diff options
| -rw-r--r-- | lib/CodeGen/StrongPHIElimination.cpp | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/lib/CodeGen/StrongPHIElimination.cpp b/lib/CodeGen/StrongPHIElimination.cpp index 545544a..b276e80 100644 --- a/lib/CodeGen/StrongPHIElimination.cpp +++ b/lib/CodeGen/StrongPHIElimination.cpp @@ -896,13 +896,16 @@ bool StrongPHIElimination::runOnMachineFunction(MachineFunction &Fn) { } } else { // Trim live intervals of input registers. They are no longer live into - // this block. + // this block if they died after the PHI. If they lived after it, don't + // trim them because they might have other legitimate uses. for (unsigned i = 1; i < PInstr->getNumOperands(); i += 2) { unsigned reg = PInstr->getOperand(i).getReg(); MachineBasicBlock* MBB = PInstr->getOperand(i+1).getMBB(); LiveInterval& InputI = LI.getInterval(reg); if (MBB != PInstr->getParent() && - InputI.liveAt(LI.getMBBStartIdx(PInstr->getParent()))) + InputI.liveAt(LI.getMBBStartIdx(PInstr->getParent())) && + InputI.expiredAt(LI.getInstructionIndex(PInstr) + + LiveIntervals::InstrSlots::NUM)) InputI.removeRange(LI.getMBBStartIdx(PInstr->getParent()), LI.getInstructionIndex(PInstr), true); |