[llvm] [TBAA] Fix the case where a subobject gets accessed at a non-zero offset. (PR #101485)

[Ivan Kosarev via llvm-commits]

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@@ -613,12 +613,13 @@ static bool mayBeAccessToSubobjectOf(TBAAStructTagNode BaseTag,
     }
 
     if (BaseType.getNode() == SubobjectTag.getBaseType()) {
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kosarev wrote:

LangRef doesn't cover the new aggregate-enabled TBAA format, which this patch is about. The latest plan documentation-wise I'm aware of is to wait until the new format is mature enough to be enabled by default, and then update the documentation, see <https://reviews.llvm.org/D40975#955973>. Until then it's all work-in-progress and not something supposed to be exposed to the user.

https://github.com/llvm/llvm-project/pull/101485