vendor/llvm-project/llvmorg-14.0.0-rc1-74-g4dc3cb8e3255

1 files changed, 14 insertions, 32 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 90753b5b4d33..a1c387574ebb 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -33418,6 +33418,20 @@ bool X86TargetLowering::isNarrowingProfitable(EVT VT1, EVT VT2) const {
   return !(VT1 == MVT::i32 && VT2 == MVT::i16);
 }
 
+bool X86TargetLowering::shouldFoldSelectWithIdentityConstant(unsigned Opcode,
+                                                             EVT VT) const {
+  // TODO: This is too general. There are cases where pre-AVX512 codegen would
+  //       benefit. The transform may also be profitable for scalar code.
+  if (!Subtarget.hasAVX512())
+    return false;
+  if (!Subtarget.hasVLX() && !VT.is512BitVector())
+    return false;
+  if (!VT.isVector())
+    return false;
+
+  return true;
+}
+
 /// Targets can use this to indicate that they only support *some*
 /// VECTOR_SHUFFLE operations, those with specific masks.
 /// By default, if a target supports the VECTOR_SHUFFLE node, all mask values
@@ -43108,38 +43122,6 @@ static SDValue combineExtractVectorElt(SDNode *N, SelectionDAG &DAG,
     }
   }
 
-  // If this extract is from a loaded vector value and will be used as an
-  // integer, that requires a potentially expensive XMM -> GPR transfer.
-  // Additionally, if we can convert to a scalar integer load, that will likely
-  // be folded into a subsequent integer op.
-  // Note: Unlike the related fold for this in DAGCombiner, this is not limited
-  //       to a single-use of the loaded vector. For the reasons above, we
-  //       expect this to be profitable even if it creates an extra load.
-  bool LikelyUsedAsVector = any_of(N->uses(), [](SDNode *Use) {
-    return Use->getOpcode() == ISD::STORE ||
-           Use->getOpcode() == ISD::INSERT_VECTOR_ELT ||
-           Use->getOpcode() == ISD::SCALAR_TO_VECTOR;
-  });
-  auto *LoadVec = dyn_cast<LoadSDNode>(InputVector);
-  if (LoadVec && CIdx && ISD::isNormalLoad(LoadVec) && VT.isInteger() &&
-      SrcVT.getVectorElementType() == VT && DCI.isAfterLegalizeDAG() &&
-      !LikelyUsedAsVector) {
-    const TargetLowering &TLI = DAG.getTargetLoweringInfo();
-    SDValue NewPtr =
-        TLI.getVectorElementPointer(DAG, LoadVec->getBasePtr(), SrcVT, EltIdx);
-    unsigned PtrOff = VT.getSizeInBits() * CIdx->getZExtValue() / 8;
-    MachinePointerInfo MPI = LoadVec->getPointerInfo().getWithOffset(PtrOff);
-    Align Alignment = commonAlignment(LoadVec->getAlign(), PtrOff);
-    SDValue Load =
-        DAG.getLoad(VT, dl, LoadVec->getChain(), NewPtr, MPI, Alignment,
-                    LoadVec->getMemOperand()->getFlags(), LoadVec->getAAInfo());
-    SDValue Chain = Load.getValue(1);
-    SDValue From[] = {SDValue(N, 0), SDValue(LoadVec, 1)};
-    SDValue To[] = {Load, Chain};
-    DAG.ReplaceAllUsesOfValuesWith(From, To, 2);
-    return SDValue(N, 0);
-  }
-
   return SDValue();
 }