diff --git a/include/llvm/CodeGen/BreakCriticalMachineEdge.h b/include/llvm/CodeGen/BreakCriticalMachineEdge.h index 743cff3f2b8..b8bb2d209c8 100644 --- a/include/llvm/CodeGen/BreakCriticalMachineEdge.h +++ b/include/llvm/CodeGen/BreakCriticalMachineEdge.h @@ -52,16 +52,27 @@ MachineBasicBlock* SplitCriticalMachineEdge(MachineBasicBlock* src, break; } - // Scan the operands of this branch, replacing any uses of dst with - // crit_mbb. + // Scan the operands of this branch, finding all uses of this MBB + std::vector toRemove; + unsigned reg = 0; for (unsigned i = 0, e = mii->getNumOperands(); i != e; ++i) { MachineOperand & mo = mii->getOperand(i); if (mo.isMachineBasicBlock() && - mo.getMachineBasicBlock() == dst) { - found_branch = true; - mo.setMachineBasicBlock(crit_mbb); - } + mo.getMachineBasicBlock() == dst) + reg = mii->getOperand(i-1).getReg(); + toRemove.push_back(i-1); } + + // Remove all uses of this MBB + for (std::vector::reverse_iterator I = toRemove.rbegin(), + E = toRemove.rend(); I != E; ++I) { + mii->RemoveOperand(*I+1); + mii->RemoveOperand(*I); + } + + // Add a single use corresponding to the new MBB + mii->addRegOperand(reg, false); + mii->addMachineBasicBlockOperand(crit_mbb); } // TODO: This is tentative. It may be necessary to fix this code. Maybe