[X86] Simplify creation of saturating truncating stores.

We just need to check if the truncating store is legal
instead of going through isSATValidOnAVX512Subtarget.

llvm-svn: 368607

1 files changed, 11 insertions, 41 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index bacb7ab74f4..7049a6877a8 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -39021,36 +39021,6 @@ static SDValue detectSSatPattern(SDValue In, EVT VT, bool MatchPackUS = false) {
   return SDValue();
 }
 
-/// Detect a pattern of truncation with signed saturation.
-/// The types should allow to use VPMOVSS* instruction on AVX512.
-/// Return the source value to be truncated or SDValue() if the pattern was not
-/// matched.
-static SDValue detectAVX512SSatPattern(SDValue In, EVT VT,
-                                       const X86Subtarget &Subtarget,
-                                       const TargetLowering &TLI) {
-  if (!TLI.isTypeLegal(In.getValueType()))
-    return SDValue();
-  if (!isSATValidOnAVX512Subtarget(In.getValueType(), VT, Subtarget))
-    return SDValue();
-  return detectSSatPattern(In, VT);
-}
-
-/// Detect a pattern of truncation with saturation:
-/// (truncate (umin (x, unsigned_max_of_dest_type)) to dest_type).
-/// The types should allow to use VPMOVUS* instruction on AVX512.
-/// Return the source value to be truncated or SDValue() if the pattern was not
-/// matched.
-static SDValue detectAVX512USatPattern(SDValue In, EVT VT, SelectionDAG &DAG,
-                                       const SDLoc &DL,
-                                       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, DAG, DL);
-}
-
 static SDValue combineTruncateWithSat(SDValue In, EVT VT, const SDLoc &DL,
                                       SelectionDAG &DAG,
                                       const X86Subtarget &Subtarget) {
@@ -39653,17 +39623,17 @@ static SDValue combineStore(SDNode *N, SelectionDAG &DAG,
                           St->getPointerInfo(), St->getAlignment(),
                           St->getMemOperand()->getFlags());
 
-    if (SDValue Val =
-        detectAVX512SSatPattern(St->getValue(), St->getMemoryVT(), Subtarget,
-                                TLI))
-      return EmitTruncSStore(true /* Signed saturation */, St->getChain(),
-                             dl, Val, St->getBasePtr(),
-                             St->getMemoryVT(), St->getMemOperand(), DAG);
-    if (SDValue Val = detectAVX512USatPattern(St->getValue(), St->getMemoryVT(),
-                                              DAG, dl, Subtarget, TLI))
-      return EmitTruncSStore(false /* Unsigned saturation */, St->getChain(),
-                             dl, Val, St->getBasePtr(),
-                             St->getMemoryVT(), St->getMemOperand(), DAG);
+    if (TLI.isTruncStoreLegal(VT, StVT)) {
+      if (SDValue Val = detectSSatPattern(St->getValue(), St->getMemoryVT()))
+        return EmitTruncSStore(true /* Signed saturation */, St->getChain(),
+                               dl, Val, St->getBasePtr(),
+                               St->getMemoryVT(), St->getMemOperand(), DAG);
+      if (SDValue Val = detectUSatPattern(St->getValue(), St->getMemoryVT(),
+                                          DAG, dl))
+        return EmitTruncSStore(false /* Unsigned saturation */, St->getChain(),
+                               dl, Val, St->getBasePtr(),
+                               St->getMemoryVT(), St->getMemOperand(), DAG);
+    }
 
     return SDValue();
   }