diff options
Diffstat (limited to 'llvm/lib/Target/X86/X86ISelLowering.cpp')
| -rw-r--r-- | llvm/lib/Target/X86/X86ISelLowering.cpp | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index e18b55b9629..368f409394e 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -40898,8 +40898,8 @@ static SDValue combineVectorTruncation(SDNode *N, SelectionDAG &DAG, static SDValue combineVectorSignBitsTruncation(SDNode *N, const SDLoc &DL, SelectionDAG &DAG, const X86Subtarget &Subtarget) { - // Requires SSE2 but AVX512 has fast truncate. - if (!Subtarget.hasSSE2() || Subtarget.hasAVX512()) + // Requires SSE2. + if (!Subtarget.hasSSE2()) return SDValue(); if (!N->getValueType(0).isVector() || !N->getValueType(0).isSimple()) @@ -40923,6 +40923,13 @@ static SDValue combineVectorSignBitsTruncation(SDNode *N, const SDLoc &DL, if (InSVT != MVT::i16 && InSVT != MVT::i32 && InSVT != MVT::i64) return SDValue(); + // AVX512 has fast truncate, but if the input is already going to be split, + // there's no harm in trying pack. + if (Subtarget.hasAVX512() && + !(!Subtarget.useAVX512Regs() && VT.is256BitVector() && + InVT.is512BitVector())) + return SDValue(); + unsigned NumPackedSignBits = std::min<unsigned>(SVT.getSizeInBits(), 16); unsigned NumPackedZeroBits = Subtarget.hasSSE41() ? NumPackedSignBits : 8; |
