VirtRegMap.cpp revision 8f1d6402ba73b96993ffd1eb9434b28c828d8856
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> 3234d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenosusing namespace llvm; 3334d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos 3434d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenosnamespace { 358c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner Statistic<> NumSpills("spiller", "Number of register spills"); 368c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner Statistic<> NumStores("spiller", "Number of stores added"); 378c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner Statistic<> NumLoads ("spiller", "Number of loads added"); 387fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner Statistic<> NumReused("spiller", "Number of values reused"); 3952b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner Statistic<> NumDSE ("spiller", "Number of dead stores elided"); 408c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 418c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner enum SpillerName { simple, local }; 428c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 438c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner cl::opt<SpillerName> 448c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner SpillerOpt("spiller", 457fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner cl::desc("Spiller to use: (default: local)"), 468c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner cl::Prefix, 478c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner cl::values(clEnumVal(simple, " simple spiller"), 488c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner clEnumVal(local, " local spiller"), 498c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner clEnumValEnd), 507fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner cl::init(local)); 518c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner} 528c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 538c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner//===----------------------------------------------------------------------===// 548c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner// VirtRegMap implementation 558c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner//===----------------------------------------------------------------------===// 568c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 578c4d88d3697835371ecf6823f4142af13603ad2dChris Lattnervoid VirtRegMap::grow() { 587f690e625807b9320bf4ae437b8f35258acc99deChris Lattner Virt2PhysMap.grow(MF.getSSARegMap()->getLastVirtReg()); 597f690e625807b9320bf4ae437b8f35258acc99deChris Lattner Virt2StackSlotMap.grow(MF.getSSARegMap()->getLastVirtReg()); 6034d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos} 6134d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos 628c4d88d3697835371ecf6823f4142af13603ad2dChris Lattnerint VirtRegMap::assignVirt2StackSlot(unsigned virtReg) { 638c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner assert(MRegisterInfo::isVirtualRegister(virtReg)); 647f690e625807b9320bf4ae437b8f35258acc99deChris Lattner assert(Virt2StackSlotMap[virtReg] == NO_STACK_SLOT && 658c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner "attempt to assign stack slot to already spilled register"); 667f690e625807b9320bf4ae437b8f35258acc99deChris Lattner const TargetRegisterClass* RC = MF.getSSARegMap()->getRegClass(virtReg); 677f690e625807b9320bf4ae437b8f35258acc99deChris Lattner int frameIndex = MF.getFrameInfo()->CreateStackObject(RC->getSize(), 687f690e625807b9320bf4ae437b8f35258acc99deChris Lattner RC->getAlignment()); 697f690e625807b9320bf4ae437b8f35258acc99deChris Lattner Virt2StackSlotMap[virtReg] = frameIndex; 708c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner ++NumSpills; 718c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner return frameIndex; 7234d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos} 7334d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos 748c4d88d3697835371ecf6823f4142af13603ad2dChris Lattnervoid VirtRegMap::assignVirt2StackSlot(unsigned virtReg, int frameIndex) { 758c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner assert(MRegisterInfo::isVirtualRegister(virtReg)); 767f690e625807b9320bf4ae437b8f35258acc99deChris Lattner assert(Virt2StackSlotMap[virtReg] == NO_STACK_SLOT && 778c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner "attempt to assign stack slot to already spilled register"); 787f690e625807b9320bf4ae437b8f35258acc99deChris Lattner Virt2StackSlotMap[virtReg] = frameIndex; 7938af59a43c4176d8f34bd26faeb18b23080a1d9bAlkis Evlogimenos} 8038af59a43c4176d8f34bd26faeb18b23080a1d9bAlkis Evlogimenos 81bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattnervoid VirtRegMap::virtFolded(unsigned VirtReg, MachineInstr *OldMI, 82bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner unsigned OpNo, MachineInstr *NewMI) { 83bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner // Move previous memory references folded to new instruction. 84bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner MI2VirtMapTy::iterator IP = MI2VirtMap.lower_bound(NewMI); 85bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner for (MI2VirtMapTy::iterator I = MI2VirtMap.lower_bound(OldMI), 86bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner E = MI2VirtMap.end(); I != E && I->first == OldMI; ) { 87bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner MI2VirtMap.insert(IP, std::make_pair(NewMI, I->second)); 88dbea9731b12e62f70d9da40cf273cdd9105f987cChris Lattner MI2VirtMap.erase(I++); 898c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 90dbea9731b12e62f70d9da40cf273cdd9105f987cChris Lattner 91bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner ModRef MRInfo; 92bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner if (!OldMI->getOperand(OpNo).isDef()) { 93bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner assert(OldMI->getOperand(OpNo).isUse() && "Operand is not use or def?"); 94bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner MRInfo = isRef; 95bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner } else { 96bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner MRInfo = OldMI->getOperand(OpNo).isUse() ? isModRef : isMod; 97bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner } 988c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 998c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner // add new memory reference 100bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner MI2VirtMap.insert(IP, std::make_pair(NewMI, std::make_pair(VirtReg, MRInfo))); 1018c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner} 1025f37502bfbadfa65de087627bd67fd58bb03725cAlkis Evlogimenos 1037f690e625807b9320bf4ae437b8f35258acc99deChris Lattnervoid VirtRegMap::print(std::ostream &OS) const { 1047f690e625807b9320bf4ae437b8f35258acc99deChris Lattner const MRegisterInfo* MRI = MF.getTarget().getRegisterInfo(); 1058c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 1067f690e625807b9320bf4ae437b8f35258acc99deChris Lattner OS << "********** REGISTER MAP **********\n"; 1078c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner for (unsigned i = MRegisterInfo::FirstVirtualRegister, 1087f690e625807b9320bf4ae437b8f35258acc99deChris Lattner e = MF.getSSARegMap()->getLastVirtReg(); i <= e; ++i) { 1097f690e625807b9320bf4ae437b8f35258acc99deChris Lattner if (Virt2PhysMap[i] != (unsigned)VirtRegMap::NO_PHYS_REG) 1107f690e625807b9320bf4ae437b8f35258acc99deChris Lattner OS << "[reg" << i << " -> " << MRI->getName(Virt2PhysMap[i]) << "]\n"; 1117f690e625807b9320bf4ae437b8f35258acc99deChris Lattner 1128c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 1138c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 1148c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner for (unsigned i = MRegisterInfo::FirstVirtualRegister, 1157f690e625807b9320bf4ae437b8f35258acc99deChris Lattner e = MF.getSSARegMap()->getLastVirtReg(); i <= e; ++i) 1167f690e625807b9320bf4ae437b8f35258acc99deChris Lattner if (Virt2StackSlotMap[i] != VirtRegMap::NO_STACK_SLOT) 1177f690e625807b9320bf4ae437b8f35258acc99deChris Lattner OS << "[reg" << i << " -> fi#" << Virt2StackSlotMap[i] << "]\n"; 1187f690e625807b9320bf4ae437b8f35258acc99deChris Lattner OS << '\n'; 1195f37502bfbadfa65de087627bd67fd58bb03725cAlkis Evlogimenos} 1205f37502bfbadfa65de087627bd67fd58bb03725cAlkis Evlogimenos 1218c4d88d3697835371ecf6823f4142af13603ad2dChris Lattnervoid VirtRegMap::dump() const { print(std::cerr); } 12234d9bc9f168d17c52eb57e024580bd9499695f91Alkis Evlogimenos 1230d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos 1248c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner//===----------------------------------------------------------------------===// 1258c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner// Simple Spiller Implementation 1268c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner//===----------------------------------------------------------------------===// 127dd420e060accd1d773c731e77335cff65ca34013Alkis Evlogimenos 1288c4d88d3697835371ecf6823f4142af13603ad2dChris LattnerSpiller::~Spiller() {} 129dd420e060accd1d773c731e77335cff65ca34013Alkis Evlogimenos 1300d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenosnamespace { 1318c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner struct SimpleSpiller : public Spiller { 1328c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner bool runOnMachineFunction(MachineFunction& mf, const VirtRegMap &VRM); 1338c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner }; 1348c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner} 1350d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos 1368c4d88d3697835371ecf6823f4142af13603ad2dChris Lattnerbool SimpleSpiller::runOnMachineFunction(MachineFunction& MF, 1378c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner const VirtRegMap& VRM) { 1388c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner DEBUG(std::cerr << "********** REWRITE MACHINE CODE **********\n"); 1398c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner DEBUG(std::cerr << "********** Function: " 1408c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner << MF.getFunction()->getName() << '\n'); 1418c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner const TargetMachine& TM = MF.getTarget(); 1427f690e625807b9320bf4ae437b8f35258acc99deChris Lattner const MRegisterInfo& MRI = *TM.getRegisterInfo(); 1438c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 1444ea1b828ebc5d2e8711acf13c2a3fdd7c14fe339Chris Lattner // LoadedRegs - Keep track of which vregs are loaded, so that we only load 1454ea1b828ebc5d2e8711acf13c2a3fdd7c14fe339Chris Lattner // each vreg once (in the case where a spilled vreg is used by multiple 1464ea1b828ebc5d2e8711acf13c2a3fdd7c14fe339Chris Lattner // operands). This is always smaller than the number of operands to the 1474ea1b828ebc5d2e8711acf13c2a3fdd7c14fe339Chris Lattner // current machine instr, so it should be small. 1484ea1b828ebc5d2e8711acf13c2a3fdd7c14fe339Chris Lattner std::vector<unsigned> LoadedRegs; 1498c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 1500fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner for (MachineFunction::iterator MBBI = MF.begin(), E = MF.end(); 1510fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner MBBI != E; ++MBBI) { 1520fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner DEBUG(std::cerr << MBBI->getBasicBlock()->getName() << ":\n"); 1530fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner MachineBasicBlock &MBB = *MBBI; 1540fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner for (MachineBasicBlock::iterator MII = MBB.begin(), 1550fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner E = MBB.end(); MII != E; ++MII) { 1560fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner MachineInstr &MI = *MII; 1570fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) { 1587fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MachineOperand &MO = MI.getOperand(i); 1597fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (MO.isRegister() && MO.getReg() && 1607fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MRegisterInfo::isVirtualRegister(MO.getReg())) { 1617fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner unsigned VirtReg = MO.getReg(); 1620fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner unsigned PhysReg = VRM.getPhys(VirtReg); 1630fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner if (VRM.hasStackSlot(VirtReg)) { 164477e4555de341c5de780de3720d6f115ec133c4eChris Lattner int StackSlot = VRM.getStackSlot(VirtReg); 1650fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner 1667fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (MO.isUse() && 1670fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner std::find(LoadedRegs.begin(), LoadedRegs.end(), VirtReg) 1680fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner == LoadedRegs.end()) { 1690fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner MRI.loadRegFromStackSlot(MBB, &MI, PhysReg, StackSlot); 1700fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner LoadedRegs.push_back(VirtReg); 1710fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner ++NumLoads; 172477e4555de341c5de780de3720d6f115ec133c4eChris Lattner DEBUG(std::cerr << '\t' << *prior(MII)); 1730fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner } 1740fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner 1757fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (MO.isDef()) { 1767fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MRI.storeRegToStackSlot(MBB, next(MII), PhysReg, StackSlot); 1770fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner ++NumStores; 1780fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner } 1798c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 1800fc27ccdd374799c8d65b61e89db53ba1ea47358Chris Lattner MI.SetMachineOperandReg(i, PhysReg); 1810d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos } 1828c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 183477e4555de341c5de780de3720d6f115ec133c4eChris Lattner DEBUG(std::cerr << '\t' << MI); 1844ea1b828ebc5d2e8711acf13c2a3fdd7c14fe339Chris Lattner LoadedRegs.clear(); 1858c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 1868c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 1878c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner return true; 1888c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner} 1890d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos 1908c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner//===----------------------------------------------------------------------===// 1918c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner// Local Spiller Implementation 1928c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner//===----------------------------------------------------------------------===// 1930d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos 1948c4d88d3697835371ecf6823f4142af13603ad2dChris Lattnernamespace { 1957fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner /// LocalSpiller - This spiller does a simple pass over the machine basic 1967fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner /// block to attempt to keep spills in registers as much as possible for 1977fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner /// blocks that have low register pressure (the vreg may be spilled due to 1987fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner /// register pressure in other blocks). 1998c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner class LocalSpiller : public Spiller { 2008c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner const MRegisterInfo *MRI; 2017fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner const TargetInstrInfo *TII; 2028c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner public: 2037fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner bool runOnMachineFunction(MachineFunction &MF, const VirtRegMap &VRM) { 2047fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MRI = MF.getTarget().getRegisterInfo(); 2057fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner TII = MF.getTarget().getInstrInfo(); 2067fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << "\n**** Local spiller rewriting function '" 2077fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner << MF.getFunction()->getName() << "':\n"); 2087fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 2097fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner for (MachineFunction::iterator MBB = MF.begin(), E = MF.end(); 2107fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MBB != E; ++MBB) 2117fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner RewriteMBB(*MBB, VRM); 2127fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner return true; 2138c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 2147fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner private: 2157fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner void RewriteMBB(MachineBasicBlock &MBB, const VirtRegMap &VRM); 2167fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner void ClobberPhysReg(unsigned PR, std::map<int, unsigned> &SpillSlots, 2177fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner std::map<unsigned, int> &PhysRegs); 2187fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner void ClobberPhysRegOnly(unsigned PR, std::map<int, unsigned> &SpillSlots, 2197fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner std::map<unsigned, int> &PhysRegs); 2208c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner }; 2218c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner} 2228c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 2237fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattnervoid LocalSpiller::ClobberPhysRegOnly(unsigned PhysReg, 2247fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner std::map<int, unsigned> &SpillSlots, 2257fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner std::map<unsigned, int> &PhysRegs) { 2267fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner std::map<unsigned, int>::iterator I = PhysRegs.find(PhysReg); 2277fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (I != PhysRegs.end()) { 2287fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner int Slot = I->second; 2297fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner PhysRegs.erase(I); 2307fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner assert(SpillSlots[Slot] == PhysReg && "Bidirectional map mismatch!"); 2317fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner SpillSlots.erase(Slot); 2327fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << "PhysReg " << MRI->getName(PhysReg) 2337fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner << " clobbered, invalidating SS#" << Slot << "\n"); 2348c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 2358c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 2368c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner} 2370d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos 2387fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattnervoid LocalSpiller::ClobberPhysReg(unsigned PhysReg, 2397fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner std::map<int, unsigned> &SpillSlots, 2407fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner std::map<unsigned, int> &PhysRegs) { 2417fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner for (const unsigned *AS = MRI->getAliasSet(PhysReg); *AS; ++AS) 2427fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ClobberPhysRegOnly(*AS, SpillSlots, PhysRegs); 2437fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ClobberPhysRegOnly(PhysReg, SpillSlots, PhysRegs); 2448c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner} 2458c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 2468c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 2477fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner// ReusedOp - For each reused operand, we keep track of a bit of information, in 2487fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner// case we need to rollback upon processing a new operand. See comments below. 2497fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattnernamespace { 2507fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner struct ReusedOp { 2517fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // The MachineInstr operand that reused an available value. 2527fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner unsigned Operand; 2537fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 2547fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // StackSlot - The spill slot of the value being reused. 2557fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner unsigned StackSlot; 2567fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 2577fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // PhysRegReused - The physical register the value was available in. 2587fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner unsigned PhysRegReused; 2597fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 2607fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // AssignedPhysReg - The physreg that was assigned for use by the reload. 2617fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner unsigned AssignedPhysReg; 2627fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 2637fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ReusedOp(unsigned o, unsigned ss, unsigned prr, unsigned apr) 2647fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner : Operand(o), StackSlot(ss), PhysRegReused(prr), AssignedPhysReg(apr) {} 2657fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner }; 2667fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner} 2677fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 2687fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 2697fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner/// rewriteMBB - Keep track of which spills are available even after the 2707fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner/// register allocator is done with them. If possible, avoid reloading vregs. 2717fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattnervoid LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, const VirtRegMap &VRM) { 2727fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 2737fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // SpillSlotsAvailable - This map keeps track of all of the spilled virtual 2747fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // register values that are still available, due to being loaded to stored to, 2757fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // but not invalidated yet. 2767fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner std::map<int, unsigned> SpillSlotsAvailable; 2777fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 2787fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // PhysRegsAvailable - This is the inverse of SpillSlotsAvailable, indicating 2797fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // which physregs are in use holding a stack slot value. 2807fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner std::map<unsigned, int> PhysRegsAvailable; 2817fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 2827fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << MBB.getBasicBlock()->getName() << ":\n"); 2837fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 2847fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner std::vector<ReusedOp> ReusedOperands; 2857fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 2867fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // DefAndUseVReg - When we see a def&use operand that is spilled, keep track 2877fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // of it. ".first" is the machine operand index (should always be 0 for now), 2887fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // and ".second" is the virtual register that is spilled. 2897fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner std::vector<std::pair<unsigned, unsigned> > DefAndUseVReg; 2907fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 29152b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner // MaybeDeadStores - When we need to write a value back into a stack slot, 29252b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner // keep track of the inserted store. If the stack slot value is never read 29352b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner // (because the value was used from some available register, for example), and 29452b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner // subsequently stored to, the original store is dead. This map keeps track 29552b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner // of inserted stores that are not used. If we see a subsequent store to the 29652b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner // same stack slot, the original store is deleted. 29752b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner std::map<int, MachineInstr*> MaybeDeadStores; 29852b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner 2997fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner for (MachineBasicBlock::iterator MII = MBB.begin(), E = MBB.end(); 3007fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MII != E; ) { 3017fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MachineInstr &MI = *MII; 3027fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MachineBasicBlock::iterator NextMII = MII; ++NextMII; 3037fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 3047fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ReusedOperands.clear(); 3057fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DefAndUseVReg.clear(); 3067fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 3077fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // Process all of the spilled uses and all non spilled reg references. 3087fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) { 3097fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MachineOperand &MO = MI.getOperand(i); 3107fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (MO.isRegister() && MO.getReg() && 3117fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MRegisterInfo::isVirtualRegister(MO.getReg())) { 3127fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner unsigned VirtReg = MO.getReg(); 3137fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 3147fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (!VRM.hasStackSlot(VirtReg)) { 3157fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // This virtual register was assigned a physreg! 3167fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MI.SetMachineOperandReg(i, VRM.getPhys(VirtReg)); 3177fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } else { 3187fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // Is this virtual register a spilled value? 3197fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (MO.isUse()) { 3207fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner int StackSlot = VRM.getStackSlot(VirtReg); 3217fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner unsigned PhysReg; 3227fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 3237fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // Check to see if this stack slot is available. 3247fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner std::map<int, unsigned>::iterator SSI = 3257fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner SpillSlotsAvailable.find(StackSlot); 3267fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (SSI != SpillSlotsAvailable.end()) { 3278df6a594d2781777cd25fe2d00818419a8b10e5cChris Lattner DEBUG(std::cerr << "Reusing SS#" << StackSlot << " from physreg " 3288df6a594d2781777cd25fe2d00818419a8b10e5cChris Lattner << MRI->getName(SSI->second) << " for vreg" 3298df6a594d2781777cd25fe2d00818419a8b10e5cChris Lattner << VirtReg <<" instead of reloading into physreg " 3308df6a594d2781777cd25fe2d00818419a8b10e5cChris Lattner << MRI->getName(VRM.getPhys(VirtReg)) << "\n"); 3317fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // If this stack slot value is already available, reuse it! 3327fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner PhysReg = SSI->second; 3337fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MI.SetMachineOperandReg(i, PhysReg); 3347fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 3357fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // The only technical detail we have is that we don't know that 3367fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // PhysReg won't be clobbered by a reloaded stack slot that occurs 3377fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // later in the instruction. In particular, consider 'op V1, V2'. 3387fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // If V1 is available in physreg R0, we would choose to reuse it 3397fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // here, instead of reloading it into the register the allocator 3407fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // indicated (say R1). However, V2 might have to be reloaded 3417fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // later, and it might indicate that it needs to live in R0. When 3427fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // this occurs, we need to have information available that 3437fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // indicates it is safe to use R1 for the reload instead of R0. 3447fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // 3457fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // To further complicate matters, we might conflict with an alias, 3467fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // or R0 and R1 might not be compatible with each other. In this 3477fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // case, we actually insert a reload for V1 in R1, ensuring that 3487fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // we can get at R0 or its alias. 3497fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ReusedOperands.push_back(ReusedOp(i, StackSlot, PhysReg, 3507fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner VRM.getPhys(VirtReg))); 3517fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ++NumReused; 3527fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } else { 3537fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // Otherwise, reload it and remember that we have it. 3547fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner PhysReg = VRM.getPhys(VirtReg); 3557fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 35647eb6567e22ecf87ebeabc566fac6c02c975a9a4Chris Lattner RecheckRegister: 3577fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // Note that, if we reused a register for a previous operand, the 3587fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // register we want to reload into might not actually be 3597fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // available. If this occurs, use the register indicated by the 3607fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // reuser. 3617fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (!ReusedOperands.empty()) // This is most often empty. 3627fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner for (unsigned ro = 0, e = ReusedOperands.size(); ro != e; ++ro) 3637fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (ReusedOperands[ro].PhysRegReused == PhysReg) { 3647fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // Yup, use the reload register that we didn't use before. 3657fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner PhysReg = ReusedOperands[ro].AssignedPhysReg; 36647eb6567e22ecf87ebeabc566fac6c02c975a9a4Chris Lattner goto RecheckRegister; 3677fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } else { 3687fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ReusedOp &Op = ReusedOperands[ro]; 3697fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner unsigned PRRU = Op.PhysRegReused; 3707fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner for (const unsigned *AS = MRI->getAliasSet(PRRU); *AS; ++AS) 3717fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (*AS == PhysReg) { 3727fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // Okay, we found out that an alias of a reused register 3737fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // was used. This isn't good because it means we have 3747fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // to undo a previous reuse. 3757fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MRI->loadRegFromStackSlot(MBB, &MI, Op.AssignedPhysReg, 3767fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner Op.StackSlot); 3777fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ClobberPhysReg(Op.AssignedPhysReg, SpillSlotsAvailable, 3787fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner PhysRegsAvailable); 3797fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 38052b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner // Any stores to this stack slot are not dead anymore. 38152b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner MaybeDeadStores.erase(Op.StackSlot); 38252b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner 3837fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MI.SetMachineOperandReg(Op.Operand, Op.AssignedPhysReg); 3847fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner PhysRegsAvailable[Op.AssignedPhysReg] = Op.StackSlot; 3857fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner SpillSlotsAvailable[Op.StackSlot] = Op.AssignedPhysReg; 3867fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner PhysRegsAvailable.erase(Op.PhysRegReused); 3877fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << "Remembering SS#" << Op.StackSlot 3887fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner << " in physreg " 3897fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner << MRI->getName(Op.AssignedPhysReg) << "\n"); 3907fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ++NumLoads; 3917fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << '\t' << *prior(MII)); 3927fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 3937fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << "Reuse undone!\n"); 3947fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ReusedOperands.erase(ReusedOperands.begin()+ro); 3957fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner --NumReused; 3967fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner goto ContinueReload; 3977fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 3987fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 3997fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ContinueReload: 4007fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 4017fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MRI->loadRegFromStackSlot(MBB, &MI, PhysReg, StackSlot); 4027fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // This invalidates PhysReg. 4037fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ClobberPhysReg(PhysReg, SpillSlotsAvailable, PhysRegsAvailable); 4047fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 40552b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner // Any stores to this stack slot are not dead anymore. 40652b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner MaybeDeadStores.erase(StackSlot); 40752b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner 4087fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MI.SetMachineOperandReg(i, PhysReg); 4097fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner PhysRegsAvailable[PhysReg] = StackSlot; 4107fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner SpillSlotsAvailable[StackSlot] = PhysReg; 4117fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << "Remembering SS#" << StackSlot <<" in physreg " 4127fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner << MRI->getName(PhysReg) << "\n"); 4137fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ++NumLoads; 4147fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << '\t' << *prior(MII)); 4157fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 4167fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 4177fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // If this is both a def and a use, we need to emit a store to the 4187fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // stack slot after the instruction. Keep track of D&U operands 4197fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // because we already changed it to a physreg here. 4207fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (MO.isDef()) { 4217fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // Remember that this was a def-and-use operand, and that the 4227fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // stack slot is live after this instruction executes. 4237fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DefAndUseVReg.push_back(std::make_pair(i, VirtReg)); 4247fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 4257fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 4260d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos } 4278c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 4288c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 4290d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos 4307fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // Loop over all of the implicit defs, clearing them from our available 4317fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // sets. 4327fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner const TargetInstrDescriptor &InstrDesc = TII->get(MI.getOpcode()); 4337fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner for (const unsigned* ImpDef = InstrDesc.ImplicitDefs; *ImpDef; ++ImpDef) 4347fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ClobberPhysReg(*ImpDef, SpillSlotsAvailable, PhysRegsAvailable); 4357fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 4367fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << '\t' << MI); 4377fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 4387fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // If we have folded references to memory operands, make sure we clear all 4397fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // physical registers that may contain the value of the spilled virtual 4407fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // register 4418f1d6402ba73b96993ffd1eb9434b28c828d8856Chris Lattner VirtRegMap::MI2VirtMapTy::const_iterator I, End; 4428f1d6402ba73b96993ffd1eb9434b28c828d8856Chris Lattner for (tie(I, End) = VRM.getFoldedVirts(&MI); I != End; ++I) { 443bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner DEBUG(std::cerr << "Folded vreg: " << I->second.first << " MR: " 444bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner << I->second.second); 445bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner unsigned VirtReg = I->second.first; 446bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner VirtRegMap::ModRef MR = I->second.second; 447bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner if (VRM.hasStackSlot(VirtReg)) { 448bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner int SS = VRM.getStackSlot(VirtReg); 4497fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << " - StackSlot: " << SS << "\n"); 4507fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 451bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner // If this reference is not a use, any previous store is now dead. 452bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner // Otherwise, the store to this stack slot is not dead anymore. 453bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner std::map<int, MachineInstr*>::iterator MDSI = MaybeDeadStores.find(SS); 454bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner if (MDSI != MaybeDeadStores.end()) { 455bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner if (MR & VirtRegMap::isRef) // Previous store is not dead. 4567cf34908920dc714eba7525d38747de2cdc81402Chris Lattner MaybeDeadStores.erase(MDSI); 457bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner else { 458bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner // If we get here, the store is dead, nuke it now. 459bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner assert(MR == VirtRegMap::isMod && "Can't be modref!"); 460bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner MBB.erase(MDSI->second); 461bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner MaybeDeadStores.erase(MDSI); 462bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner ++NumDSE; 463bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner } 464bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner } 46552b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner 466bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner // If the spill slot value is available, and this is a new definition of 467bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner // the value, the value is not available anymore. 468bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner if (MR & VirtRegMap::isMod) { 469bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner std::map<int, unsigned>::iterator It = SpillSlotsAvailable.find(SS); 470bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner if (It != SpillSlotsAvailable.end()) { 471bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner PhysRegsAvailable.erase(It->second); 472bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner SpillSlotsAvailable.erase(It); 473bec6a9ea1281a0b3b37aece91ab0df21e086af61Chris Lattner } 4747fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 4757fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } else { 4767fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << ": No stack slot!\n"); 4777fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 4788c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 4790d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos 4807fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // Process all of the spilled defs. 4817fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) { 4827fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MachineOperand &MO = MI.getOperand(i); 4837fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (MO.isRegister() && MO.getReg() && MO.isDef()) { 4847fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner unsigned VirtReg = MO.getReg(); 4857fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 4867fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner bool TakenCareOf = false; 4877fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (!MRegisterInfo::isVirtualRegister(VirtReg)) { 4887fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // Check to see if this is a def-and-use vreg operand that we do need 4897fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // to insert a store for. 4907fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner bool OpTakenCareOf = false; 4917fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (MO.isUse() && !DefAndUseVReg.empty()) { 4927fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner for (unsigned dau = 0, e = DefAndUseVReg.size(); dau != e; ++dau) 4937fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (DefAndUseVReg[dau].first == i) { 4947fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner VirtReg = DefAndUseVReg[dau].second; 4957fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner OpTakenCareOf = true; 4967fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner break; 4977fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 4987fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 4997fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 5007fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (!OpTakenCareOf) { 5017fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ClobberPhysReg(VirtReg, SpillSlotsAvailable, PhysRegsAvailable); 5027fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner TakenCareOf = true; 5037fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 5047fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 5057fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 5067fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (!TakenCareOf) { 5077fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // The only vregs left are stack slot definitions. 5087fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner int StackSlot = VRM.getStackSlot(VirtReg); 5097fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner unsigned PhysReg; 5107fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 5117fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // If this is a def&use operand, and we used a different physreg for 5127fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // it than the one assigned, make sure to execute the store from the 5137fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // correct physical register. 5147fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (MO.getReg() == VirtReg) 5157fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner PhysReg = VRM.getPhys(VirtReg); 5167fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner else 5177fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner PhysReg = MO.getReg(); 5187fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 5197fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MRI->storeRegToStackSlot(MBB, next(MII), PhysReg, StackSlot); 5207fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << "Store:\t" << *next(MII)); 5217fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MI.SetMachineOperandReg(i, PhysReg); 5227fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 52352b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner // If there is a dead store to this stack slot, nuke it now. 52452b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner MachineInstr *&LastStore = MaybeDeadStores[StackSlot]; 52552b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner if (LastStore) { 5268df6a594d2781777cd25fe2d00818419a8b10e5cChris Lattner DEBUG(std::cerr << " Killed store:\t" << *LastStore); 52752b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner ++NumDSE; 52852b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner MBB.erase(LastStore); 52952b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner } 53052b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner LastStore = next(MII); 53152b25db3ef9390271bbfa0b5c6efe0a72ce7cb8eChris Lattner 5327fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // If the stack slot value was previously available in some other 5337fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // register, change it now. Otherwise, make the register available, 5347fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // in PhysReg. 5357fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner std::map<int, unsigned>::iterator SSA = 5367fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner SpillSlotsAvailable.find(StackSlot); 5377fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner if (SSA != SpillSlotsAvailable.end()) { 5387fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner // Remove the record for physreg. 5397fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner PhysRegsAvailable.erase(SSA->second); 5407fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner SpillSlotsAvailable.erase(SSA); 5417fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 5427fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ClobberPhysReg(PhysReg, SpillSlotsAvailable, PhysRegsAvailable); 5437fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 5447fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner PhysRegsAvailable[PhysReg] = StackSlot; 5457fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner SpillSlotsAvailable[StackSlot] = PhysReg; 5467fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner DEBUG(std::cerr << "Updating SS#" << StackSlot <<" in physreg " 5478df6a594d2781777cd25fe2d00818419a8b10e5cChris Lattner << MRI->getName(PhysReg) << " for virtreg #" 5488df6a594d2781777cd25fe2d00818419a8b10e5cChris Lattner << VirtReg << "\n"); 5497fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 5507fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner ++NumStores; 5517fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner VirtReg = PhysReg; 5520d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos } 5537fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner } 5548c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 5557fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner MII = NextMII; 5568c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 5570d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos} 5580d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos 5598c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner 5607fb64347d7d1310b5f3f06f7ae97031c73a21797Chris Lattner 5618c4d88d3697835371ecf6823f4142af13603ad2dChris Lattnerllvm::Spiller* llvm::createSpiller() { 5628c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner switch (SpillerOpt) { 5638c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner default: assert(0 && "Unreachable!"); 5648c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner case local: 5658c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner return new LocalSpiller(); 5668c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner case simple: 5678c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner return new SimpleSpiller(); 5688c4d88d3697835371ecf6823f4142af13603ad2dChris Lattner } 5690d6c5b6489b9abb634a1506d183ba47f1bf4d1f0Alkis Evlogimenos} 570