SuccessChanges

Summary

  1. [Attributor] Really use the executed-context (details)
Commit eb4f41dfe58fc88794e1e227935a6f972f1a50e4 by johannes
[Attributor] Really use the executed-context
Before we did not follow casts and geps when we looked at the users of a
pointer in the pointers must-be-executed-context. This caused us to fail
to determine if it was accessed for sure. With this change we follow
such users now.
The above extension exposed problems in
getKnownNonNullAndDerefBytesForUse which did not always check what the
base pointer was. We also did not handle negative offsets as
conservative as we have to without explicit loop handling. Finally, we
should not derive a huge number if we access a pointer that was
traversed backwards first.
The problems exposed by this functional change are already tested in the
existing test cases as is the functional change.
Differential Revision: https://reviews.llvm.org/D69647
The file was modifiedllvm/test/Transforms/InferFunctionAttrs/dereferenceable.ll
The file was modifiedllvm/test/Transforms/FunctionAttrs/dereferenceable.ll
The file was modifiedllvm/test/Transforms/FunctionAttrs/nocapture.ll
The file was modifiedllvm/test/Transforms/FunctionAttrs/nosync.ll
The file was modifiedllvm/test/Transforms/FunctionAttrs/arg_nocapture.ll
The file was modifiedllvm/lib/Transforms/IPO/Attributor.cpp