[llvm] [InstCombine] Add support for cast instructions in `getFreelyInvertedImpl` (PR #82451)

[Yingwei Zheng via llvm-commits]

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@@ -769,3 +769,88 @@ entry:
   %cmp = icmp sle i32 %select, %not.c
   ret i1 %cmp
 }
+
+define i32 @test_sext(i32 %a, i32 %b){
+; CHECK-LABEL: @test_sext(
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp ne i32 [[A:%.*]], 0
+; CHECK-NEXT:    [[TMP2:%.*]] = sext i1 [[TMP1]] to i32
+; CHECK-NEXT:    [[NOT:%.*]] = sub i32 [[TMP2]], [[B:%.*]]
+; CHECK-NEXT:    ret i32 [[NOT]]
+;
+  %cmp = icmp eq i32 %a, 0
+  %sext = sext i1 %cmp to i32
+  %add = add i32 %b, %sext
+  %not = xor i32 %add, -1
+  ret i32 %not
+}
+
+define <2 x i32> @test_sext_vec(<2 x i32> %a, <2 x i32> %b){
+; CHECK-LABEL: @test_sext_vec(
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp ne <2 x i32> [[A:%.*]], zeroinitializer
+; CHECK-NEXT:    [[TMP2:%.*]] = sext <2 x i1> [[TMP1]] to <2 x i32>
+; CHECK-NEXT:    [[NOT:%.*]] = sub <2 x i32> [[TMP2]], [[B:%.*]]
+; CHECK-NEXT:    ret <2 x i32> [[NOT]]
+;
+  %cmp = icmp eq <2 x i32> %a, zeroinitializer
+  %sext = sext <2 x i1> %cmp to <2 x i32>
+  %add = add <2 x i32> %b, %sext
+  %not = xor <2 x i32> %add, <i32 -1, i32 -1>
+  ret <2 x i32> %not
+}
+
+define i32 @test_zext_nneg(i32 %a, i32 %b){
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dtcxzyw wrote:

Oh, my bad. `zext nneg i1` is always simplified into zero.

https://github.com/llvm/llvm-project/pull/82451