Reuse getBinOpIdentity in createAnyOfTargetReduction [nfc]

Consolidating code so that we have one copy instead of multiple reasoning
about identity element.  Note that we're (deliberately) not passing
the FMF flags to common utility to preserve behavior in this change.

1 files changed, 7 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Utils/LoopUtils.cpp b/llvm/lib/Transforms/Utils/LoopUtils.cpp
index a49d3b0..8a8d8af 100644
--- a/llvm/lib/Transforms/Utils/LoopUtils.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUtils.cpp
@@ -1210,6 +1210,11 @@ Value *llvm::createAnyOfTargetReduction(IRBuilderBase &Builder, Value *Src,
 Value *llvm::createSimpleTargetReduction(IRBuilderBase &Builder, Value *Src,
                                          RecurKind RdxKind) {
   auto *SrcVecEltTy = cast<VectorType>(Src->getType())->getElementType();
+  auto getIdentity = [&]() {
+    Intrinsic::ID ID = getReductionIntrinsicID(RdxKind);
+    unsigned Opc = getArithmeticReductionInstruction(ID);
+    return ConstantExpr::getBinOpIdentity(Opc, SrcVecEltTy);
+  };
   switch (RdxKind) {
   case RecurKind::Add:
   case RecurKind::Mul:
@@ -1227,10 +1232,9 @@ Value *llvm::createSimpleTargetReduction(IRBuilderBase &Builder, Value *Src,
     return Builder.CreateUnaryIntrinsic(getReductionIntrinsicID(RdxKind), Src);
   case RecurKind::FMulAdd:
   case RecurKind::FAdd:
-    return Builder.CreateFAddReduce(ConstantFP::getNegativeZero(SrcVecEltTy),
-                                    Src);
+    return Builder.CreateFAddReduce(getIdentity(), Src);
   case RecurKind::FMul:
-    return Builder.CreateFMulReduce(ConstantFP::get(SrcVecEltTy, 1.0), Src);
+    return Builder.CreateFMulReduce(getIdentity(), Src);
   default:
     llvm_unreachable("Unhandled opcode");
   }