[InstSimplify] Use poison instead of undef for unreachable inst

nikic · nikic · commit 9b8c3c687163 · 2024-06-24T16:25:40.000+02:00
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -7155,7 +7155,7 @@ Value *llvm::simplifyInstruction(Instruction *I, const SimplifyQuery &SQ) {
   /// If called on unreachable code, the instruction may simplify to itself.
   /// Make life easier for users by detecting that case here, and returning a
   /// safe value instead.
-  return Result == I ? UndefValue::get(I->getType()) : Result;
+  return Result == I ? PoisonValue::get(I->getType()) : Result;
 }
 
 /// Implementation of recursive simplification through an instruction's

Original file line number	Diff line number	Diff line change
`@@ -7155,7 +7155,7 @@ Value llvm::simplifyInstruction(Instruction I, const SimplifyQuery &SQ) {`
`7155`	`7155`	`/// If called on unreachable code, the instruction may simplify to itself.`
`7156`	`7156`	`/// Make life easier for users by detecting that case here, and returning a`
`7157`	`7157`	`/// safe value instead.`
`7158`		`- return Result == I ? UndefValue::get(I->getType()) : Result;`
	`7158`	`+ return Result == I ? PoisonValue::get(I->getType()) : Result;`
`7159`	`7159`	`}`
`7160`	`7160`
`7161`	`7161`	`/// Implementation of recursive simplification through an instruction's`