diff options
| author | Hal Finkel <hfinkel@anl.gov> | 2014-01-08 21:52:02 +0000 |
|---|---|---|
| committer | Hal Finkel <hfinkel@anl.gov> | 2014-01-08 21:52:02 +0000 |
| commit | 5bbbb37ff258229556faf238fcae489ee382bffa (patch) | |
| tree | 9af98eefbde05b96bda78135cebcf76baea8878d /include | |
| parent | b9271b0ec5dc032b39eea84a3d3dd21a73e54f2d (diff) | |
| download | llvm-5bbbb37ff258229556faf238fcae489ee382bffa.tar.gz llvm-5bbbb37ff258229556faf238fcae489ee382bffa.tar.bz2 llvm-5bbbb37ff258229556faf238fcae489ee382bffa.tar.xz | |
Conservatively handle multiple MMOs in MIsNeedChainEdge
MIsNeedChainEdge, which is used by -enable-aa-sched-mi (AA in misched), had an
llvm_unreachable when -enable-aa-sched-mi is enabled and we reach an
instruction with multiple MMOs. Instead, return a conservative answer. This
allows testing -enable-aa-sched-mi on x86.
Also, this moves the check above the isUnsafeMemoryObject checks.
isUnsafeMemoryObject is currently correct only for instructions with one MMO
(as noted in the comment in isUnsafeMemoryObject):
// We purposefully do no check for hasOneMemOperand() here
// in hope to trigger an assert downstream in order to
// finish implementation.
The problem with this is that, had the candidate edge passed the
"!MIa->mayStore() && !MIb->mayStore()" check, the hoped-for assert would never
happen (which could, in theory, lead to incorrect behavior if one of these
secondary MMOs was volatile, for example).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198795 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'include')
0 files changed, 0 insertions, 0 deletions