diff options
Diffstat (limited to 'lib/CodeGen/LiveIntervalAnalysis.cpp')
| -rw-r--r-- | lib/CodeGen/LiveIntervalAnalysis.cpp | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp index c4a548f9ea..cacbd0a61b 100644 --- a/lib/CodeGen/LiveIntervalAnalysis.cpp +++ b/lib/CodeGen/LiveIntervalAnalysis.cpp @@ -747,6 +747,9 @@ bool LiveIntervals::shrinkToUses(LiveInterval *li, // Find all the values used, including PHI kills. SmallVector<std::pair<SlotIndex, VNInfo*>, 16> WorkList; + // Blocks that have already been added to WorkList as live-out. + SmallPtrSet<MachineBasicBlock*, 16> LiveOut; + // Visit all instructions reading li->reg. for (MachineRegisterInfo::reg_iterator I = mri_->reg_begin(li->reg); MachineInstr *UseMI = I.skipInstruction();) { @@ -780,8 +783,6 @@ bool LiveIntervals::shrinkToUses(LiveInterval *li, VNInfo *VNI = *I; if (VNI->isUnused()) continue; - // We may eliminate PHI values, so recompute PHIKill flags. - VNI->setHasPHIKill(false); NewLI.addRange(LiveRange(VNI->def, VNI->def.getNextSlot(), VNI)); // A use tied to an early-clobber def ends at the load slot and isn't caught @@ -813,13 +814,12 @@ bool LiveIntervals::shrinkToUses(LiveInterval *li, // The PHI is live, make sure the predecessors are live-out. for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PE = MBB->pred_end(); PI != PE; ++PI) { + if (!LiveOut.insert(*PI)) + continue; SlotIndex Stop = getMBBEndIdx(*PI).getPrevSlot(); - VNInfo *PVNI = li->getVNInfoAt(Stop); // A predecessor is not required to have a live-out value for a PHI. - if (PVNI) { - PVNI->setHasPHIKill(true); + if (VNInfo *PVNI = li->getVNInfoAt(Stop)) WorkList.push_back(std::make_pair(Stop, PVNI)); - } } continue; } @@ -831,6 +831,8 @@ bool LiveIntervals::shrinkToUses(LiveInterval *li, // Make sure VNI is live-out from the predecessors. for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PE = MBB->pred_end(); PI != PE; ++PI) { + if (!LiveOut.insert(*PI)) + continue; SlotIndex Stop = getMBBEndIdx(*PI).getPrevSlot(); assert(li->getVNInfoAt(Stop) == VNI && "Wrong value out of predecessor"); WorkList.push_back(std::make_pair(Stop, VNI)); |