (VOIDmode, label_r, forced_labels);
      
  if (DECL_NONLOCAL (label) || FORCED_LABEL (label))
    maybe_set_first_label_num (label_r);

  if (stack_block_stack != 0)
    {
      p = ggc_alloc (sizeof (struct label_chain));
      p->next = stack_block_stack->data.block.label_chain;
      stack_block_stack->data.block.label_chain = p;
      p->label = label;
    }
}

/* Generate RTL code for a `goto' statement with target label LABEL.
   LABEL should be a LABEL_DECL tree node that was or will later be
   defined with `expand_label'.  */

void
expand_goto (tree label)
{
#ifdef ENABLE_CHECKING
  /* Check for a nonlocal goto to a containing function.  Should have
     gotten translated to __builtin_nonlocal_goto.  */
  tree context = decl_function_context (label);
  if (context != 0 && context != current_function_decl)
    abort ();
#endif

  expand_goto_internal (label, label_rtx (label), NULL_RTX);
}

/* Generate RTL code for a `goto' statement with target label BODY.
   LABEL should be a LABEL_REF.
   LAST_INSN, if non-0, is the rtx we should consider as the last
   insn emitted (for the purposes of cleaning up a return).  */

static void
expand_goto_internal (tree body, rtx label, rtx last_insn)
{
  struct nesting *block;
  rtx stack_level = 0;

  if (GET_CODE (label) != CODE_LABEL)
    abort ();

  /* If label has already been defined, we can tell now
     whether and how we must alter the stack level.  */

  if (PREV_INSN (label) != 0)
    {
      /* Find the innermost pending block that contains the label.
	 (Check containment by comparing insn-uids.)
	 Then restore the outermost stack level within that block,
	 and do cleanups of all blocks contained in it.  */
      for (block = block_stack; block; block = block->next)
	{
	  if (INSN_UID (block->data.block.first_insn) < INSN_UID (label))
	    break;
	  if (block->data.block.stack_level != 0)
	    stack_level = block->data.block.stack_level;
	  /* Execute the cleanups for blocks we are exiting.  */
	  if (block->data.block.cleanups != 0)
	    {
	      expand_cleanups (block->data.block.cleanups, 1, 1);
	      do_pending_stack_adjust ();
	    }
	}

      if (stack_level)
	{
	  /* Ensure stack adjust isn't done by emit_jump, as this
	     would clobber the stack pointer.  This one should be
	     deleted as dead by flow.  */
	  clear_pending_stack_adjust ();
	  do_pending_stack_adjust ();

	  /* Don't do this adjust if it's to the end label and this function
	     is to return with a depressed stack pointer.  */
	  if (label == return_label
	      && (((TREE_CODE (TREE_TYPE (current_function_decl))
		   == FUNCTION_TYPE)
		   && (TYPE_RETURNS_STACK_DEPRESSED
		       (TREE_TYPE (current_function_decl))))))
	    ;
	  else
	    emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX);
	}

      if (body != 0 && DECL_TOO_LATE (body))
	error ("jump to `%s' invalidly jumps into binding contour",
	       IDENTIFIER_POINTER (DECL_NAME (body)));
    }
  /* Label not yet defined: may need to put this goto
     on the fixup list.  */
  else if (! expand_fixup (body, label, last_insn))
    {
      /* No fixup needed.  Record that the label is the target
	 of at least one goto that has no fixup.  */
      if (body != 0)
	TREE_ADDRESSABLE (body) = 1;
    }

  emit_jump (label);
}

/* Generate if necessary a fixup for a goto
   whose target label in tree structure (if any) is TREE_LABEL
   and whose target in rtl is RTL_LABEL.

   If LAST_INSN is nonzero, we pretend that the jump appears
   after insn LAST_INSN instead of at the current point in the insn stream.

   The fixup will be used later to insert insns just before the goto.
   Those insns will restore the stack level as appropriate for the
   target label, and will (in the case of C++) also invoke any object
   destructors which have to be invoked when we exit the scopes which
   are exited by the goto.

   Value is nonzero if a fixup is made.  */

static int
expand_fixup (tree tree_label, rtx rtl_label, rtx last_insn)
{
  struct nesting *block, *end_block;

  /* See if we can recognize which block the label will be output in.
     This is possible in some very common cases.
     If we succeed, set END_BLOCK to that block.
     Otherwise, set it to 0.  */

  if (cond_stack
      && (rtl_label == cond_stack->data.cond.endif_label
	  || rtl_label == cond_stack->data.cond.next_label))
    end_block = cond_stack;
  /* If we are in a loop, recognize certain labels which
     are likely targets.  This reduces the number of fixups
     we need to create.  */
  else if (loop_stack
      && (rtl_label == loop_stack->data.loop.start_label
	  || rtl_label == loop_stack->data.loop.end_label
	  || rtl_label == loop_stack->data.loop.continue_label))
    end_block = loop_stack;
  else
    end_block = 0;

  /* Now set END_BLOCK to the binding level to which we will return.  */

  if (end_block)
    {
      struct nesting *next_block = end_block->all;
      block = block_stack;

      /* First see if the END_BLOCK is inside the innermost binding level.
	 If so, then no cleanups or stack levels are relevant.  */
      while (next_block && next_block != block)
	next_block = next_block->all;

      if (next_block)
	return 0;

      /* Otherwise, set END_BLOCK to the innermost binding level
	 which is outside the relevant control-structure nesting.  */
      next_block = block_stack->next;
      for (block = block_stack; block != end_block; block = block->all)
	if (block == next_block)
	  next_block = next_block->next;
      end_block = next_block;
    }

  /* Does any containing block have a stack level or cleanups?
     If not, no fixup is needed, and that is the normal case
     (the only case, for standard C).  */
  for (block = block_stack; block != end_block; block = block->next)
    if (block->data.block.stack_level != 0
	|| block->data.block.cleanups != 0)
      break;

  if (block != end_block)
    {
      /* Ok, a fixup is needed.  Add a fixup to the list of such.  */
      struct goto_fixup *fixup = ggc_alloc (sizeof (struct goto_fixup));
      /* In case an old stack level is restored, make sure that comes
	 after any pending stack adjust.  */
      /* ?? If the fixup isn't to come at the present position,
	 doing the stack adjust here isn't useful.  Doing it with our
	 settings at that location isn't useful either.  Let's hope
	 someone does it!  */
      if (last_insn == 0)
	do_pending_stack_adjust ();
      fixup->target = tree_label;
      fixup->target_rtl = rtl_label;

      /* Create a BLOCK node and a corresponding matched set of
	 NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes at
	 this point.  The notes will encapsulate any and all fixup
	 code which we might later insert at this point in the insn
	 stream.  Also, the BLOCK node will be the parent (i.e. the
	 `SUPERBLOCK') of any other BLOCK nodes which we might create
	 later on when we are expanding the fixup code.

	 Note that optimization passes (including expand_end_loop)
	 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
	 as a placeholder.  */

      {
	rtx original_before_jump
	  = last_insn ? last_insn : get_last_insn ();
	rtx start;
	rtx end;
	tree block;

	block = make_node (BLOCK);
	TREE_USED (block) = 1;

	if (!cfun->x_whole_function_mode_p)
	  lang_hooks.decls.insert_block (block);
	else
	  {
	    BLOCK_CHAIN (block)
	      = BLOCK_CHAIN (DECL_INITIAL (current_function_decl));
	    BLOCK_CHAIN (DECL_INITIAL (current_function_decl))
	      = block;
	  }

	start_sequence ();
	start = emit_note (NOTE_INSN_BLOCK_BEG);
	if (cfun->x_whole_function_mode_p)
	  NOTE_BLOCK (start) = block;
	fixup->before_jump = emit_note (NOTE_INSN_DELETED);
	end = emit_note (NOTE_INSN_BLOCK_END);
	if (cfun->x_whole_function_mode_p)
	  NOTE_BLOCK (end) = block;
	fixup->context = block;
	end_sequence ();
	emit_insn_after (start, original_before_jump);
      }

      fixup->block_start_count = current_block_start_count;
      fixup->stack_level = 0;
      fixup->cleanup_list_list
	= ((block->data.block.outer_cleanups
	    || block->data.block.cleanups)
	   ? tree_cons (NULL_TREE, block->data.block.cleanups,
			block->data.block.outer_cleanups)
	   : 0);
      fixup->next = goto_fixup_chain;
      goto_fixup_chain = fixup;
    }

  return block != 0;
}

/* Expand any needed fixups in the outputmost binding level of the
   function.  FIRST_INSN is the first insn in the function.  */

void
expand_fixups (rtx first_insn)
{
  fixup_gotos (NULL, NULL_RTX, NULL_TREE, first_insn, 0);
}

/* When exiting a binding contour, process all pending gotos requiring fixups.
   THISBLOCK is the structure that describes the block being exited.
   STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
   CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
   FIRST_INSN is the insn that began this contour.

   Gotos that jump out of this contour must restore the
   stack level and do the cleanups before actually jumping.

   DONT_JUMP_IN positive means report error if there is a jump into this
   contour from before the beginning of the contour.  This is also done if
   STACK_LEVEL is nonzero unless DONT_JUMP_IN is negative.  */

static void
fixup_gotos (struct nesting *thisblock, rtx stack_level,
	     tree cleanup_list, rtx first_insn, int dont_jump_in)
{
  struct goto_fixup *f, *prev;

  /* F is the fixup we are considering; PREV is the previous one.  */
  /* We run this loop in two passes so that cleanups of exited blocks
     are run first, and blocks that are exited are marked so
     afterwards.  */

  for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
    {
      /* Test for a fixup that is inactive because it is already handled.  */
      if (f->before_jump == 0)
	{
	  /* Delete inactive fixup from the chain, if that is easy to do.  */
	  if (prev != 0)
	    prev->next = f->next;
	}
      /* Has this fixup's target label been defined?
	 If so, we can finalize it.  */
      else if (PREV_INSN (f->target_rtl) != 0)
	{
	  rtx cleanup_insns;

	  /* If this fixup jumped into this contour from before the beginning
	     of this contour, report an error.   This code used to use
	     the first non-label insn after f->target_rtl, but that's
	     wrong since such can be added, by things like put_var_into_stack
	     and have INSN_UIDs that are out of the range of the block.  */
	  /* ??? Bug: this does not detect jumping in through intermediate
	     blocks that have stack levels or cleanups.
	     It detects only a problem with the innermost block
	     around the label.  */
	  if (f->target != 0
	      && (dont_jump_in > 0 || (dont_jump_in == 0 && stack_level)
		  || cleanup_list)
	      && INSN_UID (first_insn) < INSN_UID (f->target_rtl)
	      && INSN_UID (first_insn) > INSN_UID (f->before_jump)
	      && ! DECL_ERROR_ISSUED (f->target))
	    {
	      error ("%Jlabel '%D' used before containing binding contour",
		     f->target, f->target);
	      /* Prevent multiple errors for one label.  */
	      DECL_ERROR_ISSUED (f->target) = 1;
	    }

	  /* We will expand the cleanups into a sequence of their own and
	     then later on we will attach this new sequence to the insn
	     stream just ahead of the actual jump insn.  */

	  start_sequence ();

	  /* Temporarily restore the lexical context where we will
	     logically be inserting the fixup code.  We do this for the
	     sake of getting the debugging information right.  */

	  lang_hooks.decls.pushlevel (0);
	  lang_hooks.decls.set_block (f->context);

	  /* Expand the cleanups for blocks this jump exits.  */
	  if (f->cleanup_list_list)
	    {
	      tree lists;
	      for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists))
		/* Marked elements correspond to blocks that have been closed.
		   Do their cleanups.  */
		if (TREE_ADDRESSABLE (lists)
		    && TREE_VALUE (lists) != 0)
		  {
		    expand_cleanups (TREE_VALUE (lists), 1, 1);
		    /* Pop any pushes done in the cleanups,
		       in case function is about to return.  */
		    do_pending_stack_adjust ();
		  }
	    }

	  /* Restore stack level for the biggest contour that this
	     jump jumps out of.  */
	  if (f->stack_level
	      && ! (f->target_rtl == return_label
		    && ((TREE_CODE (TREE_TYPE (current_function_decl))
			 == FUNCTION_TYPE)
			&& (TYPE_RETURNS_STACK_DEPRESSED
			    (TREE_TYPE (current_function_decl))))))
	    emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump);

	  /* Finish up the sequence containing the insns which implement the
	     necessary cleanups, and then attach that whole sequence to the
	     insn stream just ahead of the actual jump insn.  Attaching it
	     at that point insures that any cleanups which are in fact
	     implicit C++ object destructions (which must be executed upon
	     leaving the block) appear (to the debugger) to be taking place
	     in an area of the generated code where the object(s) being
	     destructed are still "in scope".  */

	  cleanup_insns = get_insns ();
	  lang_hooks.decls.poplevel (1, 0, 0);

	  end_sequence ();
	  emit_insn_after (cleanup_insns, f->before_jump);

	  f->before_jump = 0;
	}
    }

  /* For any still-undefined labels, do the cleanups for this block now.
     We must do this now since items in the cleanup list may go out
     of scope when the block ends.  */
  for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next)
    if (f->before_jump != 0
	&& PREV_INSN (f->target_rtl) == 0
	/* Label has still not appeared.  If we are exiting a block with
	   a stack level to restore, that started before the fixup,
	   mark this stack level as needing restoration
	   when the fixup is later finalized.  */
	&& thisblock != 0
	/* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
	   means the label is undefined.  That's erroneous, but possible.  */
	&& (thisblock->data.block.block_start_count
	    <= f->block_start_count))
      {
	tree lists = f->cleanup_list_list;
	rtx cleanup_insns;

	for (; lists; lists = TREE_CHAIN (lists))
	  /* If the following elt. corresponds to our containing block
	     then the elt. must be for this block.  */
	  if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups)
	    {
	      start_sequence ();
	      lang_hooks.decls.pushlevel (0);
	      lang_hooks.decls.set_block (f->context);
	      expand_cleanups (TREE_VALUE (lists), 1, 1);
	      do_pending_stack_adjust ();
	      cleanup_insns = get_insns ();
	      lang_hooks.decls.poplevel (1, 0, 0);
	      end_sequence ();
	      if (cleanup_insns != 0)
		f->before_jump
		  = emit_insn_after (cleanup_insns, f->before_jump);

	      f->cleanup_list_list = TREE_CHAIN (lists);
	    }

	if (stack_level)
	  f->stack_level = stack_level;
      }
}

/* Return the number of times character C occurs in string S.  */
static int
n_occurrences (int c, const char *s)
{
  int n = 0;
  while (*s)
    n += (*s++ == c);
  return n;
}

/* Generate RTL for an asm statement (explicit assembler code).
   STRING is a STRING_CST node containing the assembler code text,
   or an ADDR_EXPR containing a STRING_CST.  VOL nonzero means the
   insn is volatile; don't optimize it.  */

void
expand_asm (tree string, int vol)
{
  rtx body;

  if (TREE_CODE (string) == ADDR_EXPR)
    string = TREE_OPERAND (string, 0);

  body = gen_rtx_ASM_INPUT (VOIDmode, TREE_STRING_POINTER (string));

  MEM_VOLATILE_P (body) = vol;

  emit_insn (body);

  clear_last_expr ();
}

/* Parse the output constraint pointed to by *CONSTRAINT_P.  It is the
   OPERAND_NUMth output operand, indexed from zero.  There are NINPUTS
   inputs and NOUTPUTS outputs to this extended-asm.  Upon return,
   *ALLOWS_MEM will be TRUE iff the constraint allows the use of a
   memory operand.  Similarly, *ALLOWS_REG will be TRUE iff the
   constraint allows the use of a register operand.  And, *IS_INOUT
   will be true if the operand is read-write, i.e., if it is used as
   an input as well as an output.  If *CONSTRAINT_P is not in
   canonical form, it will be made canonical.  (Note that `+' will be
   replaced with `=' as part of this process.)

   Returns TRUE if all went well; FALSE if an error occurred.  */

bool
parse_output_constraint (const char **constraint_p, int operand_num,
			 int ninputs, int noutputs, bool *allows_mem,
			 bool *allows_reg, bool *is_inout)
{
  const char *constraint = *constraint_p;
  const char *p;

  /* Assume the constraint doesn't allow the use of either a register
     or memory.  */
  *allows_mem = false;
  *allows_reg = false;

  /* Allow the `=' or `+' to not be at the beginning of the string,
     since it wasn't explicitly documented that way, and there is a
     large body of code that puts it last.  Swap the character to
     the front, so as not to uglify any place else.  */
  p = strchr (constraint, '=');
  if (!p)
    p = strchr (constraint, '+');

  /* If the string doesn't contain an `=', issue an error
     message.  */
  if (!p)
    {
      error ("output operand constraint lacks `='");
      return false;
    }

  /* If the constraint begins with `+', then the operand is both read
     from and written to.  */
  *is_inout = (*p == '+');

  /* Canonicalize the output constraint so that it begins with `='.  */
  if (p != constraint || is_inout)
    {
      char *buf;
      size_t c_len = strlen (constraint);

      if (p != constraint)
	warning ("output constraint `%c' for operand %d is not at the beginning",
		 *p, operand_num);

      /* Make a copy of the constraint.  */
      buf = alloca (c_len + 1);
      strcpy (buf, constraint);
      /* Swap the first character and the `=' or `+'.  */
      buf[p - constraint] = buf[0];
      /* Make sure the first character is an `='.  (Until we do this,
	 it might be a `+'.)  */
      buf[0] = '=';
      /* Replace the constraint with the canonicalized string.  */
      *constraint_p = ggc_alloc_string (buf, c_len);
      constraint = *constraint_p;
    }

  /* Loop through the constraint string.  */
  for (p = constraint + 1; *p; p += CONSTRAINT_LEN (*p, p))
    switch (*p)
      {
      case '+':
      case '=':
	error ("operand constraint contains incorrectly positioned '+' or '='");
	return false;

      case '%':
	if (operand_num + 1 == ninputs + noutputs)
	  {
	    error ("`%%' constraint used with last operand");
	    return false;
	  }
	break;

      case 'V':  case 'm':  case 'o':
	*allows_mem = true;
	break;

      case '?':  case '!':  case '*':  case '&':  case '#':
      case 'E':  case 'F':  case 'G':  case 'H':
      case 's':  case 'i':  case 'n':
      case 'I':  case 'J':  case 'K':  case 'L':  case 'M':
      case 'N':  case 'O':  case 'P':  case ',':
	break;

      case '0':  case '1':  case '2':  case '3':  case '4':
      case '5':  case '6':  case '7':  case '8':  case '9':
      case '[':
	error ("matching constraint not valid in output operand");
	return false;

      case '<':  case '>':
	/* ??? Before flow, auto inc/dec insns are not supposed to exist,
	   excepting those that expand_call created.  So match memory
	   and hope.  */
	*allows_mem = true;
	break;

      case 'g':  case 'X':
	*allows_reg = true;
	*allows_mem = true;
	break;

      case 'p': case 'r':
	*allows_reg = true;
	break;

      default:
	if (!ISALPHA (*p))
	  break;
	if (REG_CLASS_FROM_CONSTRAINT (*p, p) != NO_REGS)
	  *allows_reg = true;
#ifdef EXTRA_CONSTRAINT_STR
	else if (EXTRA_ADDRESS_CONSTRAINT (*p, p))
	  *allows_reg = true;
	else if (EXTRA_MEMORY_CONSTRAINT (*p, p))
	  *allows_mem = true;
	else
	  {
	    /* Otherwise we can't assume anything about the nature of
	       the constraint except that it isn't purely registers.
	       Treat it like "g" and hope for the best.  */
	    *allows_reg = true;
	    *allows_mem = true;
	  }
#endif
	break;
      }

  return true;
}

/* Similar, but for input constraints.  */

bool
parse_input_constraint (const char **constraint_p, int input_num,
			int ninputs, int noutputs, int ninout,
			const char * const * constraints,
			bool *allows_mem, bool *allows_reg)
{
  const char *constraint = *constraint_p;
  const char *orig_constraint = constraint;
  size_t c_len = strlen (constraint);
  size_t j;
  bool saw_match = false;

  /* Assume the constraint doesn't allow the use of either
     a register or memory.  */
  *allows_mem = false;
  *allows_reg = false;

  /* Make sure constraint has neither `=', `+', nor '&'.  */

  for (j = 0; j < c_len; j += CONSTRAINT_LEN (constraint[j], constraint+j))
    switch (constraint[j])
      {
      case '+':  case '=':  case '&':
	if (constraint == orig_constraint)
	  {
	    error ("input operand constraint contains `%c'", constraint[j]);
	    return false;
	  }
	break;

      case '%':
	if (constraint == orig_constraint
	    && input_num + 1 == ninputs - ninout)
	  {
	    error ("`%%' constraint used with last operand");
	    return false;
	  }
	break;

      case 'V':  case 'm':  case 'o':
	*allows_mem = true;
	break;

      case '<':  case '>':
      case '?':  case '!':  case '*':  case '#':
      case 'E':  case 'F':  case 'G':  case 'H':
      case 's':  case 'i':  case 'n':
      case 'I':  case 'J':  case 'K':  case 'L':  case 'M':
      case 'N':  case 'O':  case 'P':  case ',':
	break;

	/* Whether or not a numeric constraint allows a register is
	   decided by the matching constraint, and so there is no need
	   to do anything special with them.  We must handle them in
	   the default case, so that we don't unnecessarily force
	   operands to memory.  */
      case '0':  case '1':  case '2':  case '3':  case '4':
      case '5':  case '6':  case '7':  case '8':  case '9':
	{
	  char *end;
	  unsigned long match;

	  saw_match = true;

	  match = strtoul (constraint + j, &end, 10);
	  if (match >= (unsigned long) noutputs)
	    {
	      error ("matching constraint references invalid operand number");
	      return false;
	    }

	  /* Try and find the real constraint for this dup.  Only do this
	     if the matching constraint is the only alternative.  */
	  if (*end == '\0'
	      && (j == 0 || (j == 1 && constraint[0] == '%')))
	    {
	      constraint = constraints[match];
	      *constraint_p = constraint;
	      c_len = strlen (constraint);
	      j = 0;
	      /* ??? At the end of the loop, we will skip the first part of
		 the matched constraint.  This assumes not only that the
		 other constraint is an output constraint, but also that
		 the '=' or '+' come first.  */
	      break;
	    }
	  else
	    j = end - constraint;
	  /* Anticipate increment at end of loop.  */
	  j--;
	}
	/* Fall through.  */

      case 'p':  case 'r':
	*allows_reg = true;
	break;

      case 'g':  case 'X':
	*allows_reg = true;
	*allows_mem = true;
	break;

      default:
	if (! ISALPHA (constraint[j]))
	  {
	    error ("invalid punctuation `%c' in constraint", constraint[j]);
	    return false;
	  }
	if (REG_CLASS_FROM_CONSTRAINT (constraint[j], constraint + j)
	    != NO_REGS)
	  *allows_reg = true;
#ifdef EXTRA_CONSTRAINT_STR
	else if (EXTRA_ADDRESS_CONSTRAINT (constraint[j], constraint + j))
	  *allows_reg = true;
	else if (EXTRA_MEMORY_CONSTRAINT (constraint[j], constraint + j))
	  *allows_mem = true;
	else
	  {
	    /* Otherwise we can't assume anything about the nature of
	       the constraint except that it isn't purely registers.
	       Treat it like "g" and hope for the best.  */
	    *allows_reg = true;
	    *allows_mem = true;
	  }
#endif
	break;
      }

  if (saw_match && !*allows_reg)
    warning ("matching constraint does not allow a register");

  return true;
}

/* INPUT is one of the input operands from EXPR, an ASM_EXPR.  Returns true
   if it is an operand which must be passed in memory (i.e. an "m"
   constraint), false otherwise.  */

bool
asm_op_is_mem_input (tree input, tree expr)
{
  const char *constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (input)));
  tree outputs = ASM_OUTPUTS (expr);
  int noutputs = list_length (outputs);
  const char **constraints
    = (const char **) alloca ((noutputs) * sizeof (const char *));
  int i = 0;
  bool allows_mem, allows_reg;
  tree t;

  /* Collect output constraints.  */
  for (t = outputs; t ; t = TREE_CHAIN (t), i++)
    constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));

  /* We pass 0 for input_num, ninputs and ninout; they are only used for
     error checking which will be done at expand time.  */
  parse_input_constraint (&constraint, 0, 0, noutputs, 0, constraints,
			  &allows_mem, &allows_reg);
  return (!allows_reg && allows_mem);
}

/* Check for overlap between registers marked in CLOBBERED_REGS and
   anything inappropriate in DECL.  Emit error and return TRUE for error,
   FALSE for ok.  */

static bool
decl_conflicts_with_clobbers_p (tree decl, const HARD_REG_SET clobbered_regs)
{
  /* Conflicts between asm-declared register variables and the clobber
     list are not allowed.  */
  if ((TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == PARM_DECL)
      && DECL_REGISTER (decl)
      && REG_P (DECL_RTL (decl))
      && REGNO (DECL_RTL (decl)) < FIRST_PSEUDO_REGISTER)
    {
      rtx reg = DECL_RTL (decl);
      unsigned int regno;

      for (regno = REGNO (reg);
	   regno < (REGNO (reg)
		    + hard_regno_nregs[REGNO (reg)][GET_MODE (reg)]);
	   regno++)
	if (TEST_HARD_REG_BIT (clobbered_regs, regno))
	  {
	    error ("asm-specifier for variable `%s' conflicts with asm clobber list",
		   IDENTIFIER_POINTER (DECL_NAME (decl)));

	    /* Reset registerness to stop multiple errors emitted for a
	       single variable.  */
	    DECL_REGISTER (decl) = 0;
	    return true;
	  }
    }
  return false;
}

/* Generate RTL for an asm statement with arguments.
   STRING is the instruction template.
   OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
   Each output or input has an expression in the TREE_VALUE and
   and a tree list in TREE_PURPOSE which in turn contains a constraint
   name in TREE_VALUE (or NULL_TREE) and a constraint string
   in TREE_PURPOSE.
   CLOBBERS is a list of STRING_CST nodes each naming a hard register
   that is clobbered by this insn.

   Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
   Some elements of OUTPUTS may be replaced with trees representing temporary
   values.  The caller should copy those temporary values to the originally
   specified lvalues.

   VOL nonzero means the insn is volatile; don't optimize it.  */

void
expand_asm_operands (tree string, tree outputs, tree inputs,
		     tree clobbers, int vol, location_t locus)
{
  rtvec argvec, constraintvec;
  rtx body;
  int ninputs = list_length (inputs);
  int noutputs = list_length (outputs);
  int ninout;
  int nclobbers;
  HARD_REG_SET clobbered_regs;
  int clobber_conflict_found = 0;
  tree tail;
  tree t;
  int i;
  /* Vector of RTX's of evaluated output operands.  */
  rtx *output_rtx = alloca (noutputs * sizeof (rtx));
  int *inout_opnum = alloca (noutputs * sizeof (int));
  rtx *real_output_rtx = alloca (noutputs * sizeof (rtx));
  enum machine_mode *inout_mode
    = alloca (noutputs * sizeof (enum machine_mode));
  const char **constraints
    = alloca ((noutputs + ninputs) * sizeof (const char *));
  int old_generating_concat_p = generating_concat_p;

  /* An ASM with no outputs needs to be treated as volatile, for now.  */
  if (noutputs == 0)
    vol = 1;

  if (! check_operand_nalternatives (outputs, inputs))
    return;

  string = resolve_asm_operand_names (string, outputs, inputs);

  /* Collect constraints.  */
  i = 0;
  for (t = outputs; t ; t = TREE_CHAIN (t), i++)
    constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
  for (t = inputs; t ; t = TREE_CHAIN (t), i++)
    constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));

  /* Sometimes we wish to automatically clobber registers across an asm.
     Case in point is when the i386 backend moved from cc0 to a hard reg --
     maintaining source-level compatibility means automatically clobbering
     the flags register.  */
  clobbers = targetm.md_asm_clobbers (clobbers);

  /* Count the number of meaningful clobbered registers, ignoring what
     we would ignore later.  */
  nclobbers = 0;
  CLEAR_HARD_REG_SET (clobbered_regs);
  for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
    {
      const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));

      i = decode_reg_name (regname);
      if (i >= 0 || i == -4)
	++nclobbers;
      else if (i == -2)
	error ("unknown register name `%s' in `asm'", regname);

      /* Mark clobbered registers.  */
      if (i >= 0)
        {
	  /* Clobbering the PIC register is an error */
	  if (i == (int) PIC_OFFSET_TABLE_REGNUM)
	    {
	      error ("PIC register `%s' clobbered in `asm'", regname);
	      return;
	    }

	  SET_HARD_REG_BIT (clobbered_regs, i);
	}
    }

  clear_last_expr ();

  /* First pass over inputs and outputs checks validity and sets
     mark_addressable if needed.  */

  ninout = 0;
  for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
    {
      tree val = TREE_VALUE (tail);
      tree type = TREE_TYPE (val);
      const char *constraint;
      bool is_inout;
      bool allows_reg;
      bool allows_mem;

      /* If there's an erroneous arg, emit no insn.  */
      if (type == error_mark_node)
	return;

      /* Try to parse the output constraint.  If that fails, there's
	 no point in going further.  */
      constraint = constraints[i];
      if (!parse_output_constraint (&constraint, i, ninputs, noutputs,
				    &allows_mem, &allows_reg, &is_inout))
	return;

      if (! allows_reg
	  && (allows_mem
	      || is_inout
	      || (DECL_P (val)
		  && GET_CODE (DECL_RTL (val)) == REG
		  && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))))
	lang_hooks.mark_addressable (val);

      if (is_inout)
	ninout++;
    }

  ninputs += ninout;
  if (ninputs + noutputs > MAX_RECOG_OPERANDS)
    {
      error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS);
      return;
    }

  for (i = 0, tail = inputs; tail; i++, tail = TREE_CHAIN (tail))
    {
      bool allows_reg, allows_mem;
      const char *constraint;

      /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
	 would get VOIDmode and that could cause a crash in reload.  */
      if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
	return;

      constraint = constraints[i + noutputs];
      if (! parse_input_constraint (&constraint, i, ninputs, noutputs, ninout,
				    constraints, &allows_mem, &allows_reg))
	return;

      if (! allows_reg && allows_mem)
	lang_hooks.mark_addressable (TREE_VALUE (tail));
    }

  /* Second pass evaluates arguments.  */

  ninout = 0;
  for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
    {
      tree val = TREE_VALUE (tail);
      tree type = TREE_TYPE (val);
      bool is_inout;
      bool allows_reg;
      bool allows_mem;
      rtx op;

      if (!parse_output_constraint (&constraints[i], i, ninputs,
				    noutputs, &allows_mem, &allows_reg,
				    &is_inout))
	abort ();

      /* If an output operand is not a decl or indirect ref and our constraint
	 allows a register, make a temporary to act as an intermediate.
	 Make the asm insn write into that, then our caller will copy it to
	 the real output operand.  Likewise for promoted variables.  */

      generating_concat_p = 0;

      real_output_rtx[i] = NULL_RTX;
      if ((TREE_CODE (val) == INDIRECT_REF
	   && allows_mem)
	  || (DECL_P (val)
	      && (allows_mem || GET_CODE (DECL_RTL (val)) == REG)
	      && ! (GET_CODE (DECL_RTL (val)) == REG
		    && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
	  || ! allows_reg
	  || is_inout)
	{
	  op = expand_expr (val, NULL_RTX, VOIDmode, EXPAND_WRITE);
	  if (GET_CODE (op) == MEM)
	    op = validize_mem (op);

	  if (! allows_reg && GET_CODE (op) != MEM)
	    error ("output number %d not directly addressable", i);
	  if ((! allows_mem && GET_CODE (op) == MEM)
	      || GET_CODE (op) == CONCAT)
	    {
	      real_output_rtx[i] = protect_from_queue (op, 1);
	      op = gen_reg_rtx (GET_MODE (op));
	      if (is_inout)
		emit_move_insn (op, real_output_rtx[i]);
	    }
	}
      else
	{
	  op = assign_temp (type, 0, 0, 1);
	  op = validize_mem (op);
	  TREE_VALUE (tail) = make_tree (type, op);
	}
      output_rtx[i] = op;

      generating_concat_p = old_generating_concat_p;

      if (is_inout)
	{
	  inout_mode[ninout] = TYPE_MODE (type);
	  inout_opnum[ninout++] = i;
	}

      if (decl_conflicts_with_clobbers_p (val, clobbered_regs))
	clobber_conflict_found = 1;
    }

  /* Make vectors for the expression-rtx, constraint strings,
     and named operands.  */

  argvec = rtvec_alloc (ninputs);
  constraintvec = rtvec_alloc (ninputs);

  body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode
				: GET_MODE (output_rtx[0])),
			       TREE_STRING_POINTER (string),
			       empty_string, 0, argvec, constraintvec,
			       locus.file, locus.line);

  MEM_VOLATILE_P (body) = vol;

  /* Eval the inputs and put them into ARGVEC.
     Put their constraints into ASM_INPUTs and store in CONSTRAINTS.  */

  for (i = 0, tail = inputs; tail; tail = TREE_CHAIN (tail), ++i)
    {
      bool allows_reg, allows_mem;
      const char *constraint;
      tree val, type;
      rtx op;

      constraint = constraints[i + noutputs];
      if (! parse_input_constraint (&constraint, i, ninputs, noutputs, ninout,
				    constraints, &allows_mem, &allows_reg))
	abort ();

      generating_concat_p = 0;

      val = TREE_VALUE (tail);
      type = TREE_TYPE (val);
      op = expand_expr (val, NULL_RTX, VOIDmode,
			(allows_mem && !allows_reg
			 ? EXPAND_MEMORY : EXPAND_NORMAL));

      /* Never pass a CONCAT to an ASM.  */
      if (GET_CODE (op) == CONCAT)
	op = force_reg (GET_MODE (op), op);
      else if (GET_CODE (op) == MEM)
	op = validize_mem (op);

      if (asm_operand_ok (op, constraint) <= 0)
	{
	  if (allows_reg)
	    op = force_reg (TYPE_MODE (type), op);
	  else if (!allows_mem)
	    warning ("asm operand %d probably doesn't match constraints",
		     i + noutputs);
	  else if (GET_CODE (op) == MEM)
	    {
	      /* We won't recognize either volatile memory or memory
		 with a queued address as available a memory_operand
		 at this point.  Ignore it: clearly this *is* a memory.  */
	    }
	  else
	    {
	      warning ("use of memory input without lvalue in "
		       "asm operand %d is deprecated", i + noutputs);

	      if (CONSTANT_P (op))
		{
		  rtx mem = force_const_mem (TYPE_MODE (type), op);
		  if (mem)
		    op = validize_mem (mem);
		  else
		    op = force_reg (TYPE_MODE (type), op);
		}
	      if (GET_CODE (op) == REG
		  || GET_CODE (op) == SUBREG
		  || GET_CODE (op) == ADDRESSOF
		  || GET_CODE (op) == CONCAT)
		{
		  tree qual_type = build_qualified_type (type,
							 (TYPE_QUALS (type)
							  | TYPE_QUAL_CONST));
		  rtx memloc = assign_temp (qual_type, 1, 1, 1);
		  memloc = validize_mem (memloc);
		  emit_move_insn (memloc, op);
		  op = memloc;
		}
	    }
	}

      generating_concat_p = old_generating_concat_p;
      ASM_OPERANDS_INPUT (body, i) = op;

      ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i)
	= gen_rtx_ASM_INPUT (TYPE_MODE (type), constraints[i + noutputs]);

      if (decl_conflicts_with_clobbers_p (val, clobbered_regs))
	clobber_conflict_found = 1;
    }

  /* Protect all the operands from the queue now that they have all been
     evaluated.  */

  generating_concat_p = 0;

  for (i = 0; i < ninputs - ninout; i++)
    ASM_OPERANDS_INPUT (body, i)
      = protect_from_queue (ASM_OPERANDS_INPUT (body, i), 0);

  for (i = 0; i < noutputs; i++)
    output_rtx[i] = protect_from_queue (output_rtx[i], 1);

  /* For in-out operands, copy output rtx to input rtx.  */
  for (i = 0; i < ninout; i++)
    {
      int j = inout_opnum[i];
      char buffer[16];

      ASM_OPERANDS_INPUT (body, ninputs - ninout + i)
	= output_rtx[j];

      sprintf (buffer, "%d", j);
      ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i)
	= gen_rtx_ASM_INPUT (inout_mode[i], ggc_strdup (buffer));
    }

  generating_concat_p = old_generating_concat_p;

  /* Now, for each output, construct an rtx
     (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
			       ARGVEC CONSTRAINTS OPNAMES))
     If there is more than one, put them inside a PARALLEL.  */

  if (noutputs == 1 && nclobbers == 0)
    {
      ASM_OPERANDS_OUTPUT_CONSTRAINT (body) = constraints[0];
      emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
    }

  else if (noutputs == 0 && nclobbers == 0)
    {
      /* No output operands: put in a raw ASM_OPERANDS rtx.  */
      emit_insn (body);
    }

  else
    {
      rtx obody = body;
      int num = noutputs;

      if (num == 0)
	num = 1;

      body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));

      /* For each output operand, store a SET.  */
      for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
	{
	  XVECEXP (body, 0, i)
	    = gen_rtx_SET (VOIDmode,
			   output_rtx[i],
			   gen_rtx_ASM_OPERANDS
			   (GET_MODE (output_rtx[i]),
			    TREE_STRING_POINTER (string),
			    constraints[i], i, argvec, constraintvec,
			    locus.file, locus.line));

	  MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
	}

      /* If there are no outputs (but there are some clobbers)
	 store the bare ASM_OPERANDS into the PARALLEL.  */

      if (i == 0)
	XVECEXP (body, 0, i++) = obody;

      /* Store (clobber REG) for each clobbered register specified.  */

      for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
	{
	  const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
	  int j = decode_reg_name (regname);
	  rtx clobbered_reg;

	  if (j < 0)
	    {
	      if (j == -3)	/* `cc', which is not a register */
		continue;

	      if (j == -4)	/* `memory', don't cache memory across asm */
		{
		  XVECEXP (body, 0, i++)
		    = gen_rtx_CLOBBER (VOIDmode,
				       gen_rtx_MEM
				       (BLKmode,
					gen_rtx_SCRATCH (VOIDmode)));
		  continue;
		}

	      /* Ignore unknown register, error already signaled.  */
	      continue;
	    }

	  /* Use QImode since that's guaranteed to clobber just one reg.  */
	  clobbered_reg = gen_rtx_REG (QImode, j);

	  /* Do sanity check for overlap between clobbers and respectively
	     input and outputs that hasn't been handled.  Such overlap
	     should have been detected and reported above.  */
	  if (!clobber_conflict_found)
	    {
	      int opno;

	      /* We test the old body (obody) contents to avoid tripping
		 over the under-construction body.  */
	      for (opno = 0; opno < noutputs; opno++)
		if (reg_overlap_mentioned_p (clobbered_reg, output_rtx[opno]))
		  internal_error ("asm clobber conflict with output operand");

	      for (opno = 0; opno < ninputs - ninout; opno++)
		if (reg_overlap_mentioned_p (clobbered_reg,
					     ASM_OPERANDS_INPUT (obody, opno)))
		  internal_error ("asm clobber conflict with input operand");
	    }

	  XVECEXP (body, 0, i++)
	    = gen_rtx_CLOBBER (VOIDmode, clobbered_reg);
	}

      emit_insn (body);
    }

  /* For any outputs that needed reloading into registers, spill them
     back to where they belong.  */
  for (i = 0; i < noutputs; ++i)
    if (real_output_rtx[i])
      emit_move_insn (real_output_rtx[i], output_rtx[i]);

  free_temp_slots ();
}

void
expand_asm_expr (tree exp)
{
  int noutputs, i;
  tree outputs, tail;
  tree *o;

  if (ASM_INPUT_P (exp))
    {
      expand_asm (ASM_STRING (exp), ASM_VOLATILE_P (exp));
      return;
    }

  outputs = ASM_OUTPUTS (exp);
  noutputs = list_length (outputs);
  /* o[I] is the place that output number I should be written.  */
  o = (tree *) alloca (noutputs * sizeof (tree));

  /* Record the contents of OUTPUTS before it is modified.  */
  for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
    o[i] = TREE_VALUE (tail);

  /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
     OUTPUTS some trees for where the values were actually stored.  */
  expand_asm_operands (ASM_STRING (exp), outputs, ASM_INPUTS (exp),
		       ASM_CLOBBERS (exp), ASM_VOLATILE_P (exp),
		       input_location);

  /* Copy all the intermediate outputs into the specified outputs.  */
  for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
    {
      if (o[i] != TREE_VALUE (tail))
	{
	  expand_assignment (o[i], TREE_VALUE (tail), 0);
	  free_temp_slots ();

	  /* Restore the original value so that it's correct the next
	     time we expand this function.  */
	  TREE_VALUE (tail) = o[i];
	}
    }

  /* Those MODIFY_EXPRs could do autoincrements.  */
  emit_queue ();
}

/* A subroutine of expand_asm_operands.  Check that all operands have
   the same number of alternatives.  Return true if so.  */

static bool
check_operand_nalternatives (tree outputs, tree inputs)
{
  if (outputs || inputs)
    {
      tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
      int nalternatives
	= n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp)));
      tree next = inputs;

      if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
	{
	  error ("too many alternatives in `asm'");
	  return false;
	}

      tmp = outputs;
      while (tmp)
	{
	  const char *constraint
	    = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp)));

	  if (n_occurrences (',', constraint) != nalternatives)
	    {
	      error ("operand constraints for `asm' differ in number of alternatives");
	      return false;
	    }

	  if (TREE_CHAIN (tmp))
	    tmp = TREE_CHAIN (tmp);
	  else
	    tmp = next, next = 0;
	}
    }

  return true;
}

/* A subroutine of expand_asm_operands.  Check that all operand names
   are unique.  Return true if so.  We rely on the fact that these names
   are identifiers, and so have been canonicalized by get_identifier,
   so all we need are pointer comparisons.  */

static bool
check_unique_operand_names (tree outputs, tree inputs)
{
  tree i, j;

  for (i = outputs; i ; i = TREE_CHAIN (i))
    {
      tree i_name = TREE_PURPOSE (TREE_PURPOSE (i));
      if (! i_name)
	continue;

      for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
	if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
	  goto failure;
    }

  for (i = inputs; i ; i = TREE_CHAIN (i))
    {
      tree i_name = TREE_PURPOSE (TREE_PURPOSE (i));
      if (! i_name)
	continue;

      for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
	if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
	  goto failure;
      for (j = outputs; j ; j = TREE_CHAIN (j))
	if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
	  goto failure;
    }

  return true;

 failure:
  error ("duplicate asm operand name '%s'",
	 TREE_STRING_POINTER (TREE_PURPOSE (TREE_PURPOSE (i))));
  return false;
}

/* A subroutine of expand_asm_operands.  Resolve the names of the operands
   in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
   STRING and in the constraints to those numbers.  */

tree
resolve_asm_operand_names (tree string, tree outputs, tree inputs)
{
  char *buffer;
  char *p;
  const char *c;
  tree t;

  check_unique_operand_names (outputs, inputs);

  /* Substitute [<name>] in input constraint strings.  There should be no
     named operands in output constraints.  */
  for (t = inputs; t ; t = TREE_CHAIN (t))
    {
      c = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
      if (strchr (c, '[') != NULL)
	{
	  p = buffer = xstrdup (c);
	  while ((p = strchr (p, '[')) != NULL)
	    p = resolve_operand_name_1 (p, outputs, inputs);
	  TREE_VALUE (TREE_PURPOSE (t))
	    = build_string (strlen (buffer), buffer);
	  free (buffer);
	}
    }

  /* Now check for any needed substitutions in the template.  */
  c = TREE_STRING_POINTER (string);
  while ((c = strchr (c, '%')) != NULL)
    {
      if (c[1] == '[')
	break;
      else if (ISALPHA (c[1]) && c[2] == '[')
	break;
      else
	{
	  c += 1;
	  continue;
	}
    }

  if (c)
    {
      /* OK, we need to make a copy so we can perform the substitutions.
	 Assume that we will not need extra space--we get to remove '['
	 and ']', which means we cannot have a problem until we have more
	 than 999 operands.  */
      buffer = xstrdup (TREE_STRING_POINTER (string));
      p = buffer + (c - TREE_STRING_POINTER (string));
      
      while ((p = strchr (p, '%')) != NULL)
	{
	  if (p[1] == '[')
	    p += 1;
	  else if (ISALPHA (p[1]) && p[2] == '[')
	    p += 2;
	  else
	    {
	      p += 1;
	      continue;
	    }

	  p = resolve_operand_name_1 (p, outputs, inputs);
	}

      string = build_string (strlen (buffer), buffer);
      free (buffer);
    }

  return string;
}

/* A subroutine of resolve_operand_names.  P points to the '[' for a
   potential named operand of the form [<name>].  In place, replace
   the name and brackets with a number.  Return a pointer to the
   balance of the string after substitution.  */

static char *
resolve_operand_name_1 (char *p, tree outputs, tree inputs)
{
  char *q;
  int op;
  tree t;
  size_t len;

  /* Collect the operand name.  */
  q = strchr (p, ']');
  if (!q)
    {
      error ("missing close brace for named operand");
      return strchr (p, '\0');
    }
  len = q - p - 1;

  /* Resolve the name to a number.  */
  for (op = 0, t = outputs; t ; t = TREE_CHAIN (t), op++)
    {
      tree name = TREE_PURPOSE (TREE_PURPOSE (t));
      if (name)
	{
	  const char *c = TREE_STRING_POINTER (name);
	  if (strncmp (c, p + 1, len) == 0 && c[len] == '\0')
	    goto found;
	}
    }
  for (t = inputs; t ; t = TREE_CHAIN (t), op++)
    {
      tree name = TREE_PURPOSE (TREE_PURPOSE (t));
      if (name)
	{
	  const char *c = TREE_STRING_POINTER (name);
	  if (strncmp (c, p + 1, len) == 0 && c[len] == '\0')
	    goto found;
	}
    }

  *q = '\0';
  error ("undefined named operand '%s'", p + 1);
  op = 0;
 found:

  /* Replace the name with the number.  Unfortunately, not all libraries
     get the return value of sprintf correct, so search for the end of the
     generated string by hand.  */
  sprintf (p, "%d", op);
  p = strchr (p, '\0');

  /* Verify the no extra buffer space assumption.  */
  if (p > q)
    abort ();

  /* Shift the rest of the buffer down to fill the gap.  */
  memmove (p, q + 1, strlen (q + 1) + 1);

  return p;
}

/* Generate RTL to evaluate the expression EXP
   and remember it in case this is the VALUE in a ({... VALUE; }) constr.
   Provided just for backward-compatibility.  expand_expr_stmt_value()
   should be used for new code.  */

void
expand_expr_stmt (tree exp)
{
  expand_expr_stmt_value (exp, -1, 1);
}

/* Generate RTL to evaluate the expression EXP.  WANT_VALUE tells
   whether to (1) save the value of the expression, (0) discard it or
   (-1) use expr_stmts_for_value to tell.  The use of -1 is
   deprecated, and retained only for backward compatibility.  */

void
expand_expr_stmt_value (tree exp, int want_value, int maybe_last)
{
  rtx value;
  tree type;
  rtx alt_rtl = NULL;

  if (want_value == -1)
    want_value = expr_stmts_for_value != 0;

  /* If -Wextra, warn about statements with no side effects,
     except for an explicit cast to void (e.g. for assert()), and
     except for last statement in ({...}) where they may be useful.  */
  if (! want_value
      && (expr_stmts_for_value == 0 || ! maybe_last)
      && exp != error_mark_node
      && warn_unused_value)
    {
      if (TREE_SIDE_EFFECTS (exp))
	warn_if_unused_value (exp);
      else if (!VOID_TYPE_P (TREE_TYPE (exp)) && !TREE_NO_WARNING (exp))
	warning ("%Hstatement with no effect", &emit_locus);
    }

  /* If EXP is of function type and we are expanding statements for
     value, convert it to pointer-to-function.  */
  if (want_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE)
    exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);

  /* The call to `expand_expr' could cause last_expr_type and
     last_expr_value to get reset.  Therefore, we set last_expr_value
     and last_expr_type *after* calling expand_expr.  */
  value = expand_expr_real (exp, want_value ? NULL_RTX : const0_rtx,
			    VOIDmode, 0, &alt_rtl);
  type = TREE_TYPE (exp);

  /* If all we do is reference a volatile value in memory,
     copy it to a register to be sure it is actually touched.  */
  if (value && GET_CODE (value) == MEM && TREE_THIS_VOLATILE (exp))
    {
      if (TYPE_MODE (type) == VOIDmode)
	;
      else if (TYPE_MODE (type) != BLKmode)
	value = copy_to_reg (value);
      else
	{
	  rtx lab = gen_label_rtx ();

	  /* Compare the value with itself to reference it.  */
	  emit_cmp_and_jump_insns (value, value, EQ,
				   expand_expr (TYPE_SIZE (type),
						NULL_RTX, VOIDmode, 0),
				   BLKmode, 0, lab);
	  emit_label (lab);
	}
    }

  /* If this expression is part of a ({...}) and is in memory, we may have
     to preserve temporaries.  */
  preserve_temp_slots (value);

  /* Free any temporaries used to evaluate this expression.  Any temporary
     used as a result of this expression will already have been preserved
     above.  */
  free_temp_slots ();

  if (want_value)
    {
      last_expr_value = value;
      last_expr_alt_rtl = alt_rtl;
      last_expr_type = type;
    }

  emit_queue ();
}

/* Warn if EXP contains any computations whose results are not used.
   Return 1 if a warning is printed; 0 otherwise.  */

int
warn_if_unused_value (tree exp)
{
  if (TREE_USED (exp))
    return 0;

  /* Don't warn about void constructs.  This includes casting to void,
     void function calls, and statement expressions with a final cast
     to void.  */
  if (VOID_TYPE_P (TREE_TYPE (exp)))
    return 0;

  switch (TREE_CODE (exp))
    {
    case PREINCREMENT_EXPR:
    case POSTINCREMENT_EXPR:
    case PREDECREMENT_EXPR:
    case POSTDECREMENT_EXPR:
    case MODIFY_EXPR:
    case INIT_EXPR:
    case TARGET_EXPR:
    case CALL_EXPR:
    case RTL_EXPR:
    case TRY_CATCH_EXPR:
    case WITH_CLEANUP_EXPR:
    case EXIT_EXPR:
      return 0;

    case BIND_EXPR:
      /* For a binding, warn if no side effect within it.  */
      return warn_if_unused_value (TREE_OPERAND (exp, 1));

    case SAVE_EXPR:
      return warn_if_unused_value (TREE_OPERAND (exp, 0));

    case TRUTH_ORIF_EXPR:
    case TRUTH_ANDIF_EXPR:
      /* In && or ||, warn if 2nd operand has no side effect.  */
      return warn_if_unused_value (TREE_OPERAND (exp, 1));

    case COMPOUND_EXPR:
      if (TREE_NO_WARNING (exp))
	return 0;
      if (warn_if_unused_value (TREE_OPERAND (exp, 0)))
	return 1;
      /* Let people do `(foo (), 0)' without a warning.  */
      if (TREE_CONSTANT (TREE_OPERAND (exp, 1)))
	return 0;
      return warn_if_unused_value (TREE_OPERAND (exp, 1));

    case NOP_EXPR:
    case CONVERT_EXPR:
    case NON_LVALUE_EXPR:
      /* Don't warn about conversions not explicit in the user's program.  */
      if (TREE_NO_WARNING (exp))
	return 0;
      /* Assignment to a cast usually results in a cast of a modify.
	 Don't complain about that.  There can be an arbitrary number of
	 casts before the modify, so we must loop until we find the first
	 non-cast expression and then test to see if that is a modify.  */
      {
	tree tem = TREE_OPERAND (exp, 0);

	while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR)
	  tem = TREE_OPERAND (tem, 0);

	if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR
	    || TREE_CODE (tem) == CALL_EXPR)
	  return 0;
      }
      goto maybe_warn;

    case INDIRECT_REF:
      /* Don't warn about automatic dereferencing of references, since
	 the user cannot control it.  */
      if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE)
	return warn_if_unused_value (TREE_OPERAND (exp, 0));
      /* Fall through.  */

    default:
      /* Referencing a volatile value is a side effect, so don't warn.  */
      if ((DECL_P (exp)
	   || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r')
	  && TREE_THIS_VOLATILE (exp))
	return 0;

      /* If this is an expression which has no operands, there is no value
	 to be unused.  There are no such language-independent codes,
	 but front ends may define such.  */
      if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'e'
	  && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
	return 0;

    maybe_warn:
      /* If this is an expression with side effects, don't warn.  */
      if (TREE_SIDE_EFFECTS (exp))
	return 0;

      warning ("%Hvalue computed is not used", &emit_locus);
      return 1;
    }
}

/* Clear out the memory of the last expression evaluated.  */

void
clear_last_expr (void)
{
  last_expr_type = NULL_TREE;
  last_expr_value = NULL_RTX;
  last_expr_alt_rtl = NULL_RTX;
}

/* Begin a statement-expression, i.e., a series of statements which
   may return a value.  Return the RTL_EXPR for this statement expr.
   The caller must save that value and pass it to
   expand_end_stmt_expr.  If HAS_SCOPE is nonzero, temporaries created
   in the statement-expression are deallocated at the end of the
   expression.  */

tree
expand_start_stmt_expr (int has_scope)
{
  tree t;

  /* Make the RTL_EXPR node temporary, not momentary,
     so that rtl_expr_chain doesn't become garbage.  */
  t = make_node (RTL_EXPR);
  do_pending_stack_adjust ();
  if (has_scope)
    start_sequence_for_rtl_expr (t);
  else
    start_sequence ();
  NO_DEFER_POP;
  expr_stmts_for_value++;
  return t;
}

/* Restore the previous state at the end of a statement that returns a value.
   Returns a tree node representing the statement's value and the
   insns to compute the value.

   The nodes of that expression have been freed by now, so we cannot use them.
   But we don't want to do that anyway; the expression has already been
   evaluated and now we just want to use the value.  So generate a RTL_EXPR
   with the proper type and RTL value.

   If the last substatement was not an expression,
   return something with type `void'.  */

tree
expand_end_stmt_expr (tree t)
{
  OK_DEFER_POP;

  if (! last_expr_value || ! last_expr_type)
    {
      last_expr_value = const0_rtx;
      last_expr_alt_rtl = NULL_RTX;
      last_expr_type = void_type_node;
    }
  else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value))
    /* Remove any possible QUEUED.  */
    last_expr_value = protect_from_queue (last_expr_value, 0);

  emit_queue ();

  TREE_TYPE (t) = last_expr_type;
  RTL_EXPR_RTL (t) = last_expr_value;
  RTL_EXPR_ALT_RTL (t) = last_expr_alt_rtl;
  RTL_EXPR_SEQUENCE (t) = get_insns ();

  rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain);

  end_sequence ();

  /* Don't consider deleting this expr or containing exprs at tree level.  */
  TREE_SIDE_EFFECTS (t) = 1;
  /* Propagate volatility of the actual RTL expr.  */
  TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value);

  clear_last_expr ();
  expr_stmts_for_value--;

  return t;
}

/* Generate RTL for the start of an if-then.  COND is the expression
   whose truth should be tested.

   If EXITFLAG is nonzero, this conditional is visible to
   `exit_something'.  */

void
expand_start_cond (tree cond, int exitflag)
{
  struct nesting *thiscond = ALLOC_NESTING ();

  /* Make an entry on cond_stack for the cond we are entering.  */

  thiscond->desc = COND_NESTING;
  thiscond->next = cond_stack;
  thiscond->all = nesting_stack;
  thiscond->depth = ++nesting_depth;
  thiscond->data.cond.next_label = gen_label_rtx ();
  /* Before we encounter an `else', we don't need a separate exit label
     unless there are supposed to be exit statements
     to exit this conditional.  */
  thiscond->exit_label = exitflag ? gen_label_rtx () : 0;
  thiscond->data.cond.endif_label = thiscond->exit_label;
  cond_stack = thiscond;
  nesting_stack = thiscond;

  do_jump (cond, thiscond->data.cond.next_label, NULL_RTX);
}

/* Generate RTL between then-clause and the elseif-clause
   of an if-then-elseif-....  */

void
expand_start_elseif (tree cond)
{
  if (cond_stack->data.cond.endif_label == 0)
    cond_stack->data.cond.endif_label = gen_label_rtx ();
  emit_jump (cond_stack->data.cond.endif_label);
  emit_label (cond_stack->data.cond.next_label);
  cond_stack->data.cond.next_label = gen_label_rtx ();
  do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
}

/* Generate RTL between the then-clause and the else-clause
   of an if-then-else.  */

void
expand_start_else (void)
{
  if (cond_stack->data.cond.endif_label == 0)
    cond_stack->data.cond.endif_label = gen_label_rtx ();

  emit_jump (cond_stack->data.cond.endif_label);
  emit_label (cond_stack->data.cond.next_label);
  cond_stack->data.cond.next_label = 0;  /* No more _else or _elseif calls.  */
}

/* After calling expand_start_else, turn this "else" into an "else if"
   by providing another condition.  */

void
expand_elseif (tree cond)
{
  cond_stack->data.cond.next_label = gen_label_rtx ();
  do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX);
}

/* Generate RTL for the end of an if-then.
   Pop the record for it off of cond_stack.  */

void
expand_end_cond (void)
{
  struct nesting *thiscond = cond_stack;

  do_pending_stack_adjust ();
  if (thiscond->data.cond.next_label)
    emit_label (thiscond->data.cond.next_label);
  if (thiscond->data.cond.endif_label)
    emit_label (thiscond->data.cond.endif_label);

  POPSTACK (cond_stack);
  clear_last_expr ();
}

/* Generate RTL for the start of a loop.  EXIT_FLAG is nonzero if this
   loop should be exited by `exit_something'.  This is a loop for which
   `expand_continue' will jump to the top of the loop.

   Make an entry on loop_stack to record the labels associated with
   this loop.  */

struct nesting *
expand_start_loop (int exit_flag)
{
  struct nesting *thisloop = ALLOC_NESTING ();

  /* Make an entry on loop_stack for the loop we are entering.  */

  thisloop->desc = LOOP_NESTING;
  thisloop->next = loop_stack;
  thisloop->all = nesting_stack;
  thisloop->depth = ++nesting_depth;
  thisloop->data.loop.start_label = gen_label_rtx ();
  thisloop->data.loop.end_label = gen_label_rtx ();
  thisloop->data.loop.continue_label = thisloop->data.loop.start_label;
  thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0;
  loop_stack = thisloop;
  nesting_stack = thisloop;

  do_pending_stack_adjust ();
  emit_queue ();
  emit_label (thisloop->data.loop.start_label);

  return thisloop;
}

/* Like expand_start_loop but for a loop where the continuation point
   (for expand_continue_loop) will be specified explicitly.  */

struct nesting *
expand_start_loop_continue_elsewhere (int exit_flag)
{
  struct nesting *thisloop = expand_start_loop (exit_flag);
  loop_stack->data.loop.continue_label = gen_label_rtx ();
  return thisloop;
}

/* Begin a null, aka do { } while (0) "loop".  But since the contents
   of said loop can still contain a break, we must frob the loop nest.  */

struct nesting *
expand_start_null_loop (void)
{
  struct nesting *thisloop = ALLOC_NESTING ();

  /* Make an entry on loop_stack for the loop we are entering.  */

  thisloop->desc = LOOP_NESTING;
  thisloop->next = loop_stack;
  thisloop->all = nesting_stack;
  thisloop->depth = ++nesting_depth;
  thisloop->data.loop.start_label = emit_note (NOTE_INSN_DELETED);
  thisloop->data.loop.end_label = gen_label_rtx ();
  thisloop->data.loop.continue_label = thisloop->data.loop.end_label;
  thisloop->exit_label = thisloop->data.loop.end_label;
  loop_stack = thisloop;
  nesting_stack = thisloop;

  return thisloop;
}

/* Specify the continuation point for a loop started with
   expand_start_loop_continue_elsewhere.
   Use this at the point in the code to which a continue statement
   should jump.  */

void
expand_loop_continue_here (void)
{
  do_pending_stack_adjust ();
  emit_label (loop_stack->data.loop.continue_label);
}

/* Finish a loop.  Generate a jump back to the top and the loop-exit label.
   Pop the block off of loop_stack.  */

void
expand_end_loop (void)
{
  rtx start_label = loop_stack->data.loop.start_label;
  rtx etc_note;
  int eh_regions, debug_blocks;
  bool empty_test;

  do_pending_stack_adjust ();

  /* If the loop starts with a loop exit, roll that to the end where
     it will optimize together with the jump back.

     If the loop presently looks like this (in pseudo-C):

	start_label:
	  if (test) goto end_label;
	LOOP_END_TOP_COND
	  body;
	  goto start_label;
	end_label:

     transform it to look like:

	  goto start_label;
	top_label:
	  body;
	start_label:
	  if (test) goto end_label;
	  goto top_label;
	end_label:

     We rely on the presence of NOTE_INSN_LOOP_END_TOP_COND to mark
     the end of the entry conditional.  Without this, our lexical scan
     can't tell the difference between an entry conditional and a
     body conditional that exits the loop.  Mistaking the two means
     that we can misplace the NOTE_INSN_LOOP_CONT note, which can
     screw up loop unrolling.

     Things will be oh so much better when loop optimization is done
     off of a proper control flow graph...  */

  /* Scan insns from the top of the loop looking for the END_TOP_COND note.  */

  empty_test = true;
  eh_regions = debug_blocks = 0;
  for (etc_note = start_label; etc_note ; etc_note = NEXT_INSN (etc_note))
    if (GET_CODE (etc_note) == NOTE)
      {
	if (NOTE_LINE_NUMBER (etc_note) == NOTE_INSN_LOOP_END_TOP_COND)
	  break;

	if (NOTE_LINE_NUMBER (etc_note) == NOTE_INSN_LOOP_BEG)
	  abort ();

	/* At the same time, scan for EH region notes, as we don't want
	   to scrog region nesting.  This shouldn't happen, but...  */
	if (NOTE_LINE_NUMBER (etc_note) == NOTE_INSN_EH_REGION_BEG)
	  eh_regions++;
	else if (NOTE_LINE_NUMBER (etc_note) == NOTE_INSN_EH_REGION_END)
	  {
	    if (--eh_regions < 0)
	      /* We've come to the end of an EH region, but never saw the
		 beginning of that region.  That means that an EH region
		 begins before the top of the loop, and ends in the middle
		 of it.  The existence of such a situation violates a basic
		 assumption in this code, since that would imply that even
		 when EH_REGIONS is zero, we might move code out of an
		 exception region.  */
	      abort ();
	  }

	/* Likewise for debug scopes.  In this case we'll either (1) move
	   all of the notes if they are properly nested or (2) leave the
	   notes alone and only rotate the loop at high optimization
	   levels when we expect to scrog debug info.  */
	else if (NOTE_LINE_NUMBER (etc_note) == NOTE_INSN_BLOCK_BEG)
	  debug_blocks++;
	else if (NOTE_LINE_NUMBER (etc_note) == NOTE_INSN_BLOCK_END)
	  debug_blocks--;
      }
    else if (INSN_P (etc_note))
      empty_test = false;

  if (etc_note
      && optimize
      && ! empty_test
      && eh_regions == 0
      && (debug_blocks == 0 || optimize >= 2)
      && NEXT_INSN (etc_note) != NULL_RTX
      && ! any_condjump_p (get_last_insn ()))
    {
      /* We found one.  Move everything from START to ETC to the end
	 of the loop, and add a jump from the top of the loop.  */
      rtx top_label = gen_label_rtx ();
      rtx start_move = start_label;

      emit_label_before (top_label, start_move);

      /* Actually move the insns.  If the debug scopes are nested, we
	 can move everything at once.  Otherwise we have to move them
	 one by one and squeeze out the block notes.  */
      if (debug_blocks == 0)
	reorder_insns (start_move, etc_note, get_last_insn ());
      else
	{
	  rtx insn, next_insn;
	  for (insn = start_move; insn; insn = next_insn)
	    {
	      /* Figure out which insn comes after this one.  We have
		 to do this before we move INSN.  */
	      next_insn = (insn == etc_note ? NULL : NEXT_INSN (insn));

	      if (GET_CODE (insn) == NOTE
		  && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG
		      || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
		continue;

	      reorder_insns (insn, insn, get_last_insn ());
	    }
	}

      /* Add the jump from the top of the loop.  */
      emit_jump_insn_before (gen_jump (start_label), top_label);
      emit_barrier_before (top_label);
      start_label = top_label;
    }

  if (etc_note)
    delete_insn (etc_note);

  emit_jump (start_label);
  emit_label (loop_stack->data.loop.end_label);

  POPSTACK (loop_stack);

  clear_last_expr ();
}

/* Finish a null loop, aka do { } while (0).  */

void
expand_end_null_loop (void)
{
  do_pending_stack_adjust ();
  emit_label (loop_stack->data.loop.end_label);

  POPSTACK (loop_stack);

  clear_last_expr ();
}

/* Generate a jump to the current loop's continue-point.
   This is usually the top of the loop, but may be specified
   explicitly elsewhere.  If not currently inside a loop,
   return 0 and do nothing; caller will print an error message.  */

int
expand_continue_loop (struct nesting *whichloop)
{
  /* Emit information for branch prediction.  */
  rtx note;

  if (flag_guess_branch_prob)
    {
      note = emit_note (NOTE_INSN_PREDICTION);
      NOTE_PREDICTION (note) = NOTE_PREDICT (PRED_CONTINUE, IS_TAKEN);
    }
  clear_last_expr ();
  if (whichloop == 0)
    whichloop = loop_stack;
  if (whichloop == 0)
    return 0;
  expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label,
			NULL_RTX);
  return 1;
}

/* Generate a jump to exit the current loop.  If not currently inside a loop,
   return 0 and do nothing; caller will print an error message.  */

int
expand_exit_loop (struct nesting *whichloop)
{
  clear_last_expr ();
  if (whichloop == 0)
    whichloop = loop_stack;
  if (whichloop == 0)
    return 0;
  expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX);
  return 1;
}

/* Generate a conditional jump to exit the current loop if COND
   evaluates to zero.  If not currently inside a loop,
   return 0 and do nothing; caller will print an error message.  */

int
expand_exit_loop_if_false (struct nesting *whichloop, tree cond)
{
  rtx label;
  clear_last_expr ();

  if (whichloop == 0)
    whichloop = loop_stack;
  if (whichloop == 0)
    return 0;

  if (integer_nonzerop (cond))
    return 1;
  if (integer_zerop (cond))
    return expand_exit_loop (whichloop);

  /* Check if we definitely won't need a fixup.  */
  if (whichloop == nesting_stack)
    {
      jumpifnot (cond, whichloop->data.loop.end_label);
      return 1;
    }

  /* In order to handle fixups, we actually create a conditional jump
     around an unconditional branch to exit the loop.  If fixups are
     necessary, they go before the unconditional branch.  */

  label = gen_label_rtx ();
  jumpif (cond, label);
  expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label,
			NULL_RTX);
  emit_label (label);

  return 1;
}

/* Like expand_exit_loop_if_false except also emit a note marking
   the end of the conditional.  Should only be used immediately
   after expand_loop_start.  */

int
expand_exit_loop_top_cond (struct nesting *whichloop, tree cond)
{
  if (! expand_exit_loop_if_false (whichloop, cond))
    return 0;

  emit_note (NOTE_INSN_LOOP_END_TOP_COND);
  return 1;
}

/* Return nonzero if we should preserve sub-expressions as separate
   pseudos.  We never do so if we aren't optimizing.  We always do so
   if -fexpensive-optimizations.

   Otherwise, we only do so if we are in the "early" part of a loop.  I.e.,
   the loop may still be a small one.  */

int
preserve_subexpressions_p (void)
{
  rtx insn;

  if (flag_expensive_optimizations)
    return 1;

  if (optimize == 0 || cfun == 0 || cfun->stmt == 0 || loop_stack == 0)
    return 0;

  insn = get_last_insn_anywhere ();

  return (insn
	  && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label)
	      < n_non_fixed_regs * 3));

}

/* Generate a jump to exit the current loop, conditional, binding contour
   or case statement.  Not all such constructs are visible to this function,
   only those started with EXIT_FLAG nonzero.  Individual languages use
   the EXIT_FLAG parameter to control which kinds of constructs you can
   exit this way.

   If not currently inside anything that can be exited,
   return 0 and do nothing; caller will print an error message.  */

int
expand_exit_something (void)
{
  struct nesting *n;
  clear_last_expr ();
  for (n = nesting_stack; n; n = n->all)
    if (n->exit_label != 0)
      {
	expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX);
	return 1;
      }

  return 0;
}

/* Generate RTL to return from the current function, with no value.
   (That is, we do not do anything about returning any value.)  */

void
expand_null_return (void)
{
  rtx last_insn;

  last_insn = get_last_insn ();

  /* If this function was declared to return a value, but we
     didn't, clobber the return registers so that they are not
     propagated live to the rest of the function.  */
  clobber_return_register ();

  expand_null_return_1 (last_insn);
}

/* Generate RTL to return directly from the current function.
   (That is, we bypass any return value.)  */

void
expand_naked_return (void)
{
  rtx last_insn, end_label;

  last_insn = get_last_insn ();
  end_label = naked_return_label;

  clear_pending_stack_adjust ();
  do_pending_stack_adjust ();
  clear_last_expr ();

  if (end_label == 0)
    end_label = naked_return_label = gen_label_rtx ();
  expand_goto_internal (NULL_TREE, end_label, last_insn);
}

/* Try to guess whether the value of return means error code.  */
static enum br_predictor
return_prediction (rtx val)
{
  /* Different heuristics for pointers and scalars.  */
  if (POINTER_TYPE_P (TREE_TYPE (DECL_RESULT (current_function_decl))))
    {
      /* NULL is usually not returned.  */
      if (val == const0_rtx)
	return PRED_NULL_RETURN;
    }
  else
    {
      /* Negative return values are often used to indicate
         errors.  */
      if (GET_CODE (val) == CONST_INT
	  && INTVAL (val) < 0)
	return PRED_NEGATIVE_RETURN;
      /* Constant return values are also usually erors,
         zero/one often mean booleans so exclude them from the
	 heuristics.  */
      if (CONSTANT_P (val)
	  && (val != const0_rtx && val != const1_rtx))
	return PRED_CONST_RETURN;
    }
  return PRED_NO_PREDICTION;
}


/* If the current function returns values in the most significant part
   of a register, shift return value VAL appropriately.  The mode of
   the function's return type is known not to be BLKmode.  */

static rtx
shift_return_value (rtx val)
{
  tree type;

  type = TREE_TYPE (DECL_RESULT (current_function_decl));
  if (targetm.calls.return_in_msb (type))
    {
      rtx target;
      HOST_WIDE_INT shift;

      target = DECL_RTL (DECL_RESULT (current_function_decl));
      shift = (GET_MODE_BITSIZE (GET_MODE (target))
	       - BITS_PER_UNIT * int_size_in_bytes (type));
      if (shift > 0)
	val = expand_binop (GET_MODE (target), ashl_optab,
			    gen_lowpart (GET_MODE (target), val),
			    GEN_INT (shift), target, 1, OPTAB_WIDEN);
    }
  return val;
}


/* Generate RTL to return from the current function, with value VAL.  */

static void
expand_value_return (rtx val)
{
  rtx last_insn;
  rtx return_reg;
  enum br_predictor pred;

  if (flag_guess_branch_prob
      && (pred = return_prediction (val)) != PRED_NO_PREDICTION)
    {
      /* Emit information for branch prediction.  */
      rtx note;

      note = emit_note (NOTE_INSN_PREDICTION);

      NOTE_PREDICTION (note) = NOTE_PREDICT (pred, NOT_TAKEN);

    }

  last_insn = get_last_insn ();
  return_reg = DECL_RTL (DECL_RESULT (current_function_decl));

  /* Copy the value to the return location
     unless it's already there.  */

  if (return_reg != val)
    {
      tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
      if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
      {
	int unsignedp = TYPE_UNSIGNED (type);
	enum machine_mode old_mode
	  = DECL_MODE (DECL_RESULT (current_function_decl));
	enum machine_mode mode
	  = promote_mode (type, old_mode, &unsignedp, 1);

	if (mode != old_mode)
	  val = convert_modes (mode, old_mode, val, unsignedp);
      }
      if (GET_CODE (return_reg) == PARALLEL)
	emit_group_load (return_reg, val, type, int_size_in_bytes (type));
      else
	emit_move_insn (return_reg, val);
    }

  expand_null_return_1 (last_insn);
}

/* Output a return with no value.  If LAST_INSN is nonzero,
   pretend that the return takes place after LAST_INSN.  */

static void
expand_null_return_1 (rtx last_insn)
{
  rtx end_label = cleanup_label ? cleanup_label : return_label;

  clear_pending_stack_adjust ();
  do_pending_stack_adjust ();
  clear_last_expr ();

  if (end_label == 0)
     end_label = return_label = gen_label_rtx ();
  expand_goto_internal (NULL_TREE, end_label, last_insn);
}

/* Generate RTL to evaluate the expression RETVAL and return it
   from the current function.  */

void
expand_return (tree retval)
{
  /* If there are any cleanups to be performed, then they will
     be inserted following LAST_INSN.  It is desirable
     that the last_insn, for such purposes, should be the
     last insn before computing the return value.  Otherwise, cleanups
     which call functions can clobber the return value.  */
  /* ??? rms: I think that is erroneous, because in C++ it would
     run destructors on variables that might be used in the subsequent
     computation of the return value.  */
  rtx last_insn = 0;
  rtx result_rtl;
  rtx val = 0;
  tree retval_rhs;

  /* If function wants no value, give it none.  */
  if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
    {
      expand_expr (retval, NULL_RTX, VOIDmode, 0);
      emit_queue ();
      expand_null_return ();
      return;
    }

  if (retval == error_mark_node)
    {
      /* Treat this like a return of no value from a function that
	 returns a value.  */
      expand_null_return ();
      return;
    }
  else if (TREE_CODE (retval) == RESULT_DECL)
    retval_rhs = retval;
  else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR)
	   && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
    retval_rhs = TREE_OPERAND (retval, 1);
  else
    retval_rhs = retval;

  last_insn = get_last_insn ();

  /* Distribute return down conditional expr if either of the sides
     may involve tail recursion (see test below).  This enhances the number
     of tail recursions we see.  Don't do this always since it can produce
     sub-optimal code in some cases and we distribute assignments into
     conditional expressions when it would help.  */

  if (optimize && retval_rhs != 0
      && frame_offset == 0
      && TREE_CODE (retval_rhs) == COND_EXPR
      && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR
	  || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR))
    {
      rtx label = gen_label_rtx ();
      tree expr;

      do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX);
      start_cleanup_deferral ();
      expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
		    DECL_RESULT (current_function_decl),
		    TREE_OPERAND (retval_rhs, 1));
      TREE_SIDE_EFFECTS (expr) = 1;
      expand_return (expr);
      emit_label (label);

      expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)),
		    DECL_RESULT (current_function_decl),
		    TREE_OPERAND (retval_rhs, 2));
      TREE_SIDE_EFFECTS (expr) = 1;
      expand_return (expr);
      end_cleanup_deferral ();
      return;
    }

  result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));

  /* If the result is an aggregate that is being returned in one (or more)
     registers, load the registers here.  The compiler currently can't handle
     copying a BLKmode value into registers.  We could put this code in a
     more general area (for use by everyone instead of just function
     call/return), but until this feature is generally usable it is kept here
     (and in expand_call).  The value must go into a pseudo in case there
     are cleanups that will clobber the real return register.  */

  if (retval_rhs != 0
      && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
      && GET_CODE (result_rtl) == REG)
    {
      int i;
      unsigned HOST_WIDE_INT bitpos, xbitpos;
      unsigned HOST_WIDE_INT padding_correction = 0;
      unsigned HOST_WIDE_INT bytes
	= int_size_in_bytes (TREE_TYPE (retval_rhs));
      int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
      unsigned int bitsize
	= MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)), BITS_PER_WORD);
      rtx *result_pseudos = alloca (sizeof (rtx) * n_regs);
      rtx result_reg, src = NULL_RTX, dst = NULL_RTX;
      rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0);
      enum machine_mode tmpmode, result_reg_mode;

      if (bytes == 0)
	{
	  expand_null_return ();
	  return;
	}

      /* If the structure doesn't take up a whole number of words, see
	 whether the register value should be padded on the left or on
	 the right.  Set PADDING_CORRECTION to the number of padding
	 bits needed on the left side.

	 In most ABIs, the structure will be returned at the least end of
	 the register, which translates to right padding on little-endian
	 targets and left padding on big-endian targets.  The opposite
	 holds if the structure is returned at the most significant
	 end of the register.  */
      if (bytes % UNITS_PER_WORD != 0
	  && (targetm.calls.return_in_msb (TREE_TYPE (retval_rhs))
	      ? !BYTES_BIG_ENDIAN
	      : BYTES_BIG_ENDIAN))
	padding_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD)
					       * BITS_PER_UNIT));

      /* Copy the structure BITSIZE bits at a time.  */
      for (bitpos = 0, xbitpos = padding_correction;
	   bitpos < bytes * BITS_PER_UNIT;
	   bitpos += bitsize, xbitpos += bitsize)
	{
	  /* We need a new destination pseudo each time xbitpos is
	     on a word boundary and when xbitpos == padding_correction
	     (the first time through).  */
	  if (xbitpos % BITS_PER_WORD == 0
	      || xbitpos == padding_correction)
	    {
	      /* Generate an appropriate register.  */
	      dst = gen_reg_rtx (word_mode);
	      result_pseudos[xbitpos / BITS_PER_WORD] = dst;

	      /* Clear the destination before we move anything into it.  */
	      emit_move_insn (dst, CONST0_RTX (GET_MODE (dst)));
	    }

	  /* We need a new source operand each time bitpos is on a word
	     boundary.  */
	  if (bitpos % BITS_PER_WORD == 0)
	    src = operand_subword_force (result_val,
					 bitpos / BITS_PER_WORD,
					 BLKmode);

	  /* Use bitpos for the source extraction (left justified) and
	     xbitpos for the destination store (right justified).  */
	  store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode,
			   extract_bit_field (src, bitsize,
					      bitpos % BITS_PER_WORD, 1,
					      NULL_RTX, word_mode, word_mode,
					      BITS_PER_WORD),
			   BITS_PER_WORD);
	}

      tmpmode = GET_MODE (result_rtl);
      if (tmpmode == BLKmode)
	{
	  /* Find the smallest integer mode large enough to hold the
	     entire structure and use that mode instead of BLKmode
	     on the USE insn for the return register.  */
	  for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
	       tmpmode != VOIDmode;
	       tmpmode = GET_MODE_WIDER_MODE (tmpmode))
	    /* Have we found a large enough mode?  */
	    if (GET_MODE_SIZE (tmpmode) >= bytes)
	      break;

	  /* No suitable mode found.  */
	  if (tmpmode == VOIDmode)
	    abort ();

	  PUT_MODE (result_rtl, tmpmode);
	}

      if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode))
	result_reg_mode = word_mode;
      else
	result_reg_mode = tmpmode;
      result_reg = gen_reg_rtx (result_reg_mode);

      emit_queue ();
      for (i = 0; i < n_regs; i++)
	emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode),
			result_pseudos[i]);

      if (tmpmode != result_reg_mode)
	result_reg = gen_lowpart (tmpmode, result_reg);

      expand_value_return (result_reg);
    }
  else if (retval_rhs != 0
	   && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
	   && (GET_CODE (result_rtl) == REG
	       || (GET_CODE (result_rtl) == PARALLEL)))
    {
      /* Calculate the return value into a temporary (usually a pseudo
         reg).  */
      tree ot = TREE_TYPE (DECL_RESULT (current_function_decl));
      tree nt = build_qualified_type (ot, TYPE_QUALS (ot) | TYPE_QUAL_CONST);

      val = assign_temp (nt, 0, 0, 1);
      val = expand_expr (retval_rhs, val, GET_MODE (val), 0);
      val = force_not_mem (val);
      emit_queue ();
      /* Return the calculated value, doing cleanups first.  */
      expand_value_return (shift_return_value (val));
    }
  else
    {
      /* No cleanups or no hard reg used;
	 calculate value into hard return reg.  */
      expand_expr (retval, const0_rtx, VOIDmode, 0);
      emit_queue ();
      expand_value_return (result_rtl);
    }
}

/* Attempt to optimize a potential tail recursion call into a goto.
   ARGUMENTS are the arguments to a CALL_EXPR; LAST_INSN indicates
   where to place the jump to the tail recursion label.

   Return TRUE if the call was optimized into a goto.  */

int
optimize_tail_recursion (tree arguments, rtx last_insn)
{
  /* Finish checking validity, and if valid emit code to set the
     argument variables for the new call.  */
  if (tail_recursion_args (arguments, DECL_ARGUMENTS (current_function_decl)))
    {
      if (tail_recursion_label == 0)
	{
	  tail_recursion_label = gen_label_rtx ();
	  emit_label_after (tail_recursion_label,
			    tail_recursion_reentry);
	}
      emit_queue ();
      expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn);
      emit_barrier ();
      return 1;
    }
  return 0;
}

/* Emit code to alter this function's formal parms for a tail-recursive call.
   ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
   FORMALS is the chain of decls of formals.
   Return 1 if this can be done;
   otherwise return 0 and do not emit any code.  */

static int
tail_recursion_args (tree actuals, tree formals)
{
  tree a = actuals, f = formals;
  int i;
  rtx *argvec;

  /* Check that number and types of actuals are compatible
     with the formals.  This is not always true in valid C code.
     Also check that no formal needs to be addressable
     and that all formals are scalars.  */

  /* Also count the args.  */

  for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++)
    {
      if (!lang_hooks.types_compatible_p (TREE_TYPE (TREE_VALUE (a)), 
	      TREE_TYPE (f)))
	return 0;
      if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode)
	return 0;
    }
  if (a != 0 || f != 0)
    return 0;

  /* Compute all the actuals.  */

  argvec = alloca (i * sizeof (rtx));

  for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
    argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0);

  /* Find which actual values refer to current values of previous formals.
     Copy each of them now, before any formal is changed.  */

  for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++)
    {
      int copy = 0;
      int j;
      for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++)
	if (reg_mentioned_p (DECL_RTL (f), argvec[i]))
	  {
	    copy = 1;
	    break;
	  }
      if (copy)
	argvec[i] = copy_to_reg (argvec[i]);
    }

  /* Store the values of the actuals into the formals.  */

  for (f = formals, a = actuals, i = 0; f;
       f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++)
    {
      if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i]))
	emit_move_insn (DECL_RTL (f), argvec[i]);
      else
	{
	  rtx tmp = argvec[i];
	  int unsignedp = TYPE_UNSIGNED (TREE_TYPE (TREE_VALUE (a)));
	  promote_mode(TREE_TYPE (TREE_VALUE (a)), GET_MODE (tmp),
		       &unsignedp, 0);
	  if (DECL_MODE (f) != GET_MODE (DECL_RTL (f)))
	    {
	      tmp = gen_reg_rtx (DECL_MODE (f));
	      convert_move (tmp, argvec[i], unsignedp);
	    }
	  convert_move (DECL_RTL (f), tmp, unsignedp);
	}
    }

  free_temp_slots ();
  return 1;
}

/* Generate the RTL code for entering a binding contour.
   The variables are declared one by one, by calls to `expand_decl'.

   FLAGS is a bitwise or of the following flags:

     1 - Nonzero if this construct should be visible to
         `exit_something'.

     2 - Nonzero if this contour does not require a
	 NOTE_INSN_BLOCK_BEG note.  Virtually all calls from
	 language-independent code should set this flag because they
	 will not create corresponding BLOCK nodes.  (There should be
	 a one-to-one correspondence between NOTE_INSN_BLOCK_BEG notes
	 and BLOCKs.)  If this flag is set, MARK_ENDS should be zero
	 when expand_end_bindings is called.

    If we are creating a NOTE_INSN_BLOCK_BEG note, a BLOCK may
    optionally be supplied.  If so, it becomes the NOTE_BLOCK for the
    note.  */

void
expand_start_bindings_and_block (int flags, tree block)
{
  struct nesting *thisblock = ALLOC_NESTING ();
  rtx note;
  int exit_flag = ((flags & 1) != 0);
  int block_flag = ((flags & 2) == 0);

  /* If a BLOCK is supplied, then the caller should be requesting a
     NOTE_INSN_BLOCK_BEG note.  */
  if (!block_flag && block)
    abort ();

  /* Create a note to mark the beginning of the block.  */
  if (block_flag && !cfun->dont_emit_block_notes)
    {
      note = emit_note (NOTE_INSN_BLOCK_BEG);
      NOTE_BLOCK (note) = block;
    }
  else
    note = emit_note (NOTE_INSN_DELETED);

  /* Make an entry on block_stack for the block we are entering.  */

  thisblock->desc = BLOCK_NESTING;
  thisblock->next = block_stack;
  thisblock->all = nesting_stack;
  thisblock->depth = ++nesting_depth;
  thisblock->data.block.stack_level = 0;
  thisblock->data.block.cleanups = 0;
  thisblock->data.block.exception_region = 0;
  thisblock->data.block.block_target_temp_slot_level = target_temp_slot_level;

  thisblock->data.block.conditional_code = 0;
  thisblock->data.block.last_unconditional_cleanup = note;
  /* When we insert instructions after the last unconditional cleanup,
     we don't adjust last_insn.  That means that a later add_insn will
     clobber the instructions we've just added.  The easiest way to
     fix this is to just insert another instruction here, so that the
     instructions inserted after the last unconditional cleanup are
     never the last instruction.  */
  emit_note (NOTE_INSN_DELETED);

  if (block_stack
      && !(block_stack->data.block.cleanups == NULL_TREE
	   && block_stack->data.block.outer_cleanups == NULL_TREE))
    thisblock->data.block.outer_cleanups
      = tree_cons (NULL_TREE, block_stack->data.block.cleanups,
		   block_stack->data.block.outer_cleanups);
  else
    thisblock->data.block.outer_cleanups = 0;
  thisblock->data.block.label_chain = 0;
  thisblock->data.block.innermost_stack_block = stack_block_stack;
  thisblock->data.block.first_insn = note;
  thisblock->data.block.block_start_count = ++current_block_start_count;
  thisblock->exit_label = exit_flag ? gen_label_rtx () : 0;
  block_stack = thisblock;
  nesting_stack = thisblock;

  /* Make a new level for allocating stack slots.  */
  push_temp_slots ();
}

/* Specify the scope of temporaries created by TARGET_EXPRs.  Similar
   to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
   expand_expr are made.  After we end the region, we know that all
   space for all temporaries that were created by TARGET_EXPRs will be
   destroyed and their space freed for reuse.  */

void
expand_start_target_temps (void)
{
  /* This is so that even if the result is preserved, the space
     allocated will be freed, as we know that it is no longer in use.  */
  push_temp_slots ();

  /* Start a new binding layer that will keep track of all cleanup
     actions to be performed.  */
  expand_start_bindings (2);

  target_temp_slot_level = temp_slot_level;
}

void
expand_end_target_temps (void)
{
  expand_end_bindings (NULL_TREE, 0, 0);

  /* This is so that even if the result is preserved, the space
     allocated will be freed, as we know that it is no longer in use.  */
  pop_temp_slots ();
}

/* Given a pointer to a BLOCK node return nonzero if (and only if) the node
   in question represents the outermost pair of curly braces (i.e. the "body
   block") of a function or method.

   For any BLOCK node representing a "body block" of a function or method, the
   BLOCK_SUPERCONTEXT of the node will point to another BLOCK node which
   represents the outermost (function) scope for the function or method (i.e.
   the one which includes the formal parameters).  The BLOCK_SUPERCONTEXT of
   *that* node in turn will point to the relevant FUNCTION_DECL node.  */

int
is_body_block (tree stmt)
{
  if (lang_hooks.no_body_blocks)
    return 0;

  if (TREE_CODE (stmt) == BLOCK)
    {
      tree parent = BLOCK_SUPERCONTEXT (stmt);

      if (parent && TREE_CODE (parent) == BLOCK)
	{
	  tree grandparent = BLOCK_SUPERCONTEXT (parent);

	  if (grandparent && TREE_CODE (grandparent) == FUNCTION_DECL)
	    return 1;
	}
    }

  return 0;
}

/* True if we are currently emitting insns in an area of output code
   that is controlled by a conditional expression.  This is used by
   the cleanup handling code to generate conditional cleanup actions.  */

int
conditional_context (void)
{
  return block_stack && block_stack->data.block.conditional_code;
}

/* Return an opaque pointer to the current nesting level, so frontend code
   can check its own sanity.  */

struct nesting *
current_nesting_level (void)
{
  return cfun ? block_stack : 0;
}

/* Emit code to restore vital registers at the beginning of a nonlocal goto
   handler.  */
static void
expand_nl_goto_receiver (void)
{
  /* Clobber the FP when we get here, so we have to make sure it's
     marked as used by this function.  */
  emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));

  /* Mark the static chain as clobbered here so life information
     doesn't get messed up for it.  */
  emit_insn (gen_rtx_CLOBBER (VOIDmode, static_chain_rtx));

#ifdef HAVE_nonlocal_goto
  if (! HAVE_nonlocal_goto)
#endif
    /* First adjust our frame pointer to its actual value.  It was
       previously set to the start of the virtual area corresponding to
       the stacked variables when we branched here and now needs to be
       adjusted to the actual hardware fp value.

       Assignments are to virtual registers are converted by
       instantiate_virtual_regs into the corresponding assignment
       to the underlying register (fp in this case) that makes
       the original assignment true.
       So the following insn will actually be
       decrementing fp by STARTING_FRAME_OFFSET.  */
    emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);

#if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
  if (fixed_regs[ARG_POINTER_REGNUM])
    {
#ifdef ELIMINABLE_REGS
      /* If the argument pointer can be eliminated in favor of the
	 frame pointer, we don't need to restore it.  We assume here
	 that if such an elimination is present, it can always be used.
	 This is the case on all known machines; if we don't make this
	 assumption, we do unnecessary saving on many machines.  */
      static const struct elims {const int from, to;} elim_regs[] = ELIMINABLE_REGS;
      size_t i;

      for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
	if (elim_regs[i].from == ARG_POINTER_REGNUM
	    && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
	  break;

      if (i == ARRAY_SIZE (elim_regs))
#endif
	{
	  /* Now restore our arg pointer from the address at which it
	     was saved in our stack frame.  */
	  emit_move_insn (virtual_incoming_args_rtx,
			  copy_to_reg (get_arg_pointer_save_area (cfun)));
	}
    }
#endif

#ifdef HAVE_nonlocal_goto_receiver
  if (HAVE_nonlocal_goto_receiver)
    emit_insn (gen_nonlocal_goto_receiver ());
#endif

  /* @@@ This is a kludge.  Not all machine descriptions define a blockage
     insn, but we must not allow the code we just generated to be reordered
     by scheduling.  Specifically, the update of the frame pointer must
     happen immediately, not later.  So emit an ASM_INPUT to act as blockage
     insn.  */
  emit_insn (gen_rtx_ASM_INPUT (VOIDmode, ""));
}

/* Warn about any unused VARS (which may contain nodes other than
   VAR_DECLs, but such nodes are ignored).  The nodes are connected
   via the TREE_CHAIN field.  */

void
warn_about_unused_variables (tree vars)
{
  tree decl;

  if (warn_unused_variable)
    for (decl = vars; decl; decl = TREE_CHAIN (decl))
      if (TREE_CODE (decl) == VAR_DECL
	  && ! TREE_USED (decl)
	  && ! DECL_IN_SYSTEM_HEADER (decl)
	  && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
	warning ("%Junused variable '%D'", decl, decl);
}

/* Generate RTL code to terminate a binding contour.

   VARS is the chain of VAR_DECL nodes for the variables bound in this
   contour.  There may actually be other nodes in this chain, but any
   nodes other than VAR_DECLS are ignored.

   MARK_ENDS is nonzero if we should put a note at the beginning
   and end of this binding contour.

   DONT_JUMP_IN is positive if it is not valid to jump into this contour,
   zero if we can jump into this contour only if it does not have a saved
   stack level, and negative if we are not to check for invalid use of
   labels (because the front end does that).  */

void
expand_end_bindings (tree vars, int mark_ends, int dont_jump_in)
{
  struct nesting *thisblock = block_stack;

  /* If any of the variables in this scope were not used, warn the
     user.  */
  warn_about_unused_variables (vars);

  if (thisblock->exit_label)
    {
      do_pending_stack_adjust ();
      emit_label (thisblock->exit_label);
    }

  /* Don't allow jumping into a block that has a stack level.
     Cleanups are allowed, though.  */
  if (dont_jump_in > 0
      || (dont_jump_in == 0 && thisblock->data.block.stack_level != 0))
    {
      struct label_chain *chain;

      /* Any labels in this block are no longer valid to go to.
	 Mark them to cause an error message.  */
      for (chain = thisblock->data.block.label_chain; chain; chain = chain->next)
	{
	  DECL_TOO_LATE (chain->label) = 1;
	  /* If any goto without a fixup came to this label,
	     that must be an error, because gotos without fixups
	     come from outside all saved stack-levels.  */
	  if (TREE_ADDRESSABLE (chain->label))
	    error ("%Jlabel '%D' used before containing binding contour",
		   chain->label, chain->label);
	}
    }

  /* Restore stack level in effect before the block
     (only if variable-size objects allocated).  */
  /* Perform any cleanups associated with the block.  */

  if (thisblock->data.block.stack_level != 0
      || thisblock->data.block.cleanups != 0)
    {
      int reachable;
      rtx insn;

      /* Don't let cleanups affect ({...}) constructs.  */
      int old_expr_stmts_for_value = expr_stmts_for_value;
      rtx old_last_expr_value = last_expr_value;
      rtx old_last_expr_alt_rtl = last_expr_alt_rtl;
      tree old_last_expr_type = last_expr_type;
      expr_stmts_for_value = 0;

      /* Only clean up here if this point can actually be reached.  */
      insn = get_last_insn ();
      if (GET_CODE (insn) == NOTE)
	insn = prev_nonnote_insn (insn);
      reachable = (! insn || GET_CODE (insn) != BARRIER);

      /* Do the cleanups.  */
      expand_cleanups (thisblock->data.block.cleanups, 0, reachable);
      if (reachable)
	do_pending_stack_adjust ();

      expr_stmts_for_value = old_expr_stmts_for_value;
      last_expr_value = old_last_expr_value;
      last_expr_alt_rtl = old_last_expr_alt_rtl;
      last_expr_type = old_last_expr_type;

      /* Restore the stack level.  */

      if (reachable && thisblock->data.block.stack_level != 0)
	{
	  emit_stack_restore (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
			      thisblock->data.block.stack_level, NULL_RTX);
	  if (cfun->nonlocal_goto_save_area)
	    update_nonlocal_goto_save_area ();
	}

      /* Any gotos out of this block must also do these things.
	 Also report any gotos with fixups that came to labels in this
	 level.  */
      fixup_gotos (thisblock,
		   thisblock->data.block.stack_level,
		   thisblock->data.block.cleanups,
		   thisblock->data.block.first_insn,
		   dont_jump_in);
    }

  /* Mark the beginning and end of the scope if requested.
     We do this now, after running cleanups on the variables
     just going out of scope, so they are in scope for their cleanups.  */

  if (mark_ends && !cfun->dont_emit_block_notes)
    {
      rtx note = emit_note (NOTE_INSN_BLOCK_END);
      NOTE_BLOCK (note) = NOTE_BLOCK (thisblock->data.block.first_insn);
    }
  else
    /* Get rid of the beginning-mark if we don't make an end-mark.  */
    NOTE_LINE_NUMBER (thisblock->data.block.first_insn) = NOTE_INSN_DELETED;

  /* Restore the temporary level of TARGET_EXPRs.  */
  target_temp_slot_level = thisblock->data.block.block_target_temp_slot_level;

  /* Restore block_stack level for containing block.  */

  stack_block_stack = thisblock->data.block.innermost_stack_block;
  POPSTACK (block_stack);

  /* Pop the stack slot nesting and free any slots at this level.  */
  pop_temp_slots ();
}

/* Generate code to save the stack pointer at the start of the current block
   and set up to restore it on exit.  */

void
save_stack_pointer (void)
{
  struct nesting *thisblock = block_stack;

  if (thisblock->data.block.stack_level == 0)
    {
      emit_stack_save (thisblock->next ? SAVE_BLOCK : SAVE_FUNCTION,
		       &thisblock->data.block.stack_level,
		       thisblock->data.block.first_insn);
      stack_block_stack = thisblock;
    }
}

/* Generate RTL for the automatic variable declaration DECL.
   (Other kinds of declarations are simply ignored if seen here.)  */

void
expand_decl (tree decl)
{
  tree type;

  type = TREE_TYPE (decl);

  /* For a CONST_DECL, set mode, alignment, and sizes from those of the
     type in case this node is used in a reference.  */
  if (TREE_CODE (decl) == CONST_DECL)
    {
      DECL_MODE (decl) = TYPE_MODE (type);
      DECL_ALIGN (decl) = TYPE_ALIGN (type);
      DECL_SIZE (decl) = TYPE_SIZE (type);
      DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (type);
      return;
    }

  /* Otherwise, only automatic variables need any expansion done.  Static and
     external variables, and external functions, will be handled by
     `assemble_variable' (called from finish_decl).  TYPE_DECL requires
     nothing.  PARM_DECLs are handled in `assign_parms'.  */
  if (TREE_CODE (decl) != VAR_DECL)
    return;

  if (TREE_STATIC (decl) || DECL_EXTERNAL (decl))
    return;

  /* Create the RTL representation for the variable.  */

  if (type == error_mark_node)
    SET_DECL_RTL (decl, gen_rtx_MEM (BLKmode, const0_rtx));

  else if (DECL_SIZE (decl) == 0)
    /* Variable with incomplete type.  */
    {
      rtx x;
      if (DECL_INITIAL (decl) == 0)
	/* Error message was already done; now avoid a crash.  */
	x = gen_rtx_MEM (BLKmode, const0_rtx);
      else
	/* An initializer is going to decide the size of this array.
	   Until we know the size, represent its address with a reg.  */
	x = gen_rtx_MEM (BLKmode, gen_reg_rtx (Pmode));

      set_mem_attributes (x, decl, 1);
      SET_DECL_RTL (decl, x);
    }
  else if (DECL_MODE (decl) != BLKmode
	   /* If -ffloat-store, don't put explicit float vars
	      into regs.  */
	   && !(flag_float_store
		&& TREE_CODE (type) == REAL_TYPE)
	   && ! TREE_THIS_VOLATILE (decl)
	   && ! DECL_NONLOCAL (decl)
	   && (DECL_REGISTER (decl) || DECL_ARTIFICIAL (decl) || optimize))
    {
      /* Automatic variable that can go in a register.  */
      int unsignedp = TYPE_UNSIGNED (type);
      enum machine_mode reg_mode
	= promote_mode (type, DECL_MODE (decl), &unsignedp, 0);

      SET_DECL_RTL (decl, gen_reg_rtx (reg_mode));

      if (!DECL_ARTIFICIAL (decl))
	mark_user_reg (DECL_RTL (decl));

      if (POINTER_TYPE_P (type))
	mark_reg_pointer (DECL_RTL (decl),
			  TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl))));

      maybe_set_unchanging (DECL_RTL (decl), decl);

      /* If something wants our address, try to use ADDRESSOF.  */
      if (TREE_ADDRESSABLE (decl))
	put_var_into_stack (decl, /*rescan=*/false);
    }

  else if (TREE_CODE (DECL_SIZE_UNIT (decl)) == INTEGER_CST
	   && ! (flag_stack_check && ! STACK_CHECK_BUILTIN
		 && 0 < compare_tree_int (DECL_SIZE_UNIT (decl),
					  STACK_CHECK_MAX_VAR_SIZE)))
    {
      /* Variable of fixed size that goes on the stack.  */
      rtx oldaddr = 0;
      rtx addr;
      rtx x;

      /* If we previously made RTL for this decl, it must be an array
	 whose size was determined by the initializer.
	 The old address was a register; set that register now
	 to the proper address.  */
      if (DECL_RTL_SET_P (decl))
	{
	  if (GET_CODE (DECL_RTL (decl)) != MEM
	      || GET_CODE (XEXP (DECL_RTL (decl), 0)) != REG)
	    abort ();
	  oldaddr = XEXP (DECL_RTL (decl), 0);
	}

      /* Set alignment we actually gave this decl.  */
      DECL_ALIGN (decl) = (DECL_MODE (decl) == BLKmode ? BIGGEST_ALIGNMENT
			   : GET_MODE_BITSIZE (DECL_MODE (decl)));
      DECL_USER_ALIGN (decl) = 0;

      x = assign_temp (decl, 1, 1, 1);
      set_mem_attributes (x, decl, 1);
      SET_DECL_RTL (decl, x);

      if (oldaddr)
	{
	  addr = force_operand (XEXP (DECL_RTL (decl), 0), oldaddr);
	  if (addr != oldaddr)
	    emit_move_insn (oldaddr, addr);
	}
    }
  else
    /* Dynamic-size object: must push space on the stack.  */
    {
      rtx address, size, x;

      /* Record the stack pointer on entry to block, if have
	 not already done so.  */
      do_pending_stack_adjust ();
      save_stack_pointer ();

      /* Compute the variable's size, in bytes.  This will expand any
	 needed SAVE_EXPRs for the first time.  */
      size = expand_expr (DECL_SIZE_UNIT (decl), NULL_RTX, VOIDmode, 0);
      free_temp_slots ();

      /* Allocate space on the stack for the variable.  Note that
	 DECL_ALIGN says how the variable is to be aligned and we
	 cannot use it to conclude anything about the alignment of
	 the size.  */
      address = allocate_dynamic_stack_space (size, NULL_RTX,
					      TYPE_ALIGN (TREE_TYPE (decl)));

      /* Reference the variable indirect through that rtx.  */
      x = gen_rtx_MEM (DECL_MODE (decl), address);
      set_mem_attributes (x, decl, 1);
      SET_DECL_RTL (decl, x);


      /* Indicate the alignment we actually gave this variable.  */
#ifdef STACK_BOUNDARY
      DECL_ALIGN (decl) = STACK_BOUNDARY;
#else
      DECL_ALIGN (decl) = BIGGEST_ALIGNMENT;
#endif
      DECL_USER_ALIGN (decl) = 0;
    }
}

/* Emit code to allocate T_SIZE bytes of dynamic stack space for ALLOC.  */
void
expand_stack_alloc (tree alloc, tree t_size)
{
  rtx address, dest, size;
  tree var, type;

  if (TREE_CODE (alloc) != ADDR_EXPR)
    abort ();
  var = TREE_OPERAND (alloc, 0);
  if (TREE_CODE (var) != VAR_DECL)
    abort ();

  type = TREE_TYPE (var);

  /* In function-at-a-time mode, variable_size doesn't expand this,
     so do it now.  */
  if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
    expand_expr (TYPE_MAX_VALUE (TYPE_DOMAIN (type)),
		 const0_rtx, VOIDmode, 0);

  /* Compute the variable's size, in bytes.  */
  size = expand_expr (t_size, NULL_RTX, VOIDmode, 0);
  free_temp_slots ();

  /* Allocate space on the stack for the variable.  */
  address = XEXP (DECL_RTL (var), 0);
  dest = allocate_dynamic_stack_space (size, address, TYPE_ALIGN (type));
  if (dest != address)
    emit_move_insn (address, dest);

  /* Indicate the alignment we actually gave this variable.  */
#ifdef STACK_BOUNDARY
  DECL_ALIGN (var) = STACK_BOUNDARY;
#else
  DECL_ALIGN (var) = BIGGEST_ALIGNMENT;
#endif
  DECL_USER_ALIGN (var) = 0;
}

/* Emit code to save the current value of stack.  */
rtx
expand_stack_save (void)
{
  rtx ret = NULL_RTX;

  do_pending_stack_adjust ();
  emit_stack_save (SAVE_BLOCK, &ret, NULL_RTX);
  return ret;
}

/* Emit code to restore the current value of stack.  */
void
expand_stack_restore (tree var)
{
  rtx sa = DECL_RTL (var);

  emit_stack_restore (SAVE_BLOCK, sa, NULL_RTX);
}

/* Emit code to perform the initialization of a declaration DECL.  */

void
expand_decl_init (tree decl)
{
  int was_used = TREE_USED (decl);

  /* If this is a CONST_DECL, we don't have to generate any code.  Likewise
     for static decls.  */
  if (TREE_CODE (decl) == CONST_DECL
      || TREE_STATIC (decl))
    return;

  /* Compute and store the initial value now.  */

  push_temp_slots ();

  if (DECL_INITIAL (decl) == error_mark_node)
    {
      enum tree_code code = TREE_CODE (TREE_TYPE (decl));

      if (code == INTEGER_TYPE || code == REAL_TYPE || code == ENUMERAL_TYPE
	  || code == POINTER_TYPE || code == REFERENCE_TYPE)
	expand_assignment (decl, convert (TREE_TYPE (decl), integer_zero_node),
			   0);
      emit_queue ();
    }
  else if (DECL_INITIAL (decl) && TREE_CODE (DECL_INITIAL (decl)) != TREE_LIST)
    {
      emit_line_note (DECL_SOURCE_LOCATION (decl));
      expand_assignment (decl, DECL_INITIAL (decl), 0);
      emit_queue ();
    }

  /* Don't let the initialization count as "using" the variable.  */
  TREE_USED (decl) = was_used;

  /* Free any temporaries we made while initializing the decl.  */
  preserve_temp_slots (NULL_RTX);
  free_temp_slots ();
  pop_temp_slots ();
}

/* CLEANUP is an expression to be executed at exit from this binding contour;
   for example, in C++, it might call the destructor for this variable.

   We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
   CLEANUP multiple times, and have the correct semantics.  This
   happens in exception handling, for gotos, returns, breaks that
   leave the current scope.

   If CLEANUP is nonzero and DECL is zero, we record a cleanup
   that is not associated with any particular variable.  */

int
expand_decl_cleanup (tree decl, tree cleanup)
{
  struct nesting *thisblock;

  /* Error if we are not in any block.  */
  if (cfun == 0 || block_stack == 0)
    return 0;

  thisblock = block_stack;

  /* Record the cleanup if there is one.  */

  if (cleanup != 0)
    {
      tree t;
      rtx seq;
      tree *cleanups = &thisblock->data.block.cleanups;
      int cond_context = conditional_context ();

      if (cond_context)
	{
	  rtx flag = gen_reg_rtx (word_mode);
	  rtx set_flag_0;
	  tree cond;

	  start_sequence ();
	  emit_move_insn (flag, const0_rtx);
	  set_flag_0 = get_insns ();
	  end_sequence ();

	  thisblock->data.block.last_unconditional_cleanup
	    = emit_insn_after (set_flag_0,
				thisblock->data.block.last_unconditional_cleanup);

	  emit_move_insn (flag, const1_rtx);

	  cond = build_decl (VAR_DECL, NULL_TREE,
			     lang_hooks.types.type_for_mode (word_mode, 1));
	  SET_DECL_RTL (cond, flag);

	  /* Conditionalize the cleanup.  */
	  cleanup = build (COND_EXPR, void_type_node,
			   lang_hooks.truthvalue_conversion (cond),
			   cleanup, integer_zero_node);
	  cleanup = fold (cleanup);

	  cleanups = &thisblock->data.block.cleanups;
	}

      cleanup = unsave_expr (cleanup);

      t = *cleanups = tree_cons (decl, cleanup, *cleanups);

      if (! cond_context)
	/* If this block has a cleanup, it belongs in stack_block_stack.  */
	stack_block_stack = thisblock;

      if (cond_context)
	{
	  start_sequence ();
	}

      if (! using_eh_for_cleanups_p)
	TREE_ADDRESSABLE (t) = 1;
      else
	expand_eh_region_start ();

      if (cond_context)
	{
	  seq = get_insns ();
	  end_sequence ();
	  if (seq)
	    thisblock->data.block.last_unconditional_cleanup
	      = emit_insn_after (seq,
				 thisblock->data.block.last_unconditional_cleanup);
	}
      else
	{
	  thisblock->data.block.last_unconditional_cleanup
	    = get_last_insn ();
	  /* When we insert instructions after the last unconditional cleanup,
	     we don't adjust last_insn.  That means that a later add_insn will
	     clobber the instructions we've just added.  The easiest way to
	     fix this is to just insert another instruction here, so that the
	     instructions inserted after the last unconditional cleanup are
	     never the last instruction.  */
	  emit_note (NOTE_INSN_DELETED);
	}
    }
  return 1;
}

/* Like expand_decl_cleanup, but maybe only run the cleanup if an exception
   is thrown.  */

int
expand_decl_cleanup_eh (tree decl, tree cleanup, int eh_only)
{
  int ret = expand_decl_cleanup (decl, cleanup);
  if (cleanup && ret)
    {
      tree node = block_stack->data.block.cleanups;
      CLEANUP_EH_ONLY (node) = eh_only;
    }
  return ret;
}

/* DECL is an anonymous union.  CLEANUP is a cleanup for DECL.
   DECL_ELTS is the list of elements that belong to DECL's type.
   In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup.  */

void
expand_anon_union_decl (tree decl, tree cleanup, tree decl_elts)
{
  struct nesting *thisblock = cfun == 0 ? 0 : block_stack;
  rtx x;
  tree t;

  /* If any of the elements are addressable, so is the entire union.  */
  for (t = decl_elts; t; t = TREE_CHAIN (t))
    if (TREE_ADDRESSABLE (TREE_VALUE (t)))
      {
	TREE_ADDRESSABLE (decl) = 1;
	break;
      }

  expand_decl (decl);
  expand_decl_cleanup (decl, cleanup);
  x = DECL_RTL (decl);

  /* Go through the elements, assigning RTL to each.  */
  for (t = decl_elts; t; t = TREE_CHAIN (t))
    {
      tree decl_elt = TREE_VALUE (t);
      tree cleanup_elt = TREE_PURPOSE (t);
      enum machine_mode mode = TYPE_MODE (TREE_TYPE (decl_elt));

      /* If any of the elements are addressable, so is the entire
	 union.  */
      if (TREE_USED (decl_elt))
	TREE_USED (decl) = 1;

      /* Propagate the union's alignment to the elements.  */
      DECL_ALIGN (decl_elt) = DECL_ALIGN (decl);
      DECL_USER_ALIGN (decl_elt) = DECL_USER_ALIGN (decl);

      /* If the element has BLKmode and the union doesn't, the union is
         aligned such that the element doesn't need to have BLKmode, so
         change the element's mode to the appropriate one for its size.  */
      if (mode == BLKmode && DECL_MODE (decl) != BLKmode)
	DECL_MODE (decl_elt) = mode
	  = mode_for_size_tree (DECL_SIZE (decl_elt), MODE_INT, 1);

      /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
         instead create a new MEM rtx with the proper mode.  */
      if (GET_CODE (x) == MEM)
	{
	  if (mode == GET_MODE (x))
	    SET_DECL_RTL (decl_elt, x);
	  else
	    SET_DECL_RTL (decl_elt, adjust_address_nv (x, mode, 0));
	}
      else if (GET_CODE (x) == REG)
	{
	  if (mode == GET_MODE (x))
	    SET_DECL_RTL (decl_elt, x);
	  else
	    SET_DECL_RTL (decl_elt, gen_lowpart_SUBREG (mode, x));
	}
      else
	abort ();

      /* Record the cleanup if there is one.  */

      if (cleanup != 0)
	thisblock->data.block.cleanups
	  = tree_cons (decl_elt, cleanup_elt,
		       thisblock->data.block.cleanups);
    }
}

/* Expand a list of cleanups LIST.
   Elements may be expressions or may be nested lists.

   If IN_FIXUP is nonzero, we are generating this cleanup for a fixup
   goto and handle protection regions specially in that case.

   If REACHABLE, we emit code, otherwise just inform the exception handling
   code about this finalization.  */

static void
expand_cleanups (tree list, int in_fixup, int reachable)
{
  tree tail;
  for (tail = list; tail; tail = TREE_CHAIN (tail))
    if (TREE_CODE (TREE_VALUE (tail)) == TREE_LIST)
      expand_cleanups (TREE_VALUE (tail), in_fixup, reachable);
    else
      {
	if (! in_fixup && using_eh_for_cleanups_p)
	  expand_eh_region_end_cleanup (TREE_VALUE (tail));

	if (reachable && !CLEANUP_EH_ONLY (tail))
	  {
	    /* Cleanups may be run multiple times.  For example,
	       when exiting a binding contour, we expand the
	       cleanups associated with that contour.  When a goto
	       within that binding contour has a target outside that
	       contour, it will expand all cleanups from its scope to
	       the target.  Though the cleanups are expanded multiple
	       times, the control paths are non-overlapping so the
	       cleanups will not be executed twice.  */

	    /* We may need to protect from outer cleanups.  */
	    if (in_fixup && using_eh_for_cleanups_p)
	      {
		expand_eh_region_start ();

		expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);

		expand_eh_region_end_fixup (TREE_VALUE (tail));
	      }
	    else
	      expand_expr (TREE_VALUE (tail), const0_rtx, VOIDmode, 0);

	    free_temp_slots ();
	  }
      }
}

/* Mark when the context we are emitting RTL for as a conditional
   context, so that any cleanup actions we register with
   expand_decl_init will be properly conditionalized when those
   cleanup actions are later performed.  Must be called before any
   expression (tree) is expanded that is within a conditional context.  */

void
start_cleanup_deferral (void)
{
  /* block_stack can be NULL if we are inside the parameter list.  It is
     OK to do nothing, because cleanups aren't possible here.  */
  if (block_stack)
    ++block_stack->data.block.conditional_code;
}

/* Mark the end of a conditional region of code.  Because cleanup
   deferrals may be nested, we may still be in a conditional region
   after we end the currently deferred cleanups, only after we end all
   deferred cleanups, are we back in unconditional code.  */

void
end_cleanup_deferral (void)
{
  /* block_stack can be NULL if we are inside the parameter list.  It is
     OK to do nothing, because cleanups aren't possible here.  */
  if (block_stack)
    --block_stack->data.block.conditional_code;
}

tree
last_cleanup_this_contour (void)
{
  if (block_stack == 0)
    return 0;

  return block_stack->data.block.cleanups;
}


/* Return nonzero if any containing block has a stack level or
   cleanups.  */

int
containing_blocks_have_cleanups_or_stack_level (void)
{
  struct nesting *block;

  for (block = block_stack; block; block = block->next)
    if (block->data.block.stack_level != 0
        || block->data.block.cleanups != 0)
      return 1;

  return 0;
}

/* Return 1 if there are any pending cleanups at this point.
   Check the current contour as well as contours that enclose
   the current contour.  */

int
any_pending_cleanups (void)
{
  struct nesting *block;

  if (cfun == NULL || cfun->stmt == NULL || block_stack == 0)
    return 0;

  if (block_stack->data.block.cleanups != NULL)
    return 1;

  if (block_stack->data.block.outer_cleanups == 0)
    return 0;

  for (block = block_stack->next; block; block = block->next)
    if (block->data.block.cleanups != 0)
      return 1;

  return 0;
}

/* Enter a case (Pascal) or switch (C) statement.
   Push a block onto case_stack and nesting_stack
   to accumulate the case-labels that are seen
   and to record the labels generated for the statement.

   EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
   Otherwise, this construct is transparent for `exit_something'.

   EXPR is the index-expression to be dispatched on.
   TYPE is its nominal type.  We could simply convert EXPR to this type,
   but instead we take short cuts.  */

void
expand_start_case (int exit_flag, tree expr, tree type,
		   const char *printname)
{
  struct nesting *thiscase = ALLOC_NESTING ();

  /* Make an entry on case_stack for the case we are entering.  */

  thiscase->desc = CASE_NESTING;
  thiscase->next = case_stack;
  thiscase->all = nesting_stack;
  thiscase->depth = ++nesting_depth;
  thiscase->exit_label = exit_flag ? gen_label_rtx () : 0;
  thiscase->data.case_stmt.case_list = 0;
  thiscase->data.case_stmt.index_expr = expr;
  thiscase->data.case_stmt.nominal_type = type;
  thiscase->data.case_stmt.default_label = 0;
  thiscase->data.case_stmt.printname = printname;
  thiscase->data.case_stmt.line_number_status = force_line_numbers ();
  case_stack = thiscase;
  nesting_stack = thiscase;

  do_pending_stack_adjust ();
  emit_queue ();

  /* Make sure case_stmt.start points to something that won't
     need any transformation before expand_end_case.  */
  if (GET_CODE (get_last_insn ()) != NOTE)
    emit_note (NOTE_INSN_DELETED);

  thiscase->data.case_stmt.start = get_last_insn ();

  start_cleanup_deferral ();
}

static void
check_seenlabel (void)
{
  /* If this is the first label, warn if any insns have been emitted.  */
  if (case_stack->data.case_stmt.line_number_status >= 0)
    {
      rtx insn;

      restore_line_number_status
	(case_stack->data.case_stmt.line_number_status);
      case_stack->data.case_stmt.line_number_status = -1;

      for (insn = case_stack->data.case_stmt.start;
	   insn;
	   insn = NEXT_INSN (insn))
	{
	  if (GET_CODE (insn) == CODE_LABEL)
	    break;
	  if (GET_CODE (insn) != NOTE
	      && (GET_CODE (insn) != INSN || GET_CODE (PATTERN (insn)) != USE))
	    {
	      do
		insn = PREV_INSN (insn);
	      while (insn && (GET_CODE (insn) != NOTE || NOTE_LINE_NUMBER (insn) < 0));

	      /* If insn is zero, then there must have been a syntax error.  */
	      if (insn)
                {
                  location_t locus;
                  locus.file = NOTE_SOURCE_FILE (insn);
                  locus.line = NOTE_LINE_NUMBER (insn);
                  warning ("%Hunreachable code at beginning of %s", &locus,
                           case_stack->data.case_stmt.printname);
                }
	      break;
	    }
	}
    }
}

/* Accumulate one case or default label inside a case or switch statement.
   VALUE is the value of the case (a null pointer, for a default label).
   The function CONVERTER, when applied to arguments T and V,
   converts the value V to the type T.

   If not currently inside a case or switch statement, return 1 and do
   nothing.  The caller will print a language-specific error message.
   If VALUE is a duplicate or overlaps, return 2 and do nothing
   except store the (first) duplicate node in *DUPLICATE.
   If VALUE is out of range, return 3 and do nothing.
   If we are jumping into the scope of a cleanup or var-sized array, return 5.
   Return 0 on success.

   Extended to handle range statements.  */

int
pushcase (tree value, tree (*converter) (tree, tree), tree label,
	  tree *duplicate)
{
  tree index_type;
  tree nominal_type;

  /* Fail if not inside a real case statement.  */
  if (! (case_stack && case_stack->data.case_stmt.start))
    return 1;

  if (stack_block_stack
      && stack_block_stack->depth > case_stack->depth)
    return 5;

  index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
  nominal_type = case_stack->data.case_stmt.nominal_type;

  /* If the index is erroneous, avoid more problems: pretend to succeed.  */
  if (index_type == error_mark_node)
    return 0;

  /* Convert VALUE to the type in which the comparisons are nominally done.  */
  if (value != 0)
    value = (*converter) (nominal_type, value);

  check_seenlabel ();

  /* Fail if this value is out of range for the actual type of the index
     (which may be narrower than NOMINAL_TYPE).  */
  if (value != 0
      && (TREE_CONSTANT_OVERFLOW (value)
	  || ! int_fits_type_p (value, index_type)))
    return 3;

  return add_case_node (value, value, label, duplicate, false);
}

/* Like pushcase but this case applies to all values between VALUE1 and
   VALUE2 (inclusive).  If VALUE1 is NULL, the range starts at the lowest
   value of the index type and ends at VALUE2.  If VALUE2 is NULL, the range
   starts at VALUE1 and ends at the highest value of the index type.
   If both are NULL, this case applies to all values.

   The return value is the same as that of pushcase but there is one
   additional error code: 4 means the specified range was empty.  */

int
pushcase_range (tree value1, tree value2, tree (*converter) (tree, tree),
		tree label, tree *duplicate)
{
  tree index_type;
  tree nominal_type;

  /* Fail if not inside a real case statement.  */
  if (! (case_stack && case_stack->data.case_stmt.start))
    return 1;

  if (stack_block_stack
      && stack_block_stack->depth > case_stack->depth)
    return 5;

  index_type = TREE_TYPE (case_stack->data.case_stmt.index_expr);
  nominal_type = case_stack->data.case_stmt.nominal_type;

  /* If the index is erroneous, avoid more problems: pretend to succeed.  */
  if (index_type == error_mark_node)
    return 0;

  check_seenlabel ();

  /* Convert VALUEs to type in which the comparisons are nominally done
     and replace any unspecified value with the corresponding bound.  */
  if (value1 == 0)
    value1 = TYPE_MIN_VALUE (index_type);
  if (value2 == 0)
    value2 = TYPE_MAX_VALUE (index_type);

  /* Fail if the range is empty.  Do this before any conversion since
     we want to allow out-of-range empty ranges.  */
  if (value2 != 0 && tree_int_cst_lt (value2, value1))
    return 4;

  /* If the max was unbounded, use the max of the nominal_type we are
     converting to.  Do this after the < check above to suppress false
     positives.  */
  if (value2 == 0)
    value2 = TYPE_MAX_VALUE (nominal_type);

  value1 = (*converter) (nominal_type, value1);
  value2 = (*converter) (nominal_type, value2);

  /* Fail if these values are out of range.  */
  if (TREE_CONSTANT_OVERFLOW (value1)
      || ! int_fits_type_p (value1, index_type))
    return 3;

  if (TREE_CONSTANT_OVERFLOW (value2)
      || ! int_fits_type_p (value2, index_type))
    return 3;

  return add_case_node (value1, value2, label, duplicate, false);
}

/* Do the actual insertion of a case label for pushcase and pushcase_range
   into case_stack->data.case_stmt.case_list.  Use an AVL tree to avoid
   slowdown for large switch statements.  */

int
add_case_node (tree low, tree high, tree label, tree *duplicate,
	       bool dont_expand_label)
{
  struct case_node *p, **q, *r;

  /* If there's no HIGH value, then this is not a case range; it's
     just a simple case label.  But that's just a degenerate case
     range.  */
  if (!high)
    high = low;

  /* Handle default labels specially.  */
  if (!high && !low)
    {
      if (case_stack->data.case_stmt.default_label != 0)
	{
	  *duplicate = case_stack->data.case_stmt.default_label;
	  return 2;
	}
      case_stack->data.case_stmt.default_label = label;
      if (!dont_expand_label)
        expand_label (label);
      return 0;
    }

  q = &case_stack->data.case_stmt.case_list;
  p = *q;

  while ((r = *q))
    {
      p = r;

      /* Keep going past elements distinctly greater than HIGH.  */
      if (tree_int_cst_lt (high, p->low))
	q = &p->left;

      /* or distinctly less than LOW.  */
      else if (tree_int_cst_lt (p->high, low))
	q = &p->right;

      else
	{
	  /* We have an overlap; this is an error.  */
	  *duplicate = p->code_label;
	  return 2;
	}
    }

  /* Add this label to the chain, and succeed.  */

  r = ggc_alloc (sizeof (struct case_node));
  r->low = low;

  /* If the bounds are equal, turn this into the one-value case.  */
  if (tree_int_cst_equal (low, high))
    r->high = r->low;
  else
    r->high = high;

  r->code_label = label;
  if (!dont_expand_label)
    expand_label (label);

  *q = r;
  r->parent = p;
  r->left = 0;
  r->right = 0;
  r->balance = 0;

  while (p)
    {
      struct case_node *s;

      if (r == p->left)
	{
	  int b;

	  if (! (b = p->balance))
	    /* Growth propagation from left side.  */
	    p->balance = -1;
	  else if (b < 0)
	    {
	      if (r->balance < 0)
		{
		  /* R-Rotation */
		  if ((p->left = s = r->right))
		    s->parent = p;

		  r->right = p;
		  p->balance = 0;
		  r->balance = 0;
		  s = p->parent;
		  p->parent = r;

		  if ((r->parent = s))
		    {
		      if (s->left == p)
			s->left = r;
		      else
			s->right = r;
		    }
		  else
		    case_stack->data.case_stmt.case_list = r;
		}
	      else
		/* r->balance == +1 */
		{
		  /* LR-Rotation */

		  int b2;
		  struct case_node *t = r->right;

		  if ((p->left = s = t->right))
		    s->parent = p;

		  t->right = p;
		  if ((r->right = s = t->left))
		    s->parent = r;

		  t->left = r;
		  b = t->balance;
		  b2 = b < 0;
		  p->balance = b2;
		  b2 = -b2 - b;
		  r->balance = b2;
		  t->balance = 0;
		  s = p->parent;
		  p->parent = t;
		  r->parent = t;

		  if ((t->parent = s))
		    {
		      if (s->left == p)
			s->left = t;
		      else
			s->right = t;
		    }
		  else
		    case_stack->data.case_stmt.case_list = t;
		}
	      break;
	    }

	  else
	    {
	      /* p->balance == +1; growth of left side balances the node.  */
	      p->balance = 0;
	      break;
	    }
	}
      else
	/* r == p->right */
	{
	  int b;

	  if (! (b = p->balance))
	    /* Growth propagation from right side.  */
	    p->balance++;
	  else if (b > 0)
	    {
	      if (r->balance > 0)
		{
		  /* L-Rotation */

		  if ((p->right = s = r->left))
		    s->parent = p;

		  r->left = p;
		  p->balance = 0;
		  r->balance = 0;
		  s = p->parent;
		  p->parent = r;
		  if ((r->parent = s))
		    {
		      if (s->left == p)
			s->left = r;
		      else
			s->right = r;
		    }

		  else
		    case_stack->data.case_stmt.case_list = r;
		}

	      else
		/* r->balance == -1 */
		{
		  /* RL-Rotation */
		  int b2;
		  struct case_node *t = r->left;

		  if ((p->right = s = t->left))
		    s->parent = p;

		  t->left = p;

		  if ((r->left = s = t->right))
		    s->parent = r;

		  t->right = r;
		  b = t->balance;
		  b2 = b < 0;
		  r->balance = b2;
		  b2 = -b2 - b;
		  p->balance = b2;
		  t->balance = 0;
		  s = p->parent;
		  p->parent = t;
		  r->parent = t;

		  if ((t->parent = s))
		    {
		      if (s->left == p)
			s->left = t;
		      else
			s->right = t;
		    }

		  else
		    case_stack->data.case_stmt.case_list = t;
		}
	      break;
	    }
	  else
	    {
	      /* p->balance == -1; growth of right side balances the node.  */
	      p->balance = 0;
	      break;
	    }
	}

      r = p;
      p = p->parent;
    }

  return 0;
}

/* Maximum number of case bit tests.  */
#define MAX_CASE_BIT_TESTS  3

/* By default, enable case bit tests on targets with ashlsi3.  */
#ifndef CASE_USE_BIT_TESTS
#define CASE_USE_BIT_TESTS  (ashl_optab->handlers[word_mode].insn_code \
			     != CODE_FOR_nothing)
#endif


/* A case_bit_test represents a set of case nodes that may be
   selected from using a bit-wise comparison.  HI and LO hold
   the integer to be tested against, LABEL contains the label
   to jump to upon success and BITS counts the number of case
   nodes handled by this test, typically the number of bits
   set in HI:LO.  */

struct case_bit_test
{
  HOST_WIDE_INT hi;
  HOST_WIDE_INT lo;
  rtx label;
  int bits;
};

/* Determine whether "1 << x" is relatively cheap in word_mode.  */

static
bool lshift_cheap_p (void)
{
  static bool init = false;
  static bool cheap = true;

  if (!init)
    {
      rtx reg = gen_rtx_REG (word_mode, 10000);
      int cost = rtx_cost (gen_rtx_ASHIFT (word_mode, const1_rtx, reg), SET);
      cheap = cost < COSTS_N_INSNS (3);
      init = true;
    }

  return cheap;
}

/* Comparison function for qsort to order bit tests by decreasing
   number of case nodes, i.e. the node with the most cases gets
   tested first.  */

static
int case_bit_test_cmp (const void *p1, const void *p2)
{
  const struct case_bit_test *d1 = p1;
  const struct case_bit_test *d2 = p2;

  return d2->bits - d1->bits;
}

/*  Expand a switch statement by a short sequence of bit-wise
    comparisons.  "switch(x)" is effectively converted into
    "if ((1 << (x-MINVAL)) & CST)" where CST and MINVAL are
    integer constants.

    INDEX_EXPR is the value being switched on, which is of
    type INDEX_TYPE.  MINVAL is the lowest case value of in
    the case nodes, of INDEX_TYPE type, and RANGE is highest
    value minus MINVAL, also of type INDEX_TYPE.  NODES is
    the set of case nodes, and DEFAULT_LABEL is the label to
    branch to should none of the cases match.

    There *MUST* be MAX_CASE_BIT_TESTS or less unique case
    node targets.  */

static void
emit_case_bit_tests (tree index_type, tree index_expr, tree minval,
		     tree range, case_node_ptr nodes, rtx default_label)
{
  struct case_bit_test test[MAX_CASE_BIT_TESTS];
  enum machine_mode mode;
  rtx expr, index, label;
  unsigned int i,j,lo,hi;
  struct case_node *n;
  unsigned int count;

  count = 0;
  for (n = nodes; n; n = n->right)
    {
      label = label_rtx (n->code_label);
      for (i = 0; i < count; i++)
	if (same_case_target_p (label, test[i].label))
	  break;

      if (i == count)
	{
	  if (count >= MAX_CASE_BIT_TESTS)
	    abort ();
          test[i].hi = 0;
          test[i].lo = 0;
	  test[i].label = label;
	  test[i].bits = 1;
	  count++;
	}
      else
        test[i].bits++;

      lo = tree_low_cst (fold (build (MINUS_EXPR, index_type,
				      n->low, minval)), 1);
      hi = tree_low_cst (fold (build (MINUS_EXPR, index_type,
				      n->high, minval)), 1);
      for (j = lo; j <= hi; j++)
        if (j >= HOST_BITS_PER_WIDE_INT)
	  test[i].hi |= (HOST_WIDE_INT) 1 << (j - HOST_BITS_PER_INT);
	else
	  test[i].lo |= (HOST_WIDE_INT) 1 << j;
    }

  qsort (test, count, sizeof(*test), case_bit_test_cmp);

  index_expr = fold (build (MINUS_EXPR, index_type,
			    convert (index_type, index_expr),
			    convert (index_type, minval)));
  index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);
  emit_queue ();
  index = protect_from_queue (index, 0);
  do_pending_stack_adjust ();

  mode = TYPE_MODE (index_type);
  expr = expand_expr (range, NULL_RTX, VOIDmode, 0);
  emit_cmp_and_jump_insns (index, expr, GTU, NULL_RTX, mode, 1,
			   default_label);

  index = convert_to_mode (word_mode, index, 0);
  index = expand_binop (word_mode, ashl_optab, const1_rtx,
			index, NULL_RTX, 1, OPTAB_WIDEN);

  for (i = 0; i < count; i++)
    {
      expr = immed_double_const (test[i].lo, test[i].hi, word_mode);
      expr = expand_binop (word_mode, and_optab, index, expr,
			   NULL_RTX, 1, OPTAB_WIDEN);
      emit_cmp_and_jump_insns (expr, const0_rtx, NE, NULL_RTX,
			       word_mode, 1, test[i].label);
    }

  emit_jump (default_label);
}

#ifndef HAVE_casesi
#define HAVE_casesi 0
#endif

#ifndef HAVE_tablejump
#define HAVE_tablejump 0
#endif

/* Terminate a case (Pascal) or switch (C) statement
   in which ORIG_INDEX is the expression to be tested.
   If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
   type as given in the source before any compiler conversions.
   Generate the code to test it and jump to the right place.  */

void
expand_end_case_type (tree orig_index, tree orig_type)
{
  tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE;
  rtx default_label = 0;
  struct case_node *n, *m;
  unsigned int count, uniq;
  rtx index;
  rtx table_label;
  int ncases;
  rtx *labelvec;
  int i;
  rtx before_case, end, lab;
  struct nesting *thiscase = case_stack;
  tree index_expr, index_type;
  bool exit_done = false;
  int unsignedp;

  /* Don't crash due to previous errors.  */
  if (thiscase == NULL)
    return;

  index_expr = thiscase->data.case_stmt.index_expr;
  index_type = TREE_TYPE (index_expr);
  unsignedp = TYPE_UNSIGNED (index_type);
  if (orig_type == NULL)
    orig_type = TREE_TYPE (orig_index);

  do_pending_stack_adjust ();

  /* This might get a spurious warning in the presence of a syntax error;
     it could be fixed by moving the call to check_seenlabel after the
     check for error_mark_node, and copying the code of check_seenlabel that
     deals with case_stack->data.case_stmt.line_number_status /
     restore_line_number_status in front of the call to end_cleanup_deferral;
     However, this might miss some useful warnings in the presence of
     non-syntax errors.  */
  check_seenlabel ();

  /* An ERROR_MARK occurs for various reasons including invalid data type.  */
  if (index_type != error_mark_node)
    {
      /* If we don't have a default-label, create one here,
	 after the body of the switch.  */
      if (thiscase->data.case_stmt.default_label == 0)
	{
	  thiscase->data.case_stmt.default_label
	    = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
	  /* Share the exit label if possible.  */
          if (thiscase->exit_label)
	    {
	      SET_DECL_RTL (thiscase->data.case_stmt.default_label,
			    thiscase->exit_label);
	      exit_done = true;
	    }
	  expand_label (thiscase->data.case_stmt.default_label);
	}
      default_label = label_rtx (thiscase->data.case_stmt.default_label);

      before_case = get_last_insn ();

      if (thiscase->data.case_stmt.case_list
	  && thiscase->data.case_stmt.case_list->left)
	thiscase->data.case_stmt.case_list
	  = case_tree2list (thiscase->data.case_stmt.case_list, 0);

      /* Simplify the case-list before we count it.  */
      group_case_nodes (thiscase->data.case_stmt.case_list);
      strip_default_case_nodes (&thiscase->data.case_stmt.case_list,
				default_label);

      /* Get upper and lower bounds of case values.
	 Also convert all the case values to the index expr's data type.  */

      uniq = 0;
      count = 0;
      for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
	{
	  /* Check low and high label values are integers.  */
	  if (TREE_CODE (n->low) != INTEGER_CST)
	    abort ();
	  if (TREE_CODE (n->high) != INTEGER_CST)
	    abort ();

	  n->low = convert (index_type, n->low);
	  n->high = convert (index_type, n->high);

	  /* Count the elements and track the largest and smallest
	     of them (treating them as signed even if they are not).  */
	  if (count++ == 0)
	    {
	      minval = n->low;
	      maxval = n->high;
	    }
	  else
	    {
	      if (INT_CST_LT (n->low, minval))
		minval = n->low;
	      if (INT_CST_LT (maxval, n->high))
		maxval = n->high;
	    }
	  /* A range counts double, since it requires two compares.  */
	  if (! tree_int_cst_equal (n->low, n->high))
	    count++;

	  /* Count the number of unique case node targets.  */
          uniq++;
	  lab = label_rtx (n->code_label);
          for (m = thiscase->data.case_stmt.case_list; m != n; m = m->right)
            if (same_case_target_p (label_rtx (m->code_label), lab))
              {
                uniq--;
                break;
              }
	}

      /* Compute span of values.  */
      if (count != 0)
	range = fold (build (MINUS_EXPR, index_type, maxval, minval));

      end_cleanup_deferral ();

      if (count == 0)
	{
	  expand_expr (index_expr, const0_rtx, VOIDmode, 0);
	  emit_queue ();
	  emit_jump (default_label);
	}

      /* Try implementing this switch statement by a short sequence of
	 bit-wise comparisons.  However, we let the binary-tree case
	 below handle constant index expressions.  */
      else if (CASE_USE_BIT_TESTS
	       && ! TREE_CONSTANT (index_expr)
	       && compare_tree_int (range, GET_MODE_BITSIZE (word_mode)) < 0
	       && compare_tree_int (range, 0) > 0
	       && lshift_cheap_p ()
	       && ((uniq == 1 && count >= 3)
		   || (uniq == 2 && count >= 5)
		   || (uniq == 3 && count >= 6)))
	{
	  /* Optimize the case where all the case values fit in a
	     word without having to subtract MINVAL.  In this case,
	     we can optimize away the subtraction.  */
	  if (compare_tree_int (minval, 0) > 0
	      && compare_tree_int (maxval, GET_MODE_BITSIZE (word_mode)) < 0)
	    {
	      minval = integer_zero_node;
	      range = maxval;
	    }
	  emit_case_bit_tests (index_type, index_expr, minval, range,
			       thiscase->data.case_stmt.case_list,
			       default_label);
	}

      /* If range of values is much bigger than number of values,
	 make a sequence of conditional branches instead of a dispatch.
	 If the switch-index is a constant, do it this way
	 because we can optimize it.  */

      else if (count < case_values_threshold ()
	       || compare_tree_int (range,
				    (optimize_size ? 3 : 10) * count) > 0
	       /* RANGE may be signed, and really large ranges will show up
		  as negative numbers.  */
	       || compare_tree_int (range, 0) < 0
#ifndef ASM_OUTPUT_ADDR_DIFF_ELT
	       || flag_pic
#endif
	       || TREE_CONSTANT (index_expr)
	       /* If neither casesi or tablejump is available, we can
		  only go this way.  */
	       || (!HAVE_casesi && !HAVE_tablejump))
	{
	  index = expand_expr (index_expr, NULL_RTX, VOIDmode, 0);

	  /* If the index is a short or char that we do not have
	     an insn to handle comparisons directly, convert it to
	     a full integer now, rather than letting each comparison
	     generate the conversion.  */

	  if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
	      && ! have_insn_for (COMPARE, GET_MODE (index)))
	    {
	      enum machine_mode wider_mode;
	      for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
		   wider_mode = GET_MODE_WIDER_MODE (wider_mode))
		if (have_insn_for (COMPARE, wider_mode))
		  {
		    index = convert_to_mode (wider_mode, index, unsignedp);
		    break;
		  }
	    }

	  emit_queue ();
	  do_pending_stack_adjust ();

	  index = protect_from_queue (index, 0);
	  if (GET_CODE (index) == MEM)
	    index = copy_to_reg (index);
	  if (GET_CODE (index) == CONST_INT
	      || TREE_CODE (index_expr) == INTEGER_CST)
	    {
	      /* Make a tree node with the proper constant value
		 if we don't already have one.  */
	      if (TREE_CODE (index_expr) != INTEGER_CST)
		{
		  index_expr
		    = build_int_2 (INTVAL (index),
				   unsignedp || INTVAL (index) >= 0 ? 0 : -1);
		  index_expr = convert (index_type, index_expr);
		}

	      /* For constant index expressions we need only
		 issue an unconditional branch to the appropriate
		 target code.  The job of removing any unreachable
		 code is left to the optimization phase if the
		 "-O" option is specified.  */
	      for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
		if (! tree_int_cst_lt (index_expr, n->low)
		    && ! tree_int_cst_lt (n->high, index_expr))
		  break;

	      if (n)
		emit_jump (label_rtx (n->code_label));
	      else
		emit_jump (default_label);
	    }
	  else
	    {
	      /* If the index expression is not constant we generate
		 a binary decision tree to select the appropriate
		 target code.  This is done as follows:

		 The list of cases is rearranged into a binary tree,
		 nearly optimal assuming equal probability for each case.

		 The tree is transformed into RTL, eliminating
		 redundant test conditions at the same time.

		 If program flow could reach the end of the
		 decision tree an unconditional jump to the
		 default code is emitted.  */

	      use_cost_table
		= (TREE_CODE (orig_type) != ENUMERAL_TYPE
		   && estimate_case_costs (thiscase->data.case_stmt.case_list));
	      balance_case_nodes (&thiscase->data.case_stmt.case_list, NULL);
	      emit_case_nodes (index, thiscase->data.case_stmt.case_list,
			       default_label, index_type);
	      emit_jump_if_reachable (default_label);
	    }
	}
      else
	{
	  table_label = gen_label_rtx ();
	  if (! try_casesi (index_type, index_expr, minval, range,
			    table_label, default_label))
	    {
	      index_type = thiscase->data.case_stmt.nominal_type;

	      /* Index jumptables from zero for suitable values of
                 minval to avoid a subtraction.  */
	      if (! optimize_size
		  && compare_tree_int (minval, 0) > 0
		  && compare_tree_int (minval, 3) < 0)
		{
		  minval = integer_zero_node;
		  range = maxval;
		}

	      if (! try_tablejump (index_type, index_expr, minval, range,
				   table_label, default_label))
		abort ();
	    }

	  /* Get table of labels to jump to, in order of case index.  */

	  ncases = tree_low_cst (range, 0) + 1;
	  labelvec = alloca (ncases * sizeof (rtx));
	  memset (labelvec, 0, ncases * sizeof (rtx));

	  for (n = thiscase->data.case_stmt.case_list; n; n = n->right)
	    {
	      /* Compute the low and high bounds relative to the minimum
		 value since that should fit in a HOST_WIDE_INT while the
		 actual values may not.  */
	      HOST_WIDE_INT i_low
		= tree_low_cst (fold (build (MINUS_EXPR, index_type,
					     n->low, minval)), 1);
	      HOST_WIDE_INT i_high
		= tree_low_cst (fold (build (MINUS_EXPR, index_type,
					     n->high, minval)), 1);
	      HOST_WIDE_INT i;

	      for (i = i_low; i <= i_high; i ++)
		labelvec[i]
		  = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
	    }

	  /* Fill in the gaps with the default.  */
	  for (i = 0; i < ncases; i++)
	    if (labelvec[i] == 0)
	      labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);

	  /* Output the table.  */
	  emit_label (table_label);

	  if (CASE_VECTOR_PC_RELATIVE || flag_pic)
	    emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
						   gen_rtx_LABEL_REF (Pmode, table_label),
						   gen_rtvec_v (ncases, labelvec),
						   const0_rtx, const0_rtx));
	  else
	    emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
					      gen_rtvec_v (ncases, labelvec)));

	  /* If the case insn drops through the table,
	     after the table we must jump to the default-label.
	     Otherwise record no drop-through after the table.  */
#ifdef CASE_DROPS_THROUGH
	  emit_jump (default_label);
#else
	  emit_barrier ();
#endif
	}

      before_case = NEXT_INSN (before_case);
      end = get_last_insn ();
      if (squeeze_notes (&before_case, &end))
	abort ();
      reorder_insns (before_case, end,
		     thiscase->data.case_stmt.start);
    }
  else
    end_cleanup_deferral ();

  if (thiscase->exit_label && !exit_done)
    emit_label (thiscase->exit_label);

  POPSTACK (case_stack);

  free_temp_slots ();
}

/* Convert the tree NODE into a list linked by the right field, with the left
   field zeroed.  RIGHT is used for recursion; it is a list to be placed
   rightmost in the resulting list.  */

static struct case_node *
case_tree2list (struct case_node *node, struct case_node *right)
{
  struct case_node *left;

  if (node->right)
    right = case_tree2list (node->right, right);

  node->right = right;
  if ((left = node->left))
    {
      node->left = 0;
      return case_tree2list (left, node);
    }

  return node;
}

/* Generate code to jump to LABEL if OP1 and OP2 are equal.  */

static void
do_jump_if_equal (rtx op1, rtx op2, rtx label, int unsignedp)
{
  if (GET_CODE (op1) == CONST_INT && GET_CODE (op2) == CONST_INT)
    {
      if (op1 == op2)
	emit_jump (label);
    }
  else
    emit_cmp_and_jump_insns (op1, op2, EQ, NULL_RTX,
			     (GET_MODE (op1) == VOIDmode
			     ? GET_MODE (op2) : GET_MODE (op1)),
			     unsignedp, label);
}

/* Not all case values are encountered equally.  This function
   uses a heuristic to weight case labels, in cases where that
   looks like a reasonable thing to do.

   Right now, all we try to guess is text, and we establish the
   following weights:

	chars above space:	16
	digits:			16
	default:		12
	space, punct:		8
	tab:			4
	newline:		2
	other "\" chars:	1
	remaining chars:	0

   If we find any cases in the switch that are not either -1 or in the range
   of valid ASCII characters, or are control characters other than those
   commonly used with "\", don't treat this switch scanning text.

   Return 1 if these nodes are suitable for cost estimation, otherwise
   return 0.  */

static int
estimate_case_costs (case_node_ptr node)
{
  tree min_ascii = integer_minus_one_node;
  tree max_ascii = convert (TREE_TYPE (node->high), build_int_2 (127, 0));
  case_node_ptr n;
  int i;

  /* If we haven't already made the cost table, make it now.  Note that the
     lower bound of the table is -1, not zero.  */

  if (! cost_table_initialized)
    {
      cost_table_initialized = 1;

      for (i = 0; i < 128; i++)
	{
	  if (ISALNUM (i))
	    COST_TABLE (i) = 16;
	  else if (ISPUNCT (i))
	    COST_TABLE (i) = 8;
	  else if (ISCNTRL (i))
	    COST_TABLE (i) = -1;
	}

      COST_TABLE (' ') = 8;
      COST_TABLE ('\t') = 4;
      COST_TABLE ('\0') = 4;
      COST_TABLE ('\n') = 2;
      COST_TABLE ('\f') = 1;
      COST_TABLE ('\v') = 1;
      COST_TABLE ('\b') = 1;
    }

  /* See if all the case expressions look like text.  It is text if the
     constant is >= -1 and the highest constant is <= 127.  Do all comparisons
     as signed arithmetic since we don't want to ever access cost_table with a
     value less than -1.  Also check that none of the constants in a range
     are strange control characters.  */

  for (n = node; n; n = n->right)
    {
      if ((INT_CST_LT (n->low, min_ascii)) || INT_CST_LT (max_ascii, n->high))
	return 0;

      for (i = (HOST_WIDE_INT) TREE_INT_CST_LOW (n->low);
	   i <= (HOST_WIDE_INT) TREE_INT_CST_LOW (n->high); i++)
	if (COST_TABLE (i) < 0)
	  return 0;
    }

  /* All interesting values are within the range of interesting
     ASCII characters.  */
  return 1;
}

/* Determine whether two case labels branch to the same target.  */

static bool
same_case_target_p (rtx l1, rtx l2)
{
#if 0
  rtx i1, i2;

  if (l1 == l2)
    return true;

  i1 = next_real_insn (l1);
  i2 = next_real_insn (l2);
  if (i1 == i2)
    return true;

  if (i1 && simplejump_p (i1))
    {
      l1 = XEXP (SET_SRC (PATTERN (i1)), 0);
    }

  if (i2 && simplejump_p (i2))
    {
      l2 = XEXP (SET_SRC (PATTERN (i2)), 0);
    }
#endif
  /* When coming from gimple, we usually won't have emitted either
     the labels or the body of the switch statement.  The job being
     done here should be done via jump threading at the tree level.
     Cases that go the same place should have the same label.  */
  return l1 == l2;
}

/* Delete nodes that branch to the default label from a list of
   case nodes.  Eg. case 5: default: becomes just default:  */

static void
strip_default_case_nodes (case_node_ptr *prev, rtx deflab)
{
  case_node_ptr ptr;

  while (*prev)
    {
      ptr = *prev;
      if (same_case_target_p (label_rtx (ptr->code_label), deflab))
	*prev = ptr->right;
      else
	prev = &ptr->right;
    }
}

/* Scan an ordered list of case nodes
   combining those with consecutive values or ranges.

   Eg. three separate entries 1: 2: 3: become one entry 1..3:  */

static void
group_case_nodes (case_node_ptr head)
{
  case_node_ptr node = head;

  while (node)
    {
      rtx lab;
      case_node_ptr np = node;

      lab = label_rtx (node->code_label);

      /* Try to group the successors of NODE with NODE.  */
      while (((np = np->right) != 0)
	     /* Do they jump to the same place?  */
	     && same_case_target_p (label_rtx (np->code_label), lab)
	     /* Are their ranges consecutive?  */
	     && tree_int_cst_equal (np->low,
				    fold (build (PLUS_EXPR,
						 TREE_TYPE (node->high),
						 node->high,
						 integer_one_node)))
	     /* An overflow is not consecutive.  */
	     && tree_int_cst_lt (node->high,
				 fold (build (PLUS_EXPR,
					      TREE_TYPE (node->high),
					      node->high,
					      integer_one_node))))
	{
	  node->high = np->high;
	}
      /* NP is the first node after NODE which can't be grouped with it.
	 Delete the nodes in between, and move on to that node.  */
      node->right = np;
      node = np;
    }
}

/* Take an ordered list of case nodes
   and transform them into a near optimal binary tree,
   on the assumption that any target code selection value is as
   likely as any other.

   The transformation is performed by splitting the ordered
   list into two equal sections plus a pivot.  The parts are
   then attached to the pivot as left and right branches.  Each
   branch is then transformed recursively.  */

static void
balance_case_nodes (case_node_ptr *head, case_node_ptr parent)
{
  case_node_ptr np;

  np = *head;
  if (np)
    {
      int cost = 0;
      int i = 0;
      int ranges = 0;
      case_node_ptr *npp;
      case_node_ptr left;

      /* Count the number of entries on branch.  Also count the ranges.  */

      while (np)
	{
	  if (!tree_int_cst_equal (np->low, np->high))
	    {
	      ranges++;
	      if (use_cost_table)
		cost += COST_TABLE (TREE_INT_CST_LOW (np->high));
	    }

	  if (use_cost_table)
	    cost += COST_TABLE (TREE_INT_CST_LOW (np->low));

	  i++;
	  np = np->right;
	}

      if (i > 2)
	{
	  /* Split this list if it is long enough for that to help.  */
	  npp = head;
	  left = *npp;
	  if (use_cost_table)
	    {
	      /* Find the place in the list that bisects the list's total cost,
		 Here I gets half the total cost.  */
	      int n_moved = 0;
	      i = (cost + 1) / 2;
	      while (1)
		{
		  /* Skip nodes while their cost does not reach that amount.  */
		  if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
		    i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->high));
		  i -= COST_TABLE (TREE_INT_CST_LOW ((*npp)->low));
		  if (i <= 0)
		    break;
		  npp = &(*npp)->right;
		  n_moved += 1;
		}
	      if (n_moved == 0)
		{
		  /* Leave this branch lopsided, but optimize left-hand
		     side and fill in `parent' fields for right-hand side.  */
		  np = *head;
		  np->parent = parent;
		  balance_case_nodes (&np->left, np);
		  for (; np->right; np = np->right)
		    np->right->parent = np;
		  return;
		}
	    }
	  /* If there are just three nodes, split at the middle one.  */
	  else if (i == 3)
	    npp = &(*npp)->right;
	  else
	    {
	      /* Find the place in the list that bisects the list's total cost,
		 where ranges count as 2.
		 Here I gets half the total cost.  */
	      i = (i + ranges + 1) / 2;
	      while (1)
		{
		  /* Skip nodes while their cost does not reach that amount.  */
		  if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
		    i--;
		  i--;
		  if (i <= 0)
		    break;
		  npp = &(*npp)->right;
		}
	    }
	  *head = np = *npp;
	  *npp = 0;
	  np->parent = parent;
	  np->left = left;

	  /* Optimize each of the two split parts.  */
	  balance_case_nodes (&np->left, np);
	  balance_case_nodes (&np->right, np);
	}
      else
	{
	  /* Else leave this branch as one level,
	     but fill in `parent' fields.  */
	  np = *head;
	  np->parent = parent;
	  for (; np->right; np = np->right)
	    np->right->parent = np;
	}
    }
}

/* Search the parent sections of the case node tree
   to see if a test for the lower bound of NODE would be redundant.
   INDEX_TYPE is the type of the index expression.

   The instructions to generate the case decision tree are
   output in the same order as nodes are processed so it is
   known that if a parent node checks the range of the current
   node minus one that the current node is bounded at its lower
   span.  Thus the test would be redundant.  */

static int
node_has_low_bound (case_node_ptr node, tree index_type)
{
  tree low_minus_one;
  case_node_ptr pnode;

  /* If the lower bound of this node is the lowest value in the index type,
     we need not test it.  */

  if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
    return 1;

  /* If this node has a left branch, the value at the left must be less
     than that at this node, so it cannot be bounded at the bottom and
     we need not bother testing any further.  */

  if (node->left)
    return 0;

  low_minus_one = fold (build (MINUS_EXPR, TREE_TYPE (node->low),
			       node->low, integer_one_node));

  /* If the subtraction above overflowed, we can't verify anything.
     Otherwise, look for a parent that tests our value - 1.  */

  if (! tree_int_cst_lt (low_minus_one, node->low))
    return 0;

  for (pnode = node->parent; pnode; pnode = pnode->parent)
    if (tree_int_cst_equal (low_minus_one, pnode->high))
      return 1;

  return 0;
}

/* Search the parent sections of the case node tree
   to see if a test for the upper bound of NODE would be redundant.
   INDEX_TYPE is the type of the index expression.

   The instructions to generate the case decision tree are
   output in the same order as nodes are processed so it is
   known that if a parent node checks the range of the current
   node plus one that the current node is bounded at its upper
   span.  Thus the test would be redundant.  */

static int
node_has_high_bound (case_node_ptr node, tree index_type)
{
  tree high_plus_one;
  case_node_ptr pnode;

  /* If there is no upper bound, obviously no test is needed.  */

  if (TYPE_MAX_VALUE (index_type) == NULL)
    return 1;

  /* If the upper bound of this node is the highest value in the type
     of the index expression, we need not test against it.  */

  if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
    return 1;

  /* If this node has a right branch, the value at the right must be greater
     than that at this node, so it cannot be bounded at the top and
     we need not bother testing any further.  */

  if (node->right)
    return 0;

  high_plus_one = fold (build (PLUS_EXPR, TREE_TYPE (node->high),
			       node->high, integer_one_node));

  /* If the addition above overflowed, we can't verify anything.
     Otherwise, look for a parent that tests our value + 1.  */

  if (! tree_int_cst_lt (node->high, high_plus_one))
    return 0;

  for (pnode = node->parent; pnode; pnode = pnode->parent)
    if (tree_int_cst_equal (high_plus_one, pnode->low))
      return 1;

  return 0;
}

/* Search the parent sections of the
   case node tree to see if both tests for the upper and lower
   bounds of NODE would be redundant.  */

static int
node_is_bounded (case_node_ptr node, tree index_type)
{
  return (node_has_low_bound (node, index_type)
	  && node_has_high_bound (node, index_type));
}

/*  Emit an unconditional jump to LABEL unless it would be dead code.  */

static void
emit_jump_if_reachable (rtx label)
{
  if (GET_CODE (get_last_insn ()) != BARRIER)
    emit_jump (label);
}

/* Emit step-by-step code to select a case for the value of INDEX.
   The thus generated decision tree follows the form of the
   case-node binary tree NODE, whose nodes represent test conditions.
   INDEX_TYPE is the type of the index of the switch.

   Care is taken to prune redundant tests from the decision tree
   by detecting any boundary conditions already checked by
   emitted rtx.  (See node_has_high_bound, node_has_low_bound
   and node_is_bounded, above.)

   Where the test conditions can be shown to be redundant we emit
   an unconditional jump to the target code.  As a further
   optimization, the subordinates of a tree node are examined to
   check for bounded nodes.  In this case conditional and/or
   unconditional jumps as a result of the boundary check for the
   current node are arranged to target the subordinates associated
   code for out of bound conditions on the current node.

   We can assume that when control reaches the code generated here,
   the index value has already been compared with the parents
   of this node, and determined to be on the same side of each parent
   as this node is.  Thus, if this node tests for the value 51,
   and a parent tested for 52, we don't need to consider
   the possibility of a value greater than 51.  If another parent
   tests for the value 50, then this node need not test anything.  */

static void
emit_case_nodes (rtx index, case_node_ptr node, rtx default_label,
		 tree index_type)
{
  /* If INDEX has an unsigned type, we must make unsigned branches.  */
  int unsignedp = TYPE_UNSIGNED (index_type);
  enum machine_mode mode = GET_MODE (index);
  enum machine_mode imode = TYPE_MODE (index_type);

  /* See if our parents have already tested everything for us.
     If they have, emit an unconditional jump for this node.  */
  if (node_is_bounded (node, index_type))
    emit_jump (label_rtx (node->code_label));

  else if (tree_int_cst_equal (node->low, node->high))
    {
      /* Node is single valued.  First see if the index expression matches
	 this node and then check our children, if any.  */

      do_jump_if_equal (index,
			convert_modes (mode, imode,
				       expand_expr (node->low, NULL_RTX,
						    VOIDmode, 0),
				       unsignedp),
			label_rtx (node->code_label), unsignedp);

      if (node->right != 0 && node->left != 0)
	{
	  /* This node has children on both sides.
	     Dispatch to one side or the other
	     by comparing the index value with this node's value.
	     If one subtree is bounded, check that one first,
	     so we can avoid real branches in the tree.  */

	  if (node_is_bounded (node->right, index_type))
	    {
	      emit_cmp_and_jump_insns (index,
				       convert_modes
				       (mode, imode,
					expand_expr (node->high, NULL_RTX,
						     VOIDmode, 0),
					unsignedp),
				       GT, NULL_RTX, mode, unsignedp,
				       label_rtx (node->right->code_label));
	      emit_case_nodes (index, node->left, default_label, index_type);
	    }

	  else if (node_is_bounded (node->left, index_type))
	    {
	      emit_cmp_and_jump_insns (index,
				       convert_modes
				       (mode, imode,
					expand_expr (node->high, NULL_RTX,
						     VOIDmode, 0),
					unsignedp),
				       LT, NULL_RTX, mode, unsignedp,
				       label_rtx (node->left->code_label));
	      emit_case_nodes (index, node->right, default_label, index_type);
	    }

	  /* If both children are single-valued cases with no
	     children, finish up all the work.  This way, we can save
	     one ordered comparison.  */
	  else if (tree_int_cst_equal (node->right->low, node->right->high)
		   && node->right->left == 0
		   && node->right->right == 0
		   && tree_int_cst_equal (node->left->low, node->left->high)
		   && node->left->left == 0
		   && node->left->right == 0)
	    {
	      /* Neither node is bounded.  First distinguish the two sides;
		 then emit the code for one side at a time.  */

	      /* See if the value matches what the right hand side
		 wants.  */
	      do_jump_if_equal (index,
				convert_modes (mode, imode,
					       expand_expr (node->right->low,
							    NULL_RTX,
							    VOIDmode, 0),
					       unsignedp),
				label_rtx (node->right->code_label),
				unsignedp);

	      /* See if the value matches what the left hand side
		 wants.  */
	      do_jump_if_equal (index,
				convert_modes (mode, imode,
					       expand_expr (node->left->low,
							    NULL_RTX,
							    VOIDmode, 0),
					       unsignedp),
				label_rtx (node->left->code_label),
				unsignedp);
	    }

	  else
	    {
	      /* Neither node is bounded.  First distinguish the two sides;
		 then emit the code for one side at a time.  */

	      tree test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);

	      /* See if the value is on the right.  */
	      emit_cmp_and_jump_insns (index,
				       convert_modes
				       (mode, imode,
					expand_expr (node->high, NULL_RTX,
						     VOIDmode, 0),
					unsignedp),
				       GT, NULL_RTX, mode, unsignedp,
				       label_rtx (test_label));

	      /* Value must be on the left.
		 Handle the left-hand subtree.  */
	      emit_case_nodes (index, node->left, default_label, index_type);
	      /* If left-hand subtree does nothing,
		 go to default.  */
	      emit_jump_if_reachable (default_label);

	      /* Code branches here for the right-hand subtree.  */
	      expand_label (test_label);
	      emit_case_nodes (index, node->right, default_label, index_type);
	    }
	}

      else if (node->right != 0 && node->left == 0)
	{
	  /* Here we have a right child but no left so we issue conditional
	     branch to default and process the right child.

	     Omit the conditional branch to default if we it avoid only one
	     right child; it costs too much space to save so little time.  */

	  if (node->right->right || node->right->left
	      || !tree_int_cst_equal (node->right->low, node->right->high))
	    {
	      if (!node_has_low_bound (node, index_type))
		{
		  emit_cmp_and_jump_insns (index,
					   convert_modes
					   (mode, imode,
					    expand_expr (node->high, NULL_RTX,
							 VOIDmode, 0),
					    unsignedp),
					   LT, NULL_RTX, mode, unsignedp,
					   default_label);
		}

	      emit_case_nodes (index, node->right, default_label, index_type);
	    }
	  else
	    /* We cannot process node->right normally
	       since we haven't ruled out the numbers less than
	       this node's value.  So handle node->right explicitly.  */
	    do_jump_if_equal (index,
			      convert_modes
			      (mode, imode,
			       expand_expr (node->right->low, NULL_RTX,
					    VOIDmode, 0),
			       unsignedp),
			      label_rtx (node->right->code_label), unsignedp);
	}

      else if (node->right == 0 && node->left != 0)
	{
	  /* Just one subtree, on the left.  */
	  if (node->left->left || node->left->right
	      || !tree_int_cst_equal (node->left->low, node->left->high))
	    {
	      if (!node_has_high_bound (node, index_type))
		{
		  emit_cmp_and_jump_insns (index,
					   convert_modes
					   (mode, imode,
					    expand_expr (node->high, NULL_RTX,
							 VOIDmode, 0),
					    unsignedp),
					   GT, NULL_RTX, mode, unsignedp,
					   default_label);
		}

	      emit_case_nodes (index, node->left, default_label, index_type);
	    }
	  else
	    /* We cannot process node->left normally
	       since we haven't ruled out the numbers less than
	       this node's value.  So handle node->left explicitly.  */
	    do_jump_if_equal (index,
			      convert_modes
			      (mode, imode,
			       expand_expr (node->left->low, NULL_RTX,
					    VOIDmode, 0),
			       unsignedp),
			      label_rtx (node->left->code_label), unsignedp);
	}
    }
  else
    {
      /* Node is a range.  These cases are very similar to those for a single
	 value, except that we do not start by testing whether this node
	 is the one to branch to.  */

      if (node->right != 0 && node->left != 0)
	{
	  /* Node has subtrees on both sides.
	     If the right-hand subtree is bounded,
	     test for it first, since we can go straight there.
	     Otherwise, we need to make a branch in the control structure,
	     then handle the two subtrees.  */
	  tree test_label = 0;

	  if (node_is_bounded (node->right, index_type))
	    /* Right hand node is fully bounded so we can eliminate any
	       testing and branch directly to the target code.  */
	    emit_cmp_and_jump_insns (index,
				     convert_modes
				     (mode, imode,
				      expand_expr (node->high, NULL_RTX,
						   VOIDmode, 0),
				      unsignedp),
				     GT, NULL_RTX, mode, unsignedp,
				     label_rtx (node->right->code_label));
	  else
	    {
	      /* Right hand node requires testing.
		 Branch to a label where we will handle it later.  */

	      test_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
	      emit_cmp_and_jump_insns (index,
				       convert_modes
				       (mode, imode,
					expand_expr (node->high, NULL_RTX,
						     VOIDmode, 0),
					unsignedp),
				       GT, NULL_RTX, mode, unsignedp,
				       label_rtx (test_label));
	    }

	  /* Value belongs to this node or to the left-hand subtree.  */

	  emit_cmp_and_jump_insns (index,
				   convert_modes
				   (mode, imode,
				    expand_expr (node->low, NULL_RTX,
						 VOIDmode, 0),
				    unsignedp),
				   GE, NULL_RTX, mode, unsignedp,
				   label_rtx (node->code_label));

	  /* Handle the left-hand subtree.  */
	  emit_case_nodes (index, node->left, default_label, index_type);

	  /* If right node had to be handled later, do that now.  */

	  if (test_label)
	    {
	      /* If the left-hand subtree fell through,
		 don't let it fall into the right-hand subtree.  */
	      emit_jump_if_reachable (default_label);

	      expand_label (test_label);
	      emit_case_nodes (index, node->right, default_label, index_type);
	    }
	}

      else if (node->right != 0 && node->left == 0)
	{
	  /* Deal with values to the left of this node,
	     if they are possible.  */
	  if (!node_has_low_bound (node, index_type))
	    {
	      emit_cmp_and_jump_insns (index,
				       convert_modes
				       (mode, imode,
					expand_expr (node->low, NULL_RTX,
						     VOIDmode, 0),
					unsignedp),
				       LT, NULL_RTX, mode, unsignedp,
				       default_label);
	    }

	  /* Value belongs to this node or to the right-hand subtree.  */

	  emit_cmp_and_jump_insns (index,
				   convert_modes
				   (mode, imode,
				    expand_expr (node->high, NULL_RTX,
						 VOIDmode, 0),
				    unsignedp),
				   LE, NULL_RTX, mode, unsignedp,
				   label_rtx (node->code_label));

	  emit_case_nodes (index, node->right, default_label, index_type);
	}

      else if (node->right == 0 && node->left != 0)
	{
	  /* Deal with values to the right of this node,
	     if they are possible.  */
	  if (!node_has_high_bound (node, index_type))
	    {
	      emit_cmp_and_jump_insns (index,
				       convert_modes
				       (mode, imode,
					expand_expr (node->high, NULL_RTX,
						     VOIDmode, 0),
					unsignedp),
				       GT, NULL_RTX, mode, unsignedp,
				       default_label);
	    }

	  /* Value belongs to this node or to the left-hand subtree.  */

	  emit_cmp_and_jump_insns (index,
				   convert_modes
				   (mode, imode,
				    expand_expr (node->low, NULL_RTX,
						 VOIDmode, 0),
				    unsignedp),
				   GE, NULL_RTX, mode, unsignedp,
				   label_rtx (node->code_label));

	  emit_case_nodes (index, node->left, default_label, index_type);
	}

      else
	{
	  /* Node has no children so we check low and high bounds to remove
	     redundant tests.  Only one of the bounds can exist,
	     since otherwise this node is bounded--a case tested already.  */
	  int high_bound = node_has_high_bound (node, index_type);
	  int low_bound = node_has_low_bound (node, index_type);

	  if (!high_bound && low_bound)
	    {
	      emit_cmp_and_jump_insns (index,
				       convert_modes
				       (mode, imode,
					expand_expr (node->high, NULL_RTX,
						     VOIDmode, 0),
					unsignedp),
				       GT, NULL_RTX, mode, unsignedp,
				       default_label);
	    }

	  else if (!low_bound && high_bound)
	    {
	      emit_cmp_and_jump_insns (index,
				       convert_modes
				       (mode, imode,
					expand_expr (node->low, NULL_RTX,
						     VOIDmode, 0),
					unsignedp),
				       LT, NULL_RTX, mode, unsignedp,
				       default_label);
	    }
	  else if (!low_bound && !high_bound)
	    {
	      /* Widen LOW and HIGH to the same width as INDEX.  */
	      tree type = lang_hooks.types.type_for_mode (mode, unsignedp);
	      tree low = build1 (CONVERT_EXPR, type, node->low);
	      tree high = build1 (CONVERT_EXPR, type, node->high);
	      rtx low_rtx, new_index, new_bound;

	      /* Instead of doing two branches, emit one unsigned branch for
		 (index-low) > (high-low).  */
	      low_rtx = expand_expr (low, NULL_RTX, mode, 0);
	      new_index = expand_simple_binop (mode, MINUS, index, low_rtx,
					       NULL_RTX, unsignedp,
					       OPTAB_WIDEN);
	      new_bound = expand_expr (fold (build (MINUS_EXPR, type,
						    high, low)),
				       NULL_RTX, mode, 0);

	      emit_cmp_and_jump_insns (new_index, new_bound, GT, NULL_RTX,
				       mode, 1, default_label);
	    }

	  emit_jump (label_rtx (node->code_label));
	}
    }
}

#include "gt-stmt.h"