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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, 2007 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.

Line No.	Rev	Author	Line
1	282	jeremybenn	`Analysis of cycle costs for SH4:`
2
3			`-> udiv_le128: 5`
4			`-> udiv_ge64k: 6`
5			`-> udiv udiv_25: 10`
6			`-> pos_divisor: 3`
7			`-> pos_result linear: 5`
8			`-> pos_result - -: 5`
9			`-> div_le128: 7`
10			`-> div_ge64k: 9`
11			`sdivsi3 -> udiv_25 13`
12			`udiv25 -> div_ge64k_end: 15`
13			`div_ge64k_end -> rts: 13`
14			`div_le128 -> div_le128_2: 2, r1 latency 3`
15			`udiv_le128 -> div_le128_2: 2, r1 latency 3`
16			`(u)div_le128 -> div_by_1: 9`
17			`(u)div_le128 -> rts: 17`
18			`div_by_1(_neg) -> rts: 4`
19			`div_ge64k -> div_r8: 2`
20			`div_ge64k -> div_ge64k_2: 3`
21			`udiv_ge64k -> udiv_r8: 3`
22			`udiv_ge64k -> div_ge64k_2: 3 + LS`
23			`(u)div_ge64k -> div_ge64k_end: 13`
24			`div_r8 -> div_r8_2: 2`
25			`udiv_r8 -> div_r8_2: 2 + LS`
26			`(u)div_r8 -> rts: 21`
27
28			`-> - + neg_result: 5`
29			`-> + - neg_result: 5`
30			`-> div_le128_neg: 7`
31			`-> div_ge64k_neg: 9`
32			`-> div_r8_neg: 11`
33			`-> <64k div_ge64k_neg_end: 28`
34			`-> >=64k div_ge64k_neg_end: 22`
35			`div_ge64k_neg_end ft -> rts: 14`
36			`div_r8_neg_end -> rts: 4`
37			`div_r8_neg -> div_r8_neg_end: 18`
38			`div_le128_neg -> div_by_1_neg: 4`
39			`div_le128_neg -> rts 18`
40
41			`sh4-200 absolute divisor range:`
42			`1 [2..128] [129..64K) [64K..\|dividend\|/256] >=64K,>\|dividend/256\|`
43			`udiv 18 22 38 32 30`
44			`sdiv pos: 20 24 41 35 32`
45			`sdiv neg: 15 25 42 36 33`
46
47			`sh4-300 absolute divisor range:`
48			`8 bit 16 bit 24 bit > 24 bit`
49			`udiv 15 35 28 25`
50			`sdiv 14 36 34 31`
51
52
53			`fp-based:`
54
55			`unsigned: 42 + 3 + 3 (lingering ftrc latency + sts fpul,rx) at caller's site`
56			`signed: 33 + 3 + 3 (lingering ftrc latency + sts fpul,rx) at caller's site`
57
58			`call-div1: divisor range:`
59			`[1..64K) >= 64K`
60			`unsigned: 63 58`
61			`signed: 76 76`
62
63			`SFUNC_STATIC call overhead:`
64			`mov.l 0f,r1`
65			`bsrf r1`
66
67			`SFUNC_GOT call overhead - current:`
68			`mov.l 0f,r1`
69			`mova 0f,r0`
70			`mov.l 1f,r2`
71			`add r1,r0`
72			`mov.l @(r0,r2),r0`
73			`jmp @r0`
74			`; 3 cycles worse than SFUNC_STATIC`
75
76			`SFUNC_GOT call overhead - improved assembler:`
77			`mov.l 0f,r1`
78			`mova 0f,r0`
79			`mov.l @(r0,r1),r0`
80			`jmp @r0`
81			`; 2 cycles worse than SFUNC_STATIC`
82
83
84			`Copyright (C) 2006, 2007 Free Software Foundation, Inc.`
85
86			`Copying and distribution of this file, with or without modification,`
87			`are permitted in any medium without royalty provided the copyright`
88			`notice and this notice are preserved.`

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[/] [openrisc/] [trunk/] [gnu-src/] [gcc-4.5.1/] [gcc/] [config/] [sh/] [divcost-analysis] - Blame information for rev 282