SuccessChanges

Summary

  1. [debugserver] Use dlsym for posix_spawnattr_setarchpref_np (details)
  2. [BasicAA] Fix a bug with relational reasoning across iterations (details)
Commit 13ee00d0c95a4eede96ba9520146a01930af2a0a by Jonas Devlieghere
[debugserver] Use dlsym for posix_spawnattr_setarchpref_np

The @available check did not work as I thought it did. Use good old
dlsym instead.
The file was modifiedlldb/tools/debugserver/source/MacOSX/MachProcess.mm
Commit bfda69416c6d0a76b40644b1b0cbc1cbca254a61 by listmail
[BasicAA] Fix a bug with relational reasoning across iterations

Due to the recursion through phis basicaa does, the code needs to be extremely careful not to reason about equality between values which might represent distinct iterations. I'm generally skeptical of the correctness of the whole scheme, but this particular patch fixes one particular instance which is demonstrateable incorrect.

Interestingly, this appears to be the second attempted fix for the same issue. The former fix is incomplete and doesn't address the actual issue.

Differential Revision: https://reviews.llvm.org/D92694
The file was modifiedllvm/include/llvm/Analysis/BasicAliasAnalysis.h
The file was modifiedllvm/test/Analysis/BasicAA/phi-aa.ll
The file was modifiedllvm/lib/Analysis/BasicAliasAnalysis.cpp