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| author | Robin Morisset <morisset@google.com> | 2014-09-02 20:17:52 +0000 |
|---|---|---|
| committer | Robin Morisset <morisset@google.com> | 2014-09-02 20:17:52 +0000 |
| commit | 4f6b93b1a88cb89af8b4bd922ee0ec5c14240a3c (patch) | |
| tree | 479cd038e00f42e8b6a6eb48245c1c180dc4b5f4 /llvm/lib/Transforms/Vectorize/BBVectorize.cpp | |
| parent | b2325b9ab36584c43b762295aa36db0a62413c93 (diff) | |
| download | bcm5719-llvm-4f6b93b1a88cb89af8b4bd922ee0ec5c14240a3c.tar.gz bcm5719-llvm-4f6b93b1a88cb89af8b4bd922ee0ec5c14240a3c.zip | |
Fix MemoryDependenceAnalysis in cases where QueryInstr is a CmpXchg or a AtomicRMW
Summary:
MemoryDependenceAnalysis is currently cautious when the QueryInstr is an atomic
load or store, but I forgot to check for atomic cmpxchg/atomicrmw. This patch
is a way of fixing that, and making it less brittle (i.e. no risk that I forget
another possible kind of atomic, even if the IR ends up changing in the future),
by adding a fallback checking mayReadOrWriteFromMemory.
Thanks to Philip Reames for finding this bug and suggesting this solution in
http://reviews.llvm.org/D4845
Sadly, I don't see how to add a test for this, since the passes depending on
MemoryDependenceAnalysis won't trigger for an atomic rmw anyway. Does anyone
see a way for testing it?
Test Plan: none possible at first sight
Reviewers: jfb, reames
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D5019
llvm-svn: 216940
Diffstat (limited to 'llvm/lib/Transforms/Vectorize/BBVectorize.cpp')
0 files changed, 0 insertions, 0 deletions
