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| author | Craig Topper <craig.topper@intel.com> | 2017-11-25 18:09:37 +0000 |
|---|---|---|
| committer | Craig Topper <craig.topper@intel.com> | 2017-11-25 18:09:37 +0000 |
| commit | ea37e201ec2f9c3d8b2c9bb37ff48cacdd992f55 (patch) | |
| tree | 6bebfa5efe92abba04700e0a8ba456b2e9e7def6 /llvm/lib/Target/X86/X86TargetTransformInfo.cpp | |
| parent | e7426556c16d86d52356b23538708dbea2008a76 (diff) | |
| download | bcm5719-llvm-ea37e201ec2f9c3d8b2c9bb37ff48cacdd992f55.tar.gz bcm5719-llvm-ea37e201ec2f9c3d8b2c9bb37ff48cacdd992f55.zip | |
[X86] Don't report gather is legal on Skylake CPUs when AVX2/AVX512 is disabled. Allow gather on SKX/CNL/ICL when AVX512 is disabled by using AVX2 instructions.
Summary:
This adds a new fast gather feature bit to cover all CPUs that support fast gather that we can use independent of whether the AVX512 feature is enabled. I'm only using this new bit to qualify AVX2 codegen. AVX512 is still implicitly assuming fast gather to keep tests working and to match the scatter behavior.
Test command lines have been added for these two cases.
Reviewers: magabari, delena, RKSimon, zvi
Reviewed By: RKSimon
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D40282
llvm-svn: 318983
Diffstat (limited to 'llvm/lib/Target/X86/X86TargetTransformInfo.cpp')
| -rw-r--r-- | llvm/lib/Target/X86/X86TargetTransformInfo.cpp | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp index f878f050e4e..d06d6a5d180 100644 --- a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp +++ b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp @@ -2518,9 +2518,11 @@ bool X86TTIImpl::isLegalMaskedGather(Type *DataTy) { int DataWidth = isa<PointerType>(ScalarTy) ? DL.getPointerSizeInBits() : ScalarTy->getPrimitiveSizeInBits(); - // AVX-512 and Skylake AVX2 allows gather and scatter - return (DataWidth == 32 || DataWidth == 64) && (ST->hasAVX512() || - ST->getProcFamily() == X86Subtarget::IntelSkylake); + // Some CPUs have better gather performance than others. + // TODO: Remove the explicit ST->hasAVX512()?, That would mean we would only + // enable gather with a -march. + return (DataWidth == 32 || DataWidth == 64) && + (ST->hasAVX512() || (ST->hasFastGather() && ST->hasAVX2())); } bool X86TTIImpl::isLegalMaskedScatter(Type *DataType) { |
