http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46928
--- Comment #4 from sebpop at gmail dot com <sebpop at gmail dot com>
2010-12-13 19:05:58 UTC ---
The code that is produced looks like this just after loop
distribution, i.e., we generate memset zero only by distributing the
innermost loop:
mad_synth_mute (struct mad_synth * synth)
{
long unsigned int D.2739;
long unsigned int D.2740;
long unsigned int D.2741;
long unsigned int D.2742;
long unsigned int D.2743;
struct mad_synth * D.2744;
long unsigned int D.2730;
long unsigned int D.2731;
long unsigned int D.2732;
long unsigned int D.2733;
<unnamed-signed:64> D.2734;
<unnamed-signed:64> D.2735;
<unnamed-signed:64> D.2736;
long unsigned int D.2737;
struct mad_synth * D.2738;
long unsigned int D.2721;
long unsigned int D.2722;
long unsigned int D.2723;
long unsigned int D.2724;
<unnamed-signed:64> D.2725;
<unnamed-signed:64> D.2726;
<unnamed-signed:64> D.2727;
long unsigned int D.2728;
struct mad_synth * D.2729;
long unsigned int D.2712;
long unsigned int D.2713;
long unsigned int D.2714;
long unsigned int D.2715;
<unnamed-signed:64> D.2716;
<unnamed-signed:64> D.2717;
<unnamed-signed:64> D.2718;
long unsigned int D.2719;
struct mad_synth * D.2720;
unsigned int pretmp.2;
unsigned int v;
unsigned int s;
unsigned int ch;
<bb 2>:
goto <bb 10>;
<bb 5>:
Invalid sum of incoming frequencies 139, should be 1111
s_9 = s_29 + 1;
if (s_9 != 16)
goto <bb 6>;
else
goto <bb 8>;
<bb 6>:
<bb 7>:
Invalid sum of outgoing probabilities 12.5%
# s_29 = PHI <0(10), s_9(6)>
D.2712_25 = (long unsigned int) s_29;
D.2713_22 = (long unsigned int) ch_28;
D.2714_1 = D.2713_22 * 64;
D.2715_2 = D.2712_25 + D.2714_1;
D.2716_3 = (<unnamed-signed:64>) D.2715_2;
D.2717_26 = D.2716_3 + 48;
D.2718_27 = D.2717_26 * 32;
D.2719_24 = (long unsigned int) D.2718_27;
D.2720_23 = synth_7(D) + D.2719_24;
__builtin_memset (D.2720_23, 0, 32);
D.2721_13 = (long unsigned int) s_29;
D.2722_12 = (long unsigned int) ch_28;
D.2723_11 = D.2722_12 * 64;
D.2724_6 = D.2721_13 + D.2723_11;
D.2725_20 = (<unnamed-signed:64>) D.2724_6;
D.2726_32 = D.2725_20 + 32;
D.2727_33 = D.2726_32 * 32;
D.2728_34 = (long unsigned int) D.2727_33;
D.2729_35 = synth_7(D) + D.2728_34;
__builtin_memset (D.2729_35, 0, 32);
D.2730_36 = (long unsigned int) s_29;
D.2731_37 = (long unsigned int) ch_28;
D.2732_38 = D.2731_37 * 64;
D.2733_39 = D.2730_36 + D.2732_38;
D.2734_40 = (<unnamed-signed:64>) D.2733_39;
D.2735_41 = D.2734_40 + 16;
D.2736_42 = D.2735_41 * 32;
D.2737_43 = (long unsigned int) D.2736_42;
D.2738_44 = synth_7(D) + D.2737_43;
__builtin_memset (D.2738_44, 0, 32);
D.2739_45 = (long unsigned int) ch_28;
D.2740_46 = D.2739_45 * 64;
D.2741_47 = (long unsigned int) s_29;
D.2742_48 = D.2740_46 + D.2741_47;
D.2743_49 = D.2742_48 * 32;
D.2744_50 = synth_7(D) + D.2743_49;
__builtin_memset (D.2744_50, 0, 32);
goto <bb 5>;
<bb 8>:
ch_10 = ch_28 + 1;
if (ch_10 != 2)
goto <bb 9>;
else
goto <bb 11>;
<bb 9>:
<bb 10>:
# ch_28 = PHI <0(2), ch_10(9)>
goto <bb 7>;
<bb 11>:
return;
}
and the assembler:
mad_synth_mute:
.LFB0:
.cfi_startproc
movq %rdi, %r9
xorl %r8d, %r8d
.L2:
leaq 16(%r8), %rsi
movq %r9, %rdx
movq %r8, %rax
.p2align 4,,10
.p2align 3
.L3:
leaq 48(%rax), %rcx
salq $5, %rcx
addq %rdi, %rcx
movq $0, (%rcx)
movq $0, 8(%rcx)
movq $0, 16(%rcx)
movq $0, 24(%rcx)
leaq 32(%rax), %rcx
salq $5, %rcx
addq %rdi, %rcx
movq $0, (%rcx)
movq $0, 8(%rcx)
movq $0, 16(%rcx)
movq $0, 24(%rcx)
leaq 16(%rax), %rcx
addq $1, %rax
salq $5, %rcx
addq %rdi, %rcx
movq $0, (%rcx)
movq $0, 8(%rcx)
movq $0, 16(%rcx)
movq $0, 24(%rcx)
movq $0, (%rdx)
movq $0, 8(%rdx)
movq $0, 16(%rdx)
movq $0, 24(%rdx)
addq $32, %rdx
cmpq %rsi, %rax
jne .L3
addq $64, %r8
addq $2048, %r9
cmpq $128, %r8
jne .L2
rep
ret
