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| author | Dan Gohman <gohman@apple.com> | 2010-04-05 19:17:22 +0000 |
|---|---|---|
| committer | Dan Gohman <gohman@apple.com> | 2010-04-05 19:17:22 +0000 |
| commit | 918a90a3caf064e5d3f73736f8c0a38cc366d1aa (patch) | |
| tree | 3878d4511211956be220783a1e937c64276a3877 /llvm/lib/CodeGen/MachineSink.cpp | |
| parent | 976d1b600220301c467059c661abbcf9052cbf07 (diff) | |
| download | bcm5719-llvm-918a90a3caf064e5d3f73736f8c0a38cc366d1aa.tar.gz bcm5719-llvm-918a90a3caf064e5d3f73736f8c0a38cc366d1aa.zip | |
Don't do code sinking on unreachable blocks. It's unprofitable and hazardous.
llvm-svn: 100455
Diffstat (limited to 'llvm/lib/CodeGen/MachineSink.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/MachineSink.cpp | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/MachineSink.cpp b/llvm/lib/CodeGen/MachineSink.cpp index e47ba7c2cc3..e6596190157 100644 --- a/llvm/lib/CodeGen/MachineSink.cpp +++ b/llvm/lib/CodeGen/MachineSink.cpp @@ -126,6 +126,11 @@ bool MachineSinking::ProcessBlock(MachineBasicBlock &MBB) { // Can't sink anything out of a block that has less than two successors. if (MBB.succ_size() <= 1 || MBB.empty()) return false; + // Don't bother sinking code out of unreachable blocks. In addition to being + // unprofitable, it can also lead to infinite looping, because in an unreachable + // loop there may be nowhere to stop. + if (!DT->isReachableFromEntry(&MBB)) return false; + bool MadeChange = false; // Walk the basic block bottom-up. Remember if we saw a store. |
