[IRBuilder] Update IRBuilder::CreateFNeg(...) to return a UnaryOperator

Also update Clang to call Builder.CreateFNeg(...) for UnaryMinus.

Differential Revision: https://reviews.llvm.org/D61675

llvm-svn: 374240

1 files changed, 8 insertions, 6 deletions

diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index bff88b2feca..19b1cedf32e 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -2577,14 +2577,16 @@ ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
 
 Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
   TestAndClearIgnoreResultAssign();
+  Value *Op = Visit(E->getSubExpr());
+
+  // Generate a unary FNeg for FP ops.
+  if (Op->getType()->isFPOrFPVectorTy())
+    return Builder.CreateFNeg(Op, "fneg");
+
   // Emit unary minus with EmitSub so we handle overflow cases etc.
   BinOpInfo BinOp;
-  BinOp.RHS = Visit(E->getSubExpr());
-
-  if (BinOp.RHS->getType()->isFPOrFPVectorTy())
-    BinOp.LHS = llvm::ConstantFP::getZeroValueForNegation(BinOp.RHS->getType());
-  else
-    BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType());
+  BinOp.RHS = Op;
+  BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType());
   BinOp.Ty = E->getType();
   BinOp.Opcode = BO_Sub;
   // FIXME: once UnaryOperator carries FPFeatures, copy it here.