[InstCombine] simplify fneg+fadd folds; NFC
Two cleanups:
1. As noted in D45453, we had tests that don't need FMF that were misplaced in the 'fast-math.ll' test file.
2. This removes the final uses of dyn_castFNegVal, so that can be deleted. We use 'match' now.
llvm-svn: 330126
diff --git a/llvm/test/Transforms/InstCombine/fadd.ll b/llvm/test/Transforms/InstCombine/fadd.ll
new file mode 100644
index 0000000..f7eac8e
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/fadd.ll
@@ -0,0 +1,27 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+; -x + y => y - x
+
+define float @fneg_op0(float %x, float %y) {
+; CHECK-LABEL: @fneg_op0(
+; CHECK-NEXT: [[ADD:%.*]] = fsub float [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: ret float [[ADD]]
+;
+ %neg = fsub float -0.0, %x
+ %add = fadd float %neg, %y
+ ret float %add
+}
+
+; x + -y => x - y
+
+define float @fneg_op1(float %x, float %y) {
+; CHECK-LABEL: @fneg_op1(
+; CHECK-NEXT: [[ADD:%.*]] = fsub float [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret float [[ADD]]
+;
+ %neg = fsub float -0.0, %y
+ %add = fadd float %x, %neg
+ ret float %add
+}
+