bool GreedyAllocator::buildPhiMoves(LBlock *block) { IonSpew(IonSpew_RegAlloc, " Merging phi state."); phiMoves = Mover(); MBasicBlock *mblock = block->mir(); if (!mblock->successorWithPhis()) return true; // Insert moves from our state into our successor's phi. uint32 pos = mblock->positionInPhiSuccessor(); LBlock *successor = mblock->successorWithPhis()->lir(); for (size_t i = 0; i < successor->numPhis(); i++) { LPhi *phi = successor->getPhi(i); JS_ASSERT(phi->numDefs() == 1); VirtualRegister *phiReg = getVirtualRegister(phi->getDef(0)); allocateStack(phiReg); LAllocation *in = phi->getOperand(pos); VirtualRegister *inReg = getVirtualRegister(in->toUse()); allocateStack(inReg); // Try to get a register for the input. if (!inReg->hasRegister() && !allocatableRegs().empty(inReg->isDouble())) { if (!allocateReg(inReg)) return false; } // Add a move from the input to the phi. if (inReg->hasRegister()) { if (!phiMoves.move(inReg->reg(), phiReg->backingStack())) return false; } else { if (!phiMoves.move(inReg->backingStack(), phiReg->backingStack())) return false; } } return true; }