Fix UnitTests/2004-02-02-NegativeZero.c, which regressed when

I broke negate of FP values.

llvm-svn: 107019

2 files changed, 13 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index d0d89c66a47..e2b4d2dd155 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -1224,8 +1224,12 @@ Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) {
   TestAndClearIgnoreResultAssign();
   // Emit unary minus with EmitSub so we handle overflow cases etc.
   BinOpInfo BinOp;
-  BinOp.RHS = Visit(E->getSubExpr());;
-  BinOp.LHS = llvm::Constant::getNullValue(BinOp.RHS->getType());
+  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.Ty = E->getType();
   BinOp.Opcode = BinaryOperator::Sub;
   BinOp.E = E;
diff --git a/clang/test/CodeGen/exprs.c b/clang/test/CodeGen/exprs.c
index b3cf9133bda..f7b02bc8a09 100644
--- a/clang/test/CodeGen/exprs.c
+++ b/clang/test/CodeGen/exprs.c
@@ -137,3 +137,10 @@ int f12() {
   // CHECK: ret i32 1
   return 1||1;
 }
+
+// Make sure negate of fp uses -0.0 for proper -0 handling.
+double f13(double X) {
+  // CHECK: define double @f13
+  // CHECK: fsub double -0.000000e+00, %tmp
+  return -X;
+}