[X86][SSE] Improve target shuffle mask extraction

Add ability to extract vXi64 'vzext_movl' masks on 32-bit targets

llvm-svn: 281834

1 files changed, 14 insertions, 10 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index b7572907c43..a9051886251 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -4763,6 +4763,7 @@ static bool getTargetShuffleMaskIndices(SDValue MaskNode,
 
   MVT VT = MaskNode.getSimpleValueType();
   assert(VT.isVector() && "Can't produce a non-vector with a build_vector!");
+  unsigned NumMaskElts = VT.getSizeInBits() / MaskEltSizeInBits;
 
   // Split an APInt element into MaskEltSizeInBits sized pieces and
   // insert into the shuffle mask.
@@ -4794,17 +4795,20 @@ static bool getTargetShuffleMaskIndices(SDValue MaskNode,
 
   if (MaskNode.getOpcode() == X86ISD::VZEXT_MOVL &&
       MaskNode.getOperand(0).getOpcode() == ISD::SCALAR_TO_VECTOR) {
-
-    // TODO: Handle (MaskEltSizeInBits % VT.getScalarSizeInBits()) == 0
-    if ((VT.getScalarSizeInBits() % MaskEltSizeInBits) != 0)
-      return false;
-    unsigned ElementSplit = VT.getScalarSizeInBits() / MaskEltSizeInBits;
-
     SDValue MaskOp = MaskNode.getOperand(0).getOperand(0);
     if (auto *CN = dyn_cast<ConstantSDNode>(MaskOp)) {
-      SplitElementToMask(CN->getAPIntValue());
-      RawMask.append((VT.getVectorNumElements() - 1) * ElementSplit, 0);
-      return true;
+      if ((MaskEltSizeInBits % VT.getScalarSizeInBits()) == 0) {
+        RawMask.push_back(CN->getZExtValue());
+        RawMask.append(NumMaskElts - 1, 0);
+        return true;
+      }
+
+      if ((VT.getScalarSizeInBits() % MaskEltSizeInBits) == 0) {
+        unsigned ElementSplit = VT.getScalarSizeInBits() / MaskEltSizeInBits;
+        SplitElementToMask(CN->getAPIntValue());
+        RawMask.append((VT.getVectorNumElements() - 1) * ElementSplit, 0);
+        return true;
+      }
     }
     return false;
   }
@@ -4815,7 +4819,7 @@ static bool getTargetShuffleMaskIndices(SDValue MaskNode,
   // We can always decode if the buildvector is all zero constants,
   // but can't use isBuildVectorAllZeros as it might contain UNDEFs.
   if (all_of(MaskNode->ops(), X86::isZeroNode)) {
-    RawMask.append(VT.getSizeInBits() / MaskEltSizeInBits, 0);
+    RawMask.append(NumMaskElts, 0);
     return true;
   }