diff options
| -rw-r--r-- | llvm/lib/CodeGen/RegisterCoalescer.cpp | 33 |
1 files changed, 24 insertions, 9 deletions
diff --git a/llvm/lib/CodeGen/RegisterCoalescer.cpp b/llvm/lib/CodeGen/RegisterCoalescer.cpp index 778ea8eaca1..f4cc37d9ca0 100644 --- a/llvm/lib/CodeGen/RegisterCoalescer.cpp +++ b/llvm/lib/CodeGen/RegisterCoalescer.cpp @@ -1744,9 +1744,10 @@ bool RegisterCoalescer::joinCopy(MachineInstr *CopyMI, bool &Again) { bool RegisterCoalescer::joinReservedPhysReg(CoalescerPair &CP) { unsigned DstReg = CP.getDstReg(); + unsigned SrcReg = CP.getSrcReg(); assert(CP.isPhys() && "Must be a physreg copy"); assert(MRI->isReserved(DstReg) && "Not a reserved register"); - LiveInterval &RHS = LIS->getInterval(CP.getSrcReg()); + LiveInterval &RHS = LIS->getInterval(SrcReg); DEBUG(dbgs() << "\t\tRHS = " << RHS << '\n'); assert(RHS.containsOneValue() && "Invalid join with reserved register"); @@ -1788,17 +1789,31 @@ bool RegisterCoalescer::joinReservedPhysReg(CoalescerPair &CP) { // Delete the identity copy. MachineInstr *CopyMI; if (CP.isFlipped()) { - CopyMI = MRI->getVRegDef(RHS.reg); + // Physreg is copied into vreg + // %vregY = COPY %X + // ... //< no other def of %X here + // use %vregY + // => + // ... + // use %X + CopyMI = MRI->getVRegDef(SrcReg); } else { - if (!MRI->hasOneNonDBGUse(RHS.reg)) { + // VReg is copied into physreg: + // %vregX = def + // ... //< no other def or use of %Y here + // %Y = COPY %vregX + // => + // %Y = def + // ... + if (!MRI->hasOneNonDBGUse(SrcReg)) { DEBUG(dbgs() << "\t\tMultiple vreg uses!\n"); return false; } - MachineInstr *DestMI = MRI->getVRegDef(RHS.reg); - CopyMI = &*MRI->use_instr_nodbg_begin(RHS.reg); - const SlotIndex CopyRegIdx = LIS->getInstructionIndex(*CopyMI).getRegSlot(); - const SlotIndex DestRegIdx = LIS->getInstructionIndex(*DestMI).getRegSlot(); + MachineInstr &DestMI = *MRI->getVRegDef(SrcReg); + CopyMI = &*MRI->use_instr_nodbg_begin(SrcReg); + SlotIndex CopyRegIdx = LIS->getInstructionIndex(*CopyMI).getRegSlot(); + SlotIndex DestRegIdx = LIS->getInstructionIndex(DestMI).getRegSlot(); if (!MRI->isConstantPhysReg(DstReg)) { // We checked above that there are no interfering defs of the physical @@ -1817,8 +1832,8 @@ bool RegisterCoalescer::joinReservedPhysReg(CoalescerPair &CP) { // We're going to remove the copy which defines a physical reserved // register, so remove its valno, etc. - DEBUG(dbgs() << "\t\tRemoving phys reg def of " << DstReg << " at " - << CopyRegIdx << "\n"); + DEBUG(dbgs() << "\t\tRemoving phys reg def of " << PrintReg(DstReg, TRI) + << " at " << CopyRegIdx << "\n"); LIS->removePhysRegDefAt(DstReg, CopyRegIdx); // Create a new dead def at the new def location. |
