[NFC][InstCombine] Add tests for comparisons between x and negation of x (PR39480)

Author: LebedevRI

llvm/test/Transforms/InstCombine/cmp-x-vs-neg-x.ll

@@ -0,0 +1,174 @@
+; 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)
+
+define i1 @t0(i8 %x) {
+; CHECK-LABEL: @t0(
+; CHECK-NEXT:    [[NEG_X:%.*]] = sub nsw i8 0, [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[NEG_X]], [[X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %neg_x = sub nsw i8 0, %x
+  %cmp = icmp sgt i8 %neg_x, %x
+  ret i1 %cmp
+}
+
+define i1 @t0_commutative() {
+; CHECK-LABEL: @t0_commutative(
+; CHECK-NEXT:    [[X:%.*]] = call i8 @gen8()
+; CHECK-NEXT:    [[NEG_X:%.*]] = sub nsw i8 0, [[X]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 [[X]], [[NEG_X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %x = call i8 @gen8()
+  %neg_x = sub nsw i8 0, %x
+  %cmp = icmp slt i8 %x, %neg_x
+  ret i1 %cmp
+}
+
+define i1 @t0_extrause(i8 %x) {
+; CHECK-LABEL: @t0_extrause(
+; CHECK-NEXT:    [[NEG_X:%.*]] = sub nsw i8 0, [[X:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[NEG_X]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[NEG_X]], [[X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %neg_x = sub nsw i8 0, %x
+  call void @use8(i8 %neg_x)
+  %cmp = icmp sgt i8 %neg_x, %x
+  ret i1 %cmp
+}
+
+define i1 @t1(i8 %x) {
+; CHECK-LABEL: @t1(
+; CHECK-NEXT:    [[NEG_X:%.*]] = sub nsw i8 0, [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i8 [[NEG_X]], [[X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %neg_x = sub nsw i8 0, %x
+  %cmp = icmp sge i8 %neg_x, %x
+  ret i1 %cmp
+}
+
+define i1 @t2(i8 %x) {
+; CHECK-LABEL: @t2(
+; CHECK-NEXT:    [[NEG_X:%.*]] = sub nsw i8 0, [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 [[NEG_X]], [[X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %neg_x = sub nsw i8 0, %x
+  %cmp = icmp slt i8 %neg_x, %x
+  ret i1 %cmp
+}
+
+define i1 @t3(i8 %x) {
+; CHECK-LABEL: @t3(
+; CHECK-NEXT:    [[NEG_X:%.*]] = sub nsw i8 0, [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sle i8 [[NEG_X]], [[X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %neg_x = sub nsw i8 0, %x
+  %cmp = icmp sle i8 %neg_x, %x
+  ret i1 %cmp
+}
+
+define i1 @t4(i8 %x) {
+; CHECK-LABEL: @t4(
+; CHECK-NEXT:    [[NEG_X:%.*]] = sub nsw i8 0, [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i8 [[NEG_X]], [[X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %neg_x = sub nsw i8 0, %x
+  %cmp = icmp ugt i8 %neg_x, %x
+  ret i1 %cmp
+}
+
+define i1 @t5(i8 %x) {
+; CHECK-LABEL: @t5(
+; CHECK-NEXT:    [[NEG_X:%.*]] = sub nsw i8 0, [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp uge i8 [[NEG_X]], [[X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %neg_x = sub nsw i8 0, %x
+  %cmp = icmp uge i8 %neg_x, %x
+  ret i1 %cmp
+}
+
+define i1 @t6(i8 %x) {
+; CHECK-LABEL: @t6(
+; CHECK-NEXT:    [[NEG_X:%.*]] = sub nsw i8 0, [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i8 [[NEG_X]], [[X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %neg_x = sub nsw i8 0, %x
+  %cmp = icmp ult i8 %neg_x, %x
+  ret i1 %cmp
+}
+
+define i1 @t7(i8 %x) {
+; CHECK-LABEL: @t7(
+; CHECK-NEXT:    [[NEG_X:%.*]] = sub nsw i8 0, [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ule i8 [[NEG_X]], [[X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %neg_x = sub nsw i8 0, %x
+  %cmp = icmp ule i8 %neg_x, %x
+  ret i1 %cmp
+}
+
+define i1 @t8(i8 %x) {
+; CHECK-LABEL: @t8(
+; CHECK-NEXT:    [[NEG_X:%.*]] = sub nsw i8 0, [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[NEG_X]], [[X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %neg_x = sub nsw i8 0, %x
+  %cmp = icmp eq i8 %neg_x, %x
+  ret i1 %cmp
+}
+
+define i1 @t9(i8 %x) {
+; CHECK-LABEL: @t9(
+; CHECK-NEXT:    [[NEG_X:%.*]] = sub nsw i8 0, [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i8 [[NEG_X]], [[X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %neg_x = sub nsw i8 0, %x
+  %cmp = icmp ne i8 %neg_x, %x
+  ret i1 %cmp
+}
+
+define i1 @n10(i8 %x) {
+; CHECK-LABEL: @n10(
+; CHECK-NEXT:    [[NEG_X:%.*]] = sub i8 0, [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[NEG_X]], [[X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %neg_x = sub i8 0, %x ; not nsw
+  %cmp = icmp sgt i8 %neg_x, %x
+  ret i1 %cmp
+}
+
+define i1 @n11(i8 %x) {
+; CHECK-LABEL: @n11(
+; CHECK-NEXT:    [[NEG_X:%.*]] = sub nsw i8 1, [[X:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[NEG_X]], [[X]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %neg_x = sub nsw i8 1, %x ; not negation
+  %cmp = icmp sgt i8 %neg_x, %x
+  ret i1 %cmp
+}
+
+define i1 @n12(i8 %x1, i8 %x2) {
+; CHECK-LABEL: @n12(
+; CHECK-NEXT:    [[NEG_X:%.*]] = sub nsw i8 0, [[X1:%.*]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[NEG_X]], [[X2:%.*]]
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %neg_x = sub nsw i8 0, %x1 ; not %x2
+  %cmp = icmp sgt i8 %neg_x, %x2 ; not %x1
+  ret i1 %cmp
+}