[llvm] r350687 - [X86] Correct the MaskVT for avx512 gather/scatter intrinsics to use the min of the number of index and data elements.

[Craig Topper via llvm-commits]

Author: ctopper
Date: Tue Jan  8 20:21:12 2019
New Revision: 350687

URL: http://llvm.org/viewvc/llvm-project?rev=350687&view=rev
Log:
[X86] Correct the MaskVT for avx512 gather/scatter intrinsics to use the min of the number of index and data elements.

When the result type is v2i64/v2f64 and the index element size is i32, the index vector has two unused elements making the type v4i32. The mask VT should match the number of memory accesses that will be made.

This is consistent with the isel patterns used for the target independent gather/scatter intrinsic.

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=350687&r1=350686&r2=350687&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Tue Jan  8 20:21:12 2019
@@ -22248,14 +22248,16 @@ static SDValue getGatherNode(unsigned Op
                               SDValue Src, SDValue Mask, SDValue Base,
                               SDValue Index, SDValue ScaleOp, SDValue Chain,
                               const X86Subtarget &Subtarget) {
+  MVT VT = Op.getSimpleValueType();
   SDLoc dl(Op);
   auto *C = dyn_cast<ConstantSDNode>(ScaleOp);
   // Scale must be constant.
   if (!C)
     return SDValue();
   SDValue Scale = DAG.getTargetConstant(C->getZExtValue(), dl, MVT::i8);
-  MVT MaskVT = MVT::getVectorVT(MVT::i1,
-                             Index.getSimpleValueType().getVectorNumElements());
+  unsigned MinElts = std::min(Index.getSimpleValueType().getVectorNumElements(),
+                              VT.getVectorNumElements());
+  MVT MaskVT = MVT::getVectorVT(MVT::i1, MinElts);
 
   SDValue VMask = getMaskNode(Mask, MaskVT, Subtarget, DAG, dl);
   SDVTList VTs = DAG.getVTList(Op.getValueType(), MaskVT, MVT::Other);
@@ -22284,8 +22286,9 @@ static SDValue getScatterNode(unsigned O
   SDValue Scale = DAG.getTargetConstant(C->getZExtValue(), dl, MVT::i8);
   SDValue Disp = DAG.getTargetConstant(0, dl, MVT::i32);
   SDValue Segment = DAG.getRegister(0, MVT::i32);
-  MVT MaskVT = MVT::getVectorVT(MVT::i1,
-                             Index.getSimpleValueType().getVectorNumElements());
+  unsigned MinElts = std::min(Index.getSimpleValueType().getVectorNumElements(),
+                              Src.getSimpleValueType().getVectorNumElements());
+  MVT MaskVT = MVT::getVectorVT(MVT::i1, MinElts);
 
   SDValue VMask = getMaskNode(Mask, MaskVT, Subtarget, DAG, dl);
   SDVTList VTs = DAG.getVTList(MaskVT, MVT::Other);