-
- // Find the register class of the target register: should be the
- // same as the values we're trying to store there
- const TargetRegisterClass* regClass = PhysRegClasses[physReg];
- assert(regClass && "Target register class not found!");
- unsigned dataSize = regClass->getDataSize();
-
- for (int i = MI->getNumOperands() - 1; i >= 2; i-=2) {
- MachineOperand &opVal = MI->getOperand(i-1);
-
- // Get the MachineBasicBlock equivalent of the BasicBlock that is the
- // source path the phi
- MachineBasicBlock &opBlock = *MI->getOperand(i).getMachineBasicBlock();
- MachineBasicBlock::iterator opI = opBlock.end();
- MachineInstr *opMI = *--opI;
-
- // must backtrack over ALL the branches in the previous block, until no
- // more
- while (MII.isBranch(opMI->getOpcode()) && opI != opBlock.begin())
- opMI = *--opI;
-
- // move back to the first branch instruction so new instructions
- // are inserted right in front of it and not in front of a non-branch
- if (!MII.isBranch(opMI->getOpcode()))
- ++opI;
-
- // Retrieve the constant value from this op, move it to target
- // register of the phi
- if (opVal.isImmediate()) {
- opI = RegInfo->moveImm2Reg(opBlock, opI, physReg,
- (unsigned) opVal.getImmedValue(),
- dataSize);
- saveVirtRegToStack(opBlock, opI, virtualReg, physReg);
- } else {
- // Allocate a physical register and add a move in the BB
- unsigned opVirtualReg = (unsigned) opVal.getAllocatedRegNum();
- unsigned opPhysReg;
- opI = moveUseToReg(opBlock, opI, opVirtualReg, physReg);
-
- // Save that register value to the stack of the TARGET REG
- saveVirtRegToStack(opBlock, opI, virtualReg, physReg);