summaryrefslogtreecommitdiff
path: root/pp.c
blob: d406ee11fefc8a8ef6b682f18604f9aafe50d384 (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
6138
6139
6140
6141
6142
6143
6144
6145
6146
6147
6148
6149
6150
6151
6152
6153
6154
6155
6156
6157
6158
6159
6160
6161
6162
6163
6164
6165
6166
6167
6168
6169
6170
6171
6172
6173
6174
6175
6176
6177
6178
6179
6180
6181
6182
6183
6184
6185
6186
6187
6188
6189
6190
6191
6192
6193
6194
6195
6196
6197
6198
6199
6200
6201
6202
6203
6204
6205
6206
6207
6208
6209
6210
6211
6212
6213
6214
6215
6216
6217
6218
6219
6220
6221
6222
6223
6224
6225
6226
6227
6228
6229
6230
6231
6232
6233
6234
6235
6236
6237
6238
6239
6240
6241
6242
6243
6244
6245
6246
6247
6248
6249
6250
6251
6252
6253
6254
6255
6256
6257
6258
6259
6260
6261
6262
6263
6264
6265
6266
6267
6268
6269
6270
6271
6272
6273
6274
6275
6276
6277
6278
6279
6280
6281
6282
6283
6284
6285
6286
6287
6288
6289
6290
6291
6292
6293
6294
6295
6296
6297
6298
6299
6300
6301
6302
6303
6304
6305
6306
6307
6308
6309
6310
6311
6312
6313
6314
6315
6316
6317
6318
6319
6320
6321
6322
6323
6324
6325
6326
6327
6328
6329
6330
6331
6332
6333
6334
6335
6336
6337
6338
6339
6340
6341
6342
6343
6344
6345
6346
6347
6348
6349
6350
6351
6352
6353
6354
6355
6356
6357
6358
6359
6360
6361
6362
6363
6364
6365
6366
6367
6368
6369
6370
6371
6372
6373
6374
6375
6376
6377
6378
6379
6380
6381
6382
6383
6384
6385
6386
6387
6388
6389
6390
6391
6392
6393
6394
6395
6396
6397
6398
6399
6400
6401
6402
6403
6404
6405
6406
6407
6408
6409
6410
6411
6412
6413
6414
6415
6416
6417
6418
6419
6420
6421
6422
6423
6424
6425
6426
6427
6428
6429
6430
6431
6432
6433
6434
6435
6436
6437
6438
6439
6440
6441
6442
6443
6444
6445
6446
6447
6448
6449
6450
6451
6452
6453
6454
6455
6456
6457
6458
6459
6460
6461
6462
6463
6464
6465
6466
6467
6468
6469
6470
6471
6472
6473
6474
6475
6476
6477
6478
6479
6480
6481
6482
6483
6484
6485
6486
6487
6488
6489
6490
6491
6492
6493
6494
6495
6496
6497
6498
6499
6500
6501
6502
6503
6504
6505
6506
6507
6508
6509
6510
6511
6512
6513
6514
6515
6516
6517
6518
6519
6520
6521
6522
6523
6524
6525
6526
6527
6528
6529
6530
6531
6532
6533
6534
6535
6536
6537
6538
6539
6540
6541
6542
6543
6544
6545
6546
6547
6548
6549
6550
6551
6552
6553
6554
6555
6556
6557
6558
6559
6560
6561
6562
6563
6564
6565
6566
6567
6568
6569
6570
6571
6572
6573
6574
6575
6576
6577
6578
6579
6580
6581
6582
6583
6584
6585
6586
6587
6588
6589
6590
6591
6592
6593
6594
6595
6596
6597
6598
6599
6600
6601
6602
6603
6604
6605
6606
6607
6608
6609
6610
6611
6612
6613
6614
6615
6616
6617
6618
6619
6620
6621
6622
6623
6624
6625
6626
6627
6628
6629
6630
6631
6632
6633
6634
6635
6636
6637
6638
6639
6640
6641
6642
6643
6644
6645
6646
6647
6648
6649
6650
6651
6652
6653
6654
6655
6656
6657
6658
6659
6660
6661
6662
6663
6664
6665
6666
6667
6668
6669
6670
6671
6672
6673
6674
6675
6676
6677
6678
6679
6680
6681
6682
6683
6684
6685
6686
6687
6688
6689
6690
6691
6692
6693
6694
6695
6696
6697
6698
6699
6700
6701
6702
6703
6704
6705
6706
6707
6708
6709
6710
6711
6712
6713
6714
6715
6716
6717
6718
6719
6720
6721
6722
6723
6724
6725
6726
6727
6728
6729
6730
6731
6732
6733
6734
6735
6736
6737
6738
6739
6740
6741
6742
6743
6744
6745
6746
6747
6748
6749
6750
6751
6752
6753
6754
6755
6756
6757
6758
6759
6760
6761
6762
6763
6764
6765
6766
6767
6768
6769
6770
6771
6772
6773
6774
6775
6776
6777
6778
6779
6780
6781
6782
6783
6784
6785
6786
6787
6788
6789
6790
6791
6792
6793
6794
6795
6796
6797
6798
6799
6800
6801
6802
6803
6804
6805
6806
6807
6808
6809
6810
6811
6812
6813
6814
6815
6816
6817
6818
6819
6820
6821
6822
6823
6824
6825
6826
6827
6828
6829
6830
6831
6832
6833
6834
6835
6836
6837
6838
6839
6840
/*    pp.c
 *
 *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
 *    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
 *
 *    You may distribute under the terms of either the GNU General Public
 *    License or the Artistic License, as specified in the README file.
 *
 */

/*
 * 'It's a big house this, and very peculiar.  Always a bit more
 *  to discover, and no knowing what you'll find round a corner.
 *  And Elves, sir!'                            --Samwise Gamgee
 *
 *     [p.225 of _The Lord of the Rings_, II/i: "Many Meetings"]
 */

/* This file contains general pp ("push/pop") functions that execute the
 * opcodes that make up a perl program. A typical pp function expects to
 * find its arguments on the stack, and usually pushes its results onto
 * the stack, hence the 'pp' terminology. Each OP structure contains
 * a pointer to the relevant pp_foo() function.
 */

#include "EXTERN.h"
#define PERL_IN_PP_C
#include "perl.h"
#include "keywords.h"

#include "reentr.h"
#include "regcharclass.h"

/* XXX I can't imagine anyone who doesn't have this actually _needs_
   it, since pid_t is an integral type.
   --AD  2/20/1998
*/
#ifdef NEED_GETPID_PROTO
extern Pid_t getpid (void);
#endif

/*
 * Some BSDs and Cygwin default to POSIX math instead of IEEE.
 * This switches them over to IEEE.
 */
#if defined(LIBM_LIB_VERSION)
    _LIB_VERSION_TYPE _LIB_VERSION = _IEEE_;
#endif

static const STRLEN small_mu_len = sizeof(GREEK_SMALL_LETTER_MU_UTF8) - 1;
static const STRLEN capital_iota_len = sizeof(GREEK_CAPITAL_LETTER_IOTA_UTF8) - 1;

/* variations on pp_null */

PP(pp_stub)
{
    dSP;
    if (GIMME_V == G_SCALAR)
	XPUSHs(&PL_sv_undef);
    RETURN;
}

/* Pushy stuff. */

/* This is also called directly by pp_lvavref.  */
PP(pp_padav)
{
    dSP; dTARGET;
    U8 gimme;
    assert(SvTYPE(TARG) == SVt_PVAV);
    if (UNLIKELY( PL_op->op_private & OPpLVAL_INTRO ))
	if (LIKELY( !(PL_op->op_private & OPpPAD_STATE) ))
	    SAVECLEARSV(PAD_SVl(PL_op->op_targ));
    EXTEND(SP, 1);

    if (PL_op->op_flags & OPf_REF) {
	PUSHs(TARG);
	RETURN;
    }
    else if (PL_op->op_private & OPpMAYBE_LVSUB) {
        const I32 flags = is_lvalue_sub();
        if (flags && !(flags & OPpENTERSUB_INARGS)) {
	    if (GIMME_V == G_SCALAR)
                /* diag_listed_as: Can't return %s to lvalue scalar context */
                Perl_croak(aTHX_ "Can't return array to lvalue scalar context");
            PUSHs(TARG);
            RETURN;
       }
    }

    gimme = GIMME_V;
    if (gimme == G_ARRAY) {
        /* XXX see also S_pushav in pp_hot.c */
	const SSize_t maxarg = AvFILL(MUTABLE_AV(TARG)) + 1;
	EXTEND(SP, maxarg);
	if (SvMAGICAL(TARG)) {
	    SSize_t i;
	    for (i=0; i < maxarg; i++) {
		SV * const * const svp = av_fetch(MUTABLE_AV(TARG), i, FALSE);
		SP[i+1] = (svp) ? *svp : &PL_sv_undef;
	    }
	}
	else {
	    SSize_t i;
	    for (i=0; i < maxarg; i++) {
		SV * const sv = AvARRAY((const AV *)TARG)[i];
		SP[i+1] = sv ? sv : &PL_sv_undef;
	    }
	}
	SP += maxarg;
    }
    else if (gimme == G_SCALAR) {
	SV* const sv = sv_newmortal();
	const SSize_t maxarg = AvFILL(MUTABLE_AV(TARG)) + 1;
	sv_setiv(sv, maxarg);
	PUSHs(sv);
    }
    RETURN;
}

PP(pp_padhv)
{
    dSP; dTARGET;
    U8 gimme;

    assert(SvTYPE(TARG) == SVt_PVHV);
    XPUSHs(TARG);
    if (UNLIKELY( PL_op->op_private & OPpLVAL_INTRO ))
	if (LIKELY( !(PL_op->op_private & OPpPAD_STATE) ))
	    SAVECLEARSV(PAD_SVl(PL_op->op_targ));

    if (PL_op->op_flags & OPf_REF)
	RETURN;
    else if (PL_op->op_private & OPpMAYBE_LVSUB) {
        const I32 flags = is_lvalue_sub();
        if (flags && !(flags & OPpENTERSUB_INARGS)) {
            if (GIMME_V == G_SCALAR)
                /* diag_listed_as: Can't return %s to lvalue scalar context */
                Perl_croak(aTHX_ "Can't return hash to lvalue scalar context");
            RETURN;
        }
    }

    gimme = GIMME_V;
    if (gimme == G_ARRAY) {
	RETURNOP(Perl_do_kv(aTHX));
    }
    else if ((PL_op->op_private & OPpTRUEBOOL
	  || (  PL_op->op_private & OPpMAYBE_TRUEBOOL
	     && block_gimme() == G_VOID  ))
	  && (!SvRMAGICAL(TARG) || !mg_find(TARG, PERL_MAGIC_tied))
    )
	SETs(HvUSEDKEYS(TARG) ? &PL_sv_yes : sv_2mortal(newSViv(0)));
    else if (gimme == G_SCALAR) {
	SV* const sv = Perl_hv_scalar(aTHX_ MUTABLE_HV(TARG));
	SETs(sv);
    }
    RETURN;
}

PP(pp_padcv)
{
    dSP; dTARGET;
    assert(SvTYPE(TARG) == SVt_PVCV);
    XPUSHs(TARG);
    RETURN;
}

PP(pp_introcv)
{
    dTARGET;
    SvPADSTALE_off(TARG);
    return NORMAL;
}

PP(pp_clonecv)
{
    dTARGET;
    CV * const protocv = PadnamePROTOCV(
	PadlistNAMESARRAY(CvPADLIST(find_runcv(NULL)))[ARGTARG]
    );
    assert(SvTYPE(TARG) == SVt_PVCV);
    assert(protocv);
    if (CvISXSUB(protocv)) { /* constant */
	/* XXX Should we clone it here? */
	/* If this changes to use SAVECLEARSV, we can move the SAVECLEARSV
	   to introcv and remove the SvPADSTALE_off. */
	SAVEPADSVANDMORTALIZE(ARGTARG);
	PAD_SVl(ARGTARG) = SvREFCNT_inc_simple_NN(protocv);
    }
    else {
	if (CvROOT(protocv)) {
	    assert(CvCLONE(protocv));
	    assert(!CvCLONED(protocv));
	}
	cv_clone_into(protocv,(CV *)TARG);
	SAVECLEARSV(PAD_SVl(ARGTARG));
    }
    return NORMAL;
}

/* Translations. */

/* In some cases this function inspects PL_op.  If this function is called
   for new op types, more bool parameters may need to be added in place of
   the checks.

   When noinit is true, the absence of a gv will cause a retval of undef.
   This is unrelated to the cv-to-gv assignment case.
*/

static SV *
S_rv2gv(pTHX_ SV *sv, const bool vivify_sv, const bool strict,
              const bool noinit)
{
    if (!isGV(sv) || SvFAKE(sv)) SvGETMAGIC(sv);
    if (SvROK(sv)) {
	if (SvAMAGIC(sv)) {
	    sv = amagic_deref_call(sv, to_gv_amg);
	}
      wasref:
	sv = SvRV(sv);
	if (SvTYPE(sv) == SVt_PVIO) {
	    GV * const gv = MUTABLE_GV(sv_newmortal());
	    gv_init(gv, 0, "__ANONIO__", 10, 0);
	    GvIOp(gv) = MUTABLE_IO(sv);
	    SvREFCNT_inc_void_NN(sv);
	    sv = MUTABLE_SV(gv);
	}
	else if (!isGV_with_GP(sv)) {
	    Perl_die(aTHX_ "Not a GLOB reference");
        }
    }
    else {
	if (!isGV_with_GP(sv)) {
	    if (!SvOK(sv)) {
		/* If this is a 'my' scalar and flag is set then vivify
		 * NI-S 1999/05/07
		 */
		if (vivify_sv && sv != &PL_sv_undef) {
		    GV *gv;
		    if (SvREADONLY(sv))
			Perl_croak_no_modify();
		    if (cUNOP->op_targ) {
			SV * const namesv = PAD_SV(cUNOP->op_targ);
			HV *stash = CopSTASH(PL_curcop);
			if (SvTYPE(stash) != SVt_PVHV) stash = NULL;
			gv = MUTABLE_GV(newSV(0));
			gv_init_sv(gv, stash, namesv, 0);
		    }
		    else {
			const char * const name = CopSTASHPV(PL_curcop);
			gv = newGVgen_flags(name,
                                HvNAMEUTF8(CopSTASH(PL_curcop)) ? SVf_UTF8 : 0 );
			SvREFCNT_inc_simple_void_NN(gv);
		    }
		    prepare_SV_for_RV(sv);
		    SvRV_set(sv, MUTABLE_SV(gv));
		    SvROK_on(sv);
		    SvSETMAGIC(sv);
		    goto wasref;
		}
		if (PL_op->op_flags & OPf_REF || strict) {
		    Perl_die(aTHX_ PL_no_usym, "a symbol");
                }
		if (ckWARN(WARN_UNINITIALIZED))
		    report_uninit(sv);
		return &PL_sv_undef;
	    }
	    if (noinit)
	    {
		if (!(sv = MUTABLE_SV(gv_fetchsv_nomg(
		           sv, GV_ADDMG, SVt_PVGV
		   ))))
		    return &PL_sv_undef;
	    }
	    else {
		if (strict) {
                    Perl_die(aTHX_
                             PL_no_symref_sv,
                             sv,
                             (SvPOKp(sv) && SvCUR(sv)>32 ? "..." : ""),
                             "a symbol"
                             );
                }
		if ((PL_op->op_private & (OPpLVAL_INTRO|OPpDONT_INIT_GV))
		    == OPpDONT_INIT_GV) {
		    /* We are the target of a coderef assignment.  Return
		       the scalar unchanged, and let pp_sasssign deal with
		       things.  */
		    return sv;
		}
		sv = MUTABLE_SV(gv_fetchsv_nomg(sv, GV_ADD, SVt_PVGV));
	    }
	    /* FAKE globs in the symbol table cause weird bugs (#77810) */
	    SvFAKE_off(sv);
	}
    }
    if (SvFAKE(sv) && !(PL_op->op_private & OPpALLOW_FAKE)) {
	SV *newsv = sv_newmortal();
	sv_setsv_flags(newsv, sv, 0);
	SvFAKE_off(newsv);
	sv = newsv;
    }
    return sv;
}

PP(pp_rv2gv)
{
    dSP; dTOPss;

    sv = S_rv2gv(aTHX_
          sv, PL_op->op_private & OPpDEREF,
          PL_op->op_private & HINT_STRICT_REFS,
          ((PL_op->op_flags & OPf_SPECIAL) && !(PL_op->op_flags & OPf_MOD))
             || PL_op->op_type == OP_READLINE
         );
    if (PL_op->op_private & OPpLVAL_INTRO)
	save_gp(MUTABLE_GV(sv), !(PL_op->op_flags & OPf_SPECIAL));
    SETs(sv);
    RETURN;
}

/* Helper function for pp_rv2sv and pp_rv2av  */
GV *
Perl_softref2xv(pTHX_ SV *const sv, const char *const what,
		const svtype type, SV ***spp)
{
    GV *gv;

    PERL_ARGS_ASSERT_SOFTREF2XV;

    if (PL_op->op_private & HINT_STRICT_REFS) {
	if (SvOK(sv))
	    Perl_die(aTHX_ PL_no_symref_sv, sv,
		     (SvPOKp(sv) && SvCUR(sv)>32 ? "..." : ""), what);
	else
	    Perl_die(aTHX_ PL_no_usym, what);
    }
    if (!SvOK(sv)) {
	if (
	  PL_op->op_flags & OPf_REF
	)
	    Perl_die(aTHX_ PL_no_usym, what);
	if (ckWARN(WARN_UNINITIALIZED))
	    report_uninit(sv);
	if (type != SVt_PV && GIMME_V == G_ARRAY) {
	    (*spp)--;
	    return NULL;
	}
	**spp = &PL_sv_undef;
	return NULL;
    }
    if ((PL_op->op_flags & OPf_SPECIAL) &&
	!(PL_op->op_flags & OPf_MOD))
	{
	    if (!(gv = gv_fetchsv_nomg(sv, GV_ADDMG, type)))
		{
		    **spp = &PL_sv_undef;
		    return NULL;
		}
	}
    else {
	gv = gv_fetchsv_nomg(sv, GV_ADD, type);
    }
    return gv;
}

PP(pp_rv2sv)
{
    dSP; dTOPss;
    GV *gv = NULL;

    SvGETMAGIC(sv);
    if (SvROK(sv)) {
	if (SvAMAGIC(sv)) {
	    sv = amagic_deref_call(sv, to_sv_amg);
	}

	sv = SvRV(sv);
	if (SvTYPE(sv) >= SVt_PVAV)
	    DIE(aTHX_ "Not a SCALAR reference");
    }
    else {
	gv = MUTABLE_GV(sv);

	if (!isGV_with_GP(gv)) {
	    gv = Perl_softref2xv(aTHX_ sv, "a SCALAR", SVt_PV, &sp);
	    if (!gv)
		RETURN;
	}
	sv = GvSVn(gv);
    }
    if (PL_op->op_flags & OPf_MOD) {
	if (PL_op->op_private & OPpLVAL_INTRO) {
	    if (cUNOP->op_first->op_type == OP_NULL)
		sv = save_scalar(MUTABLE_GV(TOPs));
	    else if (gv)
		sv = save_scalar(gv);
	    else
		Perl_croak(aTHX_ "%s", PL_no_localize_ref);
	}
	else if (PL_op->op_private & OPpDEREF)
	    sv = vivify_ref(sv, PL_op->op_private & OPpDEREF);
    }
    SETs(sv);
    RETURN;
}

PP(pp_av2arylen)
{
    dSP;
    AV * const av = MUTABLE_AV(TOPs);
    const I32 lvalue = PL_op->op_flags & OPf_MOD || LVRET;
    if (lvalue) {
	SV ** const svp = Perl_av_arylen_p(aTHX_ MUTABLE_AV(av));
	if (!*svp) {
	    *svp = newSV_type(SVt_PVMG);
	    sv_magic(*svp, MUTABLE_SV(av), PERL_MAGIC_arylen, NULL, 0);
	}
	SETs(*svp);
    } else {
	SETs(sv_2mortal(newSViv(AvFILL(MUTABLE_AV(av)))));
    }
    RETURN;
}

PP(pp_pos)
{
    dSP; dTOPss;

    if (PL_op->op_flags & OPf_MOD || LVRET) {
	SV * const ret = sv_2mortal(newSV_type(SVt_PVLV));/* Not TARG RT#67838 */
	sv_magic(ret, NULL, PERL_MAGIC_pos, NULL, 0);
	LvTYPE(ret) = '.';
	LvTARG(ret) = SvREFCNT_inc_simple(sv);
	SETs(ret);    /* no SvSETMAGIC */
    }
    else {
	    const MAGIC * const mg = mg_find_mglob(sv);
	    if (mg && mg->mg_len != -1) {
		dTARGET;
		STRLEN i = mg->mg_len;
		if (mg->mg_flags & MGf_BYTES && DO_UTF8(sv))
		    i = sv_pos_b2u_flags(sv, i, SV_GMAGIC|SV_CONST_RETURN);
		SETu(i);
		return NORMAL;
	    }
	    SETs(&PL_sv_undef);
    }
    return NORMAL;
}

PP(pp_rv2cv)
{
    dSP;
    GV *gv;
    HV *stash_unused;
    const I32 flags = (PL_op->op_flags & OPf_SPECIAL)
	? GV_ADDMG
	: ((PL_op->op_private & (OPpLVAL_INTRO|OPpMAY_RETURN_CONSTANT))
                                                    == OPpMAY_RETURN_CONSTANT)
	    ? GV_ADD|GV_NOEXPAND
	    : GV_ADD;
    /* We usually try to add a non-existent subroutine in case of AUTOLOAD. */
    /* (But not in defined().) */

    CV *cv = sv_2cv(TOPs, &stash_unused, &gv, flags);
    if (cv) NOOP;
    else if ((flags == (GV_ADD|GV_NOEXPAND)) && gv && SvROK(gv)) {
	cv = SvTYPE(SvRV(gv)) == SVt_PVCV
	    ? MUTABLE_CV(SvRV(gv))
	    : MUTABLE_CV(gv);
    }    
    else
	cv = MUTABLE_CV(&PL_sv_undef);
    SETs(MUTABLE_SV(cv));
    return NORMAL;
}

PP(pp_prototype)
{
    dSP;
    CV *cv;
    HV *stash;
    GV *gv;
    SV *ret = &PL_sv_undef;

    if (SvGMAGICAL(TOPs)) SETs(sv_mortalcopy(TOPs));
    if (SvPOK(TOPs) && SvCUR(TOPs) >= 7) {
	const char * s = SvPVX_const(TOPs);
	if (strnEQ(s, "CORE::", 6)) {
	    const int code = keyword(s + 6, SvCUR(TOPs) - 6, 1);
	    if (!code)
		DIE(aTHX_ "Can't find an opnumber for \"%" UTF8f "\"",
		   UTF8fARG(SvFLAGS(TOPs) & SVf_UTF8, SvCUR(TOPs)-6, s+6));
	    {
		SV * const sv = core_prototype(NULL, s + 6, code, NULL);
		if (sv) ret = sv;
	    }
	    goto set;
	}
    }
    cv = sv_2cv(TOPs, &stash, &gv, 0);
    if (cv && SvPOK(cv))
	ret = newSVpvn_flags(
	    CvPROTO(cv), CvPROTOLEN(cv), SVs_TEMP | SvUTF8(cv)
	);
  set:
    SETs(ret);
    RETURN;
}

PP(pp_anoncode)
{
    dSP;
    CV *cv = MUTABLE_CV(PAD_SV(PL_op->op_targ));
    if (CvCLONE(cv))
	cv = MUTABLE_CV(sv_2mortal(MUTABLE_SV(cv_clone(cv))));
    EXTEND(SP,1);
    PUSHs(MUTABLE_SV(cv));
    RETURN;
}

PP(pp_srefgen)
{
    dSP;
    *SP = refto(*SP);
    return NORMAL;
}

PP(pp_refgen)
{
    dSP; dMARK;
    if (GIMME_V != G_ARRAY) {
	if (++MARK <= SP)
	    *MARK = *SP;
	else
	{
	    MEXTEND(SP, 1);
	    *MARK = &PL_sv_undef;
	}
	*MARK = refto(*MARK);
	SP = MARK;
	RETURN;
    }
    EXTEND_MORTAL(SP - MARK);
    while (++MARK <= SP)
	*MARK = refto(*MARK);
    RETURN;
}

STATIC SV*
S_refto(pTHX_ SV *sv)
{
    SV* rv;

    PERL_ARGS_ASSERT_REFTO;

    if (SvTYPE(sv) == SVt_PVLV && LvTYPE(sv) == 'y') {
	if (LvTARGLEN(sv))
	    vivify_defelem(sv);
	if (!(sv = LvTARG(sv)))
	    sv = &PL_sv_undef;
	else
	    SvREFCNT_inc_void_NN(sv);
    }
    else if (SvTYPE(sv) == SVt_PVAV) {
	if (!AvREAL((const AV *)sv) && AvREIFY((const AV *)sv))
	    av_reify(MUTABLE_AV(sv));
	SvTEMP_off(sv);
	SvREFCNT_inc_void_NN(sv);
    }
    else if (SvPADTMP(sv)) {
        sv = newSVsv(sv);
    }
    else {
	SvTEMP_off(sv);
	SvREFCNT_inc_void_NN(sv);
    }
    rv = sv_newmortal();
    sv_upgrade(rv, SVt_IV);
    SvRV_set(rv, sv);
    SvROK_on(rv);
    return rv;
}

PP(pp_ref)
{
    dSP;
    SV * const sv = TOPs;

    SvGETMAGIC(sv);
    if (!SvROK(sv))
	SETs(&PL_sv_no);
    else {
	dTARGET;
	SETs(TARG);
	/* use the return value that is in a register, its the same as TARG */
	TARG = sv_ref(TARG,SvRV(sv),TRUE);
	SvSETMAGIC(TARG);
    }

    return NORMAL;
}

PP(pp_bless)
{
    dSP;
    HV *stash;

    if (MAXARG == 1)
    {
      curstash:
	stash = CopSTASH(PL_curcop);
	if (SvTYPE(stash) != SVt_PVHV)
	    Perl_croak(aTHX_ "Attempt to bless into a freed package");
    }
    else {
	SV * const ssv = POPs;
	STRLEN len;
	const char *ptr;

	if (!ssv) goto curstash;
	SvGETMAGIC(ssv);
	if (SvROK(ssv)) {
	  if (!SvAMAGIC(ssv)) {
	   frog:
	    Perl_croak(aTHX_ "Attempt to bless into a reference");
	  }
	  /* SvAMAGIC is on here, but it only means potentially overloaded,
	     so after stringification: */
	  ptr = SvPV_nomg_const(ssv,len);
	  /* We need to check the flag again: */
	  if (!SvAMAGIC(ssv)) goto frog;
	}
	else ptr = SvPV_nomg_const(ssv,len);
	if (len == 0)
	    Perl_ck_warner(aTHX_ packWARN(WARN_MISC),
			   "Explicit blessing to '' (assuming package main)");
	stash = gv_stashpvn(ptr, len, GV_ADD|SvUTF8(ssv));
    }

    (void)sv_bless(TOPs, stash);
    RETURN;
}

PP(pp_gelem)
{
    dSP;

    SV *sv = POPs;
    STRLEN len;
    const char * const elem = SvPV_const(sv, len);
    GV * const gv = MUTABLE_GV(TOPs);
    SV * tmpRef = NULL;

    sv = NULL;
    if (elem) {
	/* elem will always be NUL terminated.  */
	switch (*elem) {
	case 'A':
	    if (memEQs(elem, len, "ARRAY"))
	    {
		tmpRef = MUTABLE_SV(GvAV(gv));
		if (tmpRef && !AvREAL((const AV *)tmpRef)
		 && AvREIFY((const AV *)tmpRef))
		    av_reify(MUTABLE_AV(tmpRef));
	    }
	    break;
	case 'C':
	    if (memEQs(elem, len, "CODE"))
		tmpRef = MUTABLE_SV(GvCVu(gv));
	    break;
	case 'F':
	    if (memEQs(elem, len, "FILEHANDLE")) {
		tmpRef = MUTABLE_SV(GvIOp(gv));
	    }
	    else
		if (memEQs(elem, len, "FORMAT"))
		    tmpRef = MUTABLE_SV(GvFORM(gv));
	    break;
	case 'G':
	    if (memEQs(elem, len, "GLOB"))
		tmpRef = MUTABLE_SV(gv);
	    break;
	case 'H':
	    if (memEQs(elem, len, "HASH"))
		tmpRef = MUTABLE_SV(GvHV(gv));
	    break;
	case 'I':
	    if (memEQs(elem, len, "IO"))
		tmpRef = MUTABLE_SV(GvIOp(gv));
	    break;
	case 'N':
	    if (memEQs(elem, len, "NAME"))
		sv = newSVhek(GvNAME_HEK(gv));
	    break;
	case 'P':
	    if (memEQs(elem, len, "PACKAGE")) {
		const HV * const stash = GvSTASH(gv);
		const HEK * const hek = stash ? HvNAME_HEK(stash) : NULL;
		sv = hek ? newSVhek(hek) : newSVpvs("__ANON__");
	    }
	    break;
	case 'S':
	    if (memEQs(elem, len, "SCALAR"))
		tmpRef = GvSVn(gv);
	    break;
	}
    }
    if (tmpRef)
	sv = newRV(tmpRef);
    if (sv)
	sv_2mortal(sv);
    else
	sv = &PL_sv_undef;
    SETs(sv);
    RETURN;
}

/* Pattern matching */

PP(pp_study)
{
    dSP; dTOPss;
    STRLEN len;

    (void)SvPV(sv, len);
    if (len == 0 || len > I32_MAX || !SvPOK(sv) || SvUTF8(sv) || SvVALID(sv)) {
	/* Historically, study was skipped in these cases. */
	SETs(&PL_sv_no);
	return NORMAL;
    }

    /* Make study a no-op. It's no longer useful and its existence
       complicates matters elsewhere. */
    SETs(&PL_sv_yes);
    return NORMAL;
}


/* also used for: pp_transr() */

PP(pp_trans)
{
    dSP; 
    SV *sv;

    if (PL_op->op_flags & OPf_STACKED)
	sv = POPs;
    else {
	EXTEND(SP,1);
	if (ARGTARG)
	    sv = PAD_SV(ARGTARG);
	else {
	    sv = DEFSV;
	}
    }
    if(PL_op->op_type == OP_TRANSR) {
	STRLEN len;
	const char * const pv = SvPV(sv,len);
	SV * const newsv = newSVpvn_flags(pv, len, SVs_TEMP|SvUTF8(sv));
	do_trans(newsv);
	PUSHs(newsv);
    }
    else {
	I32 i = do_trans(sv);
	mPUSHi(i);
    }
    RETURN;
}

/* Lvalue operators. */

static size_t
S_do_chomp(pTHX_ SV *retval, SV *sv, bool chomping)
{
    STRLEN len;
    char *s;
    size_t count = 0;

    PERL_ARGS_ASSERT_DO_CHOMP;

    if (chomping && (RsSNARF(PL_rs) || RsRECORD(PL_rs)))
	return 0;
    if (SvTYPE(sv) == SVt_PVAV) {
	I32 i;
	AV *const av = MUTABLE_AV(sv);
	const I32 max = AvFILL(av);

	for (i = 0; i <= max; i++) {
	    sv = MUTABLE_SV(av_fetch(av, i, FALSE));
	    if (sv && ((sv = *(SV**)sv), sv != &PL_sv_undef))
		count += do_chomp(retval, sv, chomping);
	}
        return count;
    }
    else if (SvTYPE(sv) == SVt_PVHV) {
	HV* const hv = MUTABLE_HV(sv);
	HE* entry;
        (void)hv_iterinit(hv);
        while ((entry = hv_iternext(hv)))
            count += do_chomp(retval, hv_iterval(hv,entry), chomping);
	return count;
    }
    else if (SvREADONLY(sv)) {
            Perl_croak_no_modify();
    }

    s = SvPV(sv, len);
    if (chomping) {
	if (s && len) {
	    char *temp_buffer = NULL;
	    SV *svrecode = NULL;
	    s += --len;
	    if (RsPARA(PL_rs)) {
		if (*s != '\n')
		    goto nope_free_nothing;
		++count;
		while (len && s[-1] == '\n') {
		    --len;
		    --s;
		    ++count;
		}
	    }
	    else {
		STRLEN rslen, rs_charlen;
		const char *rsptr = SvPV_const(PL_rs, rslen);

		rs_charlen = SvUTF8(PL_rs)
		    ? sv_len_utf8(PL_rs)
		    : rslen;

		if (SvUTF8(PL_rs) != SvUTF8(sv)) {
		    /* Assumption is that rs is shorter than the scalar.  */
		    if (SvUTF8(PL_rs)) {
			/* RS is utf8, scalar is 8 bit.  */
			bool is_utf8 = TRUE;
			temp_buffer = (char*)bytes_from_utf8((U8*)rsptr,
							     &rslen, &is_utf8);
			if (is_utf8) {
			    /* Cannot downgrade, therefore cannot possibly match.
			       At this point, temp_buffer is not alloced, and
			       is the buffer inside PL_rs, so dont free it.
			     */
			    assert (temp_buffer == rsptr);
			    goto nope_free_sv;
			}
			rsptr = temp_buffer;
		    }
		    else {
			/* RS is 8 bit, scalar is utf8.  */
			temp_buffer = (char*)bytes_to_utf8((U8*)rsptr, &rslen);
			rsptr = temp_buffer;
		    }
		}
		if (rslen == 1) {
		    if (*s != *rsptr)
			goto nope_free_all;
		    ++count;
		}
		else {
		    if (len < rslen - 1)
			goto nope_free_all;
		    len -= rslen - 1;
		    s -= rslen - 1;
		    if (memNE(s, rsptr, rslen))
			goto nope_free_all;
		    count += rs_charlen;
		}
	    }
	    SvPV_force_nomg_nolen(sv);
	    SvCUR_set(sv, len);
	    *SvEND(sv) = '\0';
	    SvNIOK_off(sv);
	    SvSETMAGIC(sv);

	    nope_free_all:
	    Safefree(temp_buffer);
	    nope_free_sv:
	    SvREFCNT_dec(svrecode);
	    nope_free_nothing: ;
	}
    } else {
	if (len && (!SvPOK(sv) || SvIsCOW(sv)))
	    s = SvPV_force_nomg(sv, len);
	if (DO_UTF8(sv)) {
	    if (s && len) {
		char * const send = s + len;
		char * const start = s;
		s = send - 1;
		while (s > start && UTF8_IS_CONTINUATION(*s))
		    s--;
		if (is_utf8_string((U8*)s, send - s)) {
		    sv_setpvn(retval, s, send - s);
		    *s = '\0';
		    SvCUR_set(sv, s - start);
		    SvNIOK_off(sv);
		    SvUTF8_on(retval);
		}
	    }
	    else
                SvPVCLEAR(retval);
	}
	else if (s && len) {
	    s += --len;
	    sv_setpvn(retval, s, 1);
	    *s = '\0';
	    SvCUR_set(sv, len);
	    SvUTF8_off(sv);
	    SvNIOK_off(sv);
	}
	else
            SvPVCLEAR(retval);
	SvSETMAGIC(sv);
    }
    return count;
}


/* also used for: pp_schomp() */

PP(pp_schop)
{
    dSP; dTARGET;
    const bool chomping = PL_op->op_type == OP_SCHOMP;

    const size_t count = do_chomp(TARG, TOPs, chomping);
    if (chomping)
	sv_setiv(TARG, count);
    SETTARG;
    return NORMAL;
}


/* also used for: pp_chomp() */

PP(pp_chop)
{
    dSP; dMARK; dTARGET; dORIGMARK;
    const bool chomping = PL_op->op_type == OP_CHOMP;
    size_t count = 0;

    while (MARK < SP)
	count += do_chomp(TARG, *++MARK, chomping);
    if (chomping)
	sv_setiv(TARG, count);
    SP = ORIGMARK;
    XPUSHTARG;
    RETURN;
}

PP(pp_undef)
{
    dSP;
    SV *sv;

    if (!PL_op->op_private) {
	EXTEND(SP, 1);
	RETPUSHUNDEF;
    }

    sv = TOPs;
    if (!sv)
    {
	SETs(&PL_sv_undef);
	return NORMAL;
    }

    if (SvTHINKFIRST(sv))
	sv_force_normal_flags(sv, SV_COW_DROP_PV|SV_IMMEDIATE_UNREF);

    switch (SvTYPE(sv)) {
    case SVt_NULL:
	break;
    case SVt_PVAV:
	av_undef(MUTABLE_AV(sv));
	break;
    case SVt_PVHV:
	hv_undef(MUTABLE_HV(sv));
	break;
    case SVt_PVCV:
	if (cv_const_sv((const CV *)sv))
	    Perl_ck_warner(aTHX_ packWARN(WARN_MISC),
                          "Constant subroutine %" SVf " undefined",
			   SVfARG(CvANON((const CV *)sv)
                             ? newSVpvs_flags("(anonymous)", SVs_TEMP)
                             : sv_2mortal(newSVhek(
                                CvNAMED(sv)
                                 ? CvNAME_HEK((CV *)sv)
                                 : GvENAME_HEK(CvGV((const CV *)sv))
                               ))
                           ));
	/* FALLTHROUGH */
    case SVt_PVFM:
	    /* let user-undef'd sub keep its identity */
	cv_undef_flags(MUTABLE_CV(sv), CV_UNDEF_KEEP_NAME);
	break;
    case SVt_PVGV:
	assert(isGV_with_GP(sv));
	assert(!SvFAKE(sv));
	{
	    GP *gp;
            HV *stash;

            /* undef *Pkg::meth_name ... */
            bool method_changed
             =   GvCVu((const GV *)sv) && (stash = GvSTASH((const GV *)sv))
	      && HvENAME_get(stash);
            /* undef *Foo:: */
            if((stash = GvHV((const GV *)sv))) {
                if(HvENAME_get(stash))
                    SvREFCNT_inc_simple_void_NN(sv_2mortal((SV *)stash));
                else stash = NULL;
            }

	    SvREFCNT_inc_simple_void_NN(sv_2mortal(sv));
	    gp_free(MUTABLE_GV(sv));
	    Newxz(gp, 1, GP);
	    GvGP_set(sv, gp_ref(gp));
#ifndef PERL_DONT_CREATE_GVSV
	    GvSV(sv) = newSV(0);
#endif
	    GvLINE(sv) = CopLINE(PL_curcop);
	    GvEGV(sv) = MUTABLE_GV(sv);
	    GvMULTI_on(sv);

            if(stash)
                mro_package_moved(NULL, stash, (const GV *)sv, 0);
            stash = NULL;
            /* undef *Foo::ISA */
            if( strEQ(GvNAME((const GV *)sv), "ISA")
             && (stash = GvSTASH((const GV *)sv))
             && (method_changed || HvENAME(stash)) )
                mro_isa_changed_in(stash);
            else if(method_changed)
                mro_method_changed_in(
                 GvSTASH((const GV *)sv)
                );

	    break;
	}
    default:
	if (SvTYPE(sv) >= SVt_PV && SvPVX_const(sv) && SvLEN(sv)) {
	    SvPV_free(sv);
	    SvPV_set(sv, NULL);
	    SvLEN_set(sv, 0);
	}
	SvOK_off(sv);
	SvSETMAGIC(sv);
    }

    SETs(&PL_sv_undef);
    return NORMAL;
}


/* common "slow" code for pp_postinc and pp_postdec */

static OP *
S_postincdec_common(pTHX_ SV *sv, SV *targ)
{
    dSP;
    const bool inc =
	PL_op->op_type == OP_POSTINC || PL_op->op_type == OP_I_POSTINC;

    if (SvROK(sv))
	TARG = sv_newmortal();
    sv_setsv(TARG, sv);
    if (inc)
	sv_inc_nomg(sv);
    else
        sv_dec_nomg(sv);
    SvSETMAGIC(sv);
    /* special case for undef: see thread at 2003-03/msg00536.html in archive */
    if (inc && !SvOK(TARG))
	sv_setiv(TARG, 0);
    SETTARG;
    return NORMAL;
}


/* also used for: pp_i_postinc() */

PP(pp_postinc)
{
    dSP; dTARGET;
    SV *sv = TOPs;

    /* special-case sv being a simple integer */
    if (LIKELY(((sv->sv_flags &
                        (SVf_THINKFIRST|SVs_GMG|SVf_IVisUV|
                         SVf_IOK|SVf_NOK|SVf_POK|SVp_NOK|SVp_POK|SVf_ROK))
                == SVf_IOK))
        && SvIVX(sv) != IV_MAX)
    {
        IV iv = SvIVX(sv);
	SvIV_set(sv,  iv + 1);
        TARGi(iv, 0); /* arg not GMG, so can't be tainted */
        SETs(TARG);
        return NORMAL;
    }

    return S_postincdec_common(aTHX_ sv, TARG);
}


/* also used for: pp_i_postdec() */

PP(pp_postdec)
{
    dSP; dTARGET;
    SV *sv = TOPs;

    /* special-case sv being a simple integer */
    if (LIKELY(((sv->sv_flags &
                        (SVf_THINKFIRST|SVs_GMG|SVf_IVisUV|
                         SVf_IOK|SVf_NOK|SVf_POK|SVp_NOK|SVp_POK|SVf_ROK))
                == SVf_IOK))
        && SvIVX(sv) != IV_MIN)
    {
        IV iv = SvIVX(sv);
	SvIV_set(sv,  iv - 1);
        TARGi(iv, 0); /* arg not GMG, so can't be tainted */
        SETs(TARG);
        return NORMAL;
    }

    return S_postincdec_common(aTHX_ sv, TARG);
}


/* Ordinary operators. */

PP(pp_pow)
{
    dSP; dATARGET; SV *svl, *svr;
#ifdef PERL_PRESERVE_IVUV
    bool is_int = 0;
#endif
    tryAMAGICbin_MG(pow_amg, AMGf_assign|AMGf_numeric);
    svr = TOPs;
    svl = TOPm1s;
#ifdef PERL_PRESERVE_IVUV
    /* For integer to integer power, we do the calculation by hand wherever
       we're sure it is safe; otherwise we call pow() and try to convert to
       integer afterwards. */
    if (SvIV_please_nomg(svr) && SvIV_please_nomg(svl)) {
		UV power;
		bool baseuok;
		UV baseuv;

		if (SvUOK(svr)) {
		    power = SvUVX(svr);
		} else {
		    const IV iv = SvIVX(svr);
		    if (iv >= 0) {
			power = iv;
		    } else {
			goto float_it; /* Can't do negative powers this way.  */
		    }
		}

		baseuok = SvUOK(svl);
		if (baseuok) {
		    baseuv = SvUVX(svl);
		} else {
		    const IV iv = SvIVX(svl);
		    if (iv >= 0) {
			baseuv = iv;
			baseuok = TRUE; /* effectively it's a UV now */
		    } else {
			baseuv = -iv; /* abs, baseuok == false records sign */
		    }
		}
                /* now we have integer ** positive integer. */
                is_int = 1;

                /* foo & (foo - 1) is zero only for a power of 2.  */
                if (!(baseuv & (baseuv - 1))) {
                    /* We are raising power-of-2 to a positive integer.
                       The logic here will work for any base (even non-integer
                       bases) but it can be less accurate than
                       pow (base,power) or exp (power * log (base)) when the
                       intermediate values start to spill out of the mantissa.
                       With powers of 2 we know this can't happen.
                       And powers of 2 are the favourite thing for perl
                       programmers to notice ** not doing what they mean. */
                    NV result = 1.0;
                    NV base = baseuok ? baseuv : -(NV)baseuv;

		    if (power & 1) {
			result *= base;
		    }
		    while (power >>= 1) {
			base *= base;
			if (power & 1) {
			    result *= base;
			}
		    }
                    SP--;
                    SETn( result );
                    SvIV_please_nomg(svr);
                    RETURN;
		} else {
		    unsigned int highbit = 8 * sizeof(UV);
		    unsigned int diff = 8 * sizeof(UV);
		    while (diff >>= 1) {
			highbit -= diff;
			if (baseuv >> highbit) {
			    highbit += diff;
			}
		    }
		    /* we now have baseuv < 2 ** highbit */
		    if (power * highbit <= 8 * sizeof(UV)) {
			/* result will definitely fit in UV, so use UV math
			   on same algorithm as above */
			UV result = 1;
			UV base = baseuv;
			const bool odd_power = cBOOL(power & 1);
			if (odd_power) {
			    result *= base;
			}
			while (power >>= 1) {
			    base *= base;
			    if (power & 1) {
				result *= base;
			    }
			}
			SP--;
			if (baseuok || !odd_power)
			    /* answer is positive */
			    SETu( result );
			else if (result <= (UV)IV_MAX)
			    /* answer negative, fits in IV */
			    SETi( -(IV)result );
			else if (result == (UV)IV_MIN) 
			    /* 2's complement assumption: special case IV_MIN */
			    SETi( IV_MIN );
			else
			    /* answer negative, doesn't fit */
			    SETn( -(NV)result );
			RETURN;
		    } 
		}
    }
  float_it:
#endif    
    {
	NV right = SvNV_nomg(svr);
	NV left  = SvNV_nomg(svl);
	(void)POPs;

#if defined(USE_LONG_DOUBLE) && defined(HAS_AIX_POWL_NEG_BASE_BUG)
    /*
    We are building perl with long double support and are on an AIX OS
    afflicted with a powl() function that wrongly returns NaNQ for any
    negative base.  This was reported to IBM as PMR #23047-379 on
    03/06/2006.  The problem exists in at least the following versions
    of AIX and the libm fileset, and no doubt others as well:

	AIX 4.3.3-ML10      bos.adt.libm 4.3.3.50
	AIX 5.1.0-ML04      bos.adt.libm 5.1.0.29
	AIX 5.2.0           bos.adt.libm 5.2.0.85

    So, until IBM fixes powl(), we provide the following workaround to
    handle the problem ourselves.  Our logic is as follows: for
    negative bases (left), we use fmod(right, 2) to check if the
    exponent is an odd or even integer:

	- if odd,  powl(left, right) == -powl(-left, right)
	- if even, powl(left, right) ==  powl(-left, right)

    If the exponent is not an integer, the result is rightly NaNQ, so
    we just return that (as NV_NAN).
    */

	if (left < 0.0) {
	    NV mod2 = Perl_fmod( right, 2.0 );
	    if (mod2 == 1.0 || mod2 == -1.0) {	/* odd integer */
		SETn( -Perl_pow( -left, right) );
	    } else if (mod2 == 0.0) {		/* even integer */
		SETn( Perl_pow( -left, right) );
	    } else {				/* fractional power */
		SETn( NV_NAN );
	    }
	} else {
	    SETn( Perl_pow( left, right) );
	}
#else
	SETn( Perl_pow( left, right) );
#endif  /* HAS_AIX_POWL_NEG_BASE_BUG */

#ifdef PERL_PRESERVE_IVUV
	if (is_int)
	    SvIV_please_nomg(svr);
#endif
	RETURN;
    }
}

PP(pp_multiply)
{
    dSP; dATARGET; SV *svl, *svr;
    tryAMAGICbin_MG(mult_amg, AMGf_assign|AMGf_numeric);
    svr = TOPs;
    svl = TOPm1s;

#ifdef PERL_PRESERVE_IVUV

    /* special-case some simple common cases */
    if (!((svl->sv_flags|svr->sv_flags) & (SVf_IVisUV|SVs_GMG))) {
        IV il, ir;
        U32 flags = (svl->sv_flags & svr->sv_flags);
        if (flags & SVf_IOK) {
            /* both args are simple IVs */
            UV topl, topr;
            il = SvIVX(svl);
            ir = SvIVX(svr);
          do_iv:
            topl = ((UV)il) >> (UVSIZE * 4 - 1);
            topr = ((UV)ir) >> (UVSIZE * 4 - 1);

            /* if both are in a range that can't under/overflow, do a
             * simple integer multiply: if the top halves(*) of both numbers
             * are 00...00  or 11...11, then it's safe.
             * (*) for 32-bits, the "top half" is the top 17 bits,
             *     for 64-bits, its 33 bits */
            if (!(
                      ((topl+1) | (topr+1))
                    & ( (((UV)1) << (UVSIZE * 4 + 1)) - 2) /* 11..110 */
            )) {
                SP--;
                TARGi(il * ir, 0); /* args not GMG, so can't be tainted */
                SETs(TARG);
                RETURN;
            }
            goto generic;
        }
        else if (flags & SVf_NOK) {
            /* both args are NVs */
            NV nl = SvNVX(svl);
            NV nr = SvNVX(svr);
            NV result;

            if (
#if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
                !Perl_isnan(nl) && nl == (NV)(il = (IV)nl)
                && !Perl_isnan(nr) && nr == (NV)(ir = (IV)nr)
#else
                nl == (NV)(il = (IV)nl) && nr == (NV)(ir = (IV)nr)
#endif
                )
                /* nothing was lost by converting to IVs */
                goto do_iv;
            SP--;
            result = nl * nr;
#  if defined(__sgi) && defined(USE_LONG_DOUBLE) && LONG_DOUBLEKIND == LONG_DOUBLE_IS_DOUBLEDOUBLE_128_BIT_BE_BE && NVSIZE == 16
            if (Perl_isinf(result)) {
                Zero((U8*)&result + 8, 8, U8);
            }
#  endif
            TARGn(result, 0); /* args not GMG, so can't be tainted */
            SETs(TARG);
            RETURN;
        }
    }

  generic:

    if (SvIV_please_nomg(svr)) {
	/* Unless the left argument is integer in range we are going to have to
	   use NV maths. Hence only attempt to coerce the right argument if
	   we know the left is integer.  */
	/* Left operand is defined, so is it IV? */
	if (SvIV_please_nomg(svl)) {
	    bool auvok = SvUOK(svl);
	    bool buvok = SvUOK(svr);
	    const UV topmask = (~ (UV)0) << (4 * sizeof (UV));
	    const UV botmask = ~((~ (UV)0) << (4 * sizeof (UV)));
	    UV alow;
	    UV ahigh;
	    UV blow;
	    UV bhigh;

	    if (auvok) {
		alow = SvUVX(svl);
	    } else {
		const IV aiv = SvIVX(svl);
		if (aiv >= 0) {
		    alow = aiv;
		    auvok = TRUE; /* effectively it's a UV now */
		} else {
                    /* abs, auvok == false records sign */
		    alow = (aiv == IV_MIN) ? (UV)aiv : (UV)(-aiv);
		}
	    }
	    if (buvok) {
		blow = SvUVX(svr);
	    } else {
		const IV biv = SvIVX(svr);
		if (biv >= 0) {
		    blow = biv;
		    buvok = TRUE; /* effectively it's a UV now */
		} else {
                    /* abs, buvok == false records sign */
		    blow = (biv == IV_MIN) ? (UV)biv : (UV)(-biv);
		}
	    }

	    /* If this does sign extension on unsigned it's time for plan B  */
	    ahigh = alow >> (4 * sizeof (UV));
	    alow &= botmask;
	    bhigh = blow >> (4 * sizeof (UV));
	    blow &= botmask;
	    if (ahigh && bhigh) {
		NOOP;
		/* eg 32 bit is at least 0x10000 * 0x10000 == 0x100000000
		   which is overflow. Drop to NVs below.  */
	    } else if (!ahigh && !bhigh) {
		/* eg 32 bit is at most 0xFFFF * 0xFFFF == 0xFFFE0001
		   so the unsigned multiply cannot overflow.  */
		const UV product = alow * blow;
		if (auvok == buvok) {
		    /* -ve * -ve or +ve * +ve gives a +ve result.  */
		    SP--;
		    SETu( product );
		    RETURN;
		} else if (product <= (UV)IV_MIN) {
		    /* 2s complement assumption that (UV)-IV_MIN is correct.  */
		    /* -ve result, which could overflow an IV  */
		    SP--;
                    /* can't negate IV_MIN, but there are aren't two
                     * integers such that !ahigh && !bhigh, where the
                     * product equals 0x800....000 */
                    assert(product != (UV)IV_MIN);
		    SETi( -(IV)product );
		    RETURN;
		} /* else drop to NVs below. */
	    } else {
		/* One operand is large, 1 small */
		UV product_middle;
		if (bhigh) {
		    /* swap the operands */
		    ahigh = bhigh;
		    bhigh = blow; /* bhigh now the temp var for the swap */
		    blow = alow;
		    alow = bhigh;
		}
		/* now, ((ahigh * blow) << half_UV_len) + (alow * blow)
		   multiplies can't overflow. shift can, add can, -ve can.  */
		product_middle = ahigh * blow;
		if (!(product_middle & topmask)) {
		    /* OK, (ahigh * blow) won't lose bits when we shift it.  */
		    UV product_low;
		    product_middle <<= (4 * sizeof (UV));
		    product_low = alow * blow;

		    /* as for pp_add, UV + something mustn't get smaller.
		       IIRC ANSI mandates this wrapping *behaviour* for
		       unsigned whatever the actual representation*/
		    product_low += product_middle;
		    if (product_low >= product_middle) {
			/* didn't overflow */
			if (auvok == buvok) {
			    /* -ve * -ve or +ve * +ve gives a +ve result.  */
			    SP--;
			    SETu( product_low );
			    RETURN;
			} else if (product_low <= (UV)IV_MIN) {
			    /* 2s complement assumption again  */
			    /* -ve result, which could overflow an IV  */
			    SP--;
			    SETi(product_low == (UV)IV_MIN
                                    ? IV_MIN : -(IV)product_low);
			    RETURN;
			} /* else drop to NVs below. */
		    }
		} /* product_middle too large */
	    } /* ahigh && bhigh */
	} /* SvIOK(svl) */
    } /* SvIOK(svr) */
#endif
    {
      NV right = SvNV_nomg(svr);
      NV left  = SvNV_nomg(svl);
      NV result = left * right;

      (void)POPs;
#if defined(__sgi) && defined(USE_LONG_DOUBLE) && LONG_DOUBLEKIND == LONG_DOUBLE_IS_DOUBLEDOUBLE_128_BIT_BE_BE && NVSIZE == 16
      if (Perl_isinf(result)) {
          Zero((U8*)&result + 8, 8, U8);
      }
#endif
      SETn(result);
      RETURN;
    }
}

PP(pp_divide)
{
    dSP; dATARGET; SV *svl, *svr;
    tryAMAGICbin_MG(div_amg, AMGf_assign|AMGf_numeric);
    svr = TOPs;
    svl = TOPm1s;
    /* Only try to do UV divide first
       if ((SLOPPYDIVIDE is true) or
           (PERL_PRESERVE_IVUV is true and one or both SV is a UV too large
            to preserve))
       The assumption is that it is better to use floating point divide
       whenever possible, only doing integer divide first if we can't be sure.
       If NV_PRESERVES_UV is true then we know at compile time that no UV
       can be too large to preserve, so don't need to compile the code to
       test the size of UVs.  */

#ifdef SLOPPYDIVIDE
#  define PERL_TRY_UV_DIVIDE
    /* ensure that 20./5. == 4. */
#else
#  ifdef PERL_PRESERVE_IVUV
#    ifndef NV_PRESERVES_UV
#      define PERL_TRY_UV_DIVIDE
#    endif
#  endif
#endif

#ifdef PERL_TRY_UV_DIVIDE
    if (SvIV_please_nomg(svr) && SvIV_please_nomg(svl)) {
            bool left_non_neg = SvUOK(svl);
            bool right_non_neg = SvUOK(svr);
            UV left;
            UV right;

            if (right_non_neg) {
                right = SvUVX(svr);
            }
	    else {
		const IV biv = SvIVX(svr);
                if (biv >= 0) {
                    right = biv;
                    right_non_neg = TRUE; /* effectively it's a UV now */
                }
		else {
                    right = (biv == IV_MIN) ? (UV)biv : (UV)(-biv);
                }
            }
            /* historically undef()/0 gives a "Use of uninitialized value"
               warning before dieing, hence this test goes here.
               If it were immediately before the second SvIV_please, then
               DIE() would be invoked before left was even inspected, so
               no inspection would give no warning.  */
            if (right == 0)
                DIE(aTHX_ "Illegal division by zero");

            if (left_non_neg) {
                left = SvUVX(svl);
            }
	    else {
		const IV aiv = SvIVX(svl);
                if (aiv >= 0) {
                    left = aiv;
                    left_non_neg = TRUE; /* effectively it's a UV now */
                }
		else {
                    left = (aiv == IV_MIN) ? (UV)aiv : (UV)(-aiv);
                }
            }

            if (left >= right
#ifdef SLOPPYDIVIDE
                /* For sloppy divide we always attempt integer division.  */
#else
                /* Otherwise we only attempt it if either or both operands
                   would not be preserved by an NV.  If both fit in NVs
                   we fall through to the NV divide code below.  However,
                   as left >= right to ensure integer result here, we know that
                   we can skip the test on the right operand - right big
                   enough not to be preserved can't get here unless left is
                   also too big.  */

                && (left > ((UV)1 << NV_PRESERVES_UV_BITS))
#endif
                ) {
                /* Integer division can't overflow, but it can be imprecise.  */
		const UV result = left / right;
                if (result * right == left) {
                    SP--; /* result is valid */
                    if (left_non_neg == right_non_neg) {
                        /* signs identical, result is positive.  */
                        SETu( result );
                        RETURN;
                    }
                    /* 2s complement assumption */
                    if (result <= (UV)IV_MIN)
                        SETi(result == (UV)IV_MIN ? IV_MIN : -(IV)result);
                    else {
                        /* It's exact but too negative for IV. */
                        SETn( -(NV)result );
                    }
                    RETURN;
                } /* tried integer divide but it was not an integer result */
            } /* else (PERL_ABS(result) < 1.0) or (both UVs in range for NV) */
    } /* one operand wasn't SvIOK */
#endif /* PERL_TRY_UV_DIVIDE */
    {
	NV right = SvNV_nomg(svr);
	NV left  = SvNV_nomg(svl);
	(void)POPs;(void)POPs;
#if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
	if (! Perl_isnan(right) && right == 0.0)
#else
	if (right == 0.0)
#endif
	    DIE(aTHX_ "Illegal division by zero");
	PUSHn( left / right );
	RETURN;
    }
}

PP(pp_modulo)
{
    dSP; dATARGET;
    tryAMAGICbin_MG(modulo_amg, AMGf_assign|AMGf_numeric);
    {
	UV left  = 0;
	UV right = 0;
	bool left_neg = FALSE;
	bool right_neg = FALSE;
	bool use_double = FALSE;
	bool dright_valid = FALSE;
	NV dright = 0.0;
	NV dleft  = 0.0;
	SV * const svr = TOPs;
	SV * const svl = TOPm1s;
        if (SvIV_please_nomg(svr)) {
            right_neg = !SvUOK(svr);
            if (!right_neg) {
                right = SvUVX(svr);
            } else {
		const IV biv = SvIVX(svr);
                if (biv >= 0) {
                    right = biv;
                    right_neg = FALSE; /* effectively it's a UV now */
                } else {
                    right = (biv == IV_MIN) ? (UV)biv : (UV)(-biv);
                }
            }
        }
        else {
	    dright = SvNV_nomg(svr);
	    right_neg = dright < 0;
	    if (right_neg)
		dright = -dright;
            if (dright < UV_MAX_P1) {
                right = U_V(dright);
                dright_valid = TRUE; /* In case we need to use double below.  */
            } else {
                use_double = TRUE;
            }
	}

        /* At this point use_double is only true if right is out of range for
           a UV.  In range NV has been rounded down to nearest UV and
           use_double false.  */
	if (!use_double && SvIV_please_nomg(svl)) {
                left_neg = !SvUOK(svl);
                if (!left_neg) {
                    left = SvUVX(svl);
                } else {
		    const IV aiv = SvIVX(svl);
                    if (aiv >= 0) {
                        left = aiv;
                        left_neg = FALSE; /* effectively it's a UV now */
                    } else {
                        left = (aiv == IV_MIN) ? (UV)aiv : (UV)(-aiv);
                    }
                }
        }
	else {
	    dleft = SvNV_nomg(svl);
	    left_neg = dleft < 0;
	    if (left_neg)
		dleft = -dleft;

            /* This should be exactly the 5.6 behaviour - if left and right are
               both in range for UV then use U_V() rather than floor.  */
	    if (!use_double) {
                if (dleft < UV_MAX_P1) {
                    /* right was in range, so is dleft, so use UVs not double.
                     */
                    left = U_V(dleft);
                }
                /* left is out of range for UV, right was in range, so promote
                   right (back) to double.  */
                else {
                    /* The +0.5 is used in 5.6 even though it is not strictly
                       consistent with the implicit +0 floor in the U_V()
                       inside the #if 1. */
                    dleft = Perl_floor(dleft + 0.5);
                    use_double = TRUE;
                    if (dright_valid)
                        dright = Perl_floor(dright + 0.5);
                    else
                        dright = right;
                }
            }
        }
	sp -= 2;
	if (use_double) {
	    NV dans;

	    if (!dright)
		DIE(aTHX_ "Illegal modulus zero");

	    dans = Perl_fmod(dleft, dright);
	    if ((left_neg != right_neg) && dans)
		dans = dright - dans;
	    if (right_neg)
		dans = -dans;
	    sv_setnv(TARG, dans);
	}
	else {
	    UV ans;

	    if (!right)
		DIE(aTHX_ "Illegal modulus zero");

	    ans = left % right;
	    if ((left_neg != right_neg) && ans)
		ans = right - ans;
	    if (right_neg) {
		/* XXX may warn: unary minus operator applied to unsigned type */
		/* could change -foo to be (~foo)+1 instead	*/
		if (ans <= ~((UV)IV_MAX)+1)
		    sv_setiv(TARG, ~ans+1);
		else
		    sv_setnv(TARG, -(NV)ans);
	    }
	    else
		sv_setuv(TARG, ans);
	}
	PUSHTARG;
	RETURN;
    }
}

PP(pp_repeat)
{
    dSP; dATARGET;
    IV count;
    SV *sv;
    bool infnan = FALSE;

    if (GIMME_V == G_ARRAY && PL_op->op_private & OPpREPEAT_DOLIST) {
	/* TODO: think of some way of doing list-repeat overloading ??? */
	sv = POPs;
	SvGETMAGIC(sv);
    }
    else {
	if (UNLIKELY(PL_op->op_private & OPpREPEAT_DOLIST)) {
	    /* The parser saw this as a list repeat, and there
	       are probably several items on the stack. But we're
	       in scalar/void context, and there's no pp_list to save us
	       now. So drop the rest of the items -- robin@kitsite.com
	     */
	    dMARK;
	    if (MARK + 1 < SP) {
		MARK[1] = TOPm1s;
		MARK[2] = TOPs;
	    }
	    else {
		dTOPss;
		ASSUME(MARK + 1 == SP);
		XPUSHs(sv);
		MARK[1] = &PL_sv_undef;
	    }
	    SP = MARK + 2;
	}
	tryAMAGICbin_MG(repeat_amg, AMGf_assign);
	sv = POPs;
    }

    if (SvIOKp(sv)) {
	 if (SvUOK(sv)) {
	      const UV uv = SvUV_nomg(sv);
	      if (uv > IV_MAX)
		   count = IV_MAX; /* The best we can do? */
	      else
		   count = uv;
	 } else {
	      count = SvIV_nomg(sv);
	 }
    }
    else if (SvNOKp(sv)) {
        const NV nv = SvNV_nomg(sv);
        infnan = Perl_isinfnan(nv);
        if (UNLIKELY(infnan)) {
            count = 0;
        } else {
            if (nv < 0.0)
                count = -1;   /* An arbitrary negative integer */
            else
                count = (IV)nv;
        }
    }
    else
	count = SvIV_nomg(sv);

    if (infnan) {
        Perl_ck_warner(aTHX_ packWARN(WARN_NUMERIC),
                       "Non-finite repeat count does nothing");
    } else if (count < 0) {
        count = 0;
        Perl_ck_warner(aTHX_ packWARN(WARN_NUMERIC),
                       "Negative repeat count does nothing");
    }

    if (GIMME_V == G_ARRAY && PL_op->op_private & OPpREPEAT_DOLIST) {
	dMARK;
	const SSize_t items = SP - MARK;
	const U8 mod = PL_op->op_flags & OPf_MOD;

	if (count > 1) {
	    SSize_t max;

            if (  items > SSize_t_MAX / count   /* max would overflow */
                                                /* repeatcpy would overflow */
               || items > I32_MAX / (I32)sizeof(SV *)
            )
               Perl_croak(aTHX_ "%s","Out of memory during list extend");
            max = items * count;
            MEXTEND(MARK, max);

	    while (SP > MARK) {
                if (*SP) {
                   if (mod && SvPADTMP(*SP)) {
                       *SP = sv_mortalcopy(*SP);
                   }
		   SvTEMP_off((*SP));
		}
		SP--;
	    }
	    MARK++;
	    repeatcpy((char*)(MARK + items), (char*)MARK,
		items * sizeof(const SV *), count - 1);
	    SP += max;
	}
	else if (count <= 0)
	    SP = MARK;
    }
    else {	/* Note: mark already snarfed by pp_list */
	SV * const tmpstr = POPs;
	STRLEN len;
	bool isutf;

	if (TARG != tmpstr)
	    sv_setsv_nomg(TARG, tmpstr);
	SvPV_force_nomg(TARG, len);
	isutf = DO_UTF8(TARG);
	if (count != 1) {
	    if (count < 1)
		SvCUR_set(TARG, 0);
	    else {
		STRLEN max;

		if (   len > (MEM_SIZE_MAX-1) / (UV)count /* max would overflow */
		    || len > (U32)I32_MAX  /* repeatcpy would overflow */
                )
		     Perl_croak(aTHX_ "%s",
                                        "Out of memory during string extend");
		max = (UV)count * len + 1;
		SvGROW(TARG, max);

		repeatcpy(SvPVX(TARG) + len, SvPVX(TARG), len, count - 1);
		SvCUR_set(TARG, SvCUR(TARG) * count);
	    }
	    *SvEND(TARG) = '\0';
	}
	if (isutf)
	    (void)SvPOK_only_UTF8(TARG);
	else
	    (void)SvPOK_only(TARG);

	PUSHTARG;
    }
    RETURN;
}

PP(pp_subtract)
{
    dSP; dATARGET; bool useleft; SV *svl, *svr;
    tryAMAGICbin_MG(subtr_amg, AMGf_assign|AMGf_numeric);
    svr = TOPs;
    svl = TOPm1s;

#ifdef PERL_PRESERVE_IVUV

    /* special-case some simple common cases */
    if (!((svl->sv_flags|svr->sv_flags) & (SVf_IVisUV|SVs_GMG))) {
        IV il, ir;
        U32 flags = (svl->sv_flags & svr->sv_flags);
        if (flags & SVf_IOK) {
            /* both args are simple IVs */
            UV topl, topr;
            il = SvIVX(svl);
            ir = SvIVX(svr);
          do_iv:
            topl = ((UV)il) >> (UVSIZE * 8 - 2);
            topr = ((UV)ir) >> (UVSIZE * 8 - 2);

            /* if both are in a range that can't under/overflow, do a
             * simple integer subtract: if the top of both numbers
             * are 00  or 11, then it's safe */
            if (!( ((topl+1) | (topr+1)) & 2)) {
                SP--;
                TARGi(il - ir, 0); /* args not GMG, so can't be tainted */
                SETs(TARG);
                RETURN;
            }
            goto generic;
        }
        else if (flags & SVf_NOK) {
            /* both args are NVs */
            NV nl = SvNVX(svl);
            NV nr = SvNVX(svr);

            if (
#if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
                !Perl_isnan(nl) && nl == (NV)(il = (IV)nl)
                && !Perl_isnan(nr) && nr == (NV)(ir = (IV)nr)
#else
                nl == (NV)(il = (IV)nl) && nr == (NV)(ir = (IV)nr)
#endif
                )
                /* nothing was lost by converting to IVs */
                goto do_iv;
            SP--;
            TARGn(nl - nr, 0); /* args not GMG, so can't be tainted */
            SETs(TARG);
            RETURN;
        }
    }

  generic:

    useleft = USE_LEFT(svl);
    /* See comments in pp_add (in pp_hot.c) about Overflow, and how
       "bad things" happen if you rely on signed integers wrapping.  */
    if (SvIV_please_nomg(svr)) {
	/* Unless the left argument is integer in range we are going to have to
	   use NV maths. Hence only attempt to coerce the right argument if
	   we know the left is integer.  */
	UV auv = 0;
	bool auvok = FALSE;
	bool a_valid = 0;

	if (!useleft) {
	    auv = 0;
	    a_valid = auvok = 1;
	    /* left operand is undef, treat as zero.  */
	} else {
	    /* Left operand is defined, so is it IV? */
	    if (SvIV_please_nomg(svl)) {
		if ((auvok = SvUOK(svl)))
		    auv = SvUVX(svl);
		else {
		    const IV aiv = SvIVX(svl);
		    if (aiv >= 0) {
			auv = aiv;
			auvok = 1;	/* Now acting as a sign flag.  */
		    } else { /* 2s complement assumption for IV_MIN */
			auv = (aiv == IV_MIN) ? (UV)aiv : (UV)-aiv;
		    }
		}
		a_valid = 1;
	    }
	}
	if (a_valid) {
	    bool result_good = 0;
	    UV result;
	    UV buv;
	    bool buvok = SvUOK(svr);
	
	    if (buvok)
		buv = SvUVX(svr);
	    else {
		const IV biv = SvIVX(svr);
		if (biv >= 0) {
		    buv = biv;
		    buvok = 1;
		} else
                    buv = (biv == IV_MIN) ? (UV)biv : (UV)-biv;
	    }
	    /* ?uvok if value is >= 0. basically, flagged as UV if it's +ve,
	       else "IV" now, independent of how it came in.
	       if a, b represents positive, A, B negative, a maps to -A etc
	       a - b =>  (a - b)
	       A - b => -(a + b)
	       a - B =>  (a + b)
	       A - B => -(a - b)
	       all UV maths. negate result if A negative.
	       subtract if signs same, add if signs differ. */

	    if (auvok ^ buvok) {
		/* Signs differ.  */
		result = auv + buv;
		if (result >= auv)
		    result_good = 1;
	    } else {
		/* Signs same */
		if (auv >= buv) {
		    result = auv - buv;
		    /* Must get smaller */
		    if (result <= auv)
			result_good = 1;
		} else {
		    result = buv - auv;
		    if (result <= buv) {
			/* result really should be -(auv-buv). as its negation
			   of true value, need to swap our result flag  */
			auvok = !auvok;
			result_good = 1;
		    }
		}
	    }
	    if (result_good) {
		SP--;
		if (auvok)
		    SETu( result );
		else {
		    /* Negate result */
		    if (result <= (UV)IV_MIN)
                        SETi(result == (UV)IV_MIN
                                ? IV_MIN : -(IV)result);
		    else {
			/* result valid, but out of range for IV.  */
			SETn( -(NV)result );
		    }
		}
		RETURN;
	    } /* Overflow, drop through to NVs.  */
	}
    }
#else
    useleft = USE_LEFT(svl);
#endif
    {
	NV value = SvNV_nomg(svr);
	(void)POPs;

	if (!useleft) {
	    /* left operand is undef, treat as zero - value */
	    SETn(-value);
	    RETURN;
	}
	SETn( SvNV_nomg(svl) - value );
	RETURN;
    }
}

#define IV_BITS (IVSIZE * 8)

static UV S_uv_shift(UV uv, int shift, bool left)
{
   if (shift < 0) {
       shift = -shift;
       left = !left;
   }
   if (shift >= IV_BITS) {
       return 0;
   }
   return left ? uv << shift : uv >> shift;
}

static IV S_iv_shift(IV iv, int shift, bool left)
{
   if (shift < 0) {
       shift = -shift;
       left = !left;
   }
   if (shift >= IV_BITS) {
       return iv < 0 && !left ? -1 : 0;
   }
   return left ? iv << shift : iv >> shift;
}

#define UV_LEFT_SHIFT(uv, shift) S_uv_shift(uv, shift, TRUE)
#define UV_RIGHT_SHIFT(uv, shift) S_uv_shift(uv, shift, FALSE)
#define IV_LEFT_SHIFT(iv, shift) S_iv_shift(iv, shift, TRUE)
#define IV_RIGHT_SHIFT(iv, shift) S_iv_shift(iv, shift, FALSE)

PP(pp_left_shift)
{
    dSP; dATARGET; SV *svl, *svr;
    tryAMAGICbin_MG(lshift_amg, AMGf_assign|AMGf_numeric);
    svr = POPs;
    svl = TOPs;
    {
      const IV shift = SvIV_nomg(svr);
      if (PL_op->op_private & HINT_INTEGER) {
          SETi(IV_LEFT_SHIFT(SvIV_nomg(svl), shift));
      }
      else {
	  SETu(UV_LEFT_SHIFT(SvUV_nomg(svl), shift));
      }
      RETURN;
    }
}

PP(pp_right_shift)
{
    dSP; dATARGET; SV *svl, *svr;
    tryAMAGICbin_MG(rshift_amg, AMGf_assign|AMGf_numeric);
    svr = POPs;
    svl = TOPs;
    {
      const IV shift = SvIV_nomg(svr);
      if (PL_op->op_private & HINT_INTEGER) {
	  SETi(IV_RIGHT_SHIFT(SvIV_nomg(svl), shift));
      }
      else {
          SETu(UV_RIGHT_SHIFT(SvUV_nomg(svl), shift));
      }
      RETURN;
    }
}

PP(pp_lt)
{
    dSP;
    SV *left, *right;

    tryAMAGICbin_MG(lt_amg, AMGf_set|AMGf_numeric);
    right = POPs;
    left  = TOPs;
    SETs(boolSV(
	(SvIOK_notUV(left) && SvIOK_notUV(right))
	? (SvIVX(left) < SvIVX(right))
	: (do_ncmp(left, right) == -1)
    ));
    RETURN;
}

PP(pp_gt)
{
    dSP;
    SV *left, *right;

    tryAMAGICbin_MG(gt_amg, AMGf_set|AMGf_numeric);
    right = POPs;
    left  = TOPs;
    SETs(boolSV(
	(SvIOK_notUV(left) && SvIOK_notUV(right))
	? (SvIVX(left) > SvIVX(right))
	: (do_ncmp(left, right) == 1)
    ));
    RETURN;
}

PP(pp_le)
{
    dSP;
    SV *left, *right;

    tryAMAGICbin_MG(le_amg, AMGf_set|AMGf_numeric);
    right = POPs;
    left  = TOPs;
    SETs(boolSV(
	(SvIOK_notUV(left) && SvIOK_notUV(right))
	? (SvIVX(left) <= SvIVX(right))
	: (do_ncmp(left, right) <= 0)
    ));
    RETURN;
}

PP(pp_ge)
{
    dSP;
    SV *left, *right;

    tryAMAGICbin_MG(ge_amg, AMGf_set|AMGf_numeric);
    right = POPs;
    left  = TOPs;
    SETs(boolSV(
	(SvIOK_notUV(left) && SvIOK_notUV(right))
	? (SvIVX(left) >= SvIVX(right))
	: ( (do_ncmp(left, right) & 2) == 0)
    ));
    RETURN;
}

PP(pp_ne)
{
    dSP;
    SV *left, *right;

    tryAMAGICbin_MG(ne_amg, AMGf_set|AMGf_numeric);
    right = POPs;
    left  = TOPs;
    SETs(boolSV(
	(SvIOK_notUV(left) && SvIOK_notUV(right))
	? (SvIVX(left) != SvIVX(right))
	: (do_ncmp(left, right) != 0)
    ));
    RETURN;
}

/* compare left and right SVs. Returns:
 * -1: <
 *  0: ==
 *  1: >
 *  2: left or right was a NaN
 */
I32
Perl_do_ncmp(pTHX_ SV* const left, SV * const right)
{
    PERL_ARGS_ASSERT_DO_NCMP;
#ifdef PERL_PRESERVE_IVUV
    /* Fortunately it seems NaN isn't IOK */
    if (SvIV_please_nomg(right) && SvIV_please_nomg(left)) {
	    if (!SvUOK(left)) {
		const IV leftiv = SvIVX(left);
		if (!SvUOK(right)) {
		    /* ## IV <=> IV ## */
		    const IV rightiv = SvIVX(right);
		    return (leftiv > rightiv) - (leftiv < rightiv);
		}
		/* ## IV <=> UV ## */
		if (leftiv < 0)
		    /* As (b) is a UV, it's >=0, so it must be < */
		    return -1;
		{
		    const UV rightuv = SvUVX(right);
		    return ((UV)leftiv > rightuv) - ((UV)leftiv < rightuv);
		}
	    }

	    if (SvUOK(right)) {
		/* ## UV <=> UV ## */
		const UV leftuv = SvUVX(left);
		const UV rightuv = SvUVX(right);
		return (leftuv > rightuv) - (leftuv < rightuv);
	    }
	    /* ## UV <=> IV ## */
	    {
		const IV rightiv = SvIVX(right);
		if (rightiv < 0)
		    /* As (a) is a UV, it's >=0, so it cannot be < */
		    return 1;
		{
		    const UV leftuv = SvUVX(left);
		    return (leftuv > (UV)rightiv) - (leftuv < (UV)rightiv);
		}
	    }
	    NOT_REACHED; /* NOTREACHED */
    }
#endif
    {
      NV const rnv = SvNV_nomg(right);
      NV const lnv = SvNV_nomg(left);

#if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
      if (Perl_isnan(lnv) || Perl_isnan(rnv)) {
	  return 2;
       }
      return (lnv > rnv) - (lnv < rnv);
#else
      if (lnv < rnv)
	return -1;
      if (lnv > rnv)
	return 1;
      if (lnv == rnv)
	return 0;
      return 2;
#endif
    }
}


PP(pp_ncmp)
{
    dSP;
    SV *left, *right;
    I32 value;
    tryAMAGICbin_MG(ncmp_amg, AMGf_numeric);
    right = POPs;
    left  = TOPs;
    value = do_ncmp(left, right);
    if (value == 2) {
	SETs(&PL_sv_undef);
    }
    else {
	dTARGET;
	SETi(value);
    }
    RETURN;
}


/* also used for: pp_sge() pp_sgt() pp_slt() */

PP(pp_sle)
{
    dSP;

    int amg_type = sle_amg;
    int multiplier = 1;
    int rhs = 1;

    switch (PL_op->op_type) {
    case OP_SLT:
	amg_type = slt_amg;
	/* cmp < 0 */
	rhs = 0;
	break;
    case OP_SGT:
	amg_type = sgt_amg;
	/* cmp > 0 */
	multiplier = -1;
	rhs = 0;
	break;
    case OP_SGE:
	amg_type = sge_amg;
	/* cmp >= 0 */
	multiplier = -1;
	break;
    }

    tryAMAGICbin_MG(amg_type, AMGf_set);
    {
      dPOPTOPssrl;
      const int cmp =
#ifdef USE_LOCALE_COLLATE
                      (IN_LC_RUNTIME(LC_COLLATE))
		      ? sv_cmp_locale_flags(left, right, 0)
                      :
#endif
		        sv_cmp_flags(left, right, 0);
      SETs(boolSV(cmp * multiplier < rhs));
      RETURN;
    }
}

PP(pp_seq)
{
    dSP;
    tryAMAGICbin_MG(seq_amg, AMGf_set);
    {
      dPOPTOPssrl;
      SETs(boolSV(sv_eq_flags(left, right, 0)));
      RETURN;
    }
}

PP(pp_sne)
{
    dSP;
    tryAMAGICbin_MG(sne_amg, AMGf_set);
    {
      dPOPTOPssrl;
      SETs(boolSV(!sv_eq_flags(left, right, 0)));
      RETURN;
    }
}

PP(pp_scmp)
{
    dSP; dTARGET;
    tryAMAGICbin_MG(scmp_amg, 0);
    {
      dPOPTOPssrl;
      const int cmp =
#ifdef USE_LOCALE_COLLATE
                      (IN_LC_RUNTIME(LC_COLLATE))
		      ? sv_cmp_locale_flags(left, right, 0)
		      :
#endif
                        sv_cmp_flags(left, right, 0);
      SETi( cmp );
      RETURN;
    }
}

PP(pp_bit_and)
{
    dSP; dATARGET;
    tryAMAGICbin_MG(band_amg, AMGf_assign);
    {
      dPOPTOPssrl;
      if (SvNIOKp(left) || SvNIOKp(right)) {
	const bool left_ro_nonnum  = !SvNIOKp(left) && SvREADONLY(left);
	const bool right_ro_nonnum = !SvNIOKp(right) && SvREADONLY(right);
	if (PL_op->op_private & HINT_INTEGER) {
	  const IV i = SvIV_nomg(left) & SvIV_nomg(right);
	  SETi(i);
	}
	else {
	  const UV u = SvUV_nomg(left) & SvUV_nomg(right);
	  SETu(u);
	}
	if (left_ro_nonnum && left != TARG) SvNIOK_off(left);
	if (right_ro_nonnum) SvNIOK_off(right);
      }
      else {
	do_vop(PL_op->op_type, TARG, left, right);
	SETTARG;
      }
      RETURN;
    }
}

PP(pp_nbit_and)
{
    dSP;
    tryAMAGICbin_MG(band_amg, AMGf_assign|AMGf_numarg);
    {
	dATARGET; dPOPTOPssrl;
	if (PL_op->op_private & HINT_INTEGER) {
	  const IV i = SvIV_nomg(left) & SvIV_nomg(right);
	  SETi(i);
	}
	else {
	  const UV u = SvUV_nomg(left) & SvUV_nomg(right);
	  SETu(u);
	}
    }
    RETURN;
}

PP(pp_sbit_and)
{
    dSP;
    tryAMAGICbin_MG(sband_amg, AMGf_assign);
    {
	dATARGET; dPOPTOPssrl;
	do_vop(OP_BIT_AND, TARG, left, right);
	RETSETTARG;
    }
}

/* also used for: pp_bit_xor() */

PP(pp_bit_or)
{
    dSP; dATARGET;
    const int op_type = PL_op->op_type;

    tryAMAGICbin_MG((op_type == OP_BIT_OR ? bor_amg : bxor_amg), AMGf_assign);
    {
      dPOPTOPssrl;
      if (SvNIOKp(left) || SvNIOKp(right)) {
	const bool left_ro_nonnum  = !SvNIOKp(left) && SvREADONLY(left);
	const bool right_ro_nonnum = !SvNIOKp(right) && SvREADONLY(right);
	if (PL_op->op_private & HINT_INTEGER) {
	  const IV l = (USE_LEFT(left) ? SvIV_nomg(left) : 0);
	  const IV r = SvIV_nomg(right);
	  const IV result = op_type == OP_BIT_OR ? (l | r) : (l ^ r);
	  SETi(result);
	}
	else {
	  const UV l = (USE_LEFT(left) ? SvUV_nomg(left) : 0);
	  const UV r = SvUV_nomg(right);
	  const UV result = op_type == OP_BIT_OR ? (l | r) : (l ^ r);
	  SETu(result);
	}
	if (left_ro_nonnum && left != TARG) SvNIOK_off(left);
	if (right_ro_nonnum) SvNIOK_off(right);
      }
      else {
	do_vop(op_type, TARG, left, right);
	SETTARG;
      }
      RETURN;
    }
}

/* also used for: pp_nbit_xor() */

PP(pp_nbit_or)
{
    dSP;
    const int op_type = PL_op->op_type;

    tryAMAGICbin_MG((op_type == OP_NBIT_OR ? bor_amg : bxor_amg),
		    AMGf_assign|AMGf_numarg);
    {
	dATARGET; dPOPTOPssrl;
	if (PL_op->op_private & HINT_INTEGER) {
	  const IV l = (USE_LEFT(left) ? SvIV_nomg(left) : 0);
	  const IV r = SvIV_nomg(right);
	  const IV result = op_type == OP_NBIT_OR ? (l | r) : (l ^ r);
	  SETi(result);
	}
	else {
	  const UV l = (USE_LEFT(left) ? SvUV_nomg(left) : 0);
	  const UV r = SvUV_nomg(right);
	  const UV result = op_type == OP_NBIT_OR ? (l | r) : (l ^ r);
	  SETu(result);
	}
    }
    RETURN;
}

/* also used for: pp_sbit_xor() */

PP(pp_sbit_or)
{
    dSP;
    const int op_type = PL_op->op_type;

    tryAMAGICbin_MG((op_type == OP_SBIT_OR ? sbor_amg : sbxor_amg),
		    AMGf_assign);
    {
	dATARGET; dPOPTOPssrl;
	do_vop(op_type == OP_SBIT_OR ? OP_BIT_OR : OP_BIT_XOR, TARG, left,
	       right);
	RETSETTARG;
    }
}

PERL_STATIC_INLINE bool
S_negate_string(pTHX)
{
    dTARGET; dSP;
    STRLEN len;
    const char *s;
    SV * const sv = TOPs;
    if (!SvPOKp(sv) || SvNIOK(sv) || (!SvPOK(sv) && SvNIOKp(sv)))
	return FALSE;
    s = SvPV_nomg_const(sv, len);
    if (isIDFIRST(*s)) {
	sv_setpvs(TARG, "-");
	sv_catsv(TARG, sv);
    }
    else if (*s == '+' || (*s == '-' && !looks_like_number(sv))) {
	sv_setsv_nomg(TARG, sv);
	*SvPV_force_nomg(TARG, len) = *s == '-' ? '+' : '-';
    }
    else return FALSE;
    SETTARG;
    return TRUE;
}

PP(pp_negate)
{
    dSP; dTARGET;
    tryAMAGICun_MG(neg_amg, AMGf_numeric);
    if (S_negate_string(aTHX)) return NORMAL;
    {
	SV * const sv = TOPs;

	if (SvIOK(sv)) {
	    /* It's publicly an integer */
	oops_its_an_int:
	    if (SvIsUV(sv)) {
		if (SvIVX(sv) == IV_MIN) {
		    /* 2s complement assumption. */
                    SETi(SvIVX(sv));	/* special case: -((UV)IV_MAX+1) ==
                                           IV_MIN */
                    return NORMAL;
		}
		else if (SvUVX(sv) <= IV_MAX) {
		    SETi(-SvIVX(sv));
		    return NORMAL;
		}
	    }
	    else if (SvIVX(sv) != IV_MIN) {
		SETi(-SvIVX(sv));
		return NORMAL;
	    }
#ifdef PERL_PRESERVE_IVUV
	    else {
		SETu((UV)IV_MIN);
		return NORMAL;
	    }
#endif
	}
	if (SvNIOKp(sv) && (SvNIOK(sv) || !SvPOK(sv)))
	    SETn(-SvNV_nomg(sv));
	else if (SvPOKp(sv) && SvIV_please_nomg(sv))
		  goto oops_its_an_int;
	else
	    SETn(-SvNV_nomg(sv));
    }
    return NORMAL;
}

PP(pp_not)
{
    dSP;
    tryAMAGICun_MG(not_amg, AMGf_set);
    *PL_stack_sp = boolSV(!SvTRUE_nomg(*PL_stack_sp));
    return NORMAL;
}

static void
S_scomplement(pTHX_ SV *targ, SV *sv)
{
	U8 *tmps;
	I32 anum;
	STRLEN len;

	sv_copypv_nomg(TARG, sv);
	tmps = (U8*)SvPV_nomg(TARG, len);
	anum = len;
	if (SvUTF8(TARG)) {
	  /* Calculate exact length, let's not estimate. */
	  STRLEN targlen = 0;
	  STRLEN l;
	  UV nchar = 0;
	  UV nwide = 0;
	  U8 * const send = tmps + len;
	  U8 * const origtmps = tmps;
	  const UV utf8flags = UTF8_ALLOW_ANYUV;

	  while (tmps < send) {
	    const UV c = utf8n_to_uvchr(tmps, send-tmps, &l, utf8flags);
	    tmps += l;
	    targlen += UVCHR_SKIP(~c);
	    nchar++;
	    if (c > 0xff)
		nwide++;
	  }

	  /* Now rewind strings and write them. */
	  tmps = origtmps;

	  if (nwide) {
	      U8 *result;
	      U8 *p;

              Perl_ck_warner_d(aTHX_ packWARN(WARN_DEPRECATED),
                        deprecated_above_ff_msg, PL_op_desc[PL_op->op_type]);
	      Newx(result, targlen + 1, U8);
	      p = result;
	      while (tmps < send) {
		  const UV c = utf8n_to_uvchr(tmps, send-tmps, &l, utf8flags);
		  tmps += l;
		  p = uvchr_to_utf8_flags(p, ~c, UNICODE_ALLOW_ANY);
	      }
	      *p = '\0';
	      sv_usepvn_flags(TARG, (char*)result, targlen,
			      SV_HAS_TRAILING_NUL);
	      SvUTF8_on(TARG);
	  }
	  else {
	      U8 *result;
	      U8 *p;

	      Newx(result, nchar + 1, U8);
	      p = result;
	      while (tmps < send) {
		  const U8 c = (U8)utf8n_to_uvchr(tmps, send-tmps, &l, utf8flags);
		  tmps += l;
		  *p++ = ~c;
	      }
	      *p = '\0';
	      sv_usepvn_flags(TARG, (char*)result, nchar, SV_HAS_TRAILING_NUL);
	      SvUTF8_off(TARG);
	  }
	  return;
	}
#ifdef LIBERAL
	{
	    long *tmpl;
	    for ( ; anum && (unsigned long)tmps % sizeof(long); anum--, tmps++)
		*tmps = ~*tmps;
	    tmpl = (long*)tmps;
	    for ( ; anum >= (I32)sizeof(long); anum -= (I32)sizeof(long), tmpl++)
		*tmpl = ~*tmpl;
	    tmps = (U8*)tmpl;
	}
#endif
	for ( ; anum > 0; anum--, tmps++)
	    *tmps = ~*tmps;
}

PP(pp_complement)
{
    dSP; dTARGET;
    tryAMAGICun_MG(compl_amg, AMGf_numeric);
    {
      dTOPss;
      if (SvNIOKp(sv)) {
	if (PL_op->op_private & HINT_INTEGER) {
	  const IV i = ~SvIV_nomg(sv);
	  SETi(i);
	}
	else {
	  const UV u = ~SvUV_nomg(sv);
	  SETu(u);
	}
      }
      else {
	S_scomplement(aTHX_ TARG, sv);
	SETTARG;
      }
      return NORMAL;
    }
}

PP(pp_ncomplement)
{
    dSP;
    tryAMAGICun_MG(compl_amg, AMGf_numeric|AMGf_numarg);
    {
	dTARGET; dTOPss;
	if (PL_op->op_private & HINT_INTEGER) {
	  const IV i = ~SvIV_nomg(sv);
	  SETi(i);
	}
	else {
	  const UV u = ~SvUV_nomg(sv);
	  SETu(u);
	}
    }
    return NORMAL;
}

PP(pp_scomplement)
{
    dSP;
    tryAMAGICun_MG(scompl_amg, AMGf_numeric);
    {
	dTARGET; dTOPss;
	S_scomplement(aTHX_ TARG, sv);
	SETTARG;
	return NORMAL;
    }
}

/* integer versions of some of the above */

PP(pp_i_multiply)
{
    dSP; dATARGET;
    tryAMAGICbin_MG(mult_amg, AMGf_assign);
    {
      dPOPTOPiirl_nomg;
      SETi( left * right );
      RETURN;
    }
}

PP(pp_i_divide)
{
    IV num;
    dSP; dATARGET;
    tryAMAGICbin_MG(div_amg, AMGf_assign);
    {
      dPOPTOPssrl;
      IV value = SvIV_nomg(right);
      if (value == 0)
	  DIE(aTHX_ "Illegal division by zero");
      num = SvIV_nomg(left);

      /* avoid FPE_INTOVF on some platforms when num is IV_MIN */
      if (value == -1)
          value = - num;
      else
          value = num / value;
      SETi(value);
      RETURN;
    }
}

PP(pp_i_modulo)
{
     /* This is the vanilla old i_modulo. */
     dSP; dATARGET;
     tryAMAGICbin_MG(modulo_amg, AMGf_assign);
     {
	  dPOPTOPiirl_nomg;
	  if (!right)
	       DIE(aTHX_ "Illegal modulus zero");
	  /* avoid FPE_INTOVF on some platforms when left is IV_MIN */
	  if (right == -1)
	      SETi( 0 );
	  else
	      SETi( left % right );
	  RETURN;
     }
}

#if defined(__GLIBC__) && IVSIZE == 8 \
    && ( __GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ < 8))

PP(pp_i_modulo_glibc_bugfix)
{
     /* This is the i_modulo with the workaround for the _moddi3 bug
      * in (at least) glibc 2.2.5 (the PERL_ABS() the workaround).
      * See below for pp_i_modulo. */
     dSP; dATARGET;
     tryAMAGICbin_MG(modulo_amg, AMGf_assign);
     {
	  dPOPTOPiirl_nomg;
	  if (!right)
	       DIE(aTHX_ "Illegal modulus zero");
	  /* avoid FPE_INTOVF on some platforms when left is IV_MIN */
	  if (right == -1)
	      SETi( 0 );
	  else
	      SETi( left % PERL_ABS(right) );
	  RETURN;
     }
}
#endif

PP(pp_i_add)
{
    dSP; dATARGET;
    tryAMAGICbin_MG(add_amg, AMGf_assign);
    {
      dPOPTOPiirl_ul_nomg;
      SETi( left + right );
      RETURN;
    }
}

PP(pp_i_subtract)
{
    dSP; dATARGET;
    tryAMAGICbin_MG(subtr_amg, AMGf_assign);
    {
      dPOPTOPiirl_ul_nomg;
      SETi( left - right );
      RETURN;
    }
}

PP(pp_i_lt)
{
    dSP;
    tryAMAGICbin_MG(lt_amg, AMGf_set);
    {
      dPOPTOPiirl_nomg;
      SETs(boolSV(left < right));
      RETURN;
    }
}

PP(pp_i_gt)
{
    dSP;
    tryAMAGICbin_MG(gt_amg, AMGf_set);
    {
      dPOPTOPiirl_nomg;
      SETs(boolSV(left > right));
      RETURN;
    }
}

PP(pp_i_le)
{
    dSP;
    tryAMAGICbin_MG(le_amg, AMGf_set);
    {
      dPOPTOPiirl_nomg;
      SETs(boolSV(left <= right));
      RETURN;
    }
}

PP(pp_i_ge)
{
    dSP;
    tryAMAGICbin_MG(ge_amg, AMGf_set);
    {
      dPOPTOPiirl_nomg;
      SETs(boolSV(left >= right));
      RETURN;
    }
}

PP(pp_i_eq)
{
    dSP;
    tryAMAGICbin_MG(eq_amg, AMGf_set);
    {
      dPOPTOPiirl_nomg;
      SETs(boolSV(left == right));
      RETURN;
    }
}

PP(pp_i_ne)
{
    dSP;
    tryAMAGICbin_MG(ne_amg, AMGf_set);
    {
      dPOPTOPiirl_nomg;
      SETs(boolSV(left != right));
      RETURN;
    }
}

PP(pp_i_ncmp)
{
    dSP; dTARGET;
    tryAMAGICbin_MG(ncmp_amg, 0);
    {
      dPOPTOPiirl_nomg;
      I32 value;

      if (left > right)
	value = 1;
      else if (left < right)
	value = -1;
      else
	value = 0;
      SETi(value);
      RETURN;
    }
}

PP(pp_i_negate)
{
    dSP; dTARGET;
    tryAMAGICun_MG(neg_amg, 0);
    if (S_negate_string(aTHX)) return NORMAL;
    {
	SV * const sv = TOPs;
	IV const i = SvIV_nomg(sv);
	SETi(-i);
	return NORMAL;
    }
}

/* High falutin' math. */

PP(pp_atan2)
{
    dSP; dTARGET;
    tryAMAGICbin_MG(atan2_amg, 0);
    {
      dPOPTOPnnrl_nomg;
      SETn(Perl_atan2(left, right));
      RETURN;
    }
}


/* also used for: pp_cos() pp_exp() pp_log() pp_sqrt() */

PP(pp_sin)
{
    dSP; dTARGET;
    int amg_type = fallback_amg;
    const char *neg_report = NULL;
    const int op_type = PL_op->op_type;

    switch (op_type) {
    case OP_SIN:  amg_type = sin_amg; break;
    case OP_COS:  amg_type = cos_amg; break;
    case OP_EXP:  amg_type = exp_amg; break;
    case OP_LOG:  amg_type = log_amg;  neg_report = "log";  break;
    case OP_SQRT: amg_type = sqrt_amg; neg_report = "sqrt"; break;
    }

    assert(amg_type != fallback_amg);

    tryAMAGICun_MG(amg_type, 0);
    {
      SV * const arg = TOPs;
      const NV value = SvNV_nomg(arg);
#ifdef NV_NAN
      NV result = NV_NAN;
#else
      NV result = 0.0;
#endif
      if (neg_report) { /* log or sqrt */
	  if (
#if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
	      ! Perl_isnan(value) &&
#endif
	      (op_type == OP_LOG ? (value <= 0.0) : (value < 0.0))) {
	      SET_NUMERIC_STANDARD();
	      /* diag_listed_as: Can't take log of %g */
	      DIE(aTHX_ "Can't take %s of %" NVgf, neg_report, value);
	  }
      }
      switch (op_type) {
      default:
      case OP_SIN:  result = Perl_sin(value);  break;
      case OP_COS:  result = Perl_cos(value);  break;
      case OP_EXP:  result = Perl_exp(value);  break;
      case OP_LOG:  result = Perl_log(value);  break;
      case OP_SQRT: result = Perl_sqrt(value); break;
      }
      SETn(result);
      return NORMAL;
    }
}

/* Support Configure command-line overrides for rand() functions.
   After 5.005, perhaps we should replace this by Configure support
   for drand48(), random(), or rand().  For 5.005, though, maintain
   compatibility by calling rand() but allow the user to override it.
   See INSTALL for details.  --Andy Dougherty  15 July 1998
*/
/* Now it's after 5.005, and Configure supports drand48() and random(),
   in addition to rand().  So the overrides should not be needed any more.
   --Jarkko Hietaniemi	27 September 1998
 */

PP(pp_rand)
{
    if (!PL_srand_called) {
	(void)seedDrand01((Rand_seed_t)seed());
	PL_srand_called = TRUE;
    }
    {
	dSP;
	NV value;
    
	if (MAXARG < 1)
	{
	    EXTEND(SP, 1);
	    value = 1.0;
	}
	else {
	    SV * const sv = POPs;
	    if(!sv)
		value = 1.0;
	    else
		value = SvNV(sv);
	}
    /* 1 of 2 things can be carried through SvNV, SP or TARG, SP was carried */
#if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
	if (! Perl_isnan(value) && value == 0.0)
#else
	if (value == 0.0)
#endif
	    value = 1.0;
	{
	    dTARGET;
	    PUSHs(TARG);
	    PUTBACK;
	    value *= Drand01();
	    sv_setnv_mg(TARG, value);
	}
    }
    return NORMAL;
}

PP(pp_srand)
{
    dSP; dTARGET;
    UV anum;

    if (MAXARG >= 1 && (TOPs || POPs)) {
        SV *top;
        char *pv;
        STRLEN len;
        int flags;

        top = POPs;
        pv = SvPV(top, len);
        flags = grok_number(pv, len, &anum);

        if (!(flags & IS_NUMBER_IN_UV)) {
            Perl_ck_warner_d(aTHX_ packWARN(WARN_OVERFLOW),
                             "Integer overflow in srand");
            anum = UV_MAX;
        }
    }
    else {
        anum = seed();
    }

    (void)seedDrand01((Rand_seed_t)anum);
    PL_srand_called = TRUE;
    if (anum)
	XPUSHu(anum);
    else {
	/* Historically srand always returned true. We can avoid breaking
	   that like this:  */
	sv_setpvs(TARG, "0 but true");
	XPUSHTARG;
    }
    RETURN;
}

PP(pp_int)
{
    dSP; dTARGET;
    tryAMAGICun_MG(int_amg, AMGf_numeric);
    {
      SV * const sv = TOPs;
      const IV iv = SvIV_nomg(sv);
      /* XXX it's arguable that compiler casting to IV might be subtly
	 different from modf (for numbers inside (IV_MIN,UV_MAX)) in which
	 else preferring IV has introduced a subtle behaviour change bug. OTOH
	 relying on floating point to be accurate is a bug.  */

      if (!SvOK(sv)) {
        SETu(0);
      }
      else if (SvIOK(sv)) {
	if (SvIsUV(sv))
	    SETu(SvUV_nomg(sv));
	else
	    SETi(iv);
      }
      else {
	  const NV value = SvNV_nomg(sv);
	  if (UNLIKELY(Perl_isinfnan(value)))
	      SETn(value);
	  else if (value >= 0.0) {
	      if (value < (NV)UV_MAX + 0.5) {
		  SETu(U_V(value));
	      } else {
		  SETn(Perl_floor(value));
	      }
	  }
	  else {
	      if (value > (NV)IV_MIN - 0.5) {
		  SETi(I_V(value));
	      } else {
		  SETn(Perl_ceil(value));
	      }
	  }
      }
    }
    return NORMAL;
}

PP(pp_abs)
{
    dSP; dTARGET;
    tryAMAGICun_MG(abs_amg, AMGf_numeric);
    {
      SV * const sv = TOPs;
      /* This will cache the NV value if string isn't actually integer  */
      const IV iv = SvIV_nomg(sv);

      if (!SvOK(sv)) {
        SETu(0);
      }
      else if (SvIOK(sv)) {
	/* IVX is precise  */
	if (SvIsUV(sv)) {
	  SETu(SvUV_nomg(sv));	/* force it to be numeric only */
	} else {
	  if (iv >= 0) {
	    SETi(iv);
	  } else {
	    if (iv != IV_MIN) {
	      SETi(-iv);
	    } else {
	      /* 2s complement assumption. Also, not really needed as
		 IV_MIN and -IV_MIN should both be %100...00 and NV-able  */
	      SETu((UV)IV_MIN);
	    }
	  }
	}
      } else{
	const NV value = SvNV_nomg(sv);
	if (value < 0.0)
	  SETn(-value);
	else
	  SETn(value);
      }
    }
    return NORMAL;
}


/* also used for: pp_hex() */

PP(pp_oct)
{
    dSP; dTARGET;
    const char *tmps;
    I32 flags = PERL_SCAN_ALLOW_UNDERSCORES;
    STRLEN len;
    NV result_nv;
    UV result_uv;
    SV* const sv = TOPs;

    tmps = (SvPV_const(sv, len));
    if (DO_UTF8(sv)) {
	 /* If Unicode, try to downgrade
	  * If not possible, croak. */
	 SV* const tsv = sv_2mortal(newSVsv(sv));
	
	 SvUTF8_on(tsv);
	 sv_utf8_downgrade(tsv, FALSE);
	 tmps = SvPV_const(tsv, len);
    }
    if (PL_op->op_type == OP_HEX)
	goto hex;

    while (*tmps && len && isSPACE(*tmps))
        tmps++, len--;
    if (*tmps == '0')
        tmps++, len--;
    if (isALPHA_FOLD_EQ(*tmps, 'x')) {
    hex:
        result_uv = grok_hex (tmps, &len, &flags, &result_nv);
    }
    else if (isALPHA_FOLD_EQ(*tmps, 'b'))
        result_uv = grok_bin (tmps, &len, &flags, &result_nv);
    else
        result_uv = grok_oct (tmps, &len, &flags, &result_nv);

    if (flags & PERL_SCAN_GREATER_THAN_UV_MAX) {
        SETn(result_nv);
    }
    else {
        SETu(result_uv);
    }
    return NORMAL;
}

/* String stuff. */

PP(pp_length)
{
    dSP; dTARGET;
    SV * const sv = TOPs;

    U32 in_bytes = IN_BYTES;
    /* simplest case shortcut */
    /* turn off SVf_UTF8 in tmp flags if HINT_BYTES on*/
    U32 svflags = (SvFLAGS(sv) ^ (in_bytes << 26)) & (SVf_POK|SVs_GMG|SVf_UTF8);
    STATIC_ASSERT_STMT(HINT_BYTES == 0x00000008 && SVf_UTF8 == 0x20000000 && (SVf_UTF8 == HINT_BYTES << 26));
    SETs(TARG);

    if(LIKELY(svflags == SVf_POK))
        goto simple_pv;
    if(svflags & SVs_GMG)
        mg_get(sv);
    if (SvOK(sv)) {
	if (!IN_BYTES) /* reread to avoid using an C auto/register */
	    sv_setiv(TARG, (IV)sv_len_utf8_nomg(sv));
	else
	{
	    STRLEN len;
            /* unrolled SvPV_nomg_const(sv,len) */
            if(SvPOK_nog(sv)){
                simple_pv:
                len = SvCUR(sv);
            } else  {
                (void)sv_2pv_flags(sv, &len, 0|SV_CONST_RETURN);
            }
	    sv_setiv(TARG, (IV)(len));
	}
    } else {
	if (!SvPADTMP(TARG)) {
            sv_set_undef(TARG);
	} else { /* TARG is on stack at this point and is overwriten by SETs.
                   This branch is the odd one out, so put TARG by default on
                   stack earlier to let local SP go out of liveness sooner */
            SETs(&PL_sv_undef);
            goto no_set_magic;
        }
    }
    SvSETMAGIC(TARG);
    no_set_magic:
    return NORMAL; /* no putback, SP didn't move in this opcode */
}

/* Returns false if substring is completely outside original string.
   No length is indicated by len_iv = 0 and len_is_uv = 0.  len_is_uv must
   always be true for an explicit 0.
*/
bool
Perl_translate_substr_offsets( STRLEN curlen, IV pos1_iv,
				bool pos1_is_uv, IV len_iv,
				bool len_is_uv, STRLEN *posp,
				STRLEN *lenp)
{
    IV pos2_iv;
    int    pos2_is_uv;

    PERL_ARGS_ASSERT_TRANSLATE_SUBSTR_OFFSETS;

    if (!pos1_is_uv && pos1_iv < 0 && curlen) {
	pos1_is_uv = curlen-1 > ~(UV)pos1_iv;
	pos1_iv += curlen;
    }
    if ((pos1_is_uv || pos1_iv > 0) && (UV)pos1_iv > curlen)
	return FALSE;

    if (len_iv || len_is_uv) {
	if (!len_is_uv && len_iv < 0) {
	    pos2_iv = curlen + len_iv;
	    if (curlen)
		pos2_is_uv = curlen-1 > ~(UV)len_iv;
	    else
		pos2_is_uv = 0;
	} else {  /* len_iv >= 0 */
	    if (!pos1_is_uv && pos1_iv < 0) {
		pos2_iv = pos1_iv + len_iv;
		pos2_is_uv = (UV)len_iv > (UV)IV_MAX;
	    } else {
		if ((UV)len_iv > curlen-(UV)pos1_iv)
		    pos2_iv = curlen;
		else
		    pos2_iv = pos1_iv+len_iv;
		pos2_is_uv = 1;
	    }
	}
    }
    else {
	pos2_iv = curlen;
	pos2_is_uv = 1;
    }

    if (!pos2_is_uv && pos2_iv < 0) {
	if (!pos1_is_uv && pos1_iv < 0)
	    return FALSE;
	pos2_iv = 0;
    }
    else if (!pos1_is_uv && pos1_iv < 0)
	pos1_iv = 0;

    if ((UV)pos2_iv < (UV)pos1_iv)
	pos2_iv = pos1_iv;
    if ((UV)pos2_iv > curlen)
	pos2_iv = curlen;

    /* pos1_iv and pos2_iv both in 0..curlen, so the cast is safe */
    *posp = (STRLEN)( (UV)pos1_iv );
    *lenp = (STRLEN)( (UV)pos2_iv - (UV)pos1_iv );

    return TRUE;
}

PP(pp_substr)
{
    dSP; dTARGET;
    SV *sv;
    STRLEN curlen;
    STRLEN utf8_curlen;
    SV *   pos_sv;
    IV     pos1_iv;
    int    pos1_is_uv;
    SV *   len_sv;
    IV     len_iv = 0;
    int    len_is_uv = 0;
    I32 lvalue = PL_op->op_flags & OPf_MOD || LVRET;
    const bool rvalue = (GIMME_V != G_VOID);
    const char *tmps;
    SV *repl_sv = NULL;
    const char *repl = NULL;
    STRLEN repl_len;
    int num_args = PL_op->op_private & 7;
    bool repl_need_utf8_upgrade = FALSE;

    if (num_args > 2) {
	if (num_args > 3) {
	  if(!(repl_sv = POPs)) num_args--;
	}
	if ((len_sv = POPs)) {
	    len_iv    = SvIV(len_sv);
	    len_is_uv = len_iv ? SvIOK_UV(len_sv) : 1;
	}
	else num_args--;
    }
    pos_sv     = POPs;
    pos1_iv    = SvIV(pos_sv);
    pos1_is_uv = SvIOK_UV(pos_sv);
    sv = POPs;
    if (PL_op->op_private & OPpSUBSTR_REPL_FIRST) {
	assert(!repl_sv);
	repl_sv = POPs;
    }
    if (lvalue && !repl_sv) {
	SV * ret;
	ret = sv_2mortal(newSV_type(SVt_PVLV));  /* Not TARG RT#67838 */
	sv_magic(ret, NULL, PERL_MAGIC_substr, NULL, 0);
	LvTYPE(ret) = 'x';
	LvTARG(ret) = SvREFCNT_inc_simple(sv);
	LvTARGOFF(ret) =
	    pos1_is_uv || pos1_iv >= 0
		? (STRLEN)(UV)pos1_iv
		: (LvFLAGS(ret) |= 1, (STRLEN)(UV)-pos1_iv);
	LvTARGLEN(ret) =
	    len_is_uv || len_iv > 0
		? (STRLEN)(UV)len_iv
		: (LvFLAGS(ret) |= 2, (STRLEN)(UV)-len_iv);

	PUSHs(ret);    /* avoid SvSETMAGIC here */
	RETURN;
    }
    if (repl_sv) {
	repl = SvPV_const(repl_sv, repl_len);
	SvGETMAGIC(sv);
	if (SvROK(sv))
	    Perl_ck_warner(aTHX_ packWARN(WARN_SUBSTR),
			    "Attempt to use reference as lvalue in substr"
	    );
	tmps = SvPV_force_nomg(sv, curlen);
	if (DO_UTF8(repl_sv) && repl_len) {
	    if (!DO_UTF8(sv)) {
		sv_utf8_upgrade_nomg(sv);
		curlen = SvCUR(sv);
	    }
	}
	else if (DO_UTF8(sv))
	    repl_need_utf8_upgrade = TRUE;
    }
    else tmps = SvPV_const(sv, curlen);
    if (DO_UTF8(sv)) {
        utf8_curlen = sv_or_pv_len_utf8(sv, tmps, curlen);
	if (utf8_curlen == curlen)
	    utf8_curlen = 0;
	else
	    curlen = utf8_curlen;
    }
    else
	utf8_curlen = 0;

    {
	STRLEN pos, len, byte_len, byte_pos;

	if (!translate_substr_offsets(
		curlen, pos1_iv, pos1_is_uv, len_iv, len_is_uv, &pos, &len
	)) goto bound_fail;

	byte_len = len;
	byte_pos = utf8_curlen
	    ? sv_or_pv_pos_u2b(sv, tmps, pos, &byte_len) : pos;

	tmps += byte_pos;

	if (rvalue) {
	    SvTAINTED_off(TARG);			/* decontaminate */
	    SvUTF8_off(TARG);			/* decontaminate */
	    sv_setpvn(TARG, tmps, byte_len);
#ifdef USE_LOCALE_COLLATE
	    sv_unmagic(TARG, PERL_MAGIC_collxfrm);
#endif
	    if (utf8_curlen)
		SvUTF8_on(TARG);
	}

	if (repl) {
	    SV* repl_sv_copy = NULL;

	    if (repl_need_utf8_upgrade) {
		repl_sv_copy = newSVsv(repl_sv);
		sv_utf8_upgrade(repl_sv_copy);
		repl = SvPV_const(repl_sv_copy, repl_len);
	    }
	    if (!SvOK(sv))
                SvPVCLEAR(sv);
	    sv_insert_flags(sv, byte_pos, byte_len, repl, repl_len, 0);
	    SvREFCNT_dec(repl_sv_copy);
	}
    }
    if (PL_op->op_private & OPpSUBSTR_REPL_FIRST)
	SP++;
    else if (rvalue) {
	SvSETMAGIC(TARG);
	PUSHs(TARG);
    }
    RETURN;

  bound_fail:
    if (repl)
	Perl_croak(aTHX_ "substr outside of string");
    Perl_ck_warner(aTHX_ packWARN(WARN_SUBSTR), "substr outside of string");
    RETPUSHUNDEF;
}

PP(pp_vec)
{
    dSP;
    const IV size   = POPi;
    const IV offset = POPi;
    SV * const src = POPs;
    const I32 lvalue = PL_op->op_flags & OPf_MOD || LVRET;
    SV * ret;

    if (lvalue) {			/* it's an lvalue! */
	ret = sv_2mortal(newSV_type(SVt_PVLV));  /* Not TARG RT#67838 */
	sv_magic(ret, NULL, PERL_MAGIC_vec, NULL, 0);
	LvTYPE(ret) = 'v';
	LvTARG(ret) = SvREFCNT_inc_simple(src);
	LvTARGOFF(ret) = offset;
	LvTARGLEN(ret) = size;
    }
    else {
	dTARGET;
	SvTAINTED_off(TARG);		/* decontaminate */
	ret = TARG;
    }

    sv_setuv(ret, do_vecget(src, offset, size));
    if (!lvalue)
	SvSETMAGIC(ret);
    PUSHs(ret);
    RETURN;
}


/* also used for: pp_rindex() */

PP(pp_index)
{
    dSP; dTARGET;
    SV *big;
    SV *little;
    SV *temp = NULL;
    STRLEN biglen;
    STRLEN llen = 0;
    SSize_t offset = 0;
    SSize_t retval;
    const char *big_p;
    const char *little_p;
    bool big_utf8;
    bool little_utf8;
    const bool is_index = PL_op->op_type == OP_INDEX;
    const bool threeargs = MAXARG >= 3 && (TOPs || ((void)POPs,0));

    if (threeargs)
	offset = POPi;
    little = POPs;
    big = POPs;
    big_p = SvPV_const(big, biglen);
    little_p = SvPV_const(little, llen);

    big_utf8 = DO_UTF8(big);
    little_utf8 = DO_UTF8(little);
    if (big_utf8 ^ little_utf8) {
	/* One needs to be upgraded.  */
	if (little_utf8) {
	    /* Well, maybe instead we might be able to downgrade the small
	       string?  */
	    char * const pv = (char*)bytes_from_utf8((U8 *)little_p, &llen,
						     &little_utf8);
	    if (little_utf8) {
		/* If the large string is ISO-8859-1, and it's not possible to
		   convert the small string to ISO-8859-1, then there is no
		   way that it could be found anywhere by index.  */
		retval = -1;
		goto fail;
	    }

	    /* At this point, pv is a malloc()ed string. So donate it to temp
	       to ensure it will get free()d  */
	    little = temp = newSV(0);
	    sv_usepvn(temp, pv, llen);
	    little_p = SvPVX(little);
	} else {
	    temp = newSVpvn(little_p, llen);

	    sv_utf8_upgrade(temp);
	    little = temp;
	    little_p = SvPV_const(little, llen);
	}
    }
    if (SvGAMAGIC(big)) {
	/* Life just becomes a lot easier if I use a temporary here.
	   Otherwise I need to avoid calls to sv_pos_u2b(), which (dangerously)
	   will trigger magic and overloading again, as will fbm_instr()
	*/
	big = newSVpvn_flags(big_p, biglen,
			     SVs_TEMP | (big_utf8 ? SVf_UTF8 : 0));
	big_p = SvPVX(big);
    }
    if (SvGAMAGIC(little) || (is_index && !SvOK(little))) {
	/* index && SvOK() is a hack. fbm_instr() calls SvPV_const, which will
	   warn on undef, and we've already triggered a warning with the
	   SvPV_const some lines above. We can't remove that, as we need to
	   call some SvPV to trigger overloading early and find out if the
	   string is UTF-8.
	   This is all getting too messy. The API isn't quite clean enough,
	   because data access has side effects.
	*/
	little = newSVpvn_flags(little_p, llen,
				SVs_TEMP | (little_utf8 ? SVf_UTF8 : 0));
	little_p = SvPVX(little);
    }

    if (!threeargs)
	offset = is_index ? 0 : biglen;
    else {
	if (big_utf8 && offset > 0)
	    offset = sv_pos_u2b_flags(big, offset, 0, SV_CONST_RETURN);
	if (!is_index)
	    offset += llen;
    }
    if (offset < 0)
	offset = 0;
    else if (offset > (SSize_t)biglen)
	offset = biglen;
    if (!(little_p = is_index
	  ? fbm_instr((unsigned char*)big_p + offset,
		      (unsigned char*)big_p + biglen, little, 0)
	  : rninstr(big_p,  big_p  + offset,
		    little_p, little_p + llen)))
	retval = -1;
    else {
	retval = little_p - big_p;
	if (retval > 1 && big_utf8)
	    retval = sv_pos_b2u_flags(big, retval, SV_CONST_RETURN);
    }
    SvREFCNT_dec(temp);
 fail:
    PUSHi(retval);
    RETURN;
}

PP(pp_sprintf)
{
    dSP; dMARK; dORIGMARK; dTARGET;
    SvTAINTED_off(TARG);
    do_sprintf(TARG, SP-MARK, MARK+1);
    TAINT_IF(SvTAINTED(TARG));
    SP = ORIGMARK;
    PUSHTARG;
    RETURN;
}

PP(pp_ord)
{
    dSP; dTARGET;

    SV *argsv = TOPs;
    STRLEN len;
    const U8 *s = (U8*)SvPV_const(argsv, len);

    SETu(DO_UTF8(argsv)
           ? utf8n_to_uvchr(s, len, 0, UTF8_ALLOW_ANYUV)
           : (UV)(*s));

    return NORMAL;
}

PP(pp_chr)
{
    dSP; dTARGET;
    char *tmps;
    UV value;
    SV *top = TOPs;

    SvGETMAGIC(top);
    if (UNLIKELY(SvAMAGIC(top)))
	top = sv_2num(top);
    if (UNLIKELY(isinfnansv(top)))
        Perl_croak(aTHX_ "Cannot chr %" NVgf, SvNV(top));
    else {
        if (!IN_BYTES /* under bytes, chr(-1) eq chr(0xff), etc. */
            && ((SvIOKp(top) && !SvIsUV(top) && SvIV_nomg(top) < 0)
                ||
                ((SvNOKp(top) || (SvOK(top) && !SvIsUV(top)))
                 && SvNV_nomg(top) < 0.0)))
        {
	    if (ckWARN(WARN_UTF8)) {
		if (SvGMAGICAL(top)) {
		    SV *top2 = sv_newmortal();
		    sv_setsv_nomg(top2, top);
		    top = top2;
		}
                Perl_warner(aTHX_ packWARN(WARN_UTF8),
                            "Invalid negative number (%" SVf ") in chr", SVfARG(top));
            }
            value = UNICODE_REPLACEMENT;
        } else {
            value = SvUV_nomg(top);
        }
    }

    SvUPGRADE(TARG,SVt_PV);

    if (value > 255 && !IN_BYTES) {
	SvGROW(TARG, (STRLEN)UVCHR_SKIP(value)+1);
	tmps = (char*)uvchr_to_utf8_flags((U8*)SvPVX(TARG), value, 0);
	SvCUR_set(TARG, tmps - SvPVX_const(TARG));
	*tmps = '\0';
	(void)SvPOK_only(TARG);
	SvUTF8_on(TARG);
	SETTARG;
	return NORMAL;
    }

    SvGROW(TARG,2);
    SvCUR_set(TARG, 1);
    tmps = SvPVX(TARG);
    *tmps++ = (char)value;
    *tmps = '\0';
    (void)SvPOK_only(TARG);

    SETTARG;
    return NORMAL;
}

PP(pp_crypt)
{
#ifdef HAS_CRYPT
    dSP; dTARGET;
    dPOPTOPssrl;
    STRLEN len;
    const char *tmps = SvPV_const(left, len);

    if (DO_UTF8(left)) {
         /* If Unicode, try to downgrade.
	  * If not possible, croak.
	  * Yes, we made this up.  */
	 SV* const tsv = newSVpvn_flags(tmps, len, SVf_UTF8|SVs_TEMP);

	 sv_utf8_downgrade(tsv, FALSE);
	 tmps = SvPV_const(tsv, len);
    }
#   ifdef USE_ITHREADS
#     ifdef HAS_CRYPT_R
    if (!PL_reentrant_buffer->_crypt_struct_buffer) {
      /* This should be threadsafe because in ithreads there is only
       * one thread per interpreter.  If this would not be true,
       * we would need a mutex to protect this malloc. */
        PL_reentrant_buffer->_crypt_struct_buffer =
	  (struct crypt_data *)safemalloc(sizeof(struct crypt_data));
#if defined(__GLIBC__) || defined(__EMX__)
	if (PL_reentrant_buffer->_crypt_struct_buffer) {
	    PL_reentrant_buffer->_crypt_struct_buffer->initialized = 0;
	    /* work around glibc-2.2.5 bug */
	    PL_reentrant_buffer->_crypt_struct_buffer->current_saltbits = 0;
	}
#endif
    }
#     endif /* HAS_CRYPT_R */
#   endif /* USE_ITHREADS */
#   ifdef FCRYPT
    sv_setpv(TARG, fcrypt(tmps, SvPV_nolen_const(right)));
#   else
    sv_setpv(TARG, PerlProc_crypt(tmps, SvPV_nolen_const(right)));
#   endif
    SvUTF8_off(TARG);
    SETTARG;
    RETURN;
#else
    DIE(aTHX_
      "The crypt() function is unimplemented due to excessive paranoia.");
#endif
}

/* Generally UTF-8 and UTF-EBCDIC are indistinguishable at this level.  So 
 * most comments below say UTF-8, when in fact they mean UTF-EBCDIC as well */


/* also used for: pp_lcfirst() */

PP(pp_ucfirst)
{
    /* Actually is both lcfirst() and ucfirst().  Only the first character
     * changes.  This means that possibly we can change in-place, ie., just
     * take the source and change that one character and store it back, but not
     * if read-only etc, or if the length changes */

    dSP;
    SV *source = TOPs;
    STRLEN slen; /* slen is the byte length of the whole SV. */
    STRLEN need;
    SV *dest;
    bool inplace;   /* ? Convert first char only, in-place */
    bool doing_utf8 = FALSE;		   /* ? using utf8 */
    bool convert_source_to_utf8 = FALSE;   /* ? need to convert */
    const int op_type = PL_op->op_type;
    const U8 *s;
    U8 *d;
    U8 tmpbuf[UTF8_MAXBYTES_CASE+1];
    STRLEN ulen;    /* ulen is the byte length of the original Unicode character
		     * stored as UTF-8 at s. */
    STRLEN tculen;  /* tculen is the byte length of the freshly titlecased (or
		     * lowercased) character stored in tmpbuf.  May be either
		     * UTF-8 or not, but in either case is the number of bytes */

    s = (const U8*)SvPV_const(source, slen);

    /* We may be able to get away with changing only the first character, in
     * place, but not if read-only, etc.  Later we may discover more reasons to
     * not convert in-place. */
    inplace = !SvREADONLY(source) && SvPADTMP(source);

    /* First calculate what the changed first character should be.  This affects
     * whether we can just swap it out, leaving the rest of the string unchanged,
     * or even if have to convert the dest to UTF-8 when the source isn't */

    if (! slen) {   /* If empty */
	need = 1; /* still need a trailing NUL */
	ulen = 0;
    }
    else if (DO_UTF8(source)) {	/* Is the source utf8? */
	doing_utf8 = TRUE;
        ulen = UTF8SKIP(s);
        if (op_type == OP_UCFIRST) {
#ifdef USE_LOCALE_CTYPE
	    _to_utf8_title_flags(s, tmpbuf, &tculen, IN_LC_RUNTIME(LC_CTYPE));
#else
	    _to_utf8_title_flags(s, tmpbuf, &tculen, 0);
#endif
	}
        else {
#ifdef USE_LOCALE_CTYPE
	    _to_utf8_lower_flags(s, tmpbuf, &tculen, IN_LC_RUNTIME(LC_CTYPE));
#else
	    _to_utf8_lower_flags(s, tmpbuf, &tculen, 0);
#endif
	}

        /* we can't do in-place if the length changes.  */
        if (ulen != tculen) inplace = FALSE;
        need = slen + 1 - ulen + tculen;
    }
    else { /* Non-zero length, non-UTF-8,  Need to consider locale and if
	    * latin1 is treated as caseless.  Note that a locale takes
	    * precedence */ 
	ulen = 1;	/* Original character is 1 byte */
	tculen = 1;	/* Most characters will require one byte, but this will
			 * need to be overridden for the tricky ones */
	need = slen + 1;

	if (op_type == OP_LCFIRST) {

	    /* lower case the first letter: no trickiness for any character */
#ifdef USE_LOCALE_CTYPE
            if (IN_LC_RUNTIME(LC_CTYPE)) {
                _CHECK_AND_WARN_PROBLEMATIC_LOCALE;
                *tmpbuf = toLOWER_LC(*s);
            }
            else
#endif
            {
                *tmpbuf = (IN_UNI_8_BIT)
                          ? toLOWER_LATIN1(*s)
                          : toLOWER(*s);
            }
	}
#ifdef USE_LOCALE_CTYPE
	/* is ucfirst() */
	else if (IN_LC_RUNTIME(LC_CTYPE)) {
            if (IN_UTF8_CTYPE_LOCALE) {
                goto do_uni_rules;
            }

            _CHECK_AND_WARN_PROBLEMATIC_LOCALE;
            *tmpbuf = (U8) toUPPER_LC(*s); /* This would be a bug if any
                                              locales have upper and title case
                                              different */
	}
#endif
	else if (! IN_UNI_8_BIT) {
	    *tmpbuf = toUPPER(*s);	/* Returns caseless for non-ascii, or
					 * on EBCDIC machines whatever the
					 * native function does */
	}
        else {
            /* Here, is ucfirst non-UTF-8, not in locale (unless that locale is
             * UTF-8, which we treat as not in locale), and cased latin1 */
	    UV title_ord;
#ifdef USE_LOCALE_CTYPE
      do_uni_rules:
#endif

	    title_ord = _to_upper_title_latin1(*s, tmpbuf, &tculen, 's');
	    if (tculen > 1) {
		assert(tculen == 2);

                /* If the result is an upper Latin1-range character, it can
                 * still be represented in one byte, which is its ordinal */
		if (UTF8_IS_DOWNGRADEABLE_START(*tmpbuf)) {
		    *tmpbuf = (U8) title_ord;
		    tculen = 1;
		}
		else {
                    /* Otherwise it became more than one ASCII character (in
                     * the case of LATIN_SMALL_LETTER_SHARP_S) or changed to
                     * beyond Latin1, so the number of bytes changed, so can't
                     * replace just the first character in place. */
		    inplace = FALSE;

                    /* If the result won't fit in a byte, the entire result
                     * will have to be in UTF-8.  Assume worst case sizing in
                     * conversion. (all latin1 characters occupy at most two
                     * bytes in utf8) */
		    if (title_ord > 255) {
			doing_utf8 = TRUE;
			convert_source_to_utf8 = TRUE;
			need = slen * 2 + 1;

                        /* The (converted) UTF-8 and UTF-EBCDIC lengths of all
                         * (both) characters whose title case is above 255 is
                         * 2. */
			ulen = 2;
		    }
                    else { /* LATIN_SMALL_LETTER_SHARP_S expands by 1 byte */
			need = slen + 1 + 1;
		    }
		}
	    }
	} /* End of use Unicode (Latin1) semantics */
    } /* End of changing the case of the first character */

    /* Here, have the first character's changed case stored in tmpbuf.  Ready to
     * generate the result */
    if (inplace) {

	/* We can convert in place.  This means we change just the first
	 * character without disturbing the rest; no need to grow */
	dest = source;
	s = d = (U8*)SvPV_force_nomg(source, slen);
    } else {
	dTARGET;

	dest = TARG;

	/* Here, we can't convert in place; we earlier calculated how much
	 * space we will need, so grow to accommodate that */
	SvUPGRADE(dest, SVt_PV);
	d = (U8*)SvGROW(dest, need);
	(void)SvPOK_only(dest);

	SETs(dest);
    }

    if (doing_utf8) {
	if (! inplace) {
	    if (! convert_source_to_utf8) {

		/* Here  both source and dest are in UTF-8, but have to create
		 * the entire output.  We initialize the result to be the
		 * title/lower cased first character, and then append the rest
		 * of the string. */
		sv_setpvn(dest, (char*)tmpbuf, tculen);
		if (slen > ulen) {
		    sv_catpvn(dest, (char*)(s + ulen), slen - ulen);
		}
	    }
	    else {
		const U8 *const send = s + slen;

		/* Here the dest needs to be in UTF-8, but the source isn't,
		 * except we earlier UTF-8'd the first character of the source
		 * into tmpbuf.  First put that into dest, and then append the
		 * rest of the source, converting it to UTF-8 as we go. */

		/* Assert tculen is 2 here because the only two characters that
		 * get to this part of the code have 2-byte UTF-8 equivalents */
		*d++ = *tmpbuf;
		*d++ = *(tmpbuf + 1);
		s++;	/* We have just processed the 1st char */

		for (; s < send; s++) {
		    d = uvchr_to_utf8(d, *s);
		}
		*d = '\0';
		SvCUR_set(dest, d - (U8*)SvPVX_const(dest));
	    }
	    SvUTF8_on(dest);
	}
	else {   /* in-place UTF-8.  Just overwrite the first character */
	    Copy(tmpbuf, d, tculen, U8);
	    SvCUR_set(dest, need - 1);
	}

    }
    else {  /* Neither source nor dest are in or need to be UTF-8 */
	if (slen) {
	    if (inplace) {  /* in-place, only need to change the 1st char */
		*d = *tmpbuf;
	    }
	    else {	/* Not in-place */

		/* Copy the case-changed character(s) from tmpbuf */
		Copy(tmpbuf, d, tculen, U8);
		d += tculen - 1; /* Code below expects d to point to final
				  * character stored */
	    }
	}
	else {	/* empty source */
	    /* See bug #39028: Don't taint if empty  */
	    *d = *s;
	}

	/* In a "use bytes" we don't treat the source as UTF-8, but, still want
	 * the destination to retain that flag */
	if (SvUTF8(source) && ! IN_BYTES)
	    SvUTF8_on(dest);

	if (!inplace) {	/* Finish the rest of the string, unchanged */
	    /* This will copy the trailing NUL  */
	    Copy(s + 1, d + 1, slen, U8);
	    SvCUR_set(dest, need - 1);
	}
    }
#ifdef USE_LOCALE_CTYPE
    if (IN_LC_RUNTIME(LC_CTYPE)) {
        TAINT;
        SvTAINTED_on(dest);
    }
#endif
    if (dest != source && SvTAINTED(source))
	SvTAINT(dest);
    SvSETMAGIC(dest);
    return NORMAL;
}

/* There's so much setup/teardown code common between uc and lc, I wonder if
   it would be worth merging the two, and just having a switch outside each
   of the three tight loops.  There is less and less commonality though */
PP(pp_uc)
{
    dSP;
    SV *source = TOPs;
    STRLEN len;
    STRLEN min;
    SV *dest;
    const U8 *s;
    U8 *d;

    SvGETMAGIC(source);

    if (   SvPADTMP(source)
	&& !SvREADONLY(source) && SvPOK(source)
	&& !DO_UTF8(source)
	&& (
#ifdef USE_LOCALE_CTYPE
            (IN_LC_RUNTIME(LC_CTYPE))
            ? ! IN_UTF8_CTYPE_LOCALE
            :
#endif
              ! IN_UNI_8_BIT))
    {

        /* We can convert in place.  The reason we can't if in UNI_8_BIT is to
         * make the loop tight, so we overwrite the source with the dest before
         * looking at it, and we need to look at the original source
         * afterwards.  There would also need to be code added to handle
         * switching to not in-place in midstream if we run into characters
         * that change the length.  Since being in locale overrides UNI_8_BIT,
         * that latter becomes irrelevant in the above test; instead for
         * locale, the size can't normally change, except if the locale is a
         * UTF-8 one */
	dest = source;
	s = d = (U8*)SvPV_force_nomg(source, len);
	min = len + 1;
    } else {
	dTARGET;

	dest = TARG;

	s = (const U8*)SvPV_nomg_const(source, len);
	min = len + 1;

	SvUPGRADE(dest, SVt_PV);
	d = (U8*)SvGROW(dest, min);
	(void)SvPOK_only(dest);

	SETs(dest);
    }

    /* Overloaded values may have toggled the UTF-8 flag on source, so we need
       to check DO_UTF8 again here.  */

    if (DO_UTF8(source)) {
	const U8 *const send = s + len;
	U8 tmpbuf[UTF8_MAXBYTES_CASE+1];

	/* All occurrences of these are to be moved to follow any other marks.
	 * This is context-dependent.  We may not be passed enough context to
	 * move the iota subscript beyond all of them, but we do the best we can
	 * with what we're given.  The result is always better than if we
	 * hadn't done this.  And, the problem would only arise if we are
	 * passed a character without all its combining marks, which would be
	 * the caller's mistake.  The information this is based on comes from a
	 * comment in Unicode SpecialCasing.txt, (and the Standard's text
	 * itself) and so can't be checked properly to see if it ever gets
	 * revised.  But the likelihood of it changing is remote */
	bool in_iota_subscript = FALSE;

	while (s < send) {
	    STRLEN u;
	    STRLEN ulen;
	    UV uv;
	    if (in_iota_subscript && ! _is_utf8_mark(s)) {

		/* A non-mark.  Time to output the iota subscript */
		Copy(GREEK_CAPITAL_LETTER_IOTA_UTF8, d, capital_iota_len, U8);
                d += capital_iota_len;
		in_iota_subscript = FALSE;
            }

            /* Then handle the current character.  Get the changed case value
             * and copy it to the output buffer */

            u = UTF8SKIP(s);
#ifdef USE_LOCALE_CTYPE
            uv = _to_utf8_upper_flags(s, tmpbuf, &ulen, IN_LC_RUNTIME(LC_CTYPE));
#else
            uv = _to_utf8_upper_flags(s, tmpbuf, &ulen, 0);
#endif
#define GREEK_CAPITAL_LETTER_IOTA 0x0399
#define COMBINING_GREEK_YPOGEGRAMMENI 0x0345
            if (uv == GREEK_CAPITAL_LETTER_IOTA
                && utf8_to_uvchr_buf(s, send, 0) == COMBINING_GREEK_YPOGEGRAMMENI)
            {
                in_iota_subscript = TRUE;
            }
            else {
                if (ulen > u && (SvLEN(dest) < (min += ulen - u))) {
                    /* If the eventually required minimum size outgrows the
                     * available space, we need to grow. */
                    const UV o = d - (U8*)SvPVX_const(dest);

                    /* If someone uppercases one million U+03B0s we SvGROW()
                     * one million times.  Or we could try guessing how much to
                     * allocate without allocating too much.  Such is life.
                     * See corresponding comment in lc code for another option
                     * */
                    d = o + (U8*) SvGROW(dest, min);
                }
                Copy(tmpbuf, d, ulen, U8);
                d += ulen;
            }
            s += u;
	}
	if (in_iota_subscript) {
            Copy(GREEK_CAPITAL_LETTER_IOTA_UTF8, d, capital_iota_len, U8);
            d += capital_iota_len;
	}
	SvUTF8_on(dest);
	*d = '\0';

	SvCUR_set(dest, d - (U8*)SvPVX_const(dest));
    }
    else {	/* Not UTF-8 */
	if (len) {
	    const U8 *const send = s + len;

	    /* Use locale casing if in locale; regular style if not treating
	     * latin1 as having case; otherwise the latin1 casing.  Do the
	     * whole thing in a tight loop, for speed, */
#ifdef USE_LOCALE_CTYPE
	    if (IN_LC_RUNTIME(LC_CTYPE)) {
                if (IN_UTF8_CTYPE_LOCALE) {
                    goto do_uni_rules;
                }
                _CHECK_AND_WARN_PROBLEMATIC_LOCALE;
		for (; s < send; d++, s++)
                    *d = (U8) toUPPER_LC(*s);
	    }
	    else
#endif
                 if (! IN_UNI_8_BIT) {
		for (; s < send; d++, s++) {
		    *d = toUPPER(*s);
		}
	    }
	    else {
#ifdef USE_LOCALE_CTYPE
          do_uni_rules:
#endif
		for (; s < send; d++, s++) {
		    *d = toUPPER_LATIN1_MOD(*s);
		    if (LIKELY(*d != LATIN_SMALL_LETTER_Y_WITH_DIAERESIS)) {
                        continue;
                    }

		    /* The mainstream case is the tight loop above.  To avoid
		     * extra tests in that, all three characters that require
		     * special handling are mapped by the MOD to the one tested
		     * just above.  
		     * Use the source to distinguish between the three cases */

#if    UNICODE_MAJOR_VERSION > 2                                        \
   || (UNICODE_MAJOR_VERSION == 2 && UNICODE_DOT_VERSION >= 1		\
                                  && UNICODE_DOT_DOT_VERSION >= 8)
		    if (*s == LATIN_SMALL_LETTER_SHARP_S) {

			/* uc() of this requires 2 characters, but they are
			 * ASCII.  If not enough room, grow the string */
			if (SvLEN(dest) < ++min) {	
			    const UV o = d - (U8*)SvPVX_const(dest);
			    d = o + (U8*) SvGROW(dest, min);
			}
			*d++ = 'S'; *d = 'S'; /* upper case is 'SS' */
			continue;   /* Back to the tight loop; still in ASCII */
		    }
#endif

		    /* The other two special handling characters have their
		     * upper cases outside the latin1 range, hence need to be
		     * in UTF-8, so the whole result needs to be in UTF-8.  So,
		     * here we are somewhere in the middle of processing a
		     * non-UTF-8 string, and realize that we will have to convert
		     * the whole thing to UTF-8.  What to do?  There are
		     * several possibilities.  The simplest to code is to
		     * convert what we have so far, set a flag, and continue on
		     * in the loop.  The flag would be tested each time through
		     * the loop, and if set, the next character would be
		     * converted to UTF-8 and stored.  But, I (khw) didn't want
		     * to slow down the mainstream case at all for this fairly
		     * rare case, so I didn't want to add a test that didn't
		     * absolutely have to be there in the loop, besides the
		     * possibility that it would get too complicated for
		     * optimizers to deal with.  Another possibility is to just
		     * give up, convert the source to UTF-8, and restart the
		     * function that way.  Another possibility is to convert
		     * both what has already been processed and what is yet to
		     * come separately to UTF-8, then jump into the loop that
		     * handles UTF-8.  But the most efficient time-wise of the
		     * ones I could think of is what follows, and turned out to
		     * not require much extra code.  */

		    /* Convert what we have so far into UTF-8, telling the
		     * function that we know it should be converted, and to
		     * allow extra space for what we haven't processed yet.
		     * Assume the worst case space requirements for converting
		     * what we haven't processed so far: that it will require
		     * two bytes for each remaining source character, plus the
		     * NUL at the end.  This may cause the string pointer to
		     * move, so re-find it. */

		    len = d - (U8*)SvPVX_const(dest);
		    SvCUR_set(dest, len);
		    len = sv_utf8_upgrade_flags_grow(dest,
						SV_GMAGIC|SV_FORCE_UTF8_UPGRADE,
						(send -s) * 2 + 1);
		    d = (U8*)SvPVX(dest) + len;

		    /* Now process the remainder of the source, converting to
		     * upper and UTF-8.  If a resulting byte is invariant in
		     * UTF-8, output it as-is, otherwise convert to UTF-8 and
		     * append it to the output. */
		    for (; s < send; s++) {
			(void) _to_upper_title_latin1(*s, d, &len, 'S');
			d += len;
		    }

		    /* Here have processed the whole source; no need to continue
		     * with the outer loop.  Each character has been converted
		     * to upper case and converted to UTF-8 */

		    break;
		} /* End of processing all latin1-style chars */
	    } /* End of processing all chars */
	} /* End of source is not empty */

	if (source != dest) {
	    *d = '\0';  /* Here d points to 1 after last char, add NUL */
	    SvCUR_set(dest, d - (U8*)SvPVX_const(dest));
	}
    } /* End of isn't utf8 */
#ifdef USE_LOCALE_CTYPE
    if (IN_LC_RUNTIME(LC_CTYPE)) {
        TAINT;
        SvTAINTED_on(dest);
    }
#endif
    if (dest != source && SvTAINTED(source))
	SvTAINT(dest);
    SvSETMAGIC(dest);
    return NORMAL;
}

PP(pp_lc)
{
    dSP;
    SV *source = TOPs;
    STRLEN len;
    STRLEN min;
    SV *dest;
    const U8 *s;
    U8 *d;

    SvGETMAGIC(source);

    if (   SvPADTMP(source)
	&& !SvREADONLY(source) && SvPOK(source)
	&& !DO_UTF8(source)) {

	/* We can convert in place, as lowercasing anything in the latin1 range
	 * (or else DO_UTF8 would have been on) doesn't lengthen it */
	dest = source;
	s = d = (U8*)SvPV_force_nomg(source, len);
	min = len + 1;
    } else {
	dTARGET;

	dest = TARG;

	s = (const U8*)SvPV_nomg_const(source, len);
	min = len + 1;

	SvUPGRADE(dest, SVt_PV);
	d = (U8*)SvGROW(dest, min);
	(void)SvPOK_only(dest);

	SETs(dest);
    }

    /* Overloaded values may have toggled the UTF-8 flag on source, so we need
       to check DO_UTF8 again here.  */

    if (DO_UTF8(source)) {
	const U8 *const send = s + len;
	U8 tmpbuf[UTF8_MAXBYTES_CASE+1];

	while (s < send) {
	    const STRLEN u = UTF8SKIP(s);
	    STRLEN ulen;

#ifdef USE_LOCALE_CTYPE
	    _to_utf8_lower_flags(s, tmpbuf, &ulen, IN_LC_RUNTIME(LC_CTYPE));
#else
	    _to_utf8_lower_flags(s, tmpbuf, &ulen, 0);
#endif

	    /* Here is where we would do context-sensitive actions.  See the
	     * commit message for 86510fb15 for why there isn't any */

	    if (ulen > u && (SvLEN(dest) < (min += ulen - u))) {

		/* If the eventually required minimum size outgrows the
		 * available space, we need to grow. */
		const UV o = d - (U8*)SvPVX_const(dest);

		/* If someone lowercases one million U+0130s we SvGROW() one
		 * million times.  Or we could try guessing how much to
		 * allocate without allocating too much.  Such is life.
		 * Another option would be to grow an extra byte or two more
		 * each time we need to grow, which would cut down the million
		 * to 500K, with little waste */
		d = o + (U8*) SvGROW(dest, min);
	    }

	    /* Copy the newly lowercased letter to the output buffer we're
	     * building */
	    Copy(tmpbuf, d, ulen, U8);
	    d += ulen;
	    s += u;
	}   /* End of looping through the source string */
	SvUTF8_on(dest);
	*d = '\0';
	SvCUR_set(dest, d - (U8*)SvPVX_const(dest));
    } else {	/* Not utf8 */
	if (len) {
	    const U8 *const send = s + len;

	    /* Use locale casing if in locale; regular style if not treating
	     * latin1 as having case; otherwise the latin1 casing.  Do the
	     * whole thing in a tight loop, for speed, */
#ifdef USE_LOCALE_CTYPE
            if (IN_LC_RUNTIME(LC_CTYPE)) {
                _CHECK_AND_WARN_PROBLEMATIC_LOCALE;
		for (; s < send; d++, s++)
		    *d = toLOWER_LC(*s);
            }
	    else
#endif
            if (! IN_UNI_8_BIT) {
		for (; s < send; d++, s++) {
		    *d = toLOWER(*s);
		}
	    }
	    else {
		for (; s < send; d++, s++) {
		    *d = toLOWER_LATIN1(*s);
		}
	    }
	}
	if (source != dest) {
	    *d = '\0';
	    SvCUR_set(dest, d - (U8*)SvPVX_const(dest));
	}
    }
#ifdef USE_LOCALE_CTYPE
    if (IN_LC_RUNTIME(LC_CTYPE)) {
        TAINT;
        SvTAINTED_on(dest);
    }
#endif
    if (dest != source && SvTAINTED(source))
	SvTAINT(dest);
    SvSETMAGIC(dest);
    return NORMAL;
}

PP(pp_quotemeta)
{
    dSP; dTARGET;
    SV * const sv = TOPs;
    STRLEN len;
    const char *s = SvPV_const(sv,len);

    SvUTF8_off(TARG);				/* decontaminate */
    if (len) {
	char *d;
	SvUPGRADE(TARG, SVt_PV);
	SvGROW(TARG, (len * 2) + 1);
	d = SvPVX(TARG);
	if (DO_UTF8(sv)) {
	    while (len) {
		STRLEN ulen = UTF8SKIP(s);
		bool to_quote = FALSE;

		if (UTF8_IS_INVARIANT(*s)) {
		    if (_isQUOTEMETA(*s)) {
			to_quote = TRUE;
		    }
		}
		else if (UTF8_IS_DOWNGRADEABLE_START(*s)) {
		    if (
#ifdef USE_LOCALE_CTYPE
		    /* In locale, we quote all non-ASCII Latin1 chars.
		     * Otherwise use the quoting rules */
		    
		    IN_LC_RUNTIME(LC_CTYPE)
			||
#endif
			_isQUOTEMETA(EIGHT_BIT_UTF8_TO_NATIVE(*s, *(s + 1))))
		    {
			to_quote = TRUE;
		    }
		}
		else if (is_QUOTEMETA_high(s)) {
		    to_quote = TRUE;
		}

		if (to_quote) {
		    *d++ = '\\';
		}
		if (ulen > len)
		    ulen = len;
		len -= ulen;
		while (ulen--)
		    *d++ = *s++;
	    }
	    SvUTF8_on(TARG);
	}
	else if (IN_UNI_8_BIT) {
	    while (len--) {
		if (_isQUOTEMETA(*s))
		    *d++ = '\\';
		*d++ = *s++;
	    }
	}
	else {
	    /* For non UNI_8_BIT (and hence in locale) just quote all \W
	     * including everything above ASCII */
	    while (len--) {
		if (!isWORDCHAR_A(*s))
		    *d++ = '\\';
		*d++ = *s++;
	    }
	}
	*d = '\0';
	SvCUR_set(TARG, d - SvPVX_const(TARG));
	(void)SvPOK_only_UTF8(TARG);
    }
    else
	sv_setpvn(TARG, s, len);
    SETTARG;
    return NORMAL;
}

PP(pp_fc)
{
    dTARGET;
    dSP;
    SV *source = TOPs;
    STRLEN len;
    STRLEN min;
    SV *dest;
    const U8 *s;
    const U8 *send;
    U8 *d;
    U8 tmpbuf[UTF8_MAXBYTES_CASE + 1];
#if    UNICODE_MAJOR_VERSION > 3 /* no multifolds in early Unicode */   \
   || (UNICODE_MAJOR_VERSION == 3 && (   UNICODE_DOT_VERSION > 0)       \
                                      || UNICODE_DOT_DOT_VERSION > 0)
    const bool full_folding = TRUE; /* This variable is here so we can easily
                                       move to more generality later */
#else
    const bool full_folding = FALSE;
#endif
    const U8 flags = ( full_folding      ? FOLD_FLAGS_FULL   : 0 )
#ifdef USE_LOCALE_CTYPE
                   | ( IN_LC_RUNTIME(LC_CTYPE) ? FOLD_FLAGS_LOCALE : 0 )
#endif
    ;

    /* This is a facsimile of pp_lc, but with a thousand bugs thanks to me.
     * You are welcome(?) -Hugmeir
     */

    SvGETMAGIC(source);

    dest = TARG;

    if (SvOK(source)) {
        s = (const U8*)SvPV_nomg_const(source, len);
    } else {
        if (ckWARN(WARN_UNINITIALIZED))
	    report_uninit(source);
	s = (const U8*)"";
	len = 0;
    }

    min = len + 1;

    SvUPGRADE(dest, SVt_PV);
    d = (U8*)SvGROW(dest, min);
    (void)SvPOK_only(dest);

    SETs(dest);

    send = s + len;
    if (DO_UTF8(source)) { /* UTF-8 flagged string. */
        while (s < send) {
            const STRLEN u = UTF8SKIP(s);
            STRLEN ulen;

            _to_utf8_fold_flags(s, tmpbuf, &ulen, flags);

            if (ulen > u && (SvLEN(dest) < (min += ulen - u))) {
                const UV o = d - (U8*)SvPVX_const(dest);
                d = o + (U8*) SvGROW(dest, min);
            }

            Copy(tmpbuf, d, ulen, U8);
            d += ulen;
            s += u;
        }
        SvUTF8_on(dest);
    } /* Unflagged string */
    else if (len) {
#ifdef USE_LOCALE_CTYPE
        if ( IN_LC_RUNTIME(LC_CTYPE) ) { /* Under locale */
            if (IN_UTF8_CTYPE_LOCALE) {
                goto do_uni_folding;
            }
            _CHECK_AND_WARN_PROBLEMATIC_LOCALE;
            for (; s < send; d++, s++)
                *d = (U8) toFOLD_LC(*s);
        }
        else
#endif
        if ( !IN_UNI_8_BIT ) { /* Under nothing, or bytes */
            for (; s < send; d++, s++)
                *d = toFOLD(*s);
        }
        else {
#ifdef USE_LOCALE_CTYPE
      do_uni_folding:
#endif
            /* For ASCII and the Latin-1 range, there's only two troublesome
             * folds, \x{DF} (\N{LATIN SMALL LETTER SHARP S}), which under full
             * casefolding becomes 'ss'; and \x{B5} (\N{MICRO SIGN}), which
             * under any fold becomes \x{3BC} (\N{GREEK SMALL LETTER MU}) --
             * For the rest, the casefold is their lowercase.  */
            for (; s < send; d++, s++) {
                if (*s == MICRO_SIGN) {
                    /* \N{MICRO SIGN}'s casefold is \N{GREEK SMALL LETTER MU},
                     * which is outside of the latin-1 range. There's a couple
                     * of ways to deal with this -- khw discusses them in
                     * pp_lc/uc, so go there :) What we do here is upgrade what
                     * we had already casefolded, then enter an inner loop that
                     * appends the rest of the characters as UTF-8. */
                    len = d - (U8*)SvPVX_const(dest);
                    SvCUR_set(dest, len);
                    len = sv_utf8_upgrade_flags_grow(dest,
                                                SV_GMAGIC|SV_FORCE_UTF8_UPGRADE,
						/* The max expansion for latin1
						 * chars is 1 byte becomes 2 */
                                                (send -s) * 2 + 1);
                    d = (U8*)SvPVX(dest) + len;

                    Copy(GREEK_SMALL_LETTER_MU_UTF8, d, small_mu_len, U8);
                    d += small_mu_len;
                    s++;
                    for (; s < send; s++) {
                        STRLEN ulen;
                        UV fc = _to_uni_fold_flags(*s, tmpbuf, &ulen, flags);
                        if UVCHR_IS_INVARIANT(fc) {
                            if (full_folding
                                && *s == LATIN_SMALL_LETTER_SHARP_S)
                            {
                                *d++ = 's';
                                *d++ = 's';
                            }
                            else
                                *d++ = (U8)fc;
                        }
                        else {
                            Copy(tmpbuf, d, ulen, U8);
                            d += ulen;
                        }
                    }
                    break;
                }
                else if (full_folding && *s == LATIN_SMALL_LETTER_SHARP_S) {
                    /* Under full casefolding, LATIN SMALL LETTER SHARP S
                     * becomes "ss", which may require growing the SV. */
                    if (SvLEN(dest) < ++min) {
                        const UV o = d - (U8*)SvPVX_const(dest);
                        d = o + (U8*) SvGROW(dest, min);
                     }
                    *(d)++ = 's';
                    *d = 's';
                }
                else { /* If it's not one of those two, the fold is their lower
                          case */
                    *d = toLOWER_LATIN1(*s);
                }
             }
        }
    }
    *d = '\0';
    SvCUR_set(dest, d - (U8*)SvPVX_const(dest));

#ifdef USE_LOCALE_CTYPE
    if (IN_LC_RUNTIME(LC_CTYPE)) {
        TAINT;
        SvTAINTED_on(dest);
    }
#endif
    if (SvTAINTED(source))
	SvTAINT(dest);
    SvSETMAGIC(dest);
    RETURN;
}

/* Arrays. */

PP(pp_aslice)
{
    dSP; dMARK; dORIGMARK;
    AV *const av = MUTABLE_AV(POPs);
    const I32 lval = (PL_op->op_flags & OPf_MOD || LVRET);

    if (SvTYPE(av) == SVt_PVAV) {
	const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
	bool can_preserve = FALSE;

	if (localizing) {
	    MAGIC *mg;
	    HV *stash;

	    can_preserve = SvCANEXISTDELETE(av);
	}

	if (lval && localizing) {
	    SV **svp;
	    SSize_t max = -1;
	    for (svp = MARK + 1; svp <= SP; svp++) {
		const SSize_t elem = SvIV(*svp);
		if (elem > max)
		    max = elem;
	    }
	    if (max > AvMAX(av))
		av_extend(av, max);
	}

	while (++MARK <= SP) {
	    SV **svp;
	    SSize_t elem = SvIV(*MARK);
	    bool preeminent = TRUE;

	    if (localizing && can_preserve) {
		/* If we can determine whether the element exist,
		 * Try to preserve the existenceness of a tied array
		 * element by using EXISTS and DELETE if possible.
		 * Fallback to FETCH and STORE otherwise. */
		preeminent = av_exists(av, elem);
	    }

	    svp = av_fetch(av, elem, lval);
	    if (lval) {
		if (!svp || !*svp)
		    DIE(aTHX_ PL_no_aelem, elem);
		if (localizing) {
		    if (preeminent)
			save_aelem(av, elem, svp);
		    else
			SAVEADELETE(av, elem);
		}
	    }
	    *MARK = svp ? *svp : &PL_sv_undef;
	}
    }
    if (GIMME_V != G_ARRAY) {
	MARK = ORIGMARK;
	*++MARK = SP > ORIGMARK ? *SP : &PL_sv_undef;
	SP = MARK;
    }
    RETURN;
}

PP(pp_kvaslice)
{
    dSP; dMARK;
    AV *const av = MUTABLE_AV(POPs);
    I32 lval = (PL_op->op_flags & OPf_MOD);
    SSize_t items = SP - MARK;

    if (PL_op->op_private & OPpMAYBE_LVSUB) {
       const I32 flags = is_lvalue_sub();
       if (flags) {
           if (!(flags & OPpENTERSUB_INARGS))
               /* diag_listed_as: Can't modify %s in %s */
	       Perl_croak(aTHX_ "Can't modify index/value array slice in list assignment");
	   lval = flags;
       }
    }

    MEXTEND(SP,items);
    while (items > 1) {
	*(MARK+items*2-1) = *(MARK+items);
	items--;
    }
    items = SP-MARK;
    SP += items;

    while (++MARK <= SP) {
        SV **svp;

	svp = av_fetch(av, SvIV(*MARK), lval);
        if (lval) {
            if (!svp || !*svp || *svp == &PL_sv_undef) {
                DIE(aTHX_ PL_no_aelem, SvIV(*MARK));
            }
	    *MARK = sv_mortalcopy(*MARK);
        }
	*++MARK = svp ? *svp : &PL_sv_undef;
    }
    if (GIMME_V != G_ARRAY) {
	MARK = SP - items*2;
	*++MARK = items > 0 ? *SP : &PL_sv_undef;
	SP = MARK;
    }
    RETURN;
}


PP(pp_aeach)
{
    dSP;
    AV *array = MUTABLE_AV(POPs);
    const U8 gimme = GIMME_V;
    IV *iterp = Perl_av_iter_p(aTHX_ array);
    const IV current = (*iterp)++;

    if (current > av_tindex(array)) {
	*iterp = 0;
	if (gimme == G_SCALAR)
	    RETPUSHUNDEF;
	else
	    RETURN;
    }

    EXTEND(SP, 2);
    mPUSHi(current);
    if (gimme == G_ARRAY) {
	SV **const element = av_fetch(array, current, 0);
        PUSHs(element ? *element : &PL_sv_undef);
    }
    RETURN;
}

/* also used for: pp_avalues()*/
PP(pp_akeys)
{
    dSP;
    AV *array = MUTABLE_AV(POPs);
    const U8 gimme = GIMME_V;

    *Perl_av_iter_p(aTHX_ array) = 0;

    if (gimme == G_SCALAR) {
	dTARGET;
	PUSHi(av_tindex(array) + 1);
    }
    else if (gimme == G_ARRAY) {
      if (UNLIKELY(PL_op->op_private & OPpMAYBE_LVSUB)) {
        const I32 flags = is_lvalue_sub();
        if (flags && !(flags & OPpENTERSUB_INARGS))
            /* diag_listed_as: Can't modify %s in %s */
            Perl_croak(aTHX_
                      "Can't modify keys on array in list assignment");
      }
      {
        IV n = Perl_av_len(aTHX_ array);
        IV i;

        EXTEND(SP, n + 1);

	if (  PL_op->op_type == OP_AKEYS
	   || (  PL_op->op_type == OP_AVHVSWITCH
	      && (PL_op->op_private & 3) + OP_AEACH == OP_AKEYS  ))
	{
	    for (i = 0;  i <= n;  i++) {
		mPUSHi(i);
	    }
	}
	else {
	    for (i = 0;  i <= n;  i++) {
		SV *const *const elem = Perl_av_fetch(aTHX_ array, i, 0);
		PUSHs(elem ? *elem : &PL_sv_undef);
	    }
	}
      }
    }
    RETURN;
}

/* Associative arrays. */

PP(pp_each)
{
    dSP;
    HV * hash = MUTABLE_HV(POPs);
    HE *entry;
    const U8 gimme = GIMME_V;

    entry = hv_iternext(hash);

    EXTEND(SP, 2);
    if (entry) {
	SV* const sv = hv_iterkeysv(entry);
	PUSHs(sv);
	if (gimme == G_ARRAY) {
	    SV *val;
	    val = hv_iterval(hash, entry);
	    PUSHs(val);
	}
    }
    else if (gimme == G_SCALAR)
	RETPUSHUNDEF;

    RETURN;
}

STATIC OP *
S_do_delete_local(pTHX)
{
    dSP;
    const U8 gimme = GIMME_V;
    const MAGIC *mg;
    HV *stash;
    const bool sliced = !!(PL_op->op_private & OPpSLICE);
    SV **unsliced_keysv = sliced ? NULL : sp--;
    SV * const osv = POPs;
    SV **mark = sliced ? PL_stack_base + POPMARK : unsliced_keysv-1;
    dORIGMARK;
    const bool tied = SvRMAGICAL(osv)
			    && mg_find((const SV *)osv, PERL_MAGIC_tied);
    const bool can_preserve = SvCANEXISTDELETE(osv);
    const U32 type = SvTYPE(osv);
    SV ** const end = sliced ? SP : unsliced_keysv;

    if (type == SVt_PVHV) {			/* hash element */
	    HV * const hv = MUTABLE_HV(osv);
	    while (++MARK <= end) {
		SV * const keysv = *MARK;
		SV *sv = NULL;
		bool preeminent = TRUE;
		if (can_preserve)
		    preeminent = hv_exists_ent(hv, keysv, 0);
		if (tied) {
		    HE *he = hv_fetch_ent(hv, keysv, 1, 0);
		    if (he)
			sv = HeVAL(he);
		    else
			preeminent = FALSE;
		}
		else {
		    sv = hv_delete_ent(hv, keysv, 0, 0);
		    if (preeminent)
			SvREFCNT_inc_simple_void(sv); /* De-mortalize */
		}
		if (preeminent) {
		    if (!sv) DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
		    save_helem_flags(hv, keysv, &sv, SAVEf_KEEPOLDELEM);
		    if (tied) {
			*MARK = sv_mortalcopy(sv);
			mg_clear(sv);
		    } else
			*MARK = sv;
		}
		else {
		    SAVEHDELETE(hv, keysv);
		    *MARK = &PL_sv_undef;
		}
	    }
    }
    else if (type == SVt_PVAV) {                  /* array element */
	    if (PL_op->op_flags & OPf_SPECIAL) {
		AV * const av = MUTABLE_AV(osv);
		while (++MARK <= end) {
		    SSize_t idx = SvIV(*MARK);
		    SV *sv = NULL;
		    bool preeminent = TRUE;
		    if (can_preserve)
			preeminent = av_exists(av, idx);
		    if (tied) {
			SV **svp = av_fetch(av, idx, 1);
			if (svp)
			    sv = *svp;
			else
			    preeminent = FALSE;
		    }
		    else {
			sv = av_delete(av, idx, 0);
			if (preeminent)
			   SvREFCNT_inc_simple_void(sv); /* De-mortalize */
		    }
		    if (preeminent) {
		        save_aelem_flags(av, idx, &sv, SAVEf_KEEPOLDELEM);
			if (tied) {
			    *MARK = sv_mortalcopy(sv);
			    mg_clear(sv);
			} else
			    *MARK = sv;
		    }
		    else {
		        SAVEADELETE(av, idx);
		        *MARK = &PL_sv_undef;
		    }
		}
	    }
	    else
		DIE(aTHX_ "panic: avhv_delete no longer supported");
    }
    else
	    DIE(aTHX_ "Not a HASH reference");
    if (sliced) {
	if (gimme == G_VOID)
	    SP = ORIGMARK;
	else if (gimme == G_SCALAR) {
	    MARK = ORIGMARK;
	    if (SP > MARK)
		*++MARK = *SP;
	    else
		*++MARK = &PL_sv_undef;
	    SP = MARK;
	}
    }
    else if (gimme != G_VOID)
	PUSHs(*unsliced_keysv);

    RETURN;
}

PP(pp_delete)
{
    dSP;
    U8 gimme;
    I32 discard;

    if (PL_op->op_private & OPpLVAL_INTRO)
	return do_delete_local();

    gimme = GIMME_V;
    discard = (gimme == G_VOID) ? G_DISCARD : 0;

    if (PL_op->op_private & OPpSLICE) {
	dMARK; dORIGMARK;
	HV * const hv = MUTABLE_HV(POPs);
	const U32 hvtype = SvTYPE(hv);
	if (hvtype == SVt_PVHV) {			/* hash element */
	    while (++MARK <= SP) {
		SV * const sv = hv_delete_ent(hv, *MARK, discard, 0);
		*MARK = sv ? sv : &PL_sv_undef;
	    }
	}
	else if (hvtype == SVt_PVAV) {                  /* array element */
            if (PL_op->op_flags & OPf_SPECIAL) {
                while (++MARK <= SP) {
                    SV * const sv = av_delete(MUTABLE_AV(hv), SvIV(*MARK), discard);
                    *MARK = sv ? sv : &PL_sv_undef;
                }
            }
	}
	else
	    DIE(aTHX_ "Not a HASH reference");
	if (discard)
	    SP = ORIGMARK;
	else if (gimme == G_SCALAR) {
	    MARK = ORIGMARK;
	    if (SP > MARK)
		*++MARK = *SP;
	    else
		*++MARK = &PL_sv_undef;
	    SP = MARK;
	}
    }
    else {
	SV *keysv = POPs;
	HV * const hv = MUTABLE_HV(POPs);
	SV *sv = NULL;
	if (SvTYPE(hv) == SVt_PVHV)
	    sv = hv_delete_ent(hv, keysv, discard, 0);
	else if (SvTYPE(hv) == SVt_PVAV) {
	    if (PL_op->op_flags & OPf_SPECIAL)
		sv = av_delete(MUTABLE_AV(hv), SvIV(keysv), discard);
	    else
		DIE(aTHX_ "panic: avhv_delete no longer supported");
	}
	else
	    DIE(aTHX_ "Not a HASH reference");
	if (!sv)
	    sv = &PL_sv_undef;
	if (!discard)
	    PUSHs(sv);
    }
    RETURN;
}

PP(pp_exists)
{
    dSP;
    SV *tmpsv;
    HV *hv;

    if (UNLIKELY( PL_op->op_private & OPpEXISTS_SUB )) {
	GV *gv;
	SV * const sv = POPs;
	CV * const cv = sv_2cv(sv, &hv, &gv, 0);
	if (cv)
	    RETPUSHYES;
	if (gv && isGV(gv) && GvCV(gv) && !GvCVGEN(gv))
	    RETPUSHYES;
	RETPUSHNO;
    }
    tmpsv = POPs;
    hv = MUTABLE_HV(POPs);
    if (LIKELY( SvTYPE(hv) == SVt_PVHV )) {
	if (hv_exists_ent(hv, tmpsv, 0))
	    RETPUSHYES;
    }
    else if (SvTYPE(hv) == SVt_PVAV) {
	if (PL_op->op_flags & OPf_SPECIAL) {		/* array element */
	    if (av_exists(MUTABLE_AV(hv), SvIV(tmpsv)))
		RETPUSHYES;
	}
    }
    else {
	DIE(aTHX_ "Not a HASH reference");
    }
    RETPUSHNO;
}

PP(pp_hslice)
{
    dSP; dMARK; dORIGMARK;
    HV * const hv = MUTABLE_HV(POPs);
    const I32 lval = (PL_op->op_flags & OPf_MOD || LVRET);
    const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
    bool can_preserve = FALSE;

    if (localizing) {
        MAGIC *mg;
        HV *stash;

	if (SvCANEXISTDELETE(hv))
	    can_preserve = TRUE;
    }

    while (++MARK <= SP) {
        SV * const keysv = *MARK;
        SV **svp;
        HE *he;
        bool preeminent = TRUE;

        if (localizing && can_preserve) {
	    /* If we can determine whether the element exist,
             * try to preserve the existenceness of a tied hash
             * element by using EXISTS and DELETE if possible.
             * Fallback to FETCH and STORE otherwise. */
            preeminent = hv_exists_ent(hv, keysv, 0);
        }

        he = hv_fetch_ent(hv, keysv, lval, 0);
        svp = he ? &HeVAL(he) : NULL;

        if (lval) {
            if (!svp || !*svp || *svp == &PL_sv_undef) {
                DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
            }
            if (localizing) {
		if (HvNAME_get(hv) && isGV(*svp))
		    save_gp(MUTABLE_GV(*svp), !(PL_op->op_flags & OPf_SPECIAL));
		else if (preeminent)
		    save_helem_flags(hv, keysv, svp,
			 (PL_op->op_flags & OPf_SPECIAL) ? 0 : SAVEf_SETMAGIC);
		else
		    SAVEHDELETE(hv, keysv);
            }
        }
        *MARK = svp && *svp ? *svp : &PL_sv_undef;
    }
    if (GIMME_V != G_ARRAY) {
	MARK = ORIGMARK;
	*++MARK = SP > ORIGMARK ? *SP : &PL_sv_undef;
	SP = MARK;
    }
    RETURN;
}

PP(pp_kvhslice)
{
    dSP; dMARK;
    HV * const hv = MUTABLE_HV(POPs);
    I32 lval = (PL_op->op_flags & OPf_MOD);
    SSize_t items = SP - MARK;

    if (PL_op->op_private & OPpMAYBE_LVSUB) {
       const I32 flags = is_lvalue_sub();
       if (flags) {
           if (!(flags & OPpENTERSUB_INARGS))
               /* diag_listed_as: Can't modify %s in %s */
	       Perl_croak(aTHX_ "Can't modify key/value hash slice in %s assignment",
				 GIMME_V == G_ARRAY ? "list" : "scalar");
	   lval = flags;
       }
    }

    MEXTEND(SP,items);
    while (items > 1) {
	*(MARK+items*2-1) = *(MARK+items);
	items--;
    }
    items = SP-MARK;
    SP += items;

    while (++MARK <= SP) {
        SV * const keysv = *MARK;
        SV **svp;
        HE *he;

        he = hv_fetch_ent(hv, keysv, lval, 0);
        svp = he ? &HeVAL(he) : NULL;

        if (lval) {
            if (!svp || !*svp || *svp == &PL_sv_undef) {
                DIE(aTHX_ PL_no_helem_sv, SVfARG(keysv));
            }
	    *MARK = sv_mortalcopy(*MARK);
        }
        *++MARK = svp && *svp ? *svp : &PL_sv_undef;
    }
    if (GIMME_V != G_ARRAY) {
	MARK = SP - items*2;
	*++MARK = items > 0 ? *SP : &PL_sv_undef;
	SP = MARK;
    }
    RETURN;
}

/* List operators. */

PP(pp_list)
{
    I32 markidx = POPMARK;
    if (GIMME_V != G_ARRAY) {
	SV **mark = PL_stack_base + markidx;
	dSP;
	if (++MARK <= SP)
	    *MARK = *SP;		/* unwanted list, return last item */
	else
	    *MARK = &PL_sv_undef;
	SP = MARK;
	PUTBACK;
    }
    return NORMAL;
}

PP(pp_lslice)
{
    dSP;
    SV ** const lastrelem = PL_stack_sp;
    SV ** const lastlelem = PL_stack_base + POPMARK;
    SV ** const firstlelem = PL_stack_base + POPMARK + 1;
    SV ** const firstrelem = lastlelem + 1;
    const U8 mod = PL_op->op_flags & OPf_MOD;

    const I32 max = lastrelem - lastlelem;
    SV **lelem;

    if (GIMME_V != G_ARRAY) {
        if (lastlelem < firstlelem) {
            *firstlelem = &PL_sv_undef;
        }
        else {
            I32 ix = SvIV(*lastlelem);
            if (ix < 0)
                ix += max;
            if (ix < 0 || ix >= max)
                *firstlelem = &PL_sv_undef;
            else
                *firstlelem = firstrelem[ix];
        }
        SP = firstlelem;
        RETURN;
    }

    if (max == 0) {
	SP = firstlelem - 1;
	RETURN;
    }

    for (lelem = firstlelem; lelem <= lastlelem; lelem++) {
	I32 ix = SvIV(*lelem);
	if (ix < 0)
	    ix += max;
	if (ix < 0 || ix >= max)
	    *lelem = &PL_sv_undef;
	else {
	    if (!(*lelem = firstrelem[ix]))
		*lelem = &PL_sv_undef;
	    else if (mod && SvPADTMP(*lelem)) {
		*lelem = firstrelem[ix] = sv_mortalcopy(*lelem);
            }
	}
    }
    SP = lastlelem;
    RETURN;
}

PP(pp_anonlist)
{
    dSP; dMARK;
    const I32 items = SP - MARK;
    SV * const av = MUTABLE_SV(av_make(items, MARK+1));
    SP = MARK;
    mXPUSHs((PL_op->op_flags & OPf_SPECIAL)
	    ? newRV_noinc(av) : av);
    RETURN;
}

PP(pp_anonhash)
{
    dSP; dMARK; dORIGMARK;
    HV* const hv = newHV();
    SV* const retval = sv_2mortal( PL_op->op_flags & OPf_SPECIAL
                                    ? newRV_noinc(MUTABLE_SV(hv))
                                    : MUTABLE_SV(hv) );

    while (MARK < SP) {
	SV * const key =
	    (MARK++, SvGMAGICAL(*MARK) ? sv_mortalcopy(*MARK) : *MARK);
	SV *val;
	if (MARK < SP)
	{
	    MARK++;
	    SvGETMAGIC(*MARK);
	    val = newSV(0);
	    sv_setsv_nomg(val, *MARK);
	}
	else
	{
	    Perl_ck_warner(aTHX_ packWARN(WARN_MISC), "Odd number of elements in anonymous hash");
	    val = newSV(0);
	}
	(void)hv_store_ent(hv,key,val,0);
    }
    SP = ORIGMARK;
    XPUSHs(retval);
    RETURN;
}

PP(pp_splice)
{
    dSP; dMARK; dORIGMARK;
    int num_args = (SP - MARK);
    AV *ary = MUTABLE_AV(*++MARK);
    SV **src;
    SV **dst;
    SSize_t i;
    SSize_t offset;
    SSize_t length;
    SSize_t newlen;
    SSize_t after;
    SSize_t diff;
    const MAGIC * const mg = SvTIED_mg((const SV *)ary, PERL_MAGIC_tied);

    if (mg) {
	return Perl_tied_method(aTHX_ SV_CONST(SPLICE), mark - 1, MUTABLE_SV(ary), mg,
				    GIMME_V | TIED_METHOD_ARGUMENTS_ON_STACK,
				    sp - mark);
    }

    SP++;

    if (++MARK < SP) {
	offset = i = SvIV(*MARK);
	if (offset < 0)
	    offset += AvFILLp(ary) + 1;
	if (offset < 0)
	    DIE(aTHX_ PL_no_aelem, i);
	if (++MARK < SP) {
	    length = SvIVx(*MARK++);
	    if (length < 0) {
		length += AvFILLp(ary) - offset + 1;
		if (length < 0)
		    length = 0;
	    }
	}
	else
	    length = AvMAX(ary) + 1;		/* close enough to infinity */
    }
    else {
	offset = 0;
	length = AvMAX(ary) + 1;
    }
    if (offset > AvFILLp(ary) + 1) {
	if (num_args > 2)
	    Perl_ck_warner(aTHX_ packWARN(WARN_MISC), "splice() offset past end of array" );
	offset = AvFILLp(ary) + 1;
    }
    after = AvFILLp(ary) + 1 - (offset + length);
    if (after < 0) {				/* not that much array */
	length += after;			/* offset+length now in array */
	after = 0;
	if (!AvALLOC(ary))
	    av_extend(ary, 0);
    }

    /* At this point, MARK .. SP-1 is our new LIST */

    newlen = SP - MARK;
    diff = newlen - length;
    if (newlen && !AvREAL(ary) && AvREIFY(ary))
	av_reify(ary);

    /* make new elements SVs now: avoid problems if they're from the array */
    for (dst = MARK, i = newlen; i; i--) {
        SV * const h = *dst;
	*dst++ = newSVsv(h);
    }

    if (diff < 0) {				/* shrinking the area */
	SV **tmparyval = NULL;
	if (newlen) {
	    Newx(tmparyval, newlen, SV*);	/* so remember insertion */
	    Copy(MARK, tmparyval, newlen, SV*);
	}

	MARK = ORIGMARK + 1;
	if (GIMME_V == G_ARRAY) {		/* copy return vals to stack */
	    const bool real = cBOOL(AvREAL(ary));
	    MEXTEND(MARK, length);
	    if (real)
		EXTEND_MORTAL(length);
	    for (i = 0, dst = MARK; i < length; i++) {
		if ((*dst = AvARRAY(ary)[i+offset])) {
		  if (real)
		    sv_2mortal(*dst);	/* free them eventually */
		}
		else
		    *dst = &PL_sv_undef;
		dst++;
	    }
	    MARK += length - 1;
	}
	else {
	    *MARK = AvARRAY(ary)[offset+length-1];
	    if (AvREAL(ary)) {
		sv_2mortal(*MARK);
		for (i = length - 1, dst = &AvARRAY(ary)[offset]; i > 0; i--)
		    SvREFCNT_dec(*dst++);	/* free them now */
	    }
	    if (!*MARK)
		*MARK = &PL_sv_undef;
	}
	AvFILLp(ary) += diff;

	/* pull up or down? */

	if (offset < after) {			/* easier to pull up */
	    if (offset) {			/* esp. if nothing to pull */
		src = &AvARRAY(ary)[offset-1];
		dst = src - diff;		/* diff is negative */
		for (i = offset; i > 0; i--)	/* can't trust Copy */
		    *dst-- = *src--;
	    }
	    dst = AvARRAY(ary);
	    AvARRAY(ary) = AvARRAY(ary) - diff; /* diff is negative */
	    AvMAX(ary) += diff;
	}
	else {
	    if (after) {			/* anything to pull down? */
		src = AvARRAY(ary) + offset + length;
		dst = src + diff;		/* diff is negative */
		Move(src, dst, after, SV*);
	    }
	    dst = &AvARRAY(ary)[AvFILLp(ary)+1];
						/* avoid later double free */
	}
	i = -diff;
	while (i)
	    dst[--i] = NULL;
	
	if (newlen) {
 	    Copy( tmparyval, AvARRAY(ary) + offset, newlen, SV* );
	    Safefree(tmparyval);
	}
    }
    else {					/* no, expanding (or same) */
	SV** tmparyval = NULL;
	if (length) {
	    Newx(tmparyval, length, SV*);	/* so remember deletion */
	    Copy(AvARRAY(ary)+offset, tmparyval, length, SV*);
	}

	if (diff > 0) {				/* expanding */
	    /* push up or down? */
	    if (offset < after && diff <= AvARRAY(ary) - AvALLOC(ary)) {
		if (offset) {
		    src = AvARRAY(ary);
		    dst = src - diff;
		    Move(src, dst, offset, SV*);
		}
		AvARRAY(ary) = AvARRAY(ary) - diff;/* diff is positive */
		AvMAX(ary) += diff;
		AvFILLp(ary) += diff;
	    }
	    else {
		if (AvFILLp(ary) + diff >= AvMAX(ary))	/* oh, well */
		    av_extend(ary, AvFILLp(ary) + diff);
		AvFILLp(ary) += diff;

		if (after) {
		    dst = AvARRAY(ary) + AvFILLp(ary);
		    src = dst - diff;
		    for (i = after; i; i--) {
			*dst-- = *src--;
		    }
		}
	    }
	}

	if (newlen) {
	    Copy( MARK, AvARRAY(ary) + offset, newlen, SV* );
	}

	MARK = ORIGMARK + 1;
	if (GIMME_V == G_ARRAY) {		/* copy return vals to stack */
	    if (length) {
		const bool real = cBOOL(AvREAL(ary));
		if (real)
		    EXTEND_MORTAL(length);
		for (i = 0, dst = MARK; i < length; i++) {
		    if ((*dst = tmparyval[i])) {
		      if (real)
			sv_2mortal(*dst);	/* free them eventually */
		    }
		    else *dst = &PL_sv_undef;
		    dst++;
		}
	    }
	    MARK += length - 1;
	}
	else if (length--) {
	    *MARK = tmparyval[length];
	    if (AvREAL(ary)) {
		sv_2mortal(*MARK);
		while (length-- > 0)
		    SvREFCNT_dec(tmparyval[length]);
	    }
	    if (!*MARK)
		*MARK = &PL_sv_undef;
	}
	else
	    *MARK = &PL_sv_undef;
	Safefree(tmparyval);
    }

    if (SvMAGICAL(ary))
	mg_set(MUTABLE_SV(ary));

    SP = MARK;
    RETURN;
}

PP(pp_push)
{
    dSP; dMARK; dORIGMARK; dTARGET;
    AV * const ary = MUTABLE_AV(*++MARK);
    const MAGIC * const mg = SvTIED_mg((const SV *)ary, PERL_MAGIC_tied);

    if (mg) {
	*MARK-- = SvTIED_obj(MUTABLE_SV(ary), mg);
	PUSHMARK(MARK);
	PUTBACK;
	ENTER_with_name("call_PUSH");
	call_sv(SV_CONST(PUSH),G_SCALAR|G_DISCARD|G_METHOD_NAMED);
	LEAVE_with_name("call_PUSH");
	/* SPAGAIN; not needed: SP is assigned to immediately below */
    }
    else {
        /* PL_delaymagic is restored by JUMPENV_POP on dieing, so we
         * only need to save locally, not on the save stack */
        U16 old_delaymagic = PL_delaymagic;

	if (SvREADONLY(ary) && MARK < SP) Perl_croak_no_modify();
	PL_delaymagic = DM_DELAY;
	for (++MARK; MARK <= SP; MARK++) {
	    SV *sv;
	    if (*MARK) SvGETMAGIC(*MARK);
	    sv = newSV(0);
	    if (*MARK)
		sv_setsv_nomg(sv, *MARK);
	    av_store(ary, AvFILLp(ary)+1, sv);
	}
	if (PL_delaymagic & DM_ARRAY_ISA)
	    mg_set(MUTABLE_SV(ary));
        PL_delaymagic = old_delaymagic;
    }
    SP = ORIGMARK;
    if (OP_GIMME(PL_op, 0) != G_VOID) {
	PUSHi( AvFILL(ary) + 1 );
    }
    RETURN;
}

/* also used for: pp_pop()*/
PP(pp_shift)
{
    dSP;
    AV * const av = PL_op->op_flags & OPf_SPECIAL
	? MUTABLE_AV(GvAVn(PL_defgv)) : MUTABLE_AV(POPs);
    SV * const sv = PL_op->op_type == OP_SHIFT ? av_shift(av) : av_pop(av);
    EXTEND(SP, 1);
    assert (sv);
    if (AvREAL(av))
	(void)sv_2mortal(sv);
    PUSHs(sv);
    RETURN;
}

PP(pp_unshift)
{
    dSP; dMARK; dORIGMARK; dTARGET;
    AV *ary = MUTABLE_AV(*++MARK);
    const MAGIC * const mg = SvTIED_mg((const SV *)ary, PERL_MAGIC_tied);

    if (mg) {
	*MARK-- = SvTIED_obj(MUTABLE_SV(ary), mg);
	PUSHMARK(MARK);
	PUTBACK;
	ENTER_with_name("call_UNSHIFT");
	call_sv(SV_CONST(UNSHIFT),G_SCALAR|G_DISCARD|G_METHOD_NAMED);
	LEAVE_with_name("call_UNSHIFT");
	/* SPAGAIN; not needed: SP is assigned to immediately below */
    }
    else {
        /* PL_delaymagic is restored by JUMPENV_POP on dieing, so we
         * only need to save locally, not on the save stack */
        U16 old_delaymagic = PL_delaymagic;
	SSize_t i = 0;

	av_unshift(ary, SP - MARK);
        PL_delaymagic = DM_DELAY;
	while (MARK < SP) {
	    SV * const sv = newSVsv(*++MARK);
	    (void)av_store(ary, i++, sv);
	}
        if (PL_delaymagic & DM_ARRAY_ISA)
            mg_set(MUTABLE_SV(ary));
        PL_delaymagic = old_delaymagic;
    }
    SP = ORIGMARK;
    if (OP_GIMME(PL_op, 0) != G_VOID) {
	PUSHi( AvFILL(ary) + 1 );
    }
    RETURN;
}

PP(pp_reverse)
{
    dSP; dMARK;

    if (GIMME_V == G_ARRAY) {
	if (PL_op->op_private & OPpREVERSE_INPLACE) {
	    AV *av;

	    /* See pp_sort() */
	    assert( MARK+1 == SP && *SP && SvTYPE(*SP) == SVt_PVAV);
	    (void)POPMARK; /* remove mark associated with ex-OP_AASSIGN */
	    av = MUTABLE_AV((*SP));
	    /* In-place reversing only happens in void context for the array
	     * assignment. We don't need to push anything on the stack. */
	    SP = MARK;

	    if (SvMAGICAL(av)) {
		SSize_t i, j;
		SV *tmp = sv_newmortal();
		/* For SvCANEXISTDELETE */
		HV *stash;
		const MAGIC *mg;
		bool can_preserve = SvCANEXISTDELETE(av);

		for (i = 0, j = av_tindex(av); i < j; ++i, --j) {
		    SV *begin, *end;

		    if (can_preserve) {
			if (!av_exists(av, i)) {
			    if (av_exists(av, j)) {
				SV *sv = av_delete(av, j, 0);
				begin = *av_fetch(av, i, TRUE);
				sv_setsv_mg(begin, sv);
			    }
			    continue;
			}
			else if (!av_exists(av, j)) {
			    SV *sv = av_delete(av, i, 0);
			    end = *av_fetch(av, j, TRUE);
			    sv_setsv_mg(end, sv);
			    continue;
			}
		    }

		    begin = *av_fetch(av, i, TRUE);
		    end   = *av_fetch(av, j, TRUE);
		    sv_setsv(tmp,      begin);
		    sv_setsv_mg(begin, end);
		    sv_setsv_mg(end,   tmp);
		}
	    }
	    else {
		SV **begin = AvARRAY(av);

		if (begin) {
		    SV **end   = begin + AvFILLp(av);

		    while (begin < end) {
			SV * const tmp = *begin;
			*begin++ = *end;
			*end--   = tmp;
		    }
		}
	    }
	}
	else {
	    SV **oldsp = SP;
	    MARK++;
	    while (MARK < SP) {
		SV * const tmp = *MARK;
		*MARK++ = *SP;
		*SP--   = tmp;
	    }
	    /* safe as long as stack cannot get extended in the above */
	    SP = oldsp;
	}
    }
    else {
	char *up;
	char *down;
	I32 tmp;
	dTARGET;
	STRLEN len;

	SvUTF8_off(TARG);				/* decontaminate */
	if (SP - MARK > 1)
	    do_join(TARG, &PL_sv_no, MARK, SP);
	else {
	    sv_setsv(TARG, SP > MARK ? *SP : DEFSV);
	}

	up = SvPV_force(TARG, len);
	if (len > 1) {
	    if (DO_UTF8(TARG)) {	/* first reverse each character */
		U8* s = (U8*)SvPVX(TARG);
		const U8* send = (U8*)(s + len);
		while (s < send) {
		    if (UTF8_IS_INVARIANT(*s)) {
			s++;
			continue;
		    }
		    else {
			if (!utf8_to_uvchr_buf(s, send, 0))
			    break;
			up = (char*)s;
			s += UTF8SKIP(s);
			down = (char*)(s - 1);
			/* reverse this character */
			while (down > up) {
			    tmp = *up;
			    *up++ = *down;
			    *down-- = (char)tmp;
			}
		    }
		}
		up = SvPVX(TARG);
	    }
	    down = SvPVX(TARG) + len - 1;
	    while (down > up) {
		tmp = *up;
		*up++ = *down;
		*down-- = (char)tmp;
	    }
	    (void)SvPOK_only_UTF8(TARG);
	}
	SP = MARK + 1;
	SETTARG;
    }
    RETURN;
}

PP(pp_split)
{
    dSP; dTARG;
    AV *ary = (   (PL_op->op_private & OPpSPLIT_ASSIGN) /* @a = split */
               && (PL_op->op_flags & OPf_STACKED))      /* @{expr} = split */
               ? (AV *)POPs : NULL;
    IV limit = POPi;			/* note, negative is forever */
    SV * const sv = POPs;
    STRLEN len;
    const char *s = SvPV_const(sv, len);
    const bool do_utf8 = DO_UTF8(sv);
    const char *strend = s + len;
    PMOP *pm = cPMOPx(PL_op);
    REGEXP *rx;
    SV *dstr;
    const char *m;
    SSize_t iters = 0;
    const STRLEN slen = do_utf8
                        ? utf8_length((U8*)s, (U8*)strend)
                        : (STRLEN)(strend - s);
    SSize_t maxiters = slen + 10;
    I32 trailing_empty = 0;
    const char *orig;
    const IV origlimit = limit;
    I32 realarray = 0;
    I32 base;
    const U8 gimme = GIMME_V;
    bool gimme_scalar;
    I32 oldsave = PL_savestack_ix;
    U32 make_mortal = SVs_TEMP;
    bool multiline = 0;
    MAGIC *mg = NULL;

    rx = PM_GETRE(pm);

    TAINT_IF(get_regex_charset(RX_EXTFLAGS(rx)) == REGEX_LOCALE_CHARSET &&
             (RX_EXTFLAGS(rx) & (RXf_WHITE | RXf_SKIPWHITE)));

    /* handle @ary = split(...) optimisation */
    if (PL_op->op_private & OPpSPLIT_ASSIGN) {
        if (!(PL_op->op_flags & OPf_STACKED)) {
            if (PL_op->op_private & OPpSPLIT_LEX) {
                if (PL_op->op_private & OPpLVAL_INTRO)
                    SAVECLEARSV(PAD_SVl(pm->op_pmreplrootu.op_pmtargetoff));
                ary = (AV *)PAD_SVl(pm->op_pmreplrootu.op_pmtargetoff);
            }
            else {
                GV *gv =
#ifdef USE_ITHREADS
                        MUTABLE_GV(PAD_SVl(pm->op_pmreplrootu.op_pmtargetoff));
#else
                        pm->op_pmreplrootu.op_pmtargetgv;
#endif
                if (PL_op->op_private & OPpLVAL_INTRO)
                    ary = save_ary(gv);
                else
                    ary = GvAVn(gv);
            }
            /* skip anything pushed by OPpLVAL_INTRO above */
            oldsave = PL_savestack_ix;
        }

	realarray = 1;
	PUTBACK;
	av_extend(ary,0);
	(void)sv_2mortal(SvREFCNT_inc_simple_NN(sv));
	av_clear(ary);
	SPAGAIN;
	if ((mg = SvTIED_mg((const SV *)ary, PERL_MAGIC_tied))) {
	    PUSHMARK(SP);
	    XPUSHs(SvTIED_obj(MUTABLE_SV(ary), mg));
	}
	else {
	    if (!AvREAL(ary)) {
		I32 i;
		AvREAL_on(ary);
		AvREIFY_off(ary);
		for (i = AvFILLp(ary); i >= 0; i--)
		    AvARRAY(ary)[i] = &PL_sv_undef; /* don't free mere refs */
	    }
	    /* temporarily switch stacks */
	    SAVESWITCHSTACK(PL_curstack, ary);
	    make_mortal = 0;
	}
    }

    base = SP - PL_stack_base;
    orig = s;
    if (RX_EXTFLAGS(rx) & RXf_SKIPWHITE) {
	if (do_utf8) {
	    while (isSPACE_utf8(s))
		s += UTF8SKIP(s);
	}
	else if (get_regex_charset(RX_EXTFLAGS(rx)) == REGEX_LOCALE_CHARSET) {
	    while (isSPACE_LC(*s))
		s++;
	}
	else {
	    while (isSPACE(*s))
		s++;
	}
    }
    if (RX_EXTFLAGS(rx) & RXf_PMf_MULTILINE) {
	multiline = 1;
    }

    gimme_scalar = gimme == G_SCALAR && !ary;

    if (!limit)
	limit = maxiters + 2;
    if (RX_EXTFLAGS(rx) & RXf_WHITE) {
	while (--limit) {
	    m = s;
	    /* this one uses 'm' and is a negative test */
	    if (do_utf8) {
		while (m < strend && ! isSPACE_utf8(m) ) {
		    const int t = UTF8SKIP(m);
		    /* isSPACE_utf8 returns FALSE for malform utf8 */
		    if (strend - m < t)
			m = strend;
		    else
			m += t;
		}
	    }
	    else if (get_regex_charset(RX_EXTFLAGS(rx)) == REGEX_LOCALE_CHARSET)
            {
	        while (m < strend && !isSPACE_LC(*m))
		    ++m;
            } else {
                while (m < strend && !isSPACE(*m))
                    ++m;
            }  
	    if (m >= strend)
		break;

	    if (gimme_scalar) {
		iters++;
		if (m-s == 0)
		    trailing_empty++;
		else
		    trailing_empty = 0;
	    } else {
		dstr = newSVpvn_flags(s, m-s,
				      (do_utf8 ? SVf_UTF8 : 0) | make_mortal);
		XPUSHs(dstr);
	    }

	    /* skip the whitespace found last */
	    if (do_utf8)
		s = m + UTF8SKIP(m);
	    else
		s = m + 1;

	    /* this one uses 's' and is a positive test */
	    if (do_utf8) {
		while (s < strend && isSPACE_utf8(s) )
	            s +=  UTF8SKIP(s);
	    }
	    else if (get_regex_charset(RX_EXTFLAGS(rx)) == REGEX_LOCALE_CHARSET)
            {
	        while (s < strend && isSPACE_LC(*s))
		    ++s;
            } else {
                while (s < strend && isSPACE(*s))
                    ++s;
            } 	    
	}
    }
    else if (RX_EXTFLAGS(rx) & RXf_START_ONLY) {
	while (--limit) {
	    for (m = s; m < strend && *m != '\n'; m++)
		;
	    m++;
	    if (m >= strend)
		break;

	    if (gimme_scalar) {
		iters++;
		if (m-s == 0)
		    trailing_empty++;
		else
		    trailing_empty = 0;
	    } else {
		dstr = newSVpvn_flags(s, m-s,
				      (do_utf8 ? SVf_UTF8 : 0) | make_mortal);
		XPUSHs(dstr);
	    }
	    s = m;
	}
    }
    else if (RX_EXTFLAGS(rx) & RXf_NULL && !(s >= strend)) {
        /*
          Pre-extend the stack, either the number of bytes or
          characters in the string or a limited amount, triggered by:

          my ($x, $y) = split //, $str;
            or
          split //, $str, $i;
        */
	if (!gimme_scalar) {
	    const IV items = limit - 1;
            /* setting it to -1 will trigger a panic in EXTEND() */
            const SSize_t sslen = slen > SSize_t_MAX ?  -1 : (SSize_t)slen;
	    if (items >=0 && items < sslen)
		EXTEND(SP, items);
	    else
		EXTEND(SP, sslen);
	}

        if (do_utf8) {
            while (--limit) {
                /* keep track of how many bytes we skip over */
                m = s;
                s += UTF8SKIP(s);
		if (gimme_scalar) {
		    iters++;
		    if (s-m == 0)
			trailing_empty++;
		    else
			trailing_empty = 0;
		} else {
		    dstr = newSVpvn_flags(m, s-m, SVf_UTF8 | make_mortal);

		    PUSHs(dstr);
		}

                if (s >= strend)
                    break;
            }
        } else {
            while (--limit) {
	        if (gimme_scalar) {
		    iters++;
		} else {
		    dstr = newSVpvn(s, 1);


		    if (make_mortal)
			sv_2mortal(dstr);

		    PUSHs(dstr);
		}

                s++;

                if (s >= strend)
                    break;
            }
        }
    }
    else if (do_utf8 == (RX_UTF8(rx) != 0) &&
	     (RX_EXTFLAGS(rx) & RXf_USE_INTUIT) && !RX_NPARENS(rx)
	     && (RX_EXTFLAGS(rx) & RXf_CHECK_ALL)
             && !(RX_EXTFLAGS(rx) & RXf_IS_ANCHORED)) {
	const int tail = (RX_EXTFLAGS(rx) & RXf_INTUIT_TAIL);
	SV * const csv = CALLREG_INTUIT_STRING(rx);

	len = RX_MINLENRET(rx);
	if (len == 1 && !RX_UTF8(rx) && !tail) {
	    const char c = *SvPV_nolen_const(csv);
	    while (--limit) {
		for (m = s; m < strend && *m != c; m++)
		    ;
		if (m >= strend)
		    break;
		if (gimme_scalar) {
		    iters++;
		    if (m-s == 0)
			trailing_empty++;
		    else
			trailing_empty = 0;
		} else {
		    dstr = newSVpvn_flags(s, m-s,
					 (do_utf8 ? SVf_UTF8 : 0) | make_mortal);
		    XPUSHs(dstr);
		}
		/* The rx->minlen is in characters but we want to step
		 * s ahead by bytes. */
 		if (do_utf8)
		    s = (char*)utf8_hop((U8*)m, len);
 		else
		    s = m + len; /* Fake \n at the end */
	    }
	}
	else {
	    while (s < strend && --limit &&
	      (m = fbm_instr((unsigned char*)s, (unsigned char*)strend,
			     csv, multiline ? FBMrf_MULTILINE : 0)) )
	    {
		if (gimme_scalar) {
		    iters++;
		    if (m-s == 0)
			trailing_empty++;
		    else
			trailing_empty = 0;
		} else {
		    dstr = newSVpvn_flags(s, m-s,
					 (do_utf8 ? SVf_UTF8 : 0) | make_mortal);
		    XPUSHs(dstr);
		}
		/* The rx->minlen is in characters but we want to step
		 * s ahead by bytes. */
 		if (do_utf8)
		    s = (char*)utf8_hop((U8*)m, len);
 		else
		    s = m + len; /* Fake \n at the end */
	    }
	}
    }
    else {
	maxiters += slen * RX_NPARENS(rx);
	while (s < strend && --limit)
	{
	    I32 rex_return;
	    PUTBACK;
	    rex_return = CALLREGEXEC(rx, (char*)s, (char*)strend, (char*)orig, 1,
				     sv, NULL, 0);
	    SPAGAIN;
	    if (rex_return == 0)
		break;
	    TAINT_IF(RX_MATCH_TAINTED(rx));
            /* we never pass the REXEC_COPY_STR flag, so it should
             * never get copied */
            assert(!RX_MATCH_COPIED(rx));
	    m = RX_OFFS(rx)[0].start + orig;

	    if (gimme_scalar) {
		iters++;
		if (m-s == 0)
		    trailing_empty++;
		else
		    trailing_empty = 0;
	    } else {
		dstr = newSVpvn_flags(s, m-s,
				      (do_utf8 ? SVf_UTF8 : 0) | make_mortal);
		XPUSHs(dstr);
	    }
	    if (RX_NPARENS(rx)) {
		I32 i;
		for (i = 1; i <= (I32)RX_NPARENS(rx); i++) {
		    s = RX_OFFS(rx)[i].start + orig;
		    m = RX_OFFS(rx)[i].end + orig;

		    /* japhy (07/27/01) -- the (m && s) test doesn't catch
		       parens that didn't match -- they should be set to
		       undef, not the empty string */
		    if (gimme_scalar) {
			iters++;
			if (m-s == 0)
			    trailing_empty++;
			else
			    trailing_empty = 0;
		    } else {
			if (m >= orig && s >= orig) {
			    dstr = newSVpvn_flags(s, m-s,
						 (do_utf8 ? SVf_UTF8 : 0)
						  | make_mortal);
			}
			else
			    dstr = &PL_sv_undef;  /* undef, not "" */
			XPUSHs(dstr);
		    }

		}
	    }
	    s = RX_OFFS(rx)[0].end + orig;
	}
    }

    if (!gimme_scalar) {
	iters = (SP - PL_stack_base) - base;
    }
    if (iters > maxiters)
	DIE(aTHX_ "Split loop");

    /* keep field after final delim? */
    if (s < strend || (iters && origlimit)) {
	if (!gimme_scalar) {
	    const STRLEN l = strend - s;
	    dstr = newSVpvn_flags(s, l, (do_utf8 ? SVf_UTF8 : 0) | make_mortal);
	    XPUSHs(dstr);
	}
	iters++;
    }
    else if (!origlimit) {
	if (gimme_scalar) {
	    iters -= trailing_empty;
	} else {
	    while (iters > 0 && (!TOPs || !SvANY(TOPs) || SvCUR(TOPs) == 0)) {
		if (TOPs && !make_mortal)
		    sv_2mortal(TOPs);
		*SP-- = &PL_sv_undef;
		iters--;
	    }
	}
    }

    PUTBACK;
    LEAVE_SCOPE(oldsave); /* may undo an earlier SWITCHSTACK */
    SPAGAIN;
    if (realarray) {
	if (!mg) {
	    if (SvSMAGICAL(ary)) {
		PUTBACK;
		mg_set(MUTABLE_SV(ary));
		SPAGAIN;
	    }
	    if (gimme == G_ARRAY) {
		EXTEND(SP, iters);
		Copy(AvARRAY(ary), SP + 1, iters, SV*);
		SP += iters;
		RETURN;
	    }
	}
	else {
	    PUTBACK;
	    ENTER_with_name("call_PUSH");
	    call_sv(SV_CONST(PUSH),G_SCALAR|G_DISCARD|G_METHOD_NAMED);
	    LEAVE_with_name("call_PUSH");
	    SPAGAIN;
	    if (gimme == G_ARRAY) {
		SSize_t i;
		/* EXTEND should not be needed - we just popped them */
		EXTEND(SP, iters);
		for (i=0; i < iters; i++) {
		    SV **svp = av_fetch(ary, i, FALSE);
		    PUSHs((svp) ? *svp : &PL_sv_undef);
		}
		RETURN;
	    }
	}
    }
    else {
	if (gimme == G_ARRAY)
	    RETURN;
    }

    GETTARGET;
    PUSHi(iters);
    RETURN;
}

PP(pp_once)
{
    dSP;
    SV *const sv = PAD_SVl(PL_op->op_targ);

    if (SvPADSTALE(sv)) {
	/* First time. */
	SvPADSTALE_off(sv);
	RETURNOP(cLOGOP->op_other);
    }
    RETURNOP(cLOGOP->op_next);
}

PP(pp_lock)
{
    dSP;
    dTOPss;
    SV *retsv = sv;
    SvLOCK(sv);
    if (SvTYPE(retsv) == SVt_PVAV || SvTYPE(retsv) == SVt_PVHV
     || SvTYPE(retsv) == SVt_PVCV) {
	retsv = refto(retsv);
    }
    SETs(retsv);
    RETURN;
}


/* used for: pp_padany(), pp_custom(); plus any system ops
 * that aren't implemented on a particular platform */

PP(unimplemented_op)
{
    const Optype op_type = PL_op->op_type;
    /* Using OP_NAME() isn't going to be helpful here. Firstly, it doesn't cope
       with out of range op numbers - it only "special" cases op_custom.
       Secondly, as the three ops we "panic" on are padmy, mapstart and custom,
       if we get here for a custom op then that means that the custom op didn't
       have an implementation. Given that OP_NAME() looks up the custom op
       by its pp_addr, likely it will return NULL, unless someone (unhelpfully)
       registers &PL_unimplemented_op as the address of their custom op.
       NULL doesn't generate a useful error message. "custom" does. */
    const char *const name = op_type >= OP_max
	? "[out of range]" : PL_op_name[PL_op->op_type];
    if(OP_IS_SOCKET(op_type))
	DIE(aTHX_ PL_no_sock_func, name);
    DIE(aTHX_ "panic: unimplemented op %s (#%d) called", name,	op_type);
}

static void
S_maybe_unwind_defav(pTHX)
{
    if (CX_CUR()->cx_type & CXp_HASARGS) {
	PERL_CONTEXT *cx = CX_CUR();

        assert(CxHASARGS(cx));
        cx_popsub_args(cx);
	cx->cx_type &= ~CXp_HASARGS;
    }
}

/* For sorting out arguments passed to a &CORE:: subroutine */
PP(pp_coreargs)
{
    dSP;
    int opnum = SvIOK(cSVOP_sv) ? (int)SvUV(cSVOP_sv) : 0;
    int defgv = PL_opargs[opnum] & OA_DEFGV ||opnum==OP_GLOB, whicharg = 0;
    AV * const at_ = GvAV(PL_defgv);
    SV **svp = at_ ? AvARRAY(at_) : NULL;
    I32 minargs = 0, maxargs = 0, numargs = at_ ? AvFILLp(at_)+1 : 0;
    I32 oa = opnum ? PL_opargs[opnum] >> OASHIFT : 0;
    bool seen_question = 0;
    const char *err = NULL;
    const bool pushmark = PL_op->op_private & OPpCOREARGS_PUSHMARK;

    /* Count how many args there are first, to get some idea how far to
       extend the stack. */
    while (oa) {
	if ((oa & 7) == OA_LIST) { maxargs = I32_MAX; break; }
	maxargs++;
	if (oa & OA_OPTIONAL) seen_question = 1;
	if (!seen_question) minargs++;
	oa >>= 4;
    }

    if(numargs < minargs) err = "Not enough";
    else if(numargs > maxargs) err = "Too many";
    if (err)
	/* diag_listed_as: Too many arguments for %s */
	Perl_croak(aTHX_
	  "%s arguments for %s", err,
	   opnum ? PL_op_desc[opnum] : SvPV_nolen_const(cSVOP_sv)
	);

    /* Reset the stack pointer.  Without this, we end up returning our own
       arguments in list context, in addition to the values we are supposed
       to return.  nextstate usually does this on sub entry, but we need
       to run the next op with the caller's hints, so we cannot have a
       nextstate. */
    SP = PL_stack_base + CX_CUR()->blk_oldsp;

    if(!maxargs) RETURN;

    /* We do this here, rather than with a separate pushmark op, as it has
       to come in between two things this function does (stack reset and
       arg pushing).  This seems the easiest way to do it. */
    if (pushmark) {
	PUTBACK;
	(void)Perl_pp_pushmark(aTHX);
    }

    EXTEND(SP, maxargs == I32_MAX ? numargs : maxargs);
    PUTBACK; /* The code below can die in various places. */

    oa = PL_opargs[opnum] >> OASHIFT;
    for (; oa&&(numargs||!pushmark); (void)(numargs&&(++svp,--numargs))) {
	whicharg++;
	switch (oa & 7) {
	case OA_SCALAR:
	  try_defsv:
	    if (!numargs && defgv && whicharg == minargs + 1) {
		PUSHs(DEFSV);
	    }
	    else PUSHs(numargs ? svp && *svp ? *svp : &PL_sv_undef : NULL);
	    break;
	case OA_LIST:
	    while (numargs--) {
		PUSHs(svp && *svp ? *svp : &PL_sv_undef);
		svp++;
	    }
	    RETURN;
	case OA_AVREF:
	    if (!numargs) {
		GV *gv;
		if (CvUNIQUE(find_runcv_where(FIND_RUNCV_level_eq,1,NULL)))
		    gv = PL_argvgv;
		else {
		    S_maybe_unwind_defav(aTHX);
		    gv = PL_defgv;
		}
		PUSHs((SV *)GvAVn(gv));
		break;
	    }
	    if (!svp || !*svp || !SvROK(*svp)
	     || SvTYPE(SvRV(*svp)) != SVt_PVAV)
		DIE(aTHX_
		/* diag_listed_as: Type of arg %d to &CORE::%s must be %s*/
		 "Type of arg %d to &CORE::%s must be array reference",
		  whicharg, PL_op_desc[opnum]
		);
	    PUSHs(SvRV(*svp));
	    break;
	case OA_HVREF:
	    if (!svp || !*svp || !SvROK(*svp)
	     || (  SvTYPE(SvRV(*svp)) != SVt_PVHV
		&& (  opnum == OP_DBMCLOSE || opnum == OP_DBMOPEN
		   || SvTYPE(SvRV(*svp)) != SVt_PVAV  )))
		DIE(aTHX_
		/* diag_listed_as: Type of arg %d to &CORE::%s must be %s*/
		 "Type of arg %d to &CORE::%s must be hash%s reference",
		  whicharg, PL_op_desc[opnum],
		  opnum == OP_DBMCLOSE || opnum == OP_DBMOPEN
		     ? ""
		     : " or array"
		);
	    PUSHs(SvRV(*svp));
	    break;
	case OA_FILEREF:
	    if (!numargs) PUSHs(NULL);
	    else if(svp && *svp && SvROK(*svp) && isGV_with_GP(SvRV(*svp)))
		/* no magic here, as the prototype will have added an extra
		   refgen and we just want what was there before that */
		PUSHs(SvRV(*svp));
	    else {
		const bool constr = PL_op->op_private & whicharg;
		PUSHs(S_rv2gv(aTHX_
		    svp && *svp ? *svp : &PL_sv_undef,
		    constr, cBOOL(CopHINTS_get(PL_curcop) & HINT_STRICT_REFS),
		    !constr
		));
	    }
	    break;
	case OA_SCALARREF:
	  if (!numargs) goto try_defsv;
	  else {
	    const bool wantscalar =
		PL_op->op_private & OPpCOREARGS_SCALARMOD;
	    if (!svp || !*svp || !SvROK(*svp)
	        /* We have to permit globrefs even for the \$ proto, as
	           *foo is indistinguishable from ${\*foo}, and the proto-
	           type permits the latter. */
	     || SvTYPE(SvRV(*svp)) > (
	             wantscalar       ? SVt_PVLV
	           : opnum == OP_LOCK || opnum == OP_UNDEF
	                              ? SVt_PVCV
	           :                    SVt_PVHV
	        )
	       )
		DIE(aTHX_
		 "Type of arg %d to &CORE::%s must be %s",
		  whicharg, PL_op_name[opnum],
		  wantscalar
		    ? "scalar reference"
		    : opnum == OP_LOCK || opnum == OP_UNDEF
		       ? "reference to one of [$@%&*]"
		       : "reference to one of [$@%*]"
		);
	    PUSHs(SvRV(*svp));
	    if (opnum == OP_UNDEF && SvRV(*svp) == (SV *)PL_defgv) {
		/* Undo @_ localisation, so that sub exit does not undo
		   part of our undeffing. */
		S_maybe_unwind_defav(aTHX);
	    }
	  }
	  break;
	default:
	    DIE(aTHX_ "panic: unknown OA_*: %x", (unsigned)(oa&7));
	}
	oa = oa >> 4;
    }

    RETURN;
}

PP(pp_avhvswitch)
{
    dVAR; dSP;
    return PL_ppaddr[
		(SvTYPE(TOPs) == SVt_PVAV ? OP_AEACH : OP_EACH)
		    + (PL_op->op_private & OPpAVHVSWITCH_MASK)
	   ](aTHX);
}

PP(pp_runcv)
{
    dSP;
    CV *cv;
    if (PL_op->op_private & OPpOFFBYONE) {
	cv = find_runcv_where(FIND_RUNCV_level_eq, 1, NULL);
    }
    else cv = find_runcv(NULL);
    XPUSHs(CvEVAL(cv) ? &PL_sv_undef : sv_2mortal(newRV((SV *)cv)));
    RETURN;
}

static void
S_localise_aelem_lval(pTHX_ AV * const av, SV * const keysv,
			    const bool can_preserve)
{
    const SSize_t ix = SvIV(keysv);
    if (can_preserve ? av_exists(av, ix) : TRUE) {
	SV ** const svp = av_fetch(av, ix, 1);
	if (!svp || !*svp)
	    Perl_croak(aTHX_ PL_no_aelem, ix);
	save_aelem(av, ix, svp);
    }
    else
	SAVEADELETE(av, ix);
}

static void
S_localise_helem_lval(pTHX_ HV * const hv, SV * const keysv,
			    const bool can_preserve)
{
    if (can_preserve ? hv_exists_ent(hv, keysv, 0) : TRUE) {
	HE * const he = hv_fetch_ent(hv, keysv, 1, 0);
	SV ** const svp = he ? &HeVAL(he) : NULL;
	if (!svp || !*svp)
	    Perl_croak(aTHX_ PL_no_helem_sv, SVfARG(keysv));
	save_helem_flags(hv, keysv, svp, 0);
    }
    else
	SAVEHDELETE(hv, keysv);
}

static void
S_localise_gv_slot(pTHX_ GV *gv, U8 type)
{
    if (type == OPpLVREF_SV) {
	save_pushptrptr(gv, SvREFCNT_inc_simple(GvSV(gv)), SAVEt_GVSV);
	GvSV(gv) = 0;
    }
    else if (type == OPpLVREF_AV)
	/* XXX Inefficient, as it creates a new AV, which we are
	       about to clobber.  */
	save_ary(gv);
    else {
	assert(type == OPpLVREF_HV);
	/* XXX Likewise inefficient.  */
	save_hash(gv);
    }
}


PP(pp_refassign)
{
    dSP;
    SV * const key = PL_op->op_private & OPpLVREF_ELEM ? POPs : NULL;
    SV * const left = PL_op->op_flags & OPf_STACKED ? POPs : NULL;
    dTOPss;
    const char *bad = NULL;
    const U8 type = PL_op->op_private & OPpLVREF_TYPE;
    if (!SvROK(sv)) DIE(aTHX_ "Assigned value is not a reference");
    switch (type) {
    case OPpLVREF_SV:
	if (SvTYPE(SvRV(sv)) > SVt_PVLV)
	    bad = " SCALAR";
	break;
    case OPpLVREF_AV:
	if (SvTYPE(SvRV(sv)) != SVt_PVAV)
	    bad = "n ARRAY";
	break;
    case OPpLVREF_HV:
	if (SvTYPE(SvRV(sv)) != SVt_PVHV)
	    bad = " HASH";
	break;
    case OPpLVREF_CV:
	if (SvTYPE(SvRV(sv)) != SVt_PVCV)
	    bad = " CODE";
    }
    if (bad)
	/* diag_listed_as: Assigned value is not %s reference */
	DIE(aTHX_ "Assigned value is not a%s reference", bad);
    {
    MAGIC *mg;
    HV *stash;
    switch (left ? SvTYPE(left) : 0) {
    case 0:
    {
	SV * const old = PAD_SV(ARGTARG);
	PAD_SETSV(ARGTARG, SvREFCNT_inc_NN(SvRV(sv)));
	SvREFCNT_dec(old);
	if ((PL_op->op_private & (OPpLVAL_INTRO|OPpPAD_STATE))
		== OPpLVAL_INTRO)
	    SAVECLEARSV(PAD_SVl(ARGTARG));
	break;
    }
    case SVt_PVGV:
	if (PL_op->op_private & OPpLVAL_INTRO) {
	    S_localise_gv_slot(aTHX_ (GV *)left, type);
	}
	gv_setref(left, sv);
	SvSETMAGIC(left);
	break;
    case SVt_PVAV:
        assert(key);
	if (UNLIKELY(PL_op->op_private & OPpLVAL_INTRO)) {
	    S_localise_aelem_lval(aTHX_ (AV *)left, key,
					SvCANEXISTDELETE(left));
	}
	av_store((AV *)left, SvIV(key), SvREFCNT_inc_simple_NN(SvRV(sv)));
	break;
    case SVt_PVHV:
        if (UNLIKELY(PL_op->op_private & OPpLVAL_INTRO)) {
            assert(key);
	    S_localise_helem_lval(aTHX_ (HV *)left, key,
					SvCANEXISTDELETE(left));
        }
	(void)hv_store_ent((HV *)left, key, SvREFCNT_inc_simple_NN(SvRV(sv)), 0);
    }
    if (PL_op->op_flags & OPf_MOD)
	SETs(sv_2mortal(newSVsv(sv)));
    /* XXX else can weak references go stale before they are read, e.g.,
       in leavesub?  */
    RETURN;
    }
}

PP(pp_lvref)
{
    dSP;
    SV * const ret = sv_2mortal(newSV_type(SVt_PVMG));
    SV * const elem = PL_op->op_private & OPpLVREF_ELEM ? POPs : NULL;
    SV * const arg = PL_op->op_flags & OPf_STACKED ? POPs : NULL;
    MAGIC * const mg = sv_magicext(ret, arg, PERL_MAGIC_lvref,
				   &PL_vtbl_lvref, (char *)elem,
				   elem ? HEf_SVKEY : (I32)ARGTARG);
    mg->mg_private = PL_op->op_private;
    if (PL_op->op_private & OPpLVREF_ITER)
	mg->mg_flags |= MGf_PERSIST;
    if (UNLIKELY(PL_op->op_private & OPpLVAL_INTRO)) {
      if (elem) {
        MAGIC *mg;
        HV *stash;
        assert(arg);
        {
            const bool can_preserve = SvCANEXISTDELETE(arg);
            if (SvTYPE(arg) == SVt_PVAV)
              S_localise_aelem_lval(aTHX_ (AV *)arg, elem, can_preserve);
            else
              S_localise_helem_lval(aTHX_ (HV *)arg, elem, can_preserve);
        }
      }
      else if (arg) {
	S_localise_gv_slot(aTHX_ (GV *)arg, 
				 PL_op->op_private & OPpLVREF_TYPE);
      }
      else if (!(PL_op->op_private & OPpPAD_STATE))
	SAVECLEARSV(PAD_SVl(ARGTARG));
    }
    XPUSHs(ret);
    RETURN;
}

PP(pp_lvrefslice)
{
    dSP; dMARK;
    AV * const av = (AV *)POPs;
    const bool localizing = PL_op->op_private & OPpLVAL_INTRO;
    bool can_preserve = FALSE;

    if (UNLIKELY(localizing)) {
	MAGIC *mg;
	HV *stash;
	SV **svp;

	can_preserve = SvCANEXISTDELETE(av);

	if (SvTYPE(av) == SVt_PVAV) {
	    SSize_t max = -1;

	    for (svp = MARK + 1; svp <= SP; svp++) {
		const SSize_t elem = SvIV(*svp);
		if (elem > max)
		    max = elem;
	    }
	    if (max > AvMAX(av))
		av_extend(av, max);
	}
    }

    while (++MARK <= SP) {
	SV * const elemsv = *MARK;
	if (SvTYPE(av) == SVt_PVAV)
	    S_localise_aelem_lval(aTHX_ av, elemsv, can_preserve);
	else
	    S_localise_helem_lval(aTHX_ (HV *)av, elemsv, can_preserve);
	*MARK = sv_2mortal(newSV_type(SVt_PVMG));
	sv_magic(*MARK,(SV *)av,PERL_MAGIC_lvref,(char *)elemsv,HEf_SVKEY);
    }
    RETURN;
}

PP(pp_lvavref)
{
    if (PL_op->op_flags & OPf_STACKED)
	Perl_pp_rv2av(aTHX);
    else
	Perl_pp_padav(aTHX);
    {
	dSP;
	dTOPss;
	SETs(0); /* special alias marker that aassign recognises */
	XPUSHs(sv);
	RETURN;
    }
}

PP(pp_anonconst)
{
    dSP;
    dTOPss;
    SETs(sv_2mortal((SV *)newCONSTSUB(SvTYPE(CopSTASH(PL_curcop))==SVt_PVHV
					? CopSTASH(PL_curcop)
					: NULL,
				      NULL, SvREFCNT_inc_simple_NN(sv))));
    RETURN;
}


/* process one subroutine argument - typically when the sub has a signature:
 * introduce PL_curpad[op_targ] and assign to it the value
 *  for $:   (OPf_STACKED ? *sp : $_[N])
 *  for @/%: @_[N..$#_]
 *
 * It's equivalent to 
 *    my $foo = $_[N];
 * or
 *    my $foo = (value-on-stack)
 * or
 *    my @foo = @_[N..$#_]
 * etc
 */

PP(pp_argelem)
{
    dTARG;
    SV *val;
    SV ** padentry;
    OP *o = PL_op;
    AV *defav = GvAV(PL_defgv); /* @_ */
    IV ix = PTR2IV(cUNOP_AUXo->op_aux);
    IV argc;

    /* do 'my $var, @var or %var' action */
    padentry = &(PAD_SVl(o->op_targ));
    save_clearsv(padentry);
    targ = *padentry;

    if ((o->op_private & OPpARGELEM_MASK) == OPpARGELEM_SV) {
        if (o->op_flags & OPf_STACKED) {
            dSP;
            val = POPs;
            PUTBACK;
        }
        else {
            SV **svp;
            /* should already have been checked */
            assert(ix >= 0);
#if IVSIZE > PTRSIZE
            assert(ix <= SSize_t_MAX);
#endif

            svp = av_fetch(defav, ix, FALSE);
            val = svp ? *svp : &PL_sv_undef;
        }

        /* $var = $val */

        /* cargo-culted from pp_sassign */
        assert(TAINTING_get || !TAINT_get);
        if (UNLIKELY(TAINT_get) && !SvTAINTED(val))
            TAINT_NOT;

        SvSetMagicSV(targ, val);
        return o->op_next;
    }

    /* must be AV or HV */

    assert(!(o->op_flags & OPf_STACKED));
    argc = ((IV)AvFILL(defav) + 1) - ix;

    /* This is a copy of the relevant parts of pp_aassign().
     */
    if ((o->op_private & OPpARGELEM_MASK) == OPpARGELEM_AV) {
        IV i;

        if (AvFILL((AV*)targ) > -1) {
            /* target should usually be empty. If we get get
             * here, someone's been doing some weird closure tricks.
             * Make a copy of all args before clearing the array,
             * to avoid the equivalent of @a = ($a[0]) prematurely freeing
             * elements. See similar code in pp_aassign.
             */
            for (i = 0; i < argc; i++) {
                SV **svp = av_fetch(defav, ix + i, FALSE);
                SV *newsv = newSV(0);
                sv_setsv_flags(newsv,
                                svp ? *svp : &PL_sv_undef,
                                (SV_DO_COW_SVSETSV|SV_NOSTEAL));
                if (!av_store(defav, ix + i, newsv))
                    SvREFCNT_dec_NN(newsv);
            }
            av_clear((AV*)targ);
        }

        if (argc <= 0)
            return o->op_next;

        av_extend((AV*)targ, argc);

        i = 0;
        while (argc--) {
            SV *tmpsv;
            SV **svp = av_fetch(defav, ix + i, FALSE);
            SV *val = svp ? *svp : &PL_sv_undef;
            tmpsv = newSV(0);
            sv_setsv(tmpsv, val);
            av_store((AV*)targ, i++, tmpsv);
            TAINT_NOT;
        }

    }
    else {
        IV i;

        assert((o->op_private & OPpARGELEM_MASK) == OPpARGELEM_HV);

        if (SvRMAGICAL(targ) || HvUSEDKEYS((HV*)targ)) {
            /* see "target should usually be empty" comment above */
            for (i = 0; i < argc; i++) {
                SV **svp = av_fetch(defav, ix + i, FALSE);
                SV *newsv = newSV(0);
                sv_setsv_flags(newsv,
                                svp ? *svp : &PL_sv_undef,
                                (SV_DO_COW_SVSETSV|SV_NOSTEAL));
                if (!av_store(defav, ix + i, newsv))
                    SvREFCNT_dec_NN(newsv);
            }
            hv_clear((HV*)targ);
        }

        if (argc <= 0)
            return o->op_next;
        assert(argc % 2 == 0);

        i = 0;
        while (argc) {
            SV *tmpsv;
            SV **svp;
            SV *key;
            SV *val;

            svp = av_fetch(defav, ix + i++, FALSE);
            key = svp ? *svp : &PL_sv_undef;
            svp = av_fetch(defav, ix + i++, FALSE);
            val = svp ? *svp : &PL_sv_undef;

            argc -= 2;
            if (UNLIKELY(SvGMAGICAL(key)))
                key = sv_mortalcopy(key);
            tmpsv = newSV(0);
            sv_setsv(tmpsv, val);
            hv_store_ent((HV*)targ, key, tmpsv, 0);
            TAINT_NOT;
        }
    }

    return o->op_next;
}

/* Handle a default value for one subroutine argument (typically as part
 * of a subroutine signature).
 * It's equivalent to
 *    @_ > op_targ ? $_[op_targ] : result_of(op_other)
 *
 * Intended to be used where op_next is an OP_ARGELEM
 *
 * We abuse the op_targ field slightly: it's an index into @_ rather than
 * into PL_curpad.
 */

PP(pp_argdefelem)
{
    OP * const o = PL_op;
    AV *defav = GvAV(PL_defgv); /* @_ */
    IV ix = (IV)o->op_targ;

    assert(ix >= 0);
#if IVSIZE > PTRSIZE
    assert(ix <= SSize_t_MAX);
#endif

    if (AvFILL(defav) >= ix) {
        dSP;
        SV **svp = av_fetch(defav, ix, FALSE);
        SV  *val = svp ? *svp : &PL_sv_undef;
        XPUSHs(val);
        RETURN;
    }
    return cLOGOPo->op_other;
}



/* Check a  a subs arguments - i.e. that it has the correct number of args
 * (and anything else we might think of in future). Typically used with
 * signatured subs.
 */

PP(pp_argcheck)
{
    OP * const o       = PL_op;
    UNOP_AUX_item *aux = cUNOP_AUXo->op_aux;
    IV   params        = aux[0].iv;
    IV   opt_params    = aux[1].iv;
    char slurpy        = (char)(aux[2].iv);
    AV  *defav         = GvAV(PL_defgv); /* @_ */
    IV   argc;
    bool too_few;

    assert(!SvMAGICAL(defav));
    argc = (AvFILLp(defav) + 1);
    too_few = (argc < (params - opt_params));

    if (UNLIKELY(too_few || (!slurpy && argc > params)))
        /* diag_listed_as: Too few arguments for subroutine */
        /* diag_listed_as: Too many arguments for subroutine */
        Perl_croak_caller("Too %s arguments for subroutine",
                            too_few ? "few" : "many");

    if (UNLIKELY(slurpy == '%' && argc > params && (argc - params) % 2))
        Perl_croak_caller("Odd name/value argument for subroutine");


    return NORMAL;
}

/*
 * ex: set ts=8 sts=4 sw=4 et:
 */