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| author | Andrew Trick <atrick@apple.com> | 2013-01-24 02:09:55 +0000 |
|---|---|---|
| committer | Andrew Trick <atrick@apple.com> | 2013-01-24 02:09:55 +0000 |
| commit | d3b8629a53ec5cc133e08b8e74a2b38988e78693 (patch) | |
| tree | 1f92d090cc64e07d8dddbae0d96622d12713c632 /llvm/lib/CodeGen/ScheduleDAG.cpp | |
| parent | 0f515f898e9e0029b8005724962ee239de291377 (diff) | |
| download | bcm5719-llvm-d3b8629a53ec5cc133e08b8e74a2b38988e78693.tar.gz bcm5719-llvm-d3b8629a53ec5cc133e08b8e74a2b38988e78693.zip | |
MIsched: Added biasCriticalPath.
Allow schedulers to order DAG edges by critical path. This makes
DFS-based heuristics more stable and effective.
llvm-svn: 173317
Diffstat (limited to 'llvm/lib/CodeGen/ScheduleDAG.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/ScheduleDAG.cpp | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/ScheduleDAG.cpp b/llvm/lib/CodeGen/ScheduleDAG.cpp index e639c55a04f..70ad9495713 100644 --- a/llvm/lib/CodeGen/ScheduleDAG.cpp +++ b/llvm/lib/CodeGen/ScheduleDAG.cpp @@ -301,6 +301,21 @@ void SUnit::ComputeHeight() { } while (!WorkList.empty()); } +void SUnit::biasCriticalPath() { + if (NumPreds < 2) + return; + + SUnit::pred_iterator BestI = Preds.begin(); + unsigned MaxDepth = BestI->getSUnit()->getDepth(); + for (SUnit::pred_iterator + I = llvm::next(BestI), E = Preds.end(); I != E; ++I) { + if (I->getKind() == SDep::Data && I->getSUnit()->getDepth() > MaxDepth) + BestI = I; + } + if (BestI != Preds.begin()) + std::swap(*Preds.begin(), *BestI); +} + #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) /// SUnit - Scheduling unit. It's an wrapper around either a single SDNode or /// a group of nodes flagged together. |
