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| author | Bob Wilson <bob.wilson@apple.com> | 2010-04-21 18:39:03 +0000 |
|---|---|---|
| committer | Bob Wilson <bob.wilson@apple.com> | 2010-04-21 18:39:03 +0000 |
| commit | 4c7f50afb8f23509d38f98012326a1a367f77284 (patch) | |
| tree | 612626678498b7bb7eac41341457c9bfe90c734e /llvm/lib/Transforms/Utils | |
| parent | d85afee1340d279b88abbca19756b37d7ce3f79b (diff) | |
| download | bcm5719-llvm-4c7f50afb8f23509d38f98012326a1a367f77284.tar.gz bcm5719-llvm-4c7f50afb8f23509d38f98012326a1a367f77284.zip | |
Fix a performance problem with the new SSAUpdater. This showed up in the
GCCAS time for MultiSource/Benchmarks/ASCI_Purple/SMG2000.
llvm-svn: 102009
Diffstat (limited to 'llvm/lib/Transforms/Utils')
| -rw-r--r-- | llvm/lib/Transforms/Utils/SSAUpdater.cpp | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/Utils/SSAUpdater.cpp b/llvm/lib/Transforms/Utils/SSAUpdater.cpp index d491cbb9155..25d50dbf2a8 100644 --- a/llvm/lib/Transforms/Utils/SSAUpdater.cpp +++ b/llvm/lib/Transforms/Utils/SSAUpdater.cpp @@ -529,9 +529,15 @@ void SSAUpdater::FindAvailableVals(BlockListTy *BlockList) { E = BlockList->rend(); I != E; ++I) { BBInfo *Info = *I; - // Check if this block contains a newly added PHI. - if (Info->DefBB != Info) + if (Info->DefBB != Info) { + // Record the available value at join nodes to speed up subsequent + // uses of this SSAUpdater for the same value. + if (Info->NumPreds > 1) + AvailableVals[Info->BB] = Info->DefBB->AvailableVal; continue; + } + + // Check if this block contains a newly added PHI. PHINode *PHI = dyn_cast<PHINode>(Info->AvailableVal); if (!PHI || PHI->getNumIncomingValues() == Info->NumPreds) continue; |
