[NFC][InstCombine] Add test coverage for (x ^ C) ^ y pattern

Author: LebedevRI

llvm/test/Transforms/InstCombine/hoist-xor-by-constant-from-xor-by-value.ll

@@ -0,0 +1,75 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+declare i8 @gen8()
+declare void @use8(i8)
+
+@a = global i8 17
+
+define i8 @t0_scalar(i8 %x, i8 %y) {
+; CHECK-LABEL: @t0_scalar(
+; CHECK-NEXT:    [[I0:%.*]] = xor i8 [[X:%.*]], 42
+; CHECK-NEXT:    [[R:%.*]] = xor i8 [[I0]], [[Y:%.*]]
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %i0 = xor i8 %x, 42
+  %r = xor i8 %i0, %y
+  ret i8 %r
+}
+
+define <2 x i8> @t1_splatvec(<2 x i8> %x, <2 x i8> %y) {
+; CHECK-LABEL: @t1_splatvec(
+; CHECK-NEXT:    [[I0:%.*]] = xor <2 x i8> [[X:%.*]], <i8 42, i8 42>
+; CHECK-NEXT:    [[R:%.*]] = xor <2 x i8> [[I0]], [[Y:%.*]]
+; CHECK-NEXT:    ret <2 x i8> [[R]]
+;
+  %i0 = xor <2 x i8> %x, <i8 42, i8 42>
+  %r = xor <2 x i8> %i0, %y
+  ret <2 x i8> %r
+}
+define <2 x i8> @t2_vec(<2 x i8> %x, <2 x i8> %y) {
+; CHECK-LABEL: @t2_vec(
+; CHECK-NEXT:    [[I0:%.*]] = xor <2 x i8> [[X:%.*]], <i8 42, i8 24>
+; CHECK-NEXT:    [[R:%.*]] = xor <2 x i8> [[I0]], [[Y:%.*]]
+; CHECK-NEXT:    ret <2 x i8> [[R]]
+;
+  %i0 = xor <2 x i8> %x, <i8 42, i8 24>
+  %r = xor <2 x i8> %i0, %y
+  ret <2 x i8> %r
+}
+define <2 x i8> @t3_vec_undef(<2 x i8> %x, <2 x i8> %y) {
+; CHECK-LABEL: @t3_vec_undef(
+; CHECK-NEXT:    [[I0:%.*]] = xor <2 x i8> [[X:%.*]], <i8 42, i8 undef>
+; CHECK-NEXT:    [[R:%.*]] = xor <2 x i8> [[I0]], [[Y:%.*]]
+; CHECK-NEXT:    ret <2 x i8> [[R]]
+;
+  %i0 = xor <2 x i8> %x, <i8 42, i8 undef>
+  %r = xor <2 x i8> %i0, %y
+  ret <2 x i8> %r
+}
+
+define i8 @t4_extrause(i8 %x, i8 %y) {
+; CHECK-LABEL: @t4_extrause(
+; CHECK-NEXT:    [[I0:%.*]] = xor i8 [[X:%.*]], 42
+; CHECK-NEXT:    call void @use8(i8 [[I0]])
+; CHECK-NEXT:    [[R:%.*]] = xor i8 [[I0]], [[Y:%.*]]
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %i0 = xor i8 %x, 42
+  call void @use8(i8 %i0)
+  %r = xor i8 %i0, %y
+  ret i8 %r
+}
+
+define i8 @t5_commutativity(i8 %x) {
+; CHECK-LABEL: @t5_commutativity(
+; CHECK-NEXT:    [[I0:%.*]] = xor i8 [[X:%.*]], 42
+; CHECK-NEXT:    [[Y:%.*]] = call i8 @gen8()
+; CHECK-NEXT:    [[R:%.*]] = xor i8 [[Y]], [[I0]]
+; CHECK-NEXT:    ret i8 [[R]]
+;
+  %i0 = xor i8 %x, 42
+  %y = call i8 @gen8()
+  %r = xor i8 %y, %i0
+  ret i8 %r
+}