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| author | liuhongt <hongtao.liu@intel.com> | 2023-10-09 15:07:54 +0800 |
|---|---|---|
| committer | liuhongt <hongtao.liu@intel.com> | 2023-10-30 11:10:01 +0800 |
| commit | 8c40b72036c967fbb1d1150515cf70aec382f0a2 (patch) | |
| tree | 416aba24f88619b92a2d3ebcd5689e1a7f58a3a8 /libcpp | |
| parent | 8111b5c23bd14f80607bd35af58ec31e38a0378e (diff) | |
| download | gcc-8c40b72036c967fbb1d1150515cf70aec382f0a2.zip gcc-8c40b72036c967fbb1d1150515cf70aec382f0a2.tar.gz gcc-8c40b72036c967fbb1d1150515cf70aec382f0a2.tar.bz2 | |
Improve memcmpeq for 512-bit vector with vpcmpeq + kortest.
When 2 vectors are equal, kmask is allones and kortest will set CF,
else CF will be cleared.
So CF bit can be used to check for the result of the comparison.
Before:
vmovdqu (%rsi), %ymm0
vpxorq (%rdi), %ymm0, %ymm0
vptest %ymm0, %ymm0
jne .L2
vmovdqu 32(%rsi), %ymm0
vpxorq 32(%rdi), %ymm0, %ymm0
vptest %ymm0, %ymm0
je .L5
.L2:
movl $1, %eax
xorl $1, %eax
vzeroupper
ret
After:
vmovdqu64 (%rsi), %zmm0
xorl %eax, %eax
vpcmpeqd (%rdi), %zmm0, %k0
kortestw %k0, %k0
setc %al
vzeroupper
ret
gcc/ChangeLog:
PR target/104610
* config/i386/i386-expand.cc (ix86_expand_branch): Handle
512-bit vector with vpcmpeq + kortest.
* config/i386/i386.md (cbranchxi4): New expander.
* config/i386/sse.md: (cbranch<mode>4): Extend to V16SImode
and V8DImode.
gcc/testsuite/ChangeLog:
* gcc.target/i386/pr104610-2.c: New test.
Diffstat (limited to 'libcpp')
0 files changed, 0 insertions, 0 deletions