SDValue DAGCombiner::visitFSUB(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
- ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
- ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
+ ConstantFPSDNode *N0CFP = isConstOrConstSplatFP(N0);
+ ConstantFPSDNode *N1CFP = isConstOrConstSplatFP(N1);
EVT VT = N->getValueType(0);
SDLoc dl(N);
const TargetOptions &Options = DAG.getTarget().Options;
--- /dev/null
+; RUN: llc < %s -enable-unsafe-fp-math -mtriple=x86_64-unknown-unknown -mcpu=corei7 | FileCheck %s
+
+; Make sure that vectors get the same benefits as scalars when using unsafe-fp-math.
+
+; Subtracting zero is free.
+define <4 x float> @vec_fsub_zero(<4 x float> %x) {
+; CHECK-LABEL: vec_fsub_zero:
+; CHECK-NOT: subps
+; CHECK-NOT: xorps
+; CHECK: retq
+ %sub = fsub <4 x float> %x, zeroinitializer
+ ret <4 x float> %sub
+}
+
+; Negating doesn't require subtraction.
+define <4 x float> @vec_fneg(<4 x float> %x) {
+; CHECK-LABEL: vec_fneg:
+; CHECK: xorps {{.*}}LCP{{.*}}, %xmm0
+; CHECK-NOT: subps
+; CHECK-NEXT: retq
+ %sub = fsub <4 x float> zeroinitializer, %x
+ ret <4 x float> %sub
+}