[StructurizeCFG] Use poison instead of undef as placeholder [NFC] (#119137)

pedroclobo · web-flow · commit 986529634368 · 2024-12-10T15:03:44.000Z
diff --git a/llvm/lib/Transforms/Scalar/StructurizeCFG.cpp b/llvm/lib/Transforms/Scalar/StructurizeCFG.cpp
@@ -686,8 +686,8 @@ void StructurizeCFG::delPhiValues(BasicBlock *From, BasicBlock *To) {
 /// Add a dummy PHI value as soon as we knew the new predecessor
 void StructurizeCFG::addPhiValues(BasicBlock *From, BasicBlock *To) {
   for (PHINode &Phi : To->phis()) {
-    Value *Undef = UndefValue::get(Phi.getType());
-    Phi.addIncoming(Undef, From);
+    Value *Poison = PoisonValue::get(Phi.getType());
+    Phi.addIncoming(Poison, From);
   }
   AddedPhis[To].push_back(From);
 }

Original file line number	Diff line number	Diff line change
`@@ -686,8 +686,8 @@ void StructurizeCFG::delPhiValues(BasicBlock From, BasicBlock To) {`
`686`	`686`	`/// Add a dummy PHI value as soon as we knew the new predecessor`
`687`	`687`	`void StructurizeCFG::addPhiValues(BasicBlock From, BasicBlock To) {`
`688`	`688`	`for (PHINode &Phi : To->phis()) {`
`689`		`- Value *Undef = UndefValue::get(Phi.getType());`
`690`		`- Phi.addIncoming(Undef, From);`
	`689`	`+ Value *Poison = PoisonValue::get(Phi.getType());`
	`690`	`+ Phi.addIncoming(Poison, From);`
`691`	`691`	`}`
`692`	`692`	`AddedPhis[To].push_back(From);`
`693`	`693`	`}`