diff --git a/llvm/lib/Transforms/Utils/InlineFunction.cpp b/llvm/lib/Transforms/Utils/InlineFunction.cpp --- a/llvm/lib/Transforms/Utils/InlineFunction.cpp +++ b/llvm/lib/Transforms/Utils/InlineFunction.cpp @@ -1077,7 +1077,8 @@ // 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 @@ -1098,14 +1099,24 @@ 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(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(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) diff --git a/llvm/test/Transforms/Inline/inline-noalias-unidentify-object.ll b/llvm/test/Transforms/Inline/inline-noalias-unidentify-object.ll --- a/llvm/test/Transforms/Inline/inline-noalias-unidentify-object.ll +++ b/llvm/test/Transforms/Inline/inline-noalias-unidentify-object.ll @@ -14,7 +14,7 @@ ; CHECK-NEXT: [[P_6_I:%.*]] = getelementptr i8, ptr [[P_5_I]], i64 1 ; CHECK-NEXT: [[P_7_I:%.*]] = getelementptr i8, ptr [[P_6_I]], i64 1 ; CHECK-NEXT: [[P_8_ALIAS_I:%.*]] = getelementptr i8, ptr [[P_7_I]], i64 1 -; CHECK-NEXT: store i32 42, ptr [[P_8_ALIAS_I]], align 4, !noalias !0 +; CHECK-NEXT: store i32 42, ptr [[P_8_ALIAS_I]], align 4 ; CHECK-NEXT: ret i32 [[V_I]] ; %v = call i32 @callee(ptr %p)