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| author | Evan Cheng <evan.cheng@apple.com> | 2008-10-26 07:49:03 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2008-10-26 07:49:03 +0000 |
| commit | aaf510c932cf194fef5e877b19283176e2608f08 (patch) | |
| tree | 10829129642768eed7eac3b15bd8a3a96631f333 /lib | |
| parent | ac1cfa09d73923082ac7fd9bbd2c1f056bc02455 (diff) | |
| download | external_llvm-aaf510c932cf194fef5e877b19283176e2608f08.zip external_llvm-aaf510c932cf194fef5e877b19283176e2608f08.tar.gz external_llvm-aaf510c932cf194fef5e877b19283176e2608f08.tar.bz2 | |
Do not shrink wrap live interval in a mbb if it's livein any of its successor blocks. The mbb can be revisited again after all of the successors are processed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58184 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/CodeGen/PreAllocSplitting.cpp | 27 |
1 files changed, 21 insertions, 6 deletions
diff --git a/lib/CodeGen/PreAllocSplitting.cpp b/lib/CodeGen/PreAllocSplitting.cpp index 456be09..547c528 100644 --- a/lib/CodeGen/PreAllocSplitting.cpp +++ b/lib/CodeGen/PreAllocSplitting.cpp @@ -122,7 +122,7 @@ namespace { SmallVector<MachineOperand*, 4>&, SmallPtrSet<MachineInstr*, 4>&); - void ShrinkWrapLiveInterval(VNInfo*, MachineBasicBlock*, + void ShrinkWrapLiveInterval(VNInfo*, MachineBasicBlock*, MachineBasicBlock*, MachineBasicBlock*, SmallPtrSet<MachineBasicBlock*, 8>&, DenseMap<MachineBasicBlock*, SmallVector<MachineOperand*, 4> >&, DenseMap<MachineBasicBlock*, SmallPtrSet<MachineInstr*, 4> >&, @@ -426,15 +426,29 @@ PreAllocSplitting::ShrinkWrapToLastUse(MachineBasicBlock *MBB, /// chain to find the new 'kills' and shrink wrap the live interval to the /// new kill indices. void -PreAllocSplitting::ShrinkWrapLiveInterval(VNInfo *ValNo, - MachineBasicBlock *MBB, MachineBasicBlock *DefMBB, +PreAllocSplitting::ShrinkWrapLiveInterval(VNInfo *ValNo, MachineBasicBlock *MBB, + MachineBasicBlock *SuccMBB, MachineBasicBlock *DefMBB, SmallPtrSet<MachineBasicBlock*, 8> &Visited, DenseMap<MachineBasicBlock*, SmallVector<MachineOperand*, 4> > &Uses, DenseMap<MachineBasicBlock*, SmallPtrSet<MachineInstr*, 4> > &UseMIs, SmallVector<MachineBasicBlock*, 4> &UseMBBs) { - if (!Visited.insert(MBB)) + if (Visited.count(MBB)) return; + // If live interval is live in another successor path, then we can't process + // this block. But we may able to do so after all the successors have been + // processed. + for (MachineBasicBlock::succ_iterator SI = MBB->succ_begin(), + SE = MBB->succ_end(); SI != SE; ++SI) { + MachineBasicBlock *SMBB = *SI; + if (SMBB == SuccMBB) + continue; + if (CurrLI->liveAt(LIs->getMBBStartIdx(SMBB))) + return; + } + + Visited.insert(MBB); + DenseMap<MachineBasicBlock*, SmallVector<MachineOperand*, 4> >::iterator UMII = Uses.find(MBB); if (UMII != Uses.end()) { @@ -480,7 +494,8 @@ PreAllocSplitting::ShrinkWrapLiveInterval(VNInfo *ValNo, // Pred is the def bb and the def reaches other val#s, we must // allow the value to be live out of the bb. continue; - ShrinkWrapLiveInterval(ValNo, Pred, DefMBB, Visited, Uses, UseMIs, UseMBBs); + ShrinkWrapLiveInterval(ValNo, Pred, MBB, DefMBB, Visited, + Uses, UseMIs, UseMBBs); } return; @@ -622,7 +637,7 @@ bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) { // Walk up the predecessor chains. SmallPtrSet<MachineBasicBlock*, 8> Visited; - ShrinkWrapLiveInterval(ValNo, BarrierMBB, DefMBB, Visited, + ShrinkWrapLiveInterval(ValNo, BarrierMBB, NULL, DefMBB, Visited, Uses, UseMIs, UseMBBs); // Remove live range from barrier to the restore. FIXME: Find a better |