[InstCombine] Support zext nneg in foldLogicCastConstant

[dtcxzyw]

This patch extends D36234 to handle zext nneg instructions.
I found this while adding support for cast instructions in getFreelyInvertedImpl.

[llvmbot]

@llvm/pr-subscribers-llvm-transforms

Author: Yingwei Zheng (dtcxzyw)

Changes

This patch extends D36234 to handle zext nneg instructions.
I found this while adding support for cast instructions in getFreelyInvertedImpl.

---

Full diff: https://github.com/llvm/llvm-project/pull/82355.diff

2 Files Affected:

• (modified) llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp (+1-1)
• (modified) llvm/test/Transforms/InstCombine/cast.ll (+2-2)

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index ba4649e50402af..bf8794bba8859f 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -1685,7 +1685,7 @@ static Instruction *foldLogicCastConstant(BinaryOperator &Logic, CastInst *Cast,
     }
   }
 
-  if (match(Cast, m_OneUse(m_SExt(m_Value(X))))) {
+  if (match(Cast, m_OneUse(m_SExtLike(m_Value(X))))) {
     if (Constant *TruncC = IC.getLosslessSignedTrunc(C, SrcTy)) {
       // LogicOpc (sext X), C --> sext (LogicOpc X, C)
       Value *NewOp = IC.Builder.CreateBinOp(LogicOpc, X, TruncC);
diff --git a/llvm/test/Transforms/InstCombine/cast.ll b/llvm/test/Transforms/InstCombine/cast.ll
index 1cda0e503ee939..85433a99f2caec 100644
--- a/llvm/test/Transforms/InstCombine/cast.ll
+++ b/llvm/test/Transforms/InstCombine/cast.ll
@@ -748,8 +748,8 @@ define i32 @test54(i64 %A) {
 define i64 @test55(i32 %A) {
 ; ALL-LABEL: @test55(
 ; ALL-NEXT:    [[TMP1:%.*]] = and i32 [[A:%.*]], 7224
-; ALL-NEXT:    [[C:%.*]] = zext nneg i32 [[TMP1]] to i64
-; ALL-NEXT:    [[D:%.*]] = or disjoint i64 [[C]], -32574
+; ALL-NEXT:    [[TMP2:%.*]] = or disjoint i32 [[TMP1]], -32574
+; ALL-NEXT:    [[D:%.*]] = sext i32 [[TMP2]] to i64
 ; ALL-NEXT:    ret i64 [[D]]
 ;
   %B = trunc i32 %A to i16

[nikic]

LGTM