[BasicAA] Make BasicAA a cfg pass.
Summary:
Part of the changes in D44564 made BasicAA not CFG only due to it
using PhiAnalysisValues which may have values invalidated. Subsequent
patches (rL340613) appear to have addressed this limitation.
BasicAA should not be invalidated by non-CFG-altering passes. A
concrete example is MemCpyOpt which preserves CFG, but we are testing
it invalidates BasicAA.
llvm-dev RFC:
https://groups.google.com/forum/#!topic/llvm-dev/eSPXuWnNfzM
Reviewers: john.brawn, sebpop, hfinkel, brzycki
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74353
This fixes an issue with clang's -fintegrated-cc1 feature, which could
make it output slightly different assembly code, depending on the way it
was invoked.
In r361755 we attempted to work around it by disabling the integrated
cc1 stage, but it did not solve the root cause for all situations.
Extensive testing and bisecting showed that the above change finally
makes the output deterministic, even if -fintegrated-cc1 is on.
Reported by: Fabian Keil <fk@fabiankeil.de>
PR: 246630
MFC after: 3 days
b32fb2a4ea