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diff --git a/llvm/lib/Transforms/Utils/InlineFunction.cpp b/llvm/lib/Transforms/Utils/InlineFunction.cpp
index c69ca70db91d..8e7f9ba4f717 100644
--- a/llvm/lib/Transforms/Utils/InlineFunction.cpp
+++ b/llvm/lib/Transforms/Utils/InlineFunction.cpp
@@ -1079,7 +1079,8 @@ static void AddAliasScopeMetadata(CallBase &CB, ValueToValueMapTy &VMap,
// Figure out if we're derived from anything that is not a noalias
// argument.
- bool RequiresNoCaptureBefore = false, UsesAliasingPtr = false;
+ bool RequiresNoCaptureBefore = false, UsesAliasingPtr = false,
+ UsesUnknownObject = false;
for (const Value *V : ObjSet) {
// Is this value a constant that cannot be derived from any pointer
// value (we need to exclude constant expressions, for example, that
@@ -1100,14 +1101,24 @@ static void AddAliasScopeMetadata(CallBase &CB, ValueToValueMapTy &VMap,
UsesAliasingPtr = true;
}
- // If this is not some identified function-local object (which cannot
- // directly alias a noalias argument), or some other argument (which,
- // by definition, also cannot alias a noalias argument), then we could
- // alias a noalias argument that has been captured).
- if (!isa<Argument>(V) && !isIdentifiedFunctionLocal(V))
+ if (isEscapeSource(V)) {
+ // An escape source can only alias with a noalias argument if it has
+ // been captured beforehand.
RequiresNoCaptureBefore = true;
+ } else if (!isa<Argument>(V) && !isIdentifiedObject(V)) {
+ // If this is neither an escape source, nor some identified object
+ // (which cannot directly alias a noalias argument), nor some other
+ // argument (which, by definition, also cannot alias a noalias
+ // argument), conservatively do not make any assumptions.
+ UsesUnknownObject = true;
+ }
}
+ // Nothing we can do if the used underlying object cannot be reliably
+ // determined.
+ if (UsesUnknownObject)
+ continue;
+
// A function call can always get captured noalias pointers (via other
// parameters, globals, etc.).
if (IsFuncCall && !IsArgMemOnlyCall)
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