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| author | Duncan P. N. Exon Smith <dexonsmith@apple.com> | 2016-08-11 20:03:09 +0000 |
|---|---|---|
| committer | Duncan P. N. Exon Smith <dexonsmith@apple.com> | 2016-08-11 20:03:09 +0000 |
| commit | 38eea4a76f015d6ee7afdb3a7a02ac6789104815 (patch) | |
| tree | 76d2c2a5a7363de797833256b510a5f65c71073b /llvm/lib/CodeGen/MachineScheduler.cpp | |
| parent | 9e4da07125504a0886fc7c224d233d317643d267 (diff) | |
| download | bcm5719-llvm-38eea4a76f015d6ee7afdb3a7a02ac6789104815.tar.gz bcm5719-llvm-38eea4a76f015d6ee7afdb3a7a02ac6789104815.zip | |
CodeGen: Avoid dereferencing end() in MachineScheduler
Check MachineInstr::isDebugValue for the same instruction as we're
calling isSchedBoundary, avoiding the possibility of dereferencing
end().
This is a functionality change even when I!=end(). Matthias had a look
and agrees this is the right resolution (as opposed to checking for
end()).
This is triggered by a huge number of tests, but they happen to
magically pass right now. I found this because WIP patches for PR26753
convert them into crashes.
llvm-svn: 278394
Diffstat (limited to 'llvm/lib/CodeGen/MachineScheduler.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/MachineScheduler.cpp | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/MachineScheduler.cpp b/llvm/lib/CodeGen/MachineScheduler.cpp index d921e2977cc..01ef9d834b6 100644 --- a/llvm/lib/CodeGen/MachineScheduler.cpp +++ b/llvm/lib/CodeGen/MachineScheduler.cpp @@ -458,9 +458,10 @@ void MachineSchedulerBase::scheduleRegions(ScheduleDAGInstrs &Scheduler, unsigned NumRegionInstrs = 0; MachineBasicBlock::iterator I = RegionEnd; for (;I != MBB->begin(); --I) { - if (isSchedBoundary(&*std::prev(I), &*MBB, MF, TII)) + MachineInstr &MI = *std::prev(I); + if (isSchedBoundary(&MI, &*MBB, MF, TII)) break; - if (!I->isDebugValue()) + if (!MI.isDebugValue()) ++NumRegionInstrs; } // Notify the scheduler of the region, even if we may skip scheduling |
