[llvm] r321968 - [X86] Remove unneeded code from combineGatherScatter that used to delte SIGN_EXTEND_INREG nodes created during legalization of v2i1/v4i1 masks on KNL.

[Craig Topper via llvm-commits]

Author: ctopper
Date: Sun Jan  7 10:34:08 2018
New Revision: 321968

URL: http://llvm.org/viewvc/llvm-project?rev=321968&view=rev
Log:
[X86] Remove unneeded code from combineGatherScatter that used to delte SIGN_EXTEND_INREG nodes created during legalization of v2i1/v4i1 masks on KNL.

v2i1/v4i1 are now legal on KNL so no sign_extend_inreg is generated.

Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=321968&r1=321967&r2=321968&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Sun Jan  7 10:34:08 2018
@@ -36479,22 +36479,12 @@ static SDValue combineGatherScatter(SDNo
     }
   }
 
-  // Gather and Scatter instructions use k-registers for masks. The type of
-  // the masks is v*i1. So the mask will be truncated anyway.
-  // The SIGN_EXTEND_INREG my be dropped.
-  SDValue Mask = N->getOperand(2);
-  if (Subtarget.hasAVX512() && Mask.getOpcode() == ISD::SIGN_EXTEND_INREG) {
-    SmallVector<SDValue, 5> NewOps(N->op_begin(), N->op_end());
-    NewOps[2] = Mask.getOperand(0);
-    DAG.UpdateNodeOperands(N, NewOps);
-    return SDValue(N, 0);
-  }
-
   // With AVX2 we only demand the upper bit of the mask.
   if (!Subtarget.hasAVX512()) {
     const TargetLowering &TLI = DAG.getTargetLoweringInfo();
     TargetLowering::TargetLoweringOpt TLO(DAG, !DCI.isBeforeLegalize(),
                                           !DCI.isBeforeLegalizeOps());
+    SDValue Mask = N->getOperand(2);
     KnownBits Known;
     APInt DemandedMask(APInt::getSignMask(Mask.getScalarValueSizeInBits()));
     if (TLI.SimplifyDemandedBits(Mask, DemandedMask, Known, TLO)) {