[llvm] [BasicAA][TLI] Local-linkage or non-thread-local globals may not alias errno (PR #170290)

[Antonio Frighetto via llvm-commits]

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@@ -1870,8 +1870,21 @@ AliasResult BasicAAResult::aliasErrno(const MemoryLocation &Loc,
       Loc.Size.getValue().getKnownMinValue() * 8 > TLI.getIntSize())
     return AliasResult::NoAlias;
 
-  if (isIdentifiedFunctionLocal(getUnderlyingObject(Loc.Ptr)))
+  const Value *Object = getUnderlyingObject(Loc.Ptr);
+  if (isIdentifiedFunctionLocal(Object))
     return AliasResult::NoAlias;
+
+  if (auto *GV = dyn_cast<GlobalVariable>(Object)) {
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antoniofrighetto wrote:

Don't believe so - if a GlobalAlias turns out to be a GlobalVariable, getUnderlyingObject() should tell us that.

https://github.com/llvm/llvm-project/pull/170290