[X86] Make the type checks in detectAVX512USatPattern more robust

This code currently uses isSimple and getSizeInBits in an attempt to prune types. But isSimple will return true for any type that any target supports natively. I don't think that's a good way to prune types. I also don't think the dest element type checks are very robust since we didn't do an isSimple check on the dest type.

This patch adds a check for the input type being legal to the one caller that didn't already check that. Then we explicitly check the element types for the destination are i8, i16, or i32

Differential Revision: https://reviews.llvm.org/D42706

llvm-svn: 323924

1 files changed, 9 insertions, 7 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 9545fcdc3d9..f7b9d2c5c23 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -34092,14 +34092,12 @@ static bool isSATValidOnAVX512Subtarget(EVT SrcVT, EVT DstVT,
     return false;
 
   // FIXME: Scalar type may be supported if we move it to vector register.
-  if (!SrcVT.isVector() || !SrcVT.isSimple() || SrcVT.getSizeInBits() > 512)
+  if (!SrcVT.isVector())
     return false;
 
   EVT SrcElVT = SrcVT.getScalarType();
   EVT DstElVT = DstVT.getScalarType();
-  if (SrcElVT.getSizeInBits() < 16 || SrcElVT.getSizeInBits() > 64)
-    return false;
-  if (DstElVT.getSizeInBits() < 8 || DstElVT.getSizeInBits() > 32)
+  if (DstElVT != MVT::i8 && DstElVT != MVT::i16 && DstElVT != MVT::i32)
     return false;
   if (SrcVT.is512BitVector() || Subtarget.hasVLX())
     return SrcElVT.getSizeInBits() >= 32 || Subtarget.hasBWI();
@@ -34169,7 +34167,10 @@ static SDValue detectSSatPattern(SDValue In, EVT VT) {
 /// Return the source value to be truncated or SDValue() if the pattern was not
 /// matched.
 static SDValue detectAVX512USatPattern(SDValue In, EVT VT,
-                                       const X86Subtarget &Subtarget) {
+                                       const X86Subtarget &Subtarget,
+                                       const TargetLowering &TLI) {
+  if (!TLI.isTypeLegal(In.getValueType()))
+    return SDValue();
   if (!isSATValidOnAVX512Subtarget(In.getValueType(), VT, Subtarget))
     return SDValue();
   return detectUSatPattern(In, VT);
@@ -34820,13 +34821,14 @@ static SDValue combineStore(SDNode *N, SelectionDAG &DAG,
                           St->getPointerInfo(), St->getAlignment(),
                           St->getMemOperand()->getFlags());
 
+    const TargetLowering &TLI = DAG.getTargetLoweringInfo();
     if (SDValue Val =
-        detectAVX512USatPattern(St->getValue(), St->getMemoryVT(), Subtarget))
+        detectAVX512USatPattern(St->getValue(), St->getMemoryVT(), Subtarget,
+                                TLI))
       return EmitTruncSStore(false /* Unsigned saturation */, St->getChain(),
                              dl, Val, St->getBasePtr(),
                              St->getMemoryVT(), St->getMemOperand(), DAG);
 
-    const TargetLowering &TLI = DAG.getTargetLoweringInfo();
     unsigned NumElems = VT.getVectorNumElements();
     assert(StVT != VT && "Cannot truncate to the same type");
     unsigned FromSz = VT.getScalarSizeInBits();