[llvm] [InstCombine] Simplify the pattern `a ne/eq (zext (a ne/eq c))` (PR #65852)

[via llvm-commits]

================
@@ -1034,6 +1034,187 @@ define i1 @icmp_ne_bool_1(ptr %ptr) {
   ret i1 %cmp
 }
 
+define i1 @icmp_ne_zext_eq_zero(i32 %a) {
+; CHECK-LABEL: @icmp_ne_zext_eq_zero(
+; CHECK-NEXT:    ret i1 true
+;
+  %cmp = icmp eq i32 %a, 0
+  %conv = zext i1 %cmp to i32
+  %cmp1 = icmp ne i32 %conv, %a
+  ret i1 %cmp1
+}
+
+define i1 @icmp_ne_zext_ne_zero(i32 %a) {
+; CHECK-LABEL: @icmp_ne_zext_ne_zero(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ugt i32 [[A:%.*]], 1
+; CHECK-NEXT:    ret i1 [[CMP1]]
+;
+  %cmp = icmp ne i32 %a, 0
+  %conv = zext i1 %cmp to i32
+  %cmp1 = icmp ne i32 %conv, %a
+  ret i1 %cmp1
+}
+
+define i1 @icmp_eq_zext_eq_zero(i32 %a) {
+; CHECK-LABEL: @icmp_eq_zext_eq_zero(
+; CHECK-NEXT:    ret i1 false
+;
+  %cmp = icmp eq i32 %a, 0
+  %conv = zext i1 %cmp to i32
+  %cmp1 = icmp eq i32 %conv, %a
+  ret i1 %cmp1
+}
+
+define i1 @icmp_eq_zext_ne_zero(i32 %a) {
+; CHECK-LABEL: @icmp_eq_zext_ne_zero(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i32 [[A:%.*]], 2
+; CHECK-NEXT:    ret i1 [[CMP1]]
+;
+  %cmp = icmp ne i32 %a, 0
+  %conv = zext i1 %cmp to i32
+  %cmp1 = icmp eq i32 %conv, %a
+  ret i1 %cmp1
+}
+
+define i1 @icmp_ne_zext_eq_one(i32 %a) {
+; CHECK-LABEL: @icmp_ne_zext_eq_one(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ugt i32 [[A:%.*]], 1
+; CHECK-NEXT:    ret i1 [[CMP1]]
+;
+  %cmp = icmp eq i32 %a, 1
+  %conv = zext i1 %cmp to i32
+  %cmp1 = icmp ne i32 %conv, %a
+  ret i1 %cmp1
+}
+
+define i1 @icmp_ne_zext_ne_one(i32 %a) {
+; CHECK-LABEL: @icmp_ne_zext_ne_one(
+; CHECK-NEXT:    ret i1 true
+;
+  %cmp = icmp ne i32 %a, 1
+  %conv = zext i1 %cmp to i32
+  %cmp1 = icmp ne i32 %conv, %a
+  ret i1 %cmp1
+}
+
+define i1 @icmp_eq_zext_eq_one(i32 %a) {
+; CHECK-LABEL: @icmp_eq_zext_eq_one(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i32 [[A:%.*]], 2
+; CHECK-NEXT:    ret i1 [[CMP1]]
+;
+  %cmp = icmp eq i32 %a, 1
+  %conv = zext i1 %cmp to i32
+  %cmp1 = icmp eq i32 %conv, %a
+  ret i1 %cmp1
+}
+
+define i1 @icmp_eq_zext_ne_one(i32 %a) {
+; CHECK-LABEL: @icmp_eq_zext_ne_one(
+; CHECK-NEXT:    ret i1 false
+;
+  %cmp = icmp ne i32 %a, 1
+  %conv = zext i1 %cmp to i32
+  %cmp1 = icmp eq i32 %conv, %a
+  ret i1 %cmp1
+}
+
+define i1 @icmp_ne_zext_eq_non_boolean(i32 %a) {
+; CHECK-LABEL: @icmp_ne_zext_eq_non_boolean(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ne i32 [[A:%.*]], 0
+; CHECK-NEXT:    ret i1 [[CMP1]]
+;
+  %cmp = icmp eq i32 %a, 2
+  %conv = zext i1 %cmp to i32
+  %cmp1 = icmp ne i32 %conv, %a
+  ret i1 %cmp1
+}
+
+define i1 @icmp_ne_zext_ne_non_boolean(i32 %a) {
+; CHECK-LABEL: @icmp_ne_zext_ne_non_boolean(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ne i32 [[A:%.*]], 1
+; CHECK-NEXT:    ret i1 [[CMP1]]
+;
+  %cmp = icmp ne i32 %a, 2
+  %conv = zext i1 %cmp to i32
+  %cmp1 = icmp ne i32 %conv, %a
+  ret i1 %cmp1
+}
+
+define i1 @icmp_eq_zext_eq_non_boolean(i32 %a) {
+; CHECK-LABEL: @icmp_eq_zext_eq_non_boolean(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i32 [[A:%.*]], 0
+; CHECK-NEXT:    ret i1 [[CMP1]]
+;
+  %cmp = icmp eq i32 %a, 2
+  %conv = zext i1 %cmp to i32
+  %cmp1 = icmp eq i32 %conv, %a
+  ret i1 %cmp1
+}
+
+define i1 @icmp_eq_zext_ne_non_boolean(i32 %a) {
+; CHECK-LABEL: @icmp_eq_zext_ne_non_boolean(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i32 [[A:%.*]], 1
+; CHECK-NEXT:    ret i1 [[CMP1]]
+;
+  %cmp = icmp ne i32 %a, 2
+  %conv = zext i1 %cmp to i32
+  %cmp1 = icmp eq i32 %conv, %a
+  ret i1 %cmp1
+}
+
+define <2 x i1> @icmp_ne_zext_eq_zero_vec(<2 x i32> %a) {
+; CHECK-LABEL: @icmp_ne_zext_eq_zero_vec(
+; CHECK-NEXT:    ret <2 x i1> <i1 true, i1 true>
+;
+  %cmp = icmp eq <2 x i32> %a, <i32 0, i32 0>
+  %conv = zext <2 x i1> %cmp to <2 x i32>
+  %cmp1 = icmp ne <2 x i32> %conv, %a
+  ret <2 x i1> %cmp1
+}
+
+define <2 x i1> @icmp_ne_zext_ne_zero_vec(<2 x i32> %a) {
+; CHECK-LABEL: @icmp_ne_zext_ne_zero_vec(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ugt <2 x i32> [[A:%.*]], <i32 1, i32 1>
+; CHECK-NEXT:    ret <2 x i1> [[CMP1]]
+;
+  %cmp = icmp ne <2 x i32> %a, <i32 0, i32 0>
+  %conv = zext <2 x i1> %cmp to <2 x i32>
+  %cmp1 = icmp ne <2 x i32> %conv, %a
+  ret <2 x i1> %cmp1
+}
+
+define <2 x i1> @icmp_ne_zext_eq_one_vec(<2 x i32> %a) {
+; CHECK-LABEL: @icmp_ne_zext_eq_one_vec(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ugt <2 x i32> [[A:%.*]], <i32 1, i32 1>
+; CHECK-NEXT:    ret <2 x i1> [[CMP1]]
+;
+  %cmp = icmp eq <2 x i32> %a, <i32 1, i32 1>
+  %conv = zext <2 x i1> %cmp to <2 x i32>
+  %cmp1 = icmp ne <2 x i32> %conv, %a
+  ret <2 x i1> %cmp1
+}
+
+define <2 x i1> @icmp_ne_zext_ne_one_vec(<2 x i32> %a) {
+; CHECK-LABEL: @icmp_ne_zext_ne_one_vec(
+; CHECK-NEXT:    ret <2 x i1> <i1 true, i1 true>
+;
+  %cmp = icmp ne <2 x i32> %a, <i32 1, i32 1>
+  %conv = zext <2 x i1> %cmp to <2 x i32>
+  %cmp1 = icmp ne <2 x i32> %conv, %a
+  ret <2 x i1> %cmp1
+}
+
+define <2 x i1> @icmp_ne_zext_eq_non_boolean_vec(<2 x i32> %a) {
+; CHECK-LABEL: @icmp_ne_zext_eq_non_boolean_vec(
+; CHECK-NEXT:    [[CMP1:%.*]] = icmp ne <2 x i32> [[A:%.*]], zeroinitializer
+; CHECK-NEXT:    ret <2 x i1> [[CMP1]]
+;
+  %cmp = icmp eq <2 x i32> %a, <i32 2, i32 2>
+  %conv = zext <2 x i1> %cmp to <2 x i32>
+  %cmp1 = icmp ne <2 x i32> %conv, %a
+  ret <2 x i1> %cmp1
+}
+
----------------
goldsteinn wrote:

As usual please split test changes into prior commit.

https://github.com/llvm/llvm-project/pull/65852