[Reassociate] add tests for binop with identity constant; NFC

llvm-svn: 336214

1 files changed, 74 insertions, 0 deletions

diff --git a/llvm/test/Transforms/Reassociate/binop-identity.ll b/llvm/test/Transforms/Reassociate/binop-identity.ll
new file mode 100644
index 00000000000..12a6c7867ec
--- /dev/null
+++ b/llvm/test/Transforms/Reassociate/binop-identity.ll
@@ -0,0 +1,74 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -reassociate -S | FileCheck %s
+
+; Don't produce an instruction that is a no-op because the constant is an identity constant.
+
+define i32 @add_0(i32 %x) {
+; CHECK-LABEL: @add_0(
+; CHECK-NEXT:    ret i32 [[X:%.*]]
+;
+  %a1 = add i32 %x, -30
+  %a2 = add i32 %a1, 30
+  ret i32 %a2
+}
+
+define i32 @mul_1(i32 %x) {
+; CHECK-LABEL: @mul_1(
+; CHECK-NEXT:    ret i32 [[X:%.*]]
+;
+  %a1 = mul i32 %x, -1
+  %a2 = mul i32 %a1, -1
+  ret i32 %a2
+}
+
+define i8 @and_neg1(i8 %x) {
+; CHECK-LABEL: @and_neg1(
+; CHECK-NEXT:    ret i8 [[X:%.*]]
+;
+  %a1 = and i8 %x, 255
+  %a2 = and i8 %a1, 255
+  ret i8 %a2
+}
+
+define i8 @or_0(i8 %x) {
+; CHECK-LABEL: @or_0(
+; CHECK-NEXT:    ret i8 [[X:%.*]]
+;
+  %a1 = or i8 %x, 0
+  %a2 = or i8 %a1, 0
+  ret i8 %a2
+}
+
+define i8 @xor_0(i8 %x) {
+; CHECK-LABEL: @xor_0(
+; CHECK-NEXT:    ret i8 [[X:%.*]]
+;
+  %a1 = xor i8 %x, 42
+  %a2 = xor i8 %a1, 42
+  ret i8 %a2
+}
+
+; FIXME
+
+define float @fadd_0(float %x) {
+; CHECK-LABEL: @fadd_0(
+; CHECK-NEXT:    [[A2:%.*]] = fadd fast float [[X:%.*]], 0.000000e+00
+; CHECK-NEXT:    ret float [[A2]]
+;
+  %a1 = fadd fast float %x, -30.0
+  %a2 = fadd fast float %a1, 30.0
+  ret float %a2
+}
+
+; FIXME
+
+define float @fmul_1(float %x) {
+; CHECK-LABEL: @fmul_1(
+; CHECK-NEXT:    [[A2:%.*]] = fmul fast float [[X:%.*]], 1.000000e+00
+; CHECK-NEXT:    ret float [[A2]]
+;
+  %a1 = fmul fast float %x, 4.0
+  %a2 = fmul fast float %a1, 0.25
+  ret float %a2
+}
+