diff options
| -rw-r--r-- | lib/CodeGen/SplitKit.cpp | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/lib/CodeGen/SplitKit.cpp b/lib/CodeGen/SplitKit.cpp index ff00bd8f38..c0f4adf077 100644 --- a/lib/CodeGen/SplitKit.cpp +++ b/lib/CodeGen/SplitKit.cpp @@ -348,6 +348,7 @@ void SplitEditor::extendRange(unsigned RegIdx, SlotIndex Idx) { // Using LiveOutCache as a visited set, perform a BFS for all reaching defs. for (unsigned i = 0; i != LiveIn.size(); ++i) { MachineBasicBlock *MBB = LiveIn[i]->getBlock(); + assert(!MBB->pred_empty() && "Value live-in to entry block?"); for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(), PE = MBB->pred_end(); PI != PE; ++PI) { MachineBasicBlock *Pred = *PI; @@ -757,7 +758,8 @@ void SplitEditor::rewriteAssigned(bool ExtendRanges) { } SlotIndex Idx = LIS.getInstructionIndex(MI); - Idx = MO.isUse() ? Idx.getUseIndex() : Idx.getDefIndex(); + if (MO.isDef()) + Idx = MO.isEarlyClobber() ? Idx.getUseIndex() : Idx.getDefIndex(); // Rewrite to the mapped register at Idx. unsigned RegIdx = RegAssign.lookup(Idx); @@ -765,9 +767,23 @@ void SplitEditor::rewriteAssigned(bool ExtendRanges) { DEBUG(dbgs() << " rewr BB#" << MI->getParent()->getNumber() << '\t' << Idx << ':' << RegIdx << '\t' << *MI); - // Extend liveness to Idx. - if (ExtendRanges) - extendRange(RegIdx, Idx); + // Extend liveness to Idx if the instruction reads reg. + if (!ExtendRanges) + continue; + + // Skip instructions that don't read Reg. + if (MO.isDef()) { + if (!MO.getSubReg() && !MO.isEarlyClobber()) + continue; + // We may wan't to extend a live range for a partial redef, or for a use + // tied to an early clobber. + Idx = Idx.getPrevSlot(); + if (!Edit->getParent().liveAt(Idx)) + continue; + } else + Idx = Idx.getUseIndex(); + + extendRange(RegIdx, Idx); } } |