VirtRegMap.cpp revision 66cf80f226e04e6704a78da83e08c7b0af944ef1
134d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos//===-- llvm/CodeGen/VirtRegMap.cpp - Virtual Register Map ----------------===// 234d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos// 334d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos// The LLVM Compiler Infrastructure 434d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos// 534d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos// This file was developed by the LLVM research group and is distributed under 634d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos// the University of Illinois Open Source License. See LICENSE.TXT for details. 734d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos// 834d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos//===----------------------------------------------------------------------===// 934d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos// 108c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner// This file implements the VirtRegMap class. 118c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner// 128c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner// It also contains implementations of the the Spiller interface, which, given a 138c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner// virtual register map and a machine function, eliminates all virtual 148c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner// references by replacing them with physical register references - adding spill 150d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos// code as necessary. 1634d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos// 1734d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos//===----------------------------------------------------------------------===// 1834d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos 198c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner#define DEBUG_TYPE "spiller" 2034d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos#include "VirtRegMap.h" 210d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos#include "llvm/Function.h" 2234d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos#include "llvm/CodeGen/MachineFrameInfo.h" 238c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner#include "llvm/CodeGen/MachineFunction.h" 248c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner#include "llvm/CodeGen/SSARegMap.h" 2534d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos#include "llvm/Target/TargetMachine.h" 260d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos#include "llvm/Target/TargetInstrInfo.h" 27551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/CommandLine.h" 28551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/Debug.h" 29551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/Statistic.h" 30551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/STLExtras.h" 3127f291600b04c382c390b16fdacd52b910b9164dChris Lattner#include <algorithm> 322c2c6c61f100bc7c3df873b11203fcea1b5e18feChris Lattner#include <iostream> 3334d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenosusing namespace llvm; 3434d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos 3534d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenosnamespace { 368c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner Statistic<> NumSpills("spiller", "Number of register spills"); 378c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner Statistic<> NumStores("spiller", "Number of stores added"); 388c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner Statistic<> NumLoads ("spiller", "Number of loads added"); 397fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner Statistic<> NumReused("spiller", "Number of values reused"); 4052b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner Statistic<> NumDSE ("spiller", "Number of dead stores elided"); 411118d25d3971bc4fce9715c8c83ea7a197bf2effChris Lattner Statistic<> NumDCE ("spiller", "Number of copies elided"); 428c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 438c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner enum SpillerName { simple, local }; 448c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 458c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner cl::opt<SpillerName> 468c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner SpillerOpt("spiller", 477fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner cl::desc("Spiller to use: (default: local)"), 488c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner cl::Prefix, 498c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner cl::values(clEnumVal(simple, " simple spiller"), 508c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner clEnumVal(local, " local spiller"), 518c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner clEnumValEnd), 527fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner cl::init(local)); 538c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner} 548c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 558c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner//===----------------------------------------------------------------------===// 568c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner// VirtRegMap implementation 578c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner//===----------------------------------------------------------------------===// 588c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 598c4d88d3697835371ecf6823f4142af13603ad2dChris Lattnervoid VirtRegMap::grow() { 607f690e625807b9320bf4ae437b8f35258acc99deChris Lattner Virt2PhysMap.grow(MF.getSSARegMap()->getLastVirtReg()); 617f690e625807b9320bf4ae437b8f35258acc99deChris Lattner Virt2StackSlotMap.grow(MF.getSSARegMap()->getLastVirtReg()); 6234d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos} 6334d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos 648c4d88d3697835371ecf6823f4142af13603ad2dChris Lattnerint VirtRegMap::assignVirt2StackSlot(unsigned virtReg) { 658c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner assert(MRegisterInfo::isVirtualRegister(virtReg)); 667f690e625807b9320bf4ae437b8f35258acc99deChris Lattner assert(Virt2StackSlotMap[virtReg] == NO_STACK_SLOT && 678c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner "attempt to assign stack slot to already spilled register"); 687f690e625807b9320bf4ae437b8f35258acc99deChris Lattner const TargetRegisterClass* RC = MF.getSSARegMap()->getRegClass(virtReg); 697f690e625807b9320bf4ae437b8f35258acc99deChris Lattner int frameIndex = MF.getFrameInfo()->CreateStackObject(RC->getSize(), 707f690e625807b9320bf4ae437b8f35258acc99deChris Lattner RC->getAlignment()); 717f690e625807b9320bf4ae437b8f35258acc99deChris Lattner Virt2StackSlotMap[virtReg] = frameIndex; 728c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner ++NumSpills; 738c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner return frameIndex; 7434d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos} 7534d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos 768c4d88d3697835371ecf6823f4142af13603ad2dChris Lattnervoid VirtRegMap::assignVirt2StackSlot(unsigned virtReg, int frameIndex) { 778c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner assert(MRegisterInfo::isVirtualRegister(virtReg)); 787f690e625807b9320bf4ae437b8f35258acc99deChris Lattner assert(Virt2StackSlotMap[virtReg] == NO_STACK_SLOT && 798c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner "attempt to assign stack slot to already spilled register"); 807f690e625807b9320bf4ae437b8f35258acc99deChris Lattner Virt2StackSlotMap[virtReg] = frameIndex; 8138af59a43c4176d8f34bd26faeb18b23080a1d9bAlkis Evlogimenos} 8238af59a43c4176d8f34bd26faeb18b23080a1d9bAlkis Evlogimenos 83bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattnervoid VirtRegMap::virtFolded(unsigned VirtReg, MachineInstr *OldMI, 84bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner unsigned OpNo, MachineInstr *NewMI) { 85bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner // Move previous memory references folded to new instruction. 86bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner MI2VirtMapTy::iterator IP = MI2VirtMap.lower_bound(NewMI); 87edf128a7fa90f2b0b7ee24741a04a7ae1ecd6f7eMisha Brukman for (MI2VirtMapTy::iterator I = MI2VirtMap.lower_bound(OldMI), 88bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner E = MI2VirtMap.end(); I != E && I->first == OldMI; ) { 89bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner MI2VirtMap.insert(IP, std::make_pair(NewMI, I->second)); 90dbea9731b12e62f70d9da40cf273cdd9105f987cChris Lattner MI2VirtMap.erase(I++); 918c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 92dbea9731b12e62f70d9da40cf273cdd9105f987cChris Lattner 93bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner ModRef MRInfo; 94bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner if (!OldMI->getOperand(OpNo).isDef()) { 95bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner assert(OldMI->getOperand(OpNo).isUse() && "Operand is not use or def?"); 96bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner MRInfo = isRef; 97bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner } else { 98bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner MRInfo = OldMI->getOperand(OpNo).isUse() ? isModRef : isMod; 99bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner } 1008c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 1018c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner // add new memory reference 102bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner MI2VirtMap.insert(IP, std::make_pair(NewMI, std::make_pair(VirtReg, MRInfo))); 1038c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner} 1045f37502bfbadfa65de087627bd67fd58bb03725cAlkis Evlogimenos 1057f690e625807b9320bf4ae437b8f35258acc99deChris Lattnervoid VirtRegMap::print(std::ostream &OS) const { 1067f690e625807b9320bf4ae437b8f35258acc99deChris Lattner const MRegisterInfo* MRI = MF.getTarget().getRegisterInfo(); 1078c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 1087f690e625807b9320bf4ae437b8f35258acc99deChris Lattner OS << "********** REGISTER MAP **********\n"; 1098c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner for (unsigned i = MRegisterInfo::FirstVirtualRegister, 1107f690e625807b9320bf4ae437b8f35258acc99deChris Lattner e = MF.getSSARegMap()->getLastVirtReg(); i <= e; ++i) { 1117f690e625807b9320bf4ae437b8f35258acc99deChris Lattner if (Virt2PhysMap[i] != (unsigned)VirtRegMap::NO_PHYS_REG) 1127f690e625807b9320bf4ae437b8f35258acc99deChris Lattner OS << "[reg" << i << " -> " << MRI->getName(Virt2PhysMap[i]) << "]\n"; 113edf128a7fa90f2b0b7ee24741a04a7ae1ecd6f7eMisha Brukman 1148c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 1158c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 1168c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner for (unsigned i = MRegisterInfo::FirstVirtualRegister, 1177f690e625807b9320bf4ae437b8f35258acc99deChris Lattner e = MF.getSSARegMap()->getLastVirtReg(); i <= e; ++i) 1187f690e625807b9320bf4ae437b8f35258acc99deChris Lattner if (Virt2StackSlotMap[i] != VirtRegMap::NO_STACK_SLOT) 1197f690e625807b9320bf4ae437b8f35258acc99deChris Lattner OS << "[reg" << i << " -> fi#" << Virt2StackSlotMap[i] << "]\n"; 1207f690e625807b9320bf4ae437b8f35258acc99deChris Lattner OS << '\n'; 1215f37502bfbadfa65de087627bd67fd58bb03725cAlkis Evlogimenos} 1225f37502bfbadfa65de087627bd67fd58bb03725cAlkis Evlogimenos 1238c4d88d3697835371ecf6823f4142af13603ad2dChris Lattnervoid VirtRegMap::dump() const { print(std::cerr); } 12434d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos 1250d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos 1268c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner//===----------------------------------------------------------------------===// 1278c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner// Simple Spiller Implementation 1288c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner//===----------------------------------------------------------------------===// 129dd420e060accd1d773c731e77335cff65ca34013Alkis Evlogimenos 1308c4d88d3697835371ecf6823f4142af13603ad2dChris LattnerSpiller::~Spiller() {} 131dd420e060accd1d773c731e77335cff65ca34013Alkis Evlogimenos 1320d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenosnamespace { 1338c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner struct SimpleSpiller : public Spiller { 1348c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner bool runOnMachineFunction(MachineFunction& mf, const VirtRegMap &VRM); 1358c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner }; 1368c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner} 1370d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos 138b0f31bf19b9cd0107900728123d4848eae462e6cChris Lattnerbool SimpleSpiller::runOnMachineFunction(MachineFunction &MF, 139b0f31bf19b9cd0107900728123d4848eae462e6cChris Lattner const VirtRegMap &VRM) { 1408c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner DEBUG(std::cerr << "********** REWRITE MACHINE CODE **********\n"); 1418c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner DEBUG(std::cerr << "********** Function: " 1428c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner << MF.getFunction()->getName() << '\n'); 143b0f31bf19b9cd0107900728123d4848eae462e6cChris Lattner const TargetMachine &TM = MF.getTarget(); 144b0f31bf19b9cd0107900728123d4848eae462e6cChris Lattner const MRegisterInfo &MRI = *TM.getRegisterInfo(); 145b0f31bf19b9cd0107900728123d4848eae462e6cChris Lattner bool *PhysRegsUsed = MF.getUsedPhysregs(); 1468c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 1474ea1b828ebc5d2e8711acf13c2a3fdd7c14fe339Chris Lattner // LoadedRegs - Keep track of which vregs are loaded, so that we only load 1484ea1b828ebc5d2e8711acf13c2a3fdd7c14fe339Chris Lattner // each vreg once (in the case where a spilled vreg is used by multiple 1494ea1b828ebc5d2e8711acf13c2a3fdd7c14fe339Chris Lattner // operands). This is always smaller than the number of operands to the 1504ea1b828ebc5d2e8711acf13c2a3fdd7c14fe339Chris Lattner // current machine instr, so it should be small. 1514ea1b828ebc5d2e8711acf13c2a3fdd7c14fe339Chris Lattner std::vector<unsigned> LoadedRegs; 1528c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 1530fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner for (MachineFunction::iterator MBBI = MF.begin(), E = MF.end(); 1540fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner MBBI != E; ++MBBI) { 1550fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner DEBUG(std::cerr << MBBI->getBasicBlock()->getName() << ":\n"); 1560fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner MachineBasicBlock &MBB = *MBBI; 1570fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner for (MachineBasicBlock::iterator MII = MBB.begin(), 1580fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner E = MBB.end(); MII != E; ++MII) { 1590fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner MachineInstr &MI = *MII; 1600fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) { 1617fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MachineOperand &MO = MI.getOperand(i); 162886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner if (MO.isRegister() && MO.getReg()) 163886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner if (MRegisterInfo::isVirtualRegister(MO.getReg())) { 164886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner unsigned VirtReg = MO.getReg(); 165886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner unsigned PhysReg = VRM.getPhys(VirtReg); 166886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner if (VRM.hasStackSlot(VirtReg)) { 167886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner int StackSlot = VRM.getStackSlot(VirtReg); 168bf9716b9c48d3b0370c715cd79540945f73dc296Chris Lattner const TargetRegisterClass* RC = 169bf9716b9c48d3b0370c715cd79540945f73dc296Chris Lattner MF.getSSARegMap()->getRegClass(VirtReg); 170edf128a7fa90f2b0b7ee24741a04a7ae1ecd6f7eMisha Brukman 171886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner if (MO.isUse() && 172886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner std::find(LoadedRegs.begin(), LoadedRegs.end(), VirtReg) 173886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner == LoadedRegs.end()) { 174bf9716b9c48d3b0370c715cd79540945f73dc296Chris Lattner MRI.loadRegFromStackSlot(MBB, &MI, PhysReg, StackSlot, RC); 175886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner LoadedRegs.push_back(VirtReg); 176886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner ++NumLoads; 177886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner DEBUG(std::cerr << '\t' << *prior(MII)); 178886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner } 179edf128a7fa90f2b0b7ee24741a04a7ae1ecd6f7eMisha Brukman 180886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner if (MO.isDef()) { 181bf9716b9c48d3b0370c715cd79540945f73dc296Chris Lattner MRI.storeRegToStackSlot(MBB, next(MII), PhysReg, StackSlot, RC); 182886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner ++NumStores; 183886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner } 1840fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner } 185886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner PhysRegsUsed[PhysReg] = true; 186886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner MI.SetMachineOperandReg(i, PhysReg); 187886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner } else { 188886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner PhysRegsUsed[MO.getReg()] = true; 1898c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 1908c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 191886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner 192477e4555de341c5de780de3720d6f115ec133c4eChris Lattner DEBUG(std::cerr << '\t' << MI); 1934ea1b828ebc5d2e8711acf13c2a3fdd7c14fe339Chris Lattner LoadedRegs.clear(); 1948c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 1958c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 1968c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner return true; 1978c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner} 1980d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos 1998c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner//===----------------------------------------------------------------------===// 2008c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner// Local Spiller Implementation 2018c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner//===----------------------------------------------------------------------===// 2020d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos 2038c4d88d3697835371ecf6823f4142af13603ad2dChris Lattnernamespace { 2047fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner /// LocalSpiller - This spiller does a simple pass over the machine basic 2057fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner /// block to attempt to keep spills in registers as much as possible for 2067fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner /// blocks that have low register pressure (the vreg may be spilled due to 2077fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner /// register pressure in other blocks). 2088c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner class LocalSpiller : public Spiller { 2098c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner const MRegisterInfo *MRI; 2107fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner const TargetInstrInfo *TII; 2118c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner public: 2127fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner bool runOnMachineFunction(MachineFunction &MF, const VirtRegMap &VRM) { 2137fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MRI = MF.getTarget().getRegisterInfo(); 2147fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner TII = MF.getTarget().getInstrInfo(); 2157fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << "\n**** Local spiller rewriting function '" 2167fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner << MF.getFunction()->getName() << "':\n"); 2177fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 2187fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner for (MachineFunction::iterator MBB = MF.begin(), E = MF.end(); 2197fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MBB != E; ++MBB) 2207fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner RewriteMBB(*MBB, VRM); 2217fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner return true; 2228c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 2237fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner private: 2247fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner void RewriteMBB(MachineBasicBlock &MBB, const VirtRegMap &VRM); 2257fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner void ClobberPhysReg(unsigned PR, std::map<int, unsigned> &SpillSlots, 22607cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner std::multimap<unsigned, int> &PhysRegs); 2277fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner void ClobberPhysRegOnly(unsigned PR, std::map<int, unsigned> &SpillSlots, 22807cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner std::multimap<unsigned, int> &PhysRegs); 22907cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner void ModifyStackSlot(int Slot, std::map<int, unsigned> &SpillSlots, 23007cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner std::multimap<unsigned, int> &PhysRegs); 2318c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner }; 2328c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner} 2338c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 23466cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner/// AvailableSpills - As the local spiller is scanning and rewriting an MBB from 23566cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner/// top down, keep track of which spills slots are available in each register. 23666cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattnerclass AvailableSpills { 23766cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner const MRegisterInfo *MRI; 23866cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner const TargetInstrInfo *TII; 23966cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner 24066cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner // SpillSlotsAvailable - This map keeps track of all of the spilled virtual 24166cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner // register values that are still available, due to being loaded or stored to, 24266cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner // but not invalidated yet. 24366cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner std::map<int, unsigned> SpillSlotsAvailable; 24466cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner 24566cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner // PhysRegsAvailable - This is the inverse of SpillSlotsAvailable, indicating 24666cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner // which stack slot values are currently held by a physreg. This is used to 24766cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner // invalidate entries in SpillSlotsAvailable when a physreg is modified. 24866cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner std::multimap<unsigned, int> PhysRegsAvailable; 24966cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner 25066cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner void ClobberPhysRegOnly(unsigned PhysReg); 25166cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattnerpublic: 25266cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner AvailableSpills(const MRegisterInfo *mri, const TargetInstrInfo *tii) 25366cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner : MRI(mri), TII(tii) { 25466cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner } 25566cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner 25666cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner /// getSpillSlotPhysReg - If the specified stack slot is available in a 25766cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner /// physical register, return that PhysReg, otherwise return 0. 25866cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner unsigned getSpillSlotPhysReg(int Slot) const { 25966cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner std::map<int, unsigned>::const_iterator I = SpillSlotsAvailable.find(Slot); 26066cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner if (I != SpillSlotsAvailable.end()) 26166cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner return I->second; 26266cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner return 0; 26366cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner } 26466cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner 26566cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner /// addAvailable - Mark that the specified stack slot is available in the 26666cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner /// specified physreg. 26766cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner void addAvailable(int Slot, unsigned Reg) { 26866cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner PhysRegsAvailable.insert(std::make_pair(Reg, Slot)); 26966cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner SpillSlotsAvailable[Slot] = Reg; 27066cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner 27166cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner DEBUG(std::cerr << "Remembering SS#" << Slot << " in physreg " 27266cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner << MRI->getName(Reg) << "\n"); 27366cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner } 27466cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner 27566cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner 27666cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner /// ClobberPhysReg - This is called when the specified physreg changes 27766cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner /// value. We use this to invalidate any info about stuff we thing lives in 27866cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner /// it and any of its aliases. 27966cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner void ClobberPhysReg(unsigned PhysReg); 28066cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner 28166cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner /// ModifyStackSlot - This method is called when the value in a stack slot 28266cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner /// changes. This removes information about which register the previous value 28366cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner /// for this slot lives in (as the previous value is dead now). 28466cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner void ModifyStackSlot(int Slot); 28566cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner}; 28666cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner 28766cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner/// ClobberPhysRegOnly - This is called when the specified physreg changes 28866cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner/// value. We use this to invalidate any info about stuff we thing lives in it. 28966cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattnervoid AvailableSpills::ClobberPhysRegOnly(unsigned PhysReg) { 29066cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner std::multimap<unsigned, int>::iterator I = 29166cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner PhysRegsAvailable.lower_bound(PhysReg); 29207cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner while (I != PhysRegsAvailable.end() && I->first == PhysReg) { 2937fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner int Slot = I->second; 29407cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner PhysRegsAvailable.erase(I++); 29566cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner assert(SpillSlotsAvailable[Slot] == PhysReg && 29666cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner "Bidirectional map mismatch!"); 29766cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner SpillSlotsAvailable.erase(Slot); 2987fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << "PhysReg " << MRI->getName(PhysReg) 29907cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner << " clobbered, invalidating SS#" << Slot << "\n"); 3008c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 3018c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner} 3020d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos 30366cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner/// ClobberPhysReg - This is called when the specified physreg changes 30466cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner/// value. We use this to invalidate any info about stuff we thing lives in 30566cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner/// it and any of its aliases. 30666cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattnervoid AvailableSpills::ClobberPhysReg(unsigned PhysReg) { 3077fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner for (const unsigned *AS = MRI->getAliasSet(PhysReg); *AS; ++AS) 30866cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner ClobberPhysRegOnly(*AS); 30966cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner ClobberPhysRegOnly(PhysReg); 31007cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner} 31107cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner 31207cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner/// ModifyStackSlot - This method is called when the value in a stack slot 31307cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner/// changes. This removes information about which register the previous value 31407cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner/// for this slot lives in (as the previous value is dead now). 31566cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattnervoid AvailableSpills::ModifyStackSlot(int Slot) { 31666cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner std::map<int, unsigned>::iterator It = SpillSlotsAvailable.find(Slot); 31766cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner if (It == SpillSlotsAvailable.end()) return; 31807cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner unsigned Reg = It->second; 31966cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner SpillSlotsAvailable.erase(It); 32007cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner 32107cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner // This register may hold the value of multiple stack slots, only remove this 32207cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner // stack slot from the set of values the register contains. 32307cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner std::multimap<unsigned, int>::iterator I = PhysRegsAvailable.lower_bound(Reg); 32407cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner for (; ; ++I) { 32507cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner assert(I != PhysRegsAvailable.end() && I->first == Reg && 32607cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner "Map inverse broken!"); 32707cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner if (I->second == Slot) break; 32807cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner } 32907cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner PhysRegsAvailable.erase(I); 3308c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner} 3318c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 3328c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 33307cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner 3347fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner// ReusedOp - For each reused operand, we keep track of a bit of information, in 3357fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner// case we need to rollback upon processing a new operand. See comments below. 3367fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattnernamespace { 3377fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner struct ReusedOp { 3387fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // The MachineInstr operand that reused an available value. 3397fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner unsigned Operand; 340edf128a7fa90f2b0b7ee24741a04a7ae1ecd6f7eMisha Brukman 3417fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // StackSlot - The spill slot of the value being reused. 3427fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner unsigned StackSlot; 343edf128a7fa90f2b0b7ee24741a04a7ae1ecd6f7eMisha Brukman 3447fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // PhysRegReused - The physical register the value was available in. 3457fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner unsigned PhysRegReused; 346edf128a7fa90f2b0b7ee24741a04a7ae1ecd6f7eMisha Brukman 3477fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // AssignedPhysReg - The physreg that was assigned for use by the reload. 3487fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner unsigned AssignedPhysReg; 3498a61a7524af19d67bd11f8e7d868ca75efbf5c91Chris Lattner 3508a61a7524af19d67bd11f8e7d868ca75efbf5c91Chris Lattner // VirtReg - The virtual register itself. 3518a61a7524af19d67bd11f8e7d868ca75efbf5c91Chris Lattner unsigned VirtReg; 3528a61a7524af19d67bd11f8e7d868ca75efbf5c91Chris Lattner 3538a61a7524af19d67bd11f8e7d868ca75efbf5c91Chris Lattner ReusedOp(unsigned o, unsigned ss, unsigned prr, unsigned apr, 3548a61a7524af19d67bd11f8e7d868ca75efbf5c91Chris Lattner unsigned vreg) 3558a61a7524af19d67bd11f8e7d868ca75efbf5c91Chris Lattner : Operand(o), StackSlot(ss), PhysRegReused(prr), AssignedPhysReg(apr), 3568a61a7524af19d67bd11f8e7d868ca75efbf5c91Chris Lattner VirtReg(vreg) {} 3577fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner }; 3587fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner} 3597fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 3607fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 3617fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner/// rewriteMBB - Keep track of which spills are available even after the 3627fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner/// register allocator is done with them. If possible, avoid reloading vregs. 3637fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattnervoid LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, const VirtRegMap &VRM) { 3647fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 3657fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << MBB.getBasicBlock()->getName() << ":\n"); 3667fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 36766cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner // Spills - Keep track of which spilled values are available in physregs so 36866cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner // that we can choose to reuse the physregs instead of emitting reloads. 36966cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner AvailableSpills Spills(MRI, TII); 37066cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner 3717fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner std::vector<ReusedOp> ReusedOperands; 3727fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 3737fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // DefAndUseVReg - When we see a def&use operand that is spilled, keep track 3747fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // of it. ".first" is the machine operand index (should always be 0 for now), 3757fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // and ".second" is the virtual register that is spilled. 3767fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner std::vector<std::pair<unsigned, unsigned> > DefAndUseVReg; 3777fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 37852b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner // MaybeDeadStores - When we need to write a value back into a stack slot, 37952b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner // keep track of the inserted store. If the stack slot value is never read 38052b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner // (because the value was used from some available register, for example), and 38152b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner // subsequently stored to, the original store is dead. This map keeps track 38252b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner // of inserted stores that are not used. If we see a subsequent store to the 38352b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner // same stack slot, the original store is deleted. 38452b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner std::map<int, MachineInstr*> MaybeDeadStores; 38552b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner 386b0f31bf19b9cd0107900728123d4848eae462e6cChris Lattner bool *PhysRegsUsed = MBB.getParent()->getUsedPhysregs(); 387b0f31bf19b9cd0107900728123d4848eae462e6cChris Lattner 3887fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner for (MachineBasicBlock::iterator MII = MBB.begin(), E = MBB.end(); 3897fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MII != E; ) { 3907fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MachineInstr &MI = *MII; 3917fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MachineBasicBlock::iterator NextMII = MII; ++NextMII; 3927fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 3937fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ReusedOperands.clear(); 3947fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DefAndUseVReg.clear(); 3957fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 3967fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // Process all of the spilled uses and all non spilled reg references. 3977fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) { 3987fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MachineOperand &MO = MI.getOperand(i); 39950ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner if (!MO.isRegister() || MO.getReg() == 0) 40050ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner continue; // Ignore non-register operands. 40150ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner 40250ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner if (MRegisterInfo::isPhysicalRegister(MO.getReg())) { 40350ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // Ignore physregs for spilling, but remember that it is used by this 40450ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // function. 405886dd9136f4c5b4523a0958e726955272eb9dfb2Chris Lattner PhysRegsUsed[MO.getReg()] = true; 40650ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner continue; 40750ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner } 40850ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner 40950ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner assert(MRegisterInfo::isVirtualRegister(MO.getReg()) && 41050ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner "Not a virtual or a physical register?"); 41150ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner 41250ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner unsigned VirtReg = MO.getReg(); 41350ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner if (!VRM.hasStackSlot(VirtReg)) { 41450ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // This virtual register was assigned a physreg! 41550ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner unsigned Phys = VRM.getPhys(VirtReg); 41650ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner PhysRegsUsed[Phys] = true; 41750ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner MI.SetMachineOperandReg(i, Phys); 41850ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner continue; 41950ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner } 42050ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner 42150ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // This virtual register is now known to be a spilled value. 42250ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner if (!MO.isUse()) 42350ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner continue; // Handle defs in the loop below (handle use&def here though) 42450ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner 42550ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // If this is both a def and a use, we need to emit a store to the 42650ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // stack slot after the instruction. Keep track of D&U operands 42750ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // because we are about to change it to a physreg here. 42850ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner if (MO.isDef()) { 42950ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // Remember that this was a def-and-use operand, and that the 43050ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // stack slot is live after this instruction executes. 43150ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner DefAndUseVReg.push_back(std::make_pair(i, VirtReg)); 43250ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner } 43350ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner 43450ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner int StackSlot = VRM.getStackSlot(VirtReg); 43550ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner unsigned PhysReg; 43650ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner 43750ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // Check to see if this stack slot is available. 43866cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner if ((PhysReg = Spills.getSpillSlotPhysReg(StackSlot))) { 43966cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner // If this stack slot value is already available, reuse it! 44050ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner DEBUG(std::cerr << "Reusing SS#" << StackSlot << " from physreg " 44166cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner << MRI->getName(PhysReg) << " for vreg" 44250ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner << VirtReg <<" instead of reloading into physreg " 44350ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner << MRI->getName(VRM.getPhys(VirtReg)) << "\n"); 44450ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner MI.SetMachineOperandReg(i, PhysReg); 44550ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner 44650ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // The only technical detail we have is that we don't know that 44750ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // PhysReg won't be clobbered by a reloaded stack slot that occurs 44850ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // later in the instruction. In particular, consider 'op V1, V2'. 44950ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // If V1 is available in physreg R0, we would choose to reuse it 45050ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // here, instead of reloading it into the register the allocator 45150ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // indicated (say R1). However, V2 might have to be reloaded 45250ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // later, and it might indicate that it needs to live in R0. When 45350ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // this occurs, we need to have information available that 45450ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // indicates it is safe to use R1 for the reload instead of R0. 45550ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // 45650ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // To further complicate matters, we might conflict with an alias, 45750ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // or R0 and R1 might not be compatible with each other. In this 45850ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // case, we actually insert a reload for V1 in R1, ensuring that 45950ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // we can get at R0 or its alias. 46050ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner ReusedOperands.push_back(ReusedOp(i, StackSlot, PhysReg, 4618a61a7524af19d67bd11f8e7d868ca75efbf5c91Chris Lattner VRM.getPhys(VirtReg), VirtReg)); 46250ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner ++NumReused; 46350ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner continue; 46450ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner } 46550ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner 46650ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // Otherwise, reload it and remember that we have it. 46750ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner PhysReg = VRM.getPhys(VirtReg); 468172c362fefe3d6e762ada119d4084ed4ed31595bChris Lattner assert(PhysReg && "Must map virtreg to physreg!"); 469bf9716b9c48d3b0370c715cd79540945f73dc296Chris Lattner const TargetRegisterClass* RC = 470bf9716b9c48d3b0370c715cd79540945f73dc296Chris Lattner MBB.getParent()->getSSARegMap()->getRegClass(VirtReg); 47150ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner 47250ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner RecheckRegister: 47350ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // Note that, if we reused a register for a previous operand, the 47450ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // register we want to reload into might not actually be 47550ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // available. If this occurs, use the register indicated by the 47650ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // reuser. 47750ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner if (!ReusedOperands.empty()) // This is most often empty. 47850ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner for (unsigned ro = 0, e = ReusedOperands.size(); ro != e; ++ro) 47950ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner if (ReusedOperands[ro].PhysRegReused == PhysReg) { 48050ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // Yup, use the reload register that we didn't use before. 48150ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner PhysReg = ReusedOperands[ro].AssignedPhysReg; 48250ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner goto RecheckRegister; 48350ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner } else { 48450ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner ReusedOp &Op = ReusedOperands[ro]; 48550ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner unsigned PRRU = Op.PhysRegReused; 48650ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner if (MRI->areAliases(PRRU, PhysReg)) { 48750ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // Okay, we found out that an alias of a reused register 48850ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // was used. This isn't good because it means we have 48950ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // to undo a previous reuse. 4908a61a7524af19d67bd11f8e7d868ca75efbf5c91Chris Lattner const TargetRegisterClass *AliasRC = 4918a61a7524af19d67bd11f8e7d868ca75efbf5c91Chris Lattner MBB.getParent()->getSSARegMap()->getRegClass(Op.VirtReg); 49250ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner MRI->loadRegFromStackSlot(MBB, &MI, Op.AssignedPhysReg, 4938a61a7524af19d67bd11f8e7d868ca75efbf5c91Chris Lattner Op.StackSlot, AliasRC); 49466cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner Spills.ClobberPhysReg(Op.AssignedPhysReg); 49566cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner Spills.ClobberPhysReg(Op.PhysRegReused); 49666cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner 49752b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner // Any stores to this stack slot are not dead anymore. 49850ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner MaybeDeadStores.erase(Op.StackSlot); 49950ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner 50050ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner MI.SetMachineOperandReg(Op.Operand, Op.AssignedPhysReg); 50166cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner 50266cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner Spills.addAvailable(Op.StackSlot, Op.AssignedPhysReg); 5037fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ++NumLoads; 5047fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << '\t' << *prior(MII)); 5057fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 50650ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner DEBUG(std::cerr << "Reuse undone!\n"); 50750ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner ReusedOperands.erase(ReusedOperands.begin()+ro); 50850ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner --NumReused; 50950ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner goto ContinueReload; 5107fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 5117fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 51250ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner ContinueReload: 51350ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner PhysRegsUsed[PhysReg] = true; 514bf9716b9c48d3b0370c715cd79540945f73dc296Chris Lattner MRI->loadRegFromStackSlot(MBB, &MI, PhysReg, StackSlot, RC); 51550ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // This invalidates PhysReg. 51666cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner Spills.ClobberPhysReg(PhysReg); 51750ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner 51850ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner // Any stores to this stack slot are not dead anymore. 51950ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner MaybeDeadStores.erase(StackSlot); 52066cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner Spills.addAvailable(StackSlot, PhysReg); 52150ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner ++NumLoads; 52266cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner MI.SetMachineOperandReg(i, PhysReg); 52350ea01ed5ba23c8988af9fed0b91178e69140a80Chris Lattner DEBUG(std::cerr << '\t' << *prior(MII)); 5248c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 5250d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos 5267fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // Loop over all of the implicit defs, clearing them from our available 5277fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // sets. 528b0f31bf19b9cd0107900728123d4848eae462e6cChris Lattner for (const unsigned *ImpDef = TII->getImplicitDefs(MI.getOpcode()); 529b0f31bf19b9cd0107900728123d4848eae462e6cChris Lattner *ImpDef; ++ImpDef) { 530b0f31bf19b9cd0107900728123d4848eae462e6cChris Lattner PhysRegsUsed[*ImpDef] = true; 53166cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner Spills.ClobberPhysReg(*ImpDef); 532b0f31bf19b9cd0107900728123d4848eae462e6cChris Lattner } 5337fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 5347fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << '\t' << MI); 5357fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 5367fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // If we have folded references to memory operands, make sure we clear all 5377fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // physical registers that may contain the value of the spilled virtual 5387fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // register 5398f1d6402ba73b96993ffd1eb9434b28c828d8856Chris Lattner VirtRegMap::MI2VirtMapTy::const_iterator I, End; 5408f1d6402ba73b96993ffd1eb9434b28c828d8856Chris Lattner for (tie(I, End) = VRM.getFoldedVirts(&MI); I != End; ++I) { 541bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner DEBUG(std::cerr << "Folded vreg: " << I->second.first << " MR: " 542bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner << I->second.second); 543bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner unsigned VirtReg = I->second.first; 544bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner VirtRegMap::ModRef MR = I->second.second; 545cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner if (!VRM.hasStackSlot(VirtReg)) { 546cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner DEBUG(std::cerr << ": No stack slot!\n"); 547cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner continue; 548cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner } 549cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner int SS = VRM.getStackSlot(VirtReg); 550cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner DEBUG(std::cerr << " - StackSlot: " << SS << "\n"); 551cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner 552cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner // If this folded instruction is just a use, check to see if it's a 553cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner // straight load from the virt reg slot. 554cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner if ((MR & VirtRegMap::isRef) && !(MR & VirtRegMap::isMod)) { 555cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner int FrameIdx; 556408396014742a05cad1c91949d2226169e3f9d80Chris Lattner if (unsigned DestReg = TII->isLoadFromStackSlot(&MI, FrameIdx)) { 557408396014742a05cad1c91949d2226169e3f9d80Chris Lattner // If this spill slot is available, turn it into a copy (or nothing) 558408396014742a05cad1c91949d2226169e3f9d80Chris Lattner // instead of leaving it as a load! 55966cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner unsigned InReg; 56066cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner if (FrameIdx == SS && (InReg = Spills.getSpillSlotPhysReg(SS))) { 561cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner DEBUG(std::cerr << "Promoted Load To Copy: " << MI); 562cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner MachineFunction &MF = *MBB.getParent(); 56366cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner if (DestReg != InReg) { 56466cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner MRI->copyRegToReg(MBB, &MI, DestReg, InReg, 565cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner MF.getSSARegMap()->getRegClass(VirtReg)); 56622480c43504eca3092f79d9b42bdbb1b413e8e53Chris Lattner // Revisit the copy so we make sure to notice the effects of the 56722480c43504eca3092f79d9b42bdbb1b413e8e53Chris Lattner // operation on the destreg (either needing to RA it if it's 56822480c43504eca3092f79d9b42bdbb1b413e8e53Chris Lattner // virtual or needing to clobber any values if it's physical). 56922480c43504eca3092f79d9b42bdbb1b413e8e53Chris Lattner NextMII = &MI; 57022480c43504eca3092f79d9b42bdbb1b413e8e53Chris Lattner --NextMII; // backtrack to the copy. 571cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner } 572cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner MBB.erase(&MI); 573cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner goto ProcessNextInst; 574bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner } 575bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner } 576cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner } 57752b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner 578cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner // If this reference is not a use, any previous store is now dead. 579cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner // Otherwise, the store to this stack slot is not dead anymore. 580cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner std::map<int, MachineInstr*>::iterator MDSI = MaybeDeadStores.find(SS); 581cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner if (MDSI != MaybeDeadStores.end()) { 582cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner if (MR & VirtRegMap::isRef) // Previous store is not dead. 583cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner MaybeDeadStores.erase(MDSI); 584cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner else { 585cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner // If we get here, the store is dead, nuke it now. 586cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner assert(MR == VirtRegMap::isMod && "Can't be modref!"); 587cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner MBB.erase(MDSI->second); 588cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner MaybeDeadStores.erase(MDSI); 589cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner ++NumDSE; 590cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner } 591cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner } 592cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner 593cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner // If the spill slot value is available, and this is a new definition of 594cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner // the value, the value is not available anymore. 595cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner if (MR & VirtRegMap::isMod) { 59607cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner // Notice that the value in this stack slot has been modified. 59766cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner Spills.ModifyStackSlot(SS); 598cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner 599cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner // If this is *just* a mod of the value, check to see if this is just a 600cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner // store to the spill slot (i.e. the spill got merged into the copy). If 601cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner // so, realize that the vreg is available now, and add the store to the 602cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner // MaybeDeadStore info. 603cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner int StackSlot; 604cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner if (!(MR & VirtRegMap::isRef)) { 605cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner if (unsigned SrcReg = TII->isStoreToStackSlot(&MI, StackSlot)) { 606cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner assert(MRegisterInfo::isPhysicalRegister(SrcReg) && 607cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner "Src hasn't been allocated yet?"); 60807cf14112dcdb9c6b20a4f8e17de717b5219dad8Chris Lattner // Okay, this is certainly a store of SrcReg to [StackSlot]. Mark 609cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner // this as a potentially dead store in case there is a subsequent 610cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner // store into the stack slot without a read from it. 611cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner MaybeDeadStores[StackSlot] = &MI; 612cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner 613cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner // If the stack slot value was previously available in some other 614cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner // register, change it now. Otherwise, make the register available, 615cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner // in PhysReg. 61666cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner Spills.addAvailable(StackSlot, SrcReg); 617cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner } 618cd81639d2e3705ee13b1869d6c166b5f5b4c29c4Chris Lattner } 6197fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 6208c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 6210d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos 6227fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // Process all of the spilled defs. 6237fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) { 6247fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MachineOperand &MO = MI.getOperand(i); 6257fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (MO.isRegister() && MO.getReg() && MO.isDef()) { 6267fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner unsigned VirtReg = MO.getReg(); 6277fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 6287fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (!MRegisterInfo::isVirtualRegister(VirtReg)) { 6297fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // Check to see if this is a def-and-use vreg operand that we do need 6307fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // to insert a store for. 6317fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner bool OpTakenCareOf = false; 6327fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (MO.isUse() && !DefAndUseVReg.empty()) { 6337fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner for (unsigned dau = 0, e = DefAndUseVReg.size(); dau != e; ++dau) 6347fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (DefAndUseVReg[dau].first == i) { 6357fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner VirtReg = DefAndUseVReg[dau].second; 6367fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner OpTakenCareOf = true; 6377fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner break; 6387fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 6397fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 640edf128a7fa90f2b0b7ee24741a04a7ae1ecd6f7eMisha Brukman 6417fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (!OpTakenCareOf) { 642109afed40bec552e4d37115c971e082e79eb0093Chris Lattner // Check to see if this is a noop copy. If so, eliminate the 643109afed40bec552e4d37115c971e082e79eb0093Chris Lattner // instruction before considering the dest reg to be changed. 644109afed40bec552e4d37115c971e082e79eb0093Chris Lattner unsigned Src, Dst; 645109afed40bec552e4d37115c971e082e79eb0093Chris Lattner if (TII->isMoveInstr(MI, Src, Dst) && Src == Dst) { 646109afed40bec552e4d37115c971e082e79eb0093Chris Lattner ++NumDCE; 647109afed40bec552e4d37115c971e082e79eb0093Chris Lattner DEBUG(std::cerr << "Removing now-noop copy: " << MI); 648109afed40bec552e4d37115c971e082e79eb0093Chris Lattner MBB.erase(&MI); 649109afed40bec552e4d37115c971e082e79eb0093Chris Lattner goto ProcessNextInst; 650109afed40bec552e4d37115c971e082e79eb0093Chris Lattner } 65166cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner Spills.ClobberPhysReg(VirtReg); 65284e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner continue; 6537fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 654edf128a7fa90f2b0b7ee24741a04a7ae1ecd6f7eMisha Brukman } 6557fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 65684e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner // The only vregs left are stack slot definitions. 65784e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner int StackSlot = VRM.getStackSlot(VirtReg); 65884e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner const TargetRegisterClass *RC = 65984e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner MBB.getParent()->getSSARegMap()->getRegClass(VirtReg); 66084e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner unsigned PhysReg; 66184e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner 66284e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner // If this is a def&use operand, and we used a different physreg for 66384e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner // it than the one assigned, make sure to execute the store from the 66484e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner // correct physical register. 66584e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner if (MO.getReg() == VirtReg) 66684e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner PhysReg = VRM.getPhys(VirtReg); 66784e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner else 66884e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner PhysReg = MO.getReg(); 66984e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner 67084e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner PhysRegsUsed[PhysReg] = true; 67184e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner MRI->storeRegToStackSlot(MBB, next(MII), PhysReg, StackSlot, RC); 67284e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner DEBUG(std::cerr << "Store:\t" << *next(MII)); 67384e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner MI.SetMachineOperandReg(i, PhysReg); 67484e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner 675109afed40bec552e4d37115c971e082e79eb0093Chris Lattner // Check to see if this is a noop copy. If so, eliminate the 676109afed40bec552e4d37115c971e082e79eb0093Chris Lattner // instruction before considering the dest reg to be changed. 677109afed40bec552e4d37115c971e082e79eb0093Chris Lattner { 678109afed40bec552e4d37115c971e082e79eb0093Chris Lattner unsigned Src, Dst; 679109afed40bec552e4d37115c971e082e79eb0093Chris Lattner if (TII->isMoveInstr(MI, Src, Dst) && Src == Dst) { 680109afed40bec552e4d37115c971e082e79eb0093Chris Lattner ++NumDCE; 681109afed40bec552e4d37115c971e082e79eb0093Chris Lattner DEBUG(std::cerr << "Removing now-noop copy: " << MI); 682109afed40bec552e4d37115c971e082e79eb0093Chris Lattner MBB.erase(&MI); 683109afed40bec552e4d37115c971e082e79eb0093Chris Lattner goto ProcessNextInst; 684109afed40bec552e4d37115c971e082e79eb0093Chris Lattner } 685109afed40bec552e4d37115c971e082e79eb0093Chris Lattner } 686109afed40bec552e4d37115c971e082e79eb0093Chris Lattner 68784e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner // If there is a dead store to this stack slot, nuke it now. 68884e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner MachineInstr *&LastStore = MaybeDeadStores[StackSlot]; 68984e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner if (LastStore) { 69084e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner DEBUG(std::cerr << " Killed store:\t" << *LastStore); 69184e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner ++NumDSE; 69284e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner MBB.erase(LastStore); 6930d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos } 69484e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner LastStore = next(MII); 69584e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner 69684e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner // If the stack slot value was previously available in some other 69784e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner // register, change it now. Otherwise, make the register available, 69884e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner // in PhysReg. 69966cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner Spills.ModifyStackSlot(StackSlot); 70066cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner Spills.ClobberPhysReg(PhysReg); 70166cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner 70266cf80f226e04e6704a78da83e08c7b0af944ef1Chris Lattner Spills.addAvailable(StackSlot, PhysReg); 70384e752a8129e7a02ee6e3c6d356a8fd68fbdf698Chris Lattner ++NumStores; 7047fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 7058c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 706cea8688ee4637e0f3cffc75e47f15be756f043bfChris Lattner ProcessNextInst: 7077fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MII = NextMII; 7088c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 7090d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos} 7100d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos 7118c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 7127fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 7138c4d88d3697835371ecf6823f4142af13603ad2dChris Lattnerllvm::Spiller* llvm::createSpiller() { 7148c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner switch (SpillerOpt) { 7158c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner default: assert(0 && "Unreachable!"); 7168c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner case local: 7178c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner return new LocalSpiller(); 7188c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner case simple: 7198c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner return new SimpleSpiller(); 7208c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 7210d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos} 722