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
|
Analysis of cycle costs for SH4:
-> udiv_le128: 5
-> udiv_ge64k: 6
-> udiv udiv_25: 10
-> pos_divisor: 3
-> pos_result linear: 5
-> pos_result - -: 5
-> div_le128: 7
-> div_ge64k: 9
sdivsi3 -> udiv_25 13
udiv25 -> div_ge64k_end: 15
div_ge64k_end -> rts: 13
div_le128 -> div_le128_2: 2, r1 latency 3
udiv_le128 -> div_le128_2: 2, r1 latency 3
(u)div_le128 -> div_by_1: 9
(u)div_le128 -> rts: 17
div_by_1(_neg) -> rts: 4
div_ge64k -> div_r8: 2
div_ge64k -> div_ge64k_2: 3
udiv_ge64k -> udiv_r8: 3
udiv_ge64k -> div_ge64k_2: 3 + LS
(u)div_ge64k -> div_ge64k_end: 13
div_r8 -> div_r8_2: 2
udiv_r8 -> div_r8_2: 2 + LS
(u)div_r8 -> rts: 21
-> - + neg_result: 5
-> + - neg_result: 5
-> div_le128_neg: 7
-> div_ge64k_neg: 9
-> div_r8_neg: 11
-> <64k div_ge64k_neg_end: 28
-> >=64k div_ge64k_neg_end: 22
div_ge64k_neg_end ft -> rts: 14
div_r8_neg_end -> rts: 4
div_r8_neg -> div_r8_neg_end: 18
div_le128_neg -> div_by_1_neg: 4
div_le128_neg -> rts 18
sh4-200 absolute divisor range:
1 [2..128] [129..64K) [64K..|dividend|/256] >=64K,>|dividend/256|
udiv 18 22 38 32 30
sdiv pos: 20 24 41 35 32
sdiv neg: 15 25 42 36 33
sh4-300 absolute divisor range:
8 bit 16 bit 24 bit > 24 bit
udiv 15 35 28 25
sdiv 14 36 34 31
fp-based:
unsigned: 42 + 3 + 3 (lingering ftrc latency + sts fpul,rx) at caller's site
signed: 33 + 3 + 3 (lingering ftrc latency + sts fpul,rx) at caller's site
call-div1: divisor range:
[1..64K) >= 64K
unsigned: 63 58
signed: 76 76
SFUNC_STATIC call overhead:
mov.l 0f,r1
bsrf r1
SFUNC_GOT call overhead - current:
mov.l 0f,r1
mova 0f,r0
mov.l 1f,r2
add r1,r0
mov.l @(r0,r2),r0
jmp @r0
; 3 cycles worse than SFUNC_STATIC
SFUNC_GOT call overhead - improved assembler:
mov.l 0f,r1
mova 0f,r0
mov.l @(r0,r1),r0
jmp @r0
; 2 cycles worse than SFUNC_STATIC
Copyright (C) 2006-2014 Free Software Foundation, Inc.
Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved.
|
