From 908f833e57bfacb310248cd9ef1c0257360a0c4e Mon Sep 17 00:00:00 2001 From: Simon Pilgrim Date: Thu, 15 Feb 2018 13:33:15 +0000 Subject: [X86][SSE] combineTruncateWithSat - use truncateVectorWithPACK to chain PACKSS vXi32-vXi8 saturated truncation We can use PACKSS to saturate each stage of the chain: PACKSSDW down to [-32768,32767] and then PACKSSWB to [-128,127]. PACKUS is a little trickier and will be handled in a separate patch. llvm-svn: 325235 --- llvm/lib/Target/X86/X86ISelLowering.cpp | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) (limited to 'llvm/lib/Target/X86/X86ISelLowering.cpp') diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index 6a82de1d7fe..d9b7f192b51 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -34212,7 +34212,9 @@ static SDValue detectAVX512USatPattern(SDValue In, EVT VT, static SDValue combineTruncateWithSat(SDValue In, EVT VT, const SDLoc &DL, SelectionDAG &DAG, const X86Subtarget &Subtarget) { + EVT SVT = VT.getScalarType(); EVT InVT = In.getValueType(); + EVT InSVT = InVT.getScalarType(); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); if (TLI.isTypeLegal(InVT) && TLI.isTypeLegal(VT) && isSATValidOnAVX512Subtarget(InVT, VT, Subtarget)) { @@ -34221,16 +34223,19 @@ static SDValue combineTruncateWithSat(SDValue In, EVT VT, const SDLoc &DL, if (auto USatVal = detectUSatPattern(In, VT)) return DAG.getNode(X86ISD::VTRUNCUS, DL, VT, USatVal); } - if (VT.isVector() && isPowerOf2_32(VT.getVectorNumElements()) && - ((VT.getScalarType() == MVT::i8 && InVT.getScalarType() == MVT::i16) || - (VT.getScalarType() == MVT::i16 && InVT.getScalarType() == MVT::i32))) { - if (auto SSatVal = detectSSatPattern(In, VT)) - return truncateVectorWithPACK(X86ISD::PACKSS, VT, SSatVal, DL, DAG, - Subtarget); - if (Subtarget.hasSSE41() || VT.getScalarType() == MVT::i8) + if (VT.isVector() && isPowerOf2_32(VT.getVectorNumElements())) { + if ((SVT == MVT::i8 || SVT == MVT::i16) && + (InSVT == MVT::i16 || InSVT == MVT::i32)) { + if (auto SSatVal = detectSSatPattern(In, VT)) + return truncateVectorWithPACK(X86ISD::PACKSS, VT, SSatVal, DL, DAG, + Subtarget); + } + if ((SVT == MVT::i8 && InSVT == MVT::i16) || + (SVT == MVT::i16 && InSVT == MVT::i32 && Subtarget.hasSSE41())) { if (auto USatVal = detectSSatPattern(In, VT, true)) return truncateVectorWithPACK(X86ISD::PACKUS, VT, USatVal, DL, DAG, Subtarget); + } } return SDValue(); } -- cgit v1.2.3