LiveIntervalAnalysis.cpp revision bfe180af9eef1cf767f61f501ca325fcce2ae7ce
1a3b8b5c0e0a1d0942288568b2012592184ca67c5Chris Lattner//===-- LiveIntervalAnalysis.cpp - Live Interval Analysis -----------------===// 2ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos// 3ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos// The LLVM Compiler Infrastructure 4ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos// 5ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos// This file was developed by the LLVM research group and is distributed under 6ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos// the University of Illinois Open Source License. See LICENSE.TXT for details. 7ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos// 8ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos//===----------------------------------------------------------------------===// 9ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos// 10ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos// This file implements the LiveInterval analysis pass which is used 11ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos// by the Linear Scan Register allocator. This pass linearizes the 12ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos// basic blocks of the function in DFS order and uses the 13ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos// LiveVariables pass to conservatively compute live intervals for 14ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos// each virtual and physical register. 15ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos// 16ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos//===----------------------------------------------------------------------===// 17ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos 18ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos#define DEBUG_TYPE "liveintervals" 193c3fe462f7978b429ecdd71750c26be25c3d1335Chris Lattner#include "llvm/CodeGen/LiveIntervalAnalysis.h" 2008a6c7614be9793754b17930ba619e875aef9585Misha Brukman#include "VirtRegMap.h" 21015959ee38e4fd4a920f6b0065c50e524762f580Chris Lattner#include "llvm/Value.h" 226b4edbaaf9021e0434f0ce0c3724eb43ed41b770Alkis Evlogimenos#include "llvm/Analysis/LoopInfo.h" 23ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos#include "llvm/CodeGen/LiveVariables.h" 24ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos#include "llvm/CodeGen/MachineFrameInfo.h" 25ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos#include "llvm/CodeGen/MachineInstr.h" 26ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos#include "llvm/CodeGen/Passes.h" 27ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos#include "llvm/CodeGen/SSARegMap.h" 28ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos#include "llvm/Target/MRegisterInfo.h" 29ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos#include "llvm/Target/TargetInstrInfo.h" 30ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos#include "llvm/Target/TargetMachine.h" 31551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/CommandLine.h" 32551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/Debug.h" 33551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/Statistic.h" 34551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/ADT/STLExtras.h" 3520aa474f8fbebde588edc101b90e834df28ce4ceAlkis Evlogimenos#include <algorithm> 3608a6c7614be9793754b17930ba619e875aef9585Misha Brukman#include <cmath> 372c2c6c61f100bc7c3df873b11203fcea1b5e18feChris Lattner#include <iostream> 38ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenosusing namespace llvm; 39ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos 40ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenosnamespace { 415d8925c7c506a54ebdfb0bc93437ec9f602eaaa0Chris Lattner RegisterPass<LiveIntervals> X("liveintervals", "Live Interval Analysis"); 42ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos 43ed41f1bb1981a98eea63f00c5988cf62bbdd7c59Andrew Lenharth static Statistic<> numIntervals 441a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos ("liveintervals", "Number of original intervals"); 45007726ca6f64ea74c20ddb90093ee8d6801733afAlkis Evlogimenos 46ed41f1bb1981a98eea63f00c5988cf62bbdd7c59Andrew Lenharth static Statistic<> numIntervalsAfter 471a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos ("liveintervals", "Number of intervals after coalescing"); 48007726ca6f64ea74c20ddb90093ee8d6801733afAlkis Evlogimenos 49ed41f1bb1981a98eea63f00c5988cf62bbdd7c59Andrew Lenharth static Statistic<> numJoins 501a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos ("liveintervals", "Number of interval joins performed"); 51007726ca6f64ea74c20ddb90093ee8d6801733afAlkis Evlogimenos 52ed41f1bb1981a98eea63f00c5988cf62bbdd7c59Andrew Lenharth static Statistic<> numPeep 531a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos ("liveintervals", "Number of identity moves eliminated after coalescing"); 54007726ca6f64ea74c20ddb90093ee8d6801733afAlkis Evlogimenos 55ed41f1bb1981a98eea63f00c5988cf62bbdd7c59Andrew Lenharth static Statistic<> numFolded 561a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos ("liveintervals", "Number of loads/stores folded into instructions"); 57007726ca6f64ea74c20ddb90093ee8d6801733afAlkis Evlogimenos 58ed41f1bb1981a98eea63f00c5988cf62bbdd7c59Andrew Lenharth static cl::opt<bool> 591a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos EnableJoining("join-liveintervals", 601a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos cl::desc("Join compatible live intervals"), 611a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos cl::init(true)); 62d74ea2bbd8bb630331f35ead42d385249bd42af8Chris Lattner} 63ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos 64f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattnervoid LiveIntervals::getAnalysisUsage(AnalysisUsage &AU) const { 651a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos AU.addRequired<LiveVariables>(); 661a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos AU.addPreservedID(PHIEliminationID); 671a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos AU.addRequiredID(PHIEliminationID); 681a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos AU.addRequiredID(TwoAddressInstructionPassID); 691a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos AU.addRequired<LoopInfo>(); 701a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos MachineFunctionPass::getAnalysisUsage(AU); 71ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos} 72ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos 73f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattnervoid LiveIntervals::releaseMemory() { 741a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos mi2iMap_.clear(); 751a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos i2miMap_.clear(); 761a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos r2iMap_.clear(); 771a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos r2rMap_.clear(); 7808cec00588ec1a8fa85b208555f006d7396ae7a4Alkis Evlogimenos} 7908cec00588ec1a8fa85b208555f006d7396ae7a4Alkis Evlogimenos 8008cec00588ec1a8fa85b208555f006d7396ae7a4Alkis Evlogimenos 81993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Chengstatic bool isZeroLengthInterval(LiveInterval *li) { 82993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Cheng for (LiveInterval::Ranges::const_iterator 83993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Cheng i = li->ranges.begin(), e = li->ranges.end(); i != e; ++i) 84993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Cheng if (i->end - i->start > LiveIntervals::InstrSlots::NUM) 85993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Cheng return false; 86993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Cheng return true; 87993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Cheng} 88993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Cheng 89993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Cheng 90ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos/// runOnMachineFunction - Register allocate the whole function 91ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos/// 92ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenosbool LiveIntervals::runOnMachineFunction(MachineFunction &fn) { 931a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos mf_ = &fn; 941a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos tm_ = &fn.getTarget(); 951a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos mri_ = tm_->getRegisterInfo(); 96f768bba43f5c036039851d2fcca8212edca18467Chris Lattner tii_ = tm_->getInstrInfo(); 971a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos lv_ = &getAnalysis<LiveVariables>(); 985327801fb87e3eda52a33f82e6211181030ecb93Alkis Evlogimenos allocatableRegs_ = mri_->getAllocatableSet(fn); 992c4f7b5faaeedd97058ec4cfa44177124c42b9e1Alkis Evlogimenos r2rMap_.grow(mf_->getSSARegMap()->getLastVirtReg()); 1001a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 101799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner // If this function has any live ins, insert a dummy instruction at the 102799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner // beginning of the function that we will pretend "defines" the values. This 103799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner // is to make the interval analysis simpler by providing a number. 104799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner if (fn.livein_begin() != fn.livein_end()) { 105712ad0c36dcfacb30620c793a6ffe4e80bd5d569Chris Lattner unsigned FirstLiveIn = fn.livein_begin()->first; 106799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner 107799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner // Find a reg class that contains this live in. 108799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner const TargetRegisterClass *RC = 0; 109799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner for (MRegisterInfo::regclass_iterator RCI = mri_->regclass_begin(), 110799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner E = mri_->regclass_end(); RCI != E; ++RCI) 111799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner if ((*RCI)->contains(FirstLiveIn)) { 112799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner RC = *RCI; 113799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner break; 114799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner } 115799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner 116799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner MachineInstr *OldFirstMI = fn.begin()->begin(); 117799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner mri_->copyRegToReg(*fn.begin(), fn.begin()->begin(), 118799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner FirstLiveIn, FirstLiveIn, RC); 119799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner assert(OldFirstMI != fn.begin()->begin() && 120799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner "copyRetToReg didn't insert anything!"); 121799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner } 122799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner 1231a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // number MachineInstrs 1241a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned miIndex = 0; 1251a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos for (MachineFunction::iterator mbb = mf_->begin(), mbbEnd = mf_->end(); 1261a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos mbb != mbbEnd; ++mbb) 1271a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos for (MachineBasicBlock::iterator mi = mbb->begin(), miEnd = mbb->end(); 1281a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos mi != miEnd; ++mi) { 1291a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos bool inserted = mi2iMap_.insert(std::make_pair(mi, miIndex)).second; 1301a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos assert(inserted && "multiple MachineInstr -> index mappings"); 1311a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos i2miMap_.push_back(mi); 1321a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos miIndex += InstrSlots::NUM; 1331a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 134ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos 135799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner // Note intervals due to live-in values. 136799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner if (fn.livein_begin() != fn.livein_end()) { 137799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner MachineBasicBlock *Entry = fn.begin(); 138712ad0c36dcfacb30620c793a6ffe4e80bd5d569Chris Lattner for (MachineFunction::livein_iterator I = fn.livein_begin(), 139799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner E = fn.livein_end(); I != E; ++I) { 140799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner handlePhysicalRegisterDef(Entry, Entry->begin(), 14191725b75852443923b419fd23215194cfc65dd88Chris Lattner getOrCreateInterval(I->first), 0); 142712ad0c36dcfacb30620c793a6ffe4e80bd5d569Chris Lattner for (const unsigned* AS = mri_->getAliasSet(I->first); *AS; ++AS) 143799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner handlePhysicalRegisterDef(Entry, Entry->begin(), 14491725b75852443923b419fd23215194cfc65dd88Chris Lattner getOrCreateInterval(*AS), 0); 145799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner } 146799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner } 147799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner 1481a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos computeIntervals(); 149ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos 1501a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos numIntervals += getNumIntervals(); 151843b160a2040b3ec4d3452678450afa11704c473Alkis Evlogimenos 15238135af219c48a8626d6af34a92e7e8bb957c81fChris Lattner DEBUG(std::cerr << "********** INTERVALS **********\n"; 15338135af219c48a8626d6af34a92e7e8bb957c81fChris Lattner for (iterator I = begin(), E = end(); I != E; ++I) { 15438135af219c48a8626d6af34a92e7e8bb957c81fChris Lattner I->second.print(std::cerr, mri_); 15538135af219c48a8626d6af34a92e7e8bb957c81fChris Lattner std::cerr << "\n"; 15638135af219c48a8626d6af34a92e7e8bb957c81fChris Lattner }); 1577ac2d3146a196fa0120c579ecd2ddd69652ad230Chris Lattner 1581a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // join intervals if requested 1591a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos if (EnableJoining) joinIntervals(); 1601a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 1611a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos numIntervalsAfter += getNumIntervals(); 1621a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 1631a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // perform a final pass over the instructions and compute spill 1641a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // weights, coalesce virtual registers and remove identity moves 1651a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos const LoopInfo& loopInfo = getAnalysis<LoopInfo>(); 1661a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 1671a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos for (MachineFunction::iterator mbbi = mf_->begin(), mbbe = mf_->end(); 1681a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos mbbi != mbbe; ++mbbi) { 1691a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos MachineBasicBlock* mbb = mbbi; 1701a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned loopDepth = loopInfo.getLoopDepth(mbb->getBasicBlock()); 1711a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 1721a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos for (MachineBasicBlock::iterator mii = mbb->begin(), mie = mbb->end(); 1731a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos mii != mie; ) { 1741a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // if the move will be an identity move delete it 1751a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned srcReg, dstReg, RegRep; 176f768bba43f5c036039851d2fcca8212edca18467Chris Lattner if (tii_->isMoveInstr(*mii, srcReg, dstReg) && 1771a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos (RegRep = rep(srcReg)) == rep(dstReg)) { 1781a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // remove from def list 1791a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos LiveInterval &interval = getOrCreateInterval(RegRep); 180f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner RemoveMachineInstrFromMaps(mii); 1811a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos mii = mbbi->erase(mii); 1821a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos ++numPeep; 1831a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 1841a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos else { 1851a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos for (unsigned i = 0; i < mii->getNumOperands(); ++i) { 1861a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos const MachineOperand& mop = mii->getOperand(i); 1871a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos if (mop.isRegister() && mop.getReg() && 1881a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos MRegisterInfo::isVirtualRegister(mop.getReg())) { 1891a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // replace register with representative register 1901a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned reg = rep(mop.getReg()); 191e53f4a055f74bded20d6129b4724ddd17fd199f6Chris Lattner mii->getOperand(i).setReg(reg); 1921a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 1931a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos LiveInterval &RegInt = getInterval(reg); 1941a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos RegInt.weight += 1957a36ae8b0103088328e3a4992ac08b3dce312248Chris Lattner (mop.isUse() + mop.isDef()) * pow(10.0F, (int)loopDepth); 1961a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 1971a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 1981a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos ++mii; 1991a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 2001a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 2011a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 2027a40eaaceec0af76d5b97610f3d4e7a47a19d245Alkis Evlogimenos 203993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Cheng for (iterator I = begin(), E = end(); I != E; ++I) { 204993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Cheng LiveInterval &li = I->second; 205c9d94d12900bd0d2bd482ef31f8f1deb3ffafa23Chris Lattner if (MRegisterInfo::isVirtualRegister(li.reg)) { 206c9d94d12900bd0d2bd482ef31f8f1deb3ffafa23Chris Lattner // If the live interval length is essentially zero, i.e. in every live 207993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Cheng // range the use follows def immediately, it doesn't make sense to spill 208993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Cheng // it and hope it will be easier to allocate for this li. 209993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Cheng if (isZeroLengthInterval(&li)) 210993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Cheng li.weight = float(HUGE_VAL); 211c9d94d12900bd0d2bd482ef31f8f1deb3ffafa23Chris Lattner } 212993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Cheng } 213993141402f57b4d4cbb7f8a3113f19c61688f9b7Evan Cheng 21470ca358b7d540b6061236ddf757085042873c12cChris Lattner DEBUG(dump()); 2151a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos return true; 216ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos} 217ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos 21870ca358b7d540b6061236ddf757085042873c12cChris Lattner/// print - Implement the dump method. 219ce9653ce449f1409815547e1bf60abcd1332d2c9Reid Spencervoid LiveIntervals::print(std::ostream &O, const Module* ) const { 22070ca358b7d540b6061236ddf757085042873c12cChris Lattner O << "********** INTERVALS **********\n"; 2218e7a70976deee78a84099b916591d40f7a1cdc34Chris Lattner for (const_iterator I = begin(), E = end(); I != E; ++I) { 2228e7a70976deee78a84099b916591d40f7a1cdc34Chris Lattner I->second.print(std::cerr, mri_); 2238e7a70976deee78a84099b916591d40f7a1cdc34Chris Lattner std::cerr << "\n"; 2248e7a70976deee78a84099b916591d40f7a1cdc34Chris Lattner } 22570ca358b7d540b6061236ddf757085042873c12cChris Lattner 22670ca358b7d540b6061236ddf757085042873c12cChris Lattner O << "********** MACHINEINSTRS **********\n"; 22770ca358b7d540b6061236ddf757085042873c12cChris Lattner for (MachineFunction::iterator mbbi = mf_->begin(), mbbe = mf_->end(); 22870ca358b7d540b6061236ddf757085042873c12cChris Lattner mbbi != mbbe; ++mbbi) { 22970ca358b7d540b6061236ddf757085042873c12cChris Lattner O << ((Value*)mbbi->getBasicBlock())->getName() << ":\n"; 23070ca358b7d540b6061236ddf757085042873c12cChris Lattner for (MachineBasicBlock::iterator mii = mbbi->begin(), 23170ca358b7d540b6061236ddf757085042873c12cChris Lattner mie = mbbi->end(); mii != mie; ++mii) { 232477e4555de341c5de780de3720d6f115ec133c4eChris Lattner O << getInstructionIndex(mii) << '\t' << *mii; 23370ca358b7d540b6061236ddf757085042873c12cChris Lattner } 23470ca358b7d540b6061236ddf757085042873c12cChris Lattner } 23570ca358b7d540b6061236ddf757085042873c12cChris Lattner} 23670ca358b7d540b6061236ddf757085042873c12cChris Lattner 23770ca358b7d540b6061236ddf757085042873c12cChris Lattnerstd::vector<LiveInterval*> LiveIntervals:: 23870ca358b7d540b6061236ddf757085042873c12cChris LattneraddIntervalsForSpills(const LiveInterval &li, VirtRegMap &vrm, int slot) { 239d8d26b3268acf7f157028f0cb60a545b185e8905Alkis Evlogimenos // since this is called after the analysis is done we don't know if 240d8d26b3268acf7f157028f0cb60a545b185e8905Alkis Evlogimenos // LiveVariables is available 241d8d26b3268acf7f157028f0cb60a545b185e8905Alkis Evlogimenos lv_ = getAnalysisToUpdate<LiveVariables>(); 242d8d26b3268acf7f157028f0cb60a545b185e8905Alkis Evlogimenos 2431a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos std::vector<LiveInterval*> added; 2441a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 2451a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos assert(li.weight != HUGE_VAL && 2461a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos "attempt to spill already spilled interval!"); 2471a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 248f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << "\t\t\t\tadding intervals for spills for interval: "; 249f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner li.print(std::cerr, mri_); std::cerr << '\n'); 2501a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 2511a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos const TargetRegisterClass* rc = mf_->getSSARegMap()->getRegClass(li.reg); 2521a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 2531a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos for (LiveInterval::Ranges::const_iterator 2541a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos i = li.ranges.begin(), e = li.ranges.end(); i != e; ++i) { 2551a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned index = getBaseIndex(i->start); 2561a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned end = getBaseIndex(i->end-1) + InstrSlots::NUM; 2571a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos for (; index != end; index += InstrSlots::NUM) { 2581a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // skip deleted instructions 2591a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos while (index != end && !getInstructionFromIndex(index)) 2601a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos index += InstrSlots::NUM; 2611a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos if (index == end) break; 2621a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 2633b9db830f7f0ed33af13459be3fd60ebe01a13caChris Lattner MachineInstr *MI = getInstructionFromIndex(index); 2641a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 265b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner // NewRegLiveIn - This instruction might have multiple uses of the spilled 266b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner // register. In this case, for the first use, keep track of the new vreg 267b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner // that we reload it into. If we see a second use, reuse this vreg 268b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner // instead of creating live ranges for two reloads. 269b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner unsigned NewRegLiveIn = 0; 270b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner 2711a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos for_operand: 2723b9db830f7f0ed33af13459be3fd60ebe01a13caChris Lattner for (unsigned i = 0; i != MI->getNumOperands(); ++i) { 2733b9db830f7f0ed33af13459be3fd60ebe01a13caChris Lattner MachineOperand& mop = MI->getOperand(i); 2741a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos if (mop.isRegister() && mop.getReg() == li.reg) { 275b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner if (NewRegLiveIn && mop.isUse()) { 276b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner // We already emitted a reload of this value, reuse it for 277b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner // subsequent operands. 278e53f4a055f74bded20d6129b4724ddd17fd199f6Chris Lattner MI->getOperand(i).setReg(NewRegLiveIn); 279b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner DEBUG(std::cerr << "\t\t\t\treused reload into reg" << NewRegLiveIn 280b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner << " for operand #" << i << '\n'); 2813b9db830f7f0ed33af13459be3fd60ebe01a13caChris Lattner } else if (MachineInstr* fmi = mri_->foldMemoryOperand(MI, i, slot)) { 282b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner // Attempt to fold the memory reference into the instruction. If we 283b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner // can do this, we don't need to insert spill code. 284d8d26b3268acf7f157028f0cb60a545b185e8905Alkis Evlogimenos if (lv_) 2853b9db830f7f0ed33af13459be3fd60ebe01a13caChris Lattner lv_->instructionChanged(MI, fmi); 286200370fb5617a1719f0054804b412469ce486ebdEvan Cheng MachineBasicBlock &MBB = *MI->getParent(); 28735f2705e3de4600c3621b883eed9b22e4607ddf4Chris Lattner vrm.virtFolded(li.reg, MI, i, fmi); 2883b9db830f7f0ed33af13459be3fd60ebe01a13caChris Lattner mi2iMap_.erase(MI); 2891a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos i2miMap_[index/InstrSlots::NUM] = fmi; 2901a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos mi2iMap_[fmi] = index; 2913b9db830f7f0ed33af13459be3fd60ebe01a13caChris Lattner MI = MBB.insert(MBB.erase(MI), fmi); 2921a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos ++numFolded; 293477e4555de341c5de780de3720d6f115ec133c4eChris Lattner // Folding the load/store can completely change the instruction in 294477e4555de341c5de780de3720d6f115ec133c4eChris Lattner // unpredictable ways, rescan it from the beginning. 2951a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos goto for_operand; 296477e4555de341c5de780de3720d6f115ec133c4eChris Lattner } else { 29770ca358b7d540b6061236ddf757085042873c12cChris Lattner // This is tricky. We need to add information in the interval about 29870ca358b7d540b6061236ddf757085042873c12cChris Lattner // the spill code so we have to use our extra load/store slots. 2991a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // 30070ca358b7d540b6061236ddf757085042873c12cChris Lattner // If we have a use we are going to have a load so we start the 30170ca358b7d540b6061236ddf757085042873c12cChris Lattner // interval from the load slot onwards. Otherwise we start from the 30270ca358b7d540b6061236ddf757085042873c12cChris Lattner // def slot. 3031a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned start = (mop.isUse() ? 3041a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos getLoadIndex(index) : 3051a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos getDefIndex(index)); 30670ca358b7d540b6061236ddf757085042873c12cChris Lattner // If we have a def we are going to have a store right after it so 30770ca358b7d540b6061236ddf757085042873c12cChris Lattner // we end the interval after the use of the next 30870ca358b7d540b6061236ddf757085042873c12cChris Lattner // instruction. Otherwise we end after the use of this instruction. 3091a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned end = 1 + (mop.isDef() ? 3101a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos getStoreIndex(index) : 3111a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos getUseIndex(index)); 3121a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 3131a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // create a new register for this spill 314b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner NewRegLiveIn = mf_->getSSARegMap()->createVirtualRegister(rc); 315e53f4a055f74bded20d6129b4724ddd17fd199f6Chris Lattner MI->getOperand(i).setReg(NewRegLiveIn); 3161a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos vrm.grow(); 317b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner vrm.assignVirt2StackSlot(NewRegLiveIn, slot); 318b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner LiveInterval& nI = getOrCreateInterval(NewRegLiveIn); 3191a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos assert(nI.empty()); 32070ca358b7d540b6061236ddf757085042873c12cChris Lattner 3211a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // the spill weight is now infinity as it 3221a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // cannot be spilled again 32328696bee024805a6b191cfe12e1a24784dae8aa7Chris Lattner nI.weight = float(HUGE_VAL); 32491725b75852443923b419fd23215194cfc65dd88Chris Lattner LiveRange LR(start, end, nI.getNextValue(~0U, 0)); 3251a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos DEBUG(std::cerr << " +" << LR); 3261a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos nI.addRange(LR); 3271a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos added.push_back(&nI); 32870ca358b7d540b6061236ddf757085042873c12cChris Lattner 329d8d26b3268acf7f157028f0cb60a545b185e8905Alkis Evlogimenos // update live variables if it is available 330d8d26b3268acf7f157028f0cb60a545b185e8905Alkis Evlogimenos if (lv_) 3313b9db830f7f0ed33af13459be3fd60ebe01a13caChris Lattner lv_->addVirtualRegisterKilled(NewRegLiveIn, MI); 332b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner 333b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner // If this is a live in, reuse it for subsequent live-ins. If it's 334b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner // a def, we can't do this. 335b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner if (!mop.isUse()) NewRegLiveIn = 0; 336b11443dc8458b0ba72d484dacf99dffa2e8d3b51Chris Lattner 337f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << "\t\t\t\tadded new interval: "; 338f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner nI.print(std::cerr, mri_); std::cerr << '\n'); 3391a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 340843b160a2040b3ec4d3452678450afa11704c473Alkis Evlogimenos } 3411a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 342843b160a2040b3ec4d3452678450afa11704c473Alkis Evlogimenos } 3431a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 34426f5a69e52b64e035d26c135979a39b39fd6ba3eAlkis Evlogimenos 3451a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos return added; 346843b160a2040b3ec4d3452678450afa11704c473Alkis Evlogimenos} 347843b160a2040b3ec4d3452678450afa11704c473Alkis Evlogimenos 348be4f88a8b8bb3311e0dc4cde8533763d7923c3eaChris Lattnervoid LiveIntervals::printRegName(unsigned reg) const { 3491a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos if (MRegisterInfo::isPhysicalRegister(reg)) 3501a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos std::cerr << mri_->getName(reg); 3511a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos else 3521a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos std::cerr << "%reg" << reg; 353ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos} 354ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos 355be4f88a8b8bb3311e0dc4cde8533763d7923c3eaChris Lattnervoid LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb, 356ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos MachineBasicBlock::iterator mi, 357be4f88a8b8bb3311e0dc4cde8533763d7923c3eaChris Lattner LiveInterval &interval) { 3581a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos DEBUG(std::cerr << "\t\tregister: "; printRegName(interval.reg)); 3591a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos LiveVariables::VarInfo& vi = lv_->getVarInfo(interval.reg); 3601a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 361706515727c6d024015fffded2b3109a4f0ac5299Alkis Evlogimenos // Virtual registers may be defined multiple times (due to phi 362706515727c6d024015fffded2b3109a4f0ac5299Alkis Evlogimenos // elimination and 2-addr elimination). Much of what we do only has to be 363706515727c6d024015fffded2b3109a4f0ac5299Alkis Evlogimenos // done once for the vreg. We use an empty interval to detect the first 3641a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // time we see a vreg. 3651a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos if (interval.empty()) { 3661a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // Get the Idx of the defining instructions. 3671a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned defIndex = getDefIndex(getInstructionIndex(mi)); 3681a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 36991725b75852443923b419fd23215194cfc65dd88Chris Lattner unsigned ValNum; 37091725b75852443923b419fd23215194cfc65dd88Chris Lattner unsigned SrcReg, DstReg; 37191725b75852443923b419fd23215194cfc65dd88Chris Lattner if (!tii_->isMoveInstr(*mi, SrcReg, DstReg)) 37291725b75852443923b419fd23215194cfc65dd88Chris Lattner ValNum = interval.getNextValue(~0U, 0); 37391725b75852443923b419fd23215194cfc65dd88Chris Lattner else 37491725b75852443923b419fd23215194cfc65dd88Chris Lattner ValNum = interval.getNextValue(defIndex, SrcReg); 37591725b75852443923b419fd23215194cfc65dd88Chris Lattner 3761a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos assert(ValNum == 0 && "First value in interval is not 0?"); 3771a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos ValNum = 0; // Clue in the optimizer. 3781a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 3791a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // Loop over all of the blocks that the vreg is defined in. There are 3801a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // two cases we have to handle here. The most common case is a vreg 3811a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // whose lifetime is contained within a basic block. In this case there 3821a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // will be a single kill, in MBB, which comes after the definition. 3831a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos if (vi.Kills.size() == 1 && vi.Kills[0]->getParent() == mbb) { 3841a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // FIXME: what about dead vars? 3851a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned killIdx; 3861a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos if (vi.Kills[0] != mi) 3871a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos killIdx = getUseIndex(getInstructionIndex(vi.Kills[0]))+1; 3881a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos else 3891a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos killIdx = defIndex+1; 3901a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 3911a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // If the kill happens after the definition, we have an intra-block 3921a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // live range. 3931a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos if (killIdx > defIndex) { 394706515727c6d024015fffded2b3109a4f0ac5299Alkis Evlogimenos assert(vi.AliveBlocks.empty() && 3951a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos "Shouldn't be alive across any blocks!"); 3961a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos LiveRange LR(defIndex, killIdx, ValNum); 3971a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos interval.addRange(LR); 3981a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos DEBUG(std::cerr << " +" << LR << "\n"); 3991a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos return; 4001a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 4011a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 4026097d13b2a624048dbe02e39e2dfb23bfa269b64Chris Lattner 4031a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // The other case we handle is when a virtual register lives to the end 4041a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // of the defining block, potentially live across some blocks, then is 4051a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // live into some number of blocks, but gets killed. Start by adding a 4061a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // range that goes from this definition to the end of the defining block. 407d19e2901c1b79d287d01079659684f3a4951a69eAlkis Evlogimenos LiveRange NewLR(defIndex, 408d19e2901c1b79d287d01079659684f3a4951a69eAlkis Evlogimenos getInstructionIndex(&mbb->back()) + InstrSlots::NUM, 409d19e2901c1b79d287d01079659684f3a4951a69eAlkis Evlogimenos ValNum); 4101a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos DEBUG(std::cerr << " +" << NewLR); 4111a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos interval.addRange(NewLR); 4121a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 4131a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // Iterate over all of the blocks that the variable is completely 4141a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // live in, adding [insrtIndex(begin), instrIndex(end)+4) to the 4151a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // live interval. 4161a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos for (unsigned i = 0, e = vi.AliveBlocks.size(); i != e; ++i) { 4171a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos if (vi.AliveBlocks[i]) { 4181a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos MachineBasicBlock* mbb = mf_->getBlockNumbered(i); 4191a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos if (!mbb->empty()) { 4201a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos LiveRange LR(getInstructionIndex(&mbb->front()), 421d19e2901c1b79d287d01079659684f3a4951a69eAlkis Evlogimenos getInstructionIndex(&mbb->back()) + InstrSlots::NUM, 4221a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos ValNum); 4231a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos interval.addRange(LR); 4241a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos DEBUG(std::cerr << " +" << LR); 4251a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 4261a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 4271a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 4281a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 4291a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // Finally, this virtual register is live from the start of any killing 4301a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // block to the 'use' slot of the killing instruction. 4311a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos for (unsigned i = 0, e = vi.Kills.size(); i != e; ++i) { 4321a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos MachineInstr *Kill = vi.Kills[i]; 4331a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos LiveRange LR(getInstructionIndex(Kill->getParent()->begin()), 434d19e2901c1b79d287d01079659684f3a4951a69eAlkis Evlogimenos getUseIndex(getInstructionIndex(Kill))+1, 435d19e2901c1b79d287d01079659684f3a4951a69eAlkis Evlogimenos ValNum); 4361a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos interval.addRange(LR); 4371a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos DEBUG(std::cerr << " +" << LR); 4381a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 4391a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 4401a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } else { 4411a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // If this is the second time we see a virtual register definition, it 4421a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // must be due to phi elimination or two addr elimination. If this is 4431a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // the result of two address elimination, then the vreg is the first 4441a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // operand, and is a def-and-use. 445706515727c6d024015fffded2b3109a4f0ac5299Alkis Evlogimenos if (mi->getOperand(0).isRegister() && 4461a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos mi->getOperand(0).getReg() == interval.reg && 4471a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos mi->getOperand(0).isDef() && mi->getOperand(0).isUse()) { 4481a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // If this is a two-address definition, then we have already processed 4491a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // the live range. The only problem is that we didn't realize there 4501a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // are actually two values in the live interval. Because of this we 4511a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // need to take the LiveRegion that defines this register and split it 4521a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // into two values. 4531a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned DefIndex = getDefIndex(getInstructionIndex(vi.DefInst)); 4541a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned RedefIndex = getDefIndex(getInstructionIndex(mi)); 4551a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 4561a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // Delete the initial value, which should be short and continuous, 457be4f88a8b8bb3311e0dc4cde8533763d7923c3eaChris Lattner // because the 2-addr copy must be in the same MBB as the redef. 4581a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos interval.removeRange(DefIndex, RedefIndex); 459706515727c6d024015fffded2b3109a4f0ac5299Alkis Evlogimenos 460be4f88a8b8bb3311e0dc4cde8533763d7923c3eaChris Lattner // Two-address vregs should always only be redefined once. This means 461be4f88a8b8bb3311e0dc4cde8533763d7923c3eaChris Lattner // that at this point, there should be exactly one value number in it. 462be4f88a8b8bb3311e0dc4cde8533763d7923c3eaChris Lattner assert(interval.containsOneValue() && "Unexpected 2-addr liveint!"); 463be4f88a8b8bb3311e0dc4cde8533763d7923c3eaChris Lattner 46491725b75852443923b419fd23215194cfc65dd88Chris Lattner // The new value number (#1) is defined by the instruction we claimed 46591725b75852443923b419fd23215194cfc65dd88Chris Lattner // defined value #0. 46691725b75852443923b419fd23215194cfc65dd88Chris Lattner unsigned ValNo = interval.getNextValue(0, 0); 46791725b75852443923b419fd23215194cfc65dd88Chris Lattner interval.setValueNumberInfo(1, interval.getValNumInfo(0)); 468be4f88a8b8bb3311e0dc4cde8533763d7923c3eaChris Lattner 46991725b75852443923b419fd23215194cfc65dd88Chris Lattner // Value#0 is now defined by the 2-addr instruction. 47091725b75852443923b419fd23215194cfc65dd88Chris Lattner interval.setValueNumberInfo(0, std::make_pair(~0U, 0U)); 471be4f88a8b8bb3311e0dc4cde8533763d7923c3eaChris Lattner 472be4f88a8b8bb3311e0dc4cde8533763d7923c3eaChris Lattner // Add the new live interval which replaces the range for the input copy. 473be4f88a8b8bb3311e0dc4cde8533763d7923c3eaChris Lattner LiveRange LR(DefIndex, RedefIndex, ValNo); 4741a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos DEBUG(std::cerr << " replace range with " << LR); 4751a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos interval.addRange(LR); 4761a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 4771a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // If this redefinition is dead, we need to add a dummy unit live 4781a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // range covering the def slot. 479ab4b66d4c279e8cd9e448687020fc838e7881dbcChris Lattner if (lv_->RegisterDefIsDead(mi, interval.reg)) 480ab4b66d4c279e8cd9e448687020fc838e7881dbcChris Lattner interval.addRange(LiveRange(RedefIndex, RedefIndex+1, 0)); 4811a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 482f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << "RESULT: "; interval.print(std::cerr, mri_)); 4831a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 4841a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } else { 4851a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // Otherwise, this must be because of phi elimination. If this is the 4861a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // first redefinition of the vreg that we have seen, go back and change 4871a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // the live range in the PHI block to be a different value number. 4881a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos if (interval.containsOneValue()) { 4891a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos assert(vi.Kills.size() == 1 && 4901a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos "PHI elimination vreg should have one kill, the PHI itself!"); 4911a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 4921a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // Remove the old range that we now know has an incorrect number. 4931a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos MachineInstr *Killer = vi.Kills[0]; 4941a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned Start = getInstructionIndex(Killer->getParent()->begin()); 4951a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned End = getUseIndex(getInstructionIndex(Killer))+1; 496f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << "Removing [" << Start << "," << End << "] from: "; 497f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner interval.print(std::cerr, mri_); std::cerr << "\n"); 4981a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos interval.removeRange(Start, End); 499f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << "RESULT: "; interval.print(std::cerr, mri_)); 5001a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 501be4f88a8b8bb3311e0dc4cde8533763d7923c3eaChris Lattner // Replace the interval with one of a NEW value number. Note that this 502be4f88a8b8bb3311e0dc4cde8533763d7923c3eaChris Lattner // value number isn't actually defined by an instruction, weird huh? :) 50391725b75852443923b419fd23215194cfc65dd88Chris Lattner LiveRange LR(Start, End, interval.getNextValue(~0U, 0)); 5041a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos DEBUG(std::cerr << " replace range with " << LR); 5051a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos interval.addRange(LR); 506f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << "RESULT: "; interval.print(std::cerr, mri_)); 5071a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 5081a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 5091a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // In the case of PHI elimination, each variable definition is only 5101a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // live until the end of the block. We've already taken care of the 5111a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // rest of the live range. 5121a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned defIndex = getDefIndex(getInstructionIndex(mi)); 51391725b75852443923b419fd23215194cfc65dd88Chris Lattner 51491725b75852443923b419fd23215194cfc65dd88Chris Lattner unsigned ValNum; 51591725b75852443923b419fd23215194cfc65dd88Chris Lattner unsigned SrcReg, DstReg; 51691725b75852443923b419fd23215194cfc65dd88Chris Lattner if (!tii_->isMoveInstr(*mi, SrcReg, DstReg)) 51791725b75852443923b419fd23215194cfc65dd88Chris Lattner ValNum = interval.getNextValue(~0U, 0); 51891725b75852443923b419fd23215194cfc65dd88Chris Lattner else 51991725b75852443923b419fd23215194cfc65dd88Chris Lattner ValNum = interval.getNextValue(defIndex, SrcReg); 52091725b75852443923b419fd23215194cfc65dd88Chris Lattner 521706515727c6d024015fffded2b3109a4f0ac5299Alkis Evlogimenos LiveRange LR(defIndex, 52291725b75852443923b419fd23215194cfc65dd88Chris Lattner getInstructionIndex(&mbb->back()) + InstrSlots::NUM, ValNum); 5231a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos interval.addRange(LR); 5241a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos DEBUG(std::cerr << " +" << LR); 525dd2cc65f34f9b7bfda1cd0c42becedfc361d46f8Alkis Evlogimenos } 5261a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 527ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos 5281a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos DEBUG(std::cerr << '\n'); 529ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos} 530ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos 531f35fef7060c465dd7b578bf6339a18e8a8911888Chris Lattnervoid LiveIntervals::handlePhysicalRegisterDef(MachineBasicBlock *MBB, 532ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos MachineBasicBlock::iterator mi, 53391725b75852443923b419fd23215194cfc65dd88Chris Lattner LiveInterval &interval, 53491725b75852443923b419fd23215194cfc65dd88Chris Lattner unsigned SrcReg) { 5351a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // A physical register cannot be live across basic block, so its 5361a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // lifetime must end somewhere in its defining basic block. 5371a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos DEBUG(std::cerr << "\t\tregister: "; printRegName(interval.reg)); 5381a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos typedef LiveVariables::killed_iterator KillIter; 5391a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 5401a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned baseIndex = getInstructionIndex(mi); 5411a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned start = getDefIndex(baseIndex); 5421a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos unsigned end = start; 5431a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 5441a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // If it is not used after definition, it is considered dead at 5451a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // the instruction defining it. Hence its interval is: 5461a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // [defSlot(def), defSlot(def)+1) 547ab4b66d4c279e8cd9e448687020fc838e7881dbcChris Lattner if (lv_->RegisterDefIsDead(mi, interval.reg)) { 548ab4b66d4c279e8cd9e448687020fc838e7881dbcChris Lattner DEBUG(std::cerr << " dead"); 549ab4b66d4c279e8cd9e448687020fc838e7881dbcChris Lattner end = getDefIndex(start) + 1; 550ab4b66d4c279e8cd9e448687020fc838e7881dbcChris Lattner goto exit; 5511a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 552ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos 5531a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // If it is not dead on definition, it must be killed by a 5541a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // subsequent instruction. Hence its interval is: 5551a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // [defSlot(def), useSlot(kill)+1) 5565ab6f5fe666d0e3403d9b777324d1a1999118153Chris Lattner while (++mi != MBB->end()) { 5571a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos baseIndex += InstrSlots::NUM; 558ab4b66d4c279e8cd9e448687020fc838e7881dbcChris Lattner if (lv_->KillsRegister(mi, interval.reg)) { 559ab4b66d4c279e8cd9e448687020fc838e7881dbcChris Lattner DEBUG(std::cerr << " killed"); 560ab4b66d4c279e8cd9e448687020fc838e7881dbcChris Lattner end = getUseIndex(baseIndex) + 1; 561ab4b66d4c279e8cd9e448687020fc838e7881dbcChris Lattner goto exit; 562f35fef7060c465dd7b578bf6339a18e8a8911888Chris Lattner } 5631a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 5645ab6f5fe666d0e3403d9b777324d1a1999118153Chris Lattner 5655ab6f5fe666d0e3403d9b777324d1a1999118153Chris Lattner // The only case we should have a dead physreg here without a killing or 5665ab6f5fe666d0e3403d9b777324d1a1999118153Chris Lattner // instruction where we know it's dead is if it is live-in to the function 5675ab6f5fe666d0e3403d9b777324d1a1999118153Chris Lattner // and never used. 56891725b75852443923b419fd23215194cfc65dd88Chris Lattner assert(!SrcReg && "physreg was not killed in defining block!"); 5695ab6f5fe666d0e3403d9b777324d1a1999118153Chris Lattner end = getDefIndex(start) + 1; // It's dead. 57002ba13c9897ae2b19f9201e57460d7ee2b753a0bAlkis Evlogimenos 571ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenosexit: 5721a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos assert(start < end && "did not find end of interval?"); 573f768bba43f5c036039851d2fcca8212edca18467Chris Lattner 57491725b75852443923b419fd23215194cfc65dd88Chris Lattner LiveRange LR(start, end, interval.getNextValue(SrcReg != 0 ? start : ~0U, 57591725b75852443923b419fd23215194cfc65dd88Chris Lattner SrcReg)); 5761a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos interval.addRange(LR); 5771a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos DEBUG(std::cerr << " +" << LR << '\n'); 578ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos} 579ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos 580f35fef7060c465dd7b578bf6339a18e8a8911888Chris Lattnervoid LiveIntervals::handleRegisterDef(MachineBasicBlock *MBB, 581f35fef7060c465dd7b578bf6339a18e8a8911888Chris Lattner MachineBasicBlock::iterator MI, 582f35fef7060c465dd7b578bf6339a18e8a8911888Chris Lattner unsigned reg) { 583f35fef7060c465dd7b578bf6339a18e8a8911888Chris Lattner if (MRegisterInfo::isVirtualRegister(reg)) 584f35fef7060c465dd7b578bf6339a18e8a8911888Chris Lattner handleVirtualRegisterDef(MBB, MI, getOrCreateInterval(reg)); 5855327801fb87e3eda52a33f82e6211181030ecb93Alkis Evlogimenos else if (allocatableRegs_[reg]) { 58691725b75852443923b419fd23215194cfc65dd88Chris Lattner unsigned SrcReg, DstReg; 58791725b75852443923b419fd23215194cfc65dd88Chris Lattner if (!tii_->isMoveInstr(*MI, SrcReg, DstReg)) 58891725b75852443923b419fd23215194cfc65dd88Chris Lattner SrcReg = 0; 58991725b75852443923b419fd23215194cfc65dd88Chris Lattner handlePhysicalRegisterDef(MBB, MI, getOrCreateInterval(reg), SrcReg); 590f35fef7060c465dd7b578bf6339a18e8a8911888Chris Lattner for (const unsigned* AS = mri_->getAliasSet(reg); *AS; ++AS) 59191725b75852443923b419fd23215194cfc65dd88Chris Lattner handlePhysicalRegisterDef(MBB, MI, getOrCreateInterval(*AS), 0); 592f35fef7060c465dd7b578bf6339a18e8a8911888Chris Lattner } 5934d46e1e521c0df1990ea50f8146d22bd77ea71a6Alkis Evlogimenos} 5944d46e1e521c0df1990ea50f8146d22bd77ea71a6Alkis Evlogimenos 595ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos/// computeIntervals - computes the live intervals for virtual 5964d46e1e521c0df1990ea50f8146d22bd77ea71a6Alkis Evlogimenos/// registers. for some ordering of the machine instructions [1,N] a 59708cec00588ec1a8fa85b208555f006d7396ae7a4Alkis Evlogimenos/// live interval is an interval [i, j) where 1 <= i <= j < N for 598ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos/// which a variable is live 599f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattnervoid LiveIntervals::computeIntervals() { 6001a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos DEBUG(std::cerr << "********** COMPUTING LIVE INTERVALS **********\n"); 6011a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos DEBUG(std::cerr << "********** Function: " 6021a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos << ((Value*)mf_->getFunction())->getName() << '\n'); 603799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner bool IgnoreFirstInstr = mf_->livein_begin() != mf_->livein_end(); 6041a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 605706515727c6d024015fffded2b3109a4f0ac5299Alkis Evlogimenos for (MachineFunction::iterator I = mf_->begin(), E = mf_->end(); 6061a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos I != E; ++I) { 6071a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos MachineBasicBlock* mbb = I; 6081a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos DEBUG(std::cerr << ((Value*)mbb->getBasicBlock())->getName() << ":\n"); 6091a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 610799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner MachineBasicBlock::iterator mi = mbb->begin(), miEnd = mbb->end(); 611799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner if (IgnoreFirstInstr) { ++mi; IgnoreFirstInstr = false; } 612799a919dbc03d8451434a1f3afc6fe571212d19cChris Lattner for (; mi != miEnd; ++mi) { 6131a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos const TargetInstrDescriptor& tid = 6141a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos tm_->getInstrInfo()->get(mi->getOpcode()); 615477e4555de341c5de780de3720d6f115ec133c4eChris Lattner DEBUG(std::cerr << getInstructionIndex(mi) << "\t" << *mi); 6161a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 6171a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // handle implicit defs 618cd4317efcf334be10d9a98008a1445d6e12a7712Jim Laskey if (tid.ImplicitDefs) { 619cd4317efcf334be10d9a98008a1445d6e12a7712Jim Laskey for (const unsigned* id = tid.ImplicitDefs; *id; ++id) 620cd4317efcf334be10d9a98008a1445d6e12a7712Jim Laskey handleRegisterDef(mbb, mi, *id); 621cd4317efcf334be10d9a98008a1445d6e12a7712Jim Laskey } 6221a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos 6231a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // handle explicit defs 6241a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos for (int i = mi->getNumOperands() - 1; i >= 0; --i) { 6251a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos MachineOperand& mop = mi->getOperand(i); 6261a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos // handle register defs - build intervals 6271a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos if (mop.isRegister() && mop.getReg() && mop.isDef()) 6281a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos handleRegisterDef(mbb, mi, mop.getReg()); 6291a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 630ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos } 6311a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos } 632ff0cbe175df40e0d2b36e59c6fb72f211f1cba4cAlkis Evlogimenos} 633b27ef248f579b354aab434f63c417ab1103e47e2Alkis Evlogimenos 634f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// AdjustCopiesBackFrom - We found a non-trivially-coallescable copy with IntA 635f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// being the source and IntB being the dest, thus this defines a value number 636f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// in IntB. If the source value number (in IntA) is defined by a copy from B, 637f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// see if we can merge these two pieces of B into a single value number, 638f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// eliminating a copy. For example: 639f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// 640f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// A3 = B0 641f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// ... 642f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// B1 = A3 <- this copy 643f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// 644f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// In this case, B0 can be extended to where the B1 copy lives, allowing the B1 645f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// value number to be replaced with B0 (which simplifies the B liveinterval). 646f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// 647f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// This returns true if an interval was modified. 648f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// 649f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattnerbool LiveIntervals::AdjustCopiesBackFrom(LiveInterval &IntA, LiveInterval &IntB, 6506d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner MachineInstr *CopyMI) { 6516d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner unsigned CopyIdx = getDefIndex(getInstructionIndex(CopyMI)); 6526d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 653f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // BValNo is a value number in B that is defined by a copy from A. 'B3' in 654f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // the example above. 655f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner LiveInterval::iterator BLR = IntB.FindLiveRangeContaining(CopyIdx); 656f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner unsigned BValNo = BLR->ValId; 657f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 658f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // Get the location that B is defined at. Two options: either this value has 659f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // an unknown definition point or it is defined at CopyIdx. If unknown, we 660f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // can't process it. 661f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner unsigned BValNoDefIdx = IntB.getInstForValNum(BValNo); 662f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner if (BValNoDefIdx == ~0U) return false; 663f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner assert(BValNoDefIdx == CopyIdx && 664f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner "Copy doesn't define the value?"); 665f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 666f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // AValNo is the value number in A that defines the copy, A0 in the example. 667f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner LiveInterval::iterator AValLR = IntA.FindLiveRangeContaining(CopyIdx-1); 668f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner unsigned AValNo = AValLR->ValId; 669aa51a484e188ecb8d3e4b6ac852c553a4aacc89aChris Lattner 670f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // If AValNo is defined as a copy from IntB, we can potentially process this. 671aa51a484e188ecb8d3e4b6ac852c553a4aacc89aChris Lattner 672f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // Get the instruction that defines this value number. 67391725b75852443923b419fd23215194cfc65dd88Chris Lattner unsigned SrcReg = IntA.getSrcRegForValNum(AValNo); 67491725b75852443923b419fd23215194cfc65dd88Chris Lattner if (!SrcReg) return false; // Not defined by a copy. 675aa51a484e188ecb8d3e4b6ac852c553a4aacc89aChris Lattner 676f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // If the value number is not defined by a copy instruction, ignore it. 677aa51a484e188ecb8d3e4b6ac852c553a4aacc89aChris Lattner 678f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // If the source register comes from an interval other than IntB, we can't 679f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // handle this. 680f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner if (rep(SrcReg) != IntB.reg) return false; 68191725b75852443923b419fd23215194cfc65dd88Chris Lattner 682f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // Get the LiveRange in IntB that this value number starts with. 68391725b75852443923b419fd23215194cfc65dd88Chris Lattner unsigned AValNoInstIdx = IntA.getInstForValNum(AValNo); 684f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner LiveInterval::iterator ValLR = IntB.FindLiveRangeContaining(AValNoInstIdx-1); 685aa51a484e188ecb8d3e4b6ac852c553a4aacc89aChris Lattner 686f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // Make sure that the end of the live range is inside the same block as 687f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // CopyMI. 688f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner MachineInstr *ValLREndInst = getInstructionFromIndex(ValLR->end-1); 689c114b2cad7293d98686d380273085f5c32966b52Chris Lattner if (!ValLREndInst || 690c114b2cad7293d98686d380273085f5c32966b52Chris Lattner ValLREndInst->getParent() != CopyMI->getParent()) return false; 691f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 692f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // Okay, we now know that ValLR ends in the same block that the CopyMI 693f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // live-range starts. If there are no intervening live ranges between them in 694f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // IntB, we can merge them. 695f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner if (ValLR+1 != BLR) return false; 696aa51a484e188ecb8d3e4b6ac852c553a4aacc89aChris Lattner 697f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << "\nExtending: "; IntB.print(std::cerr, mri_)); 698ba256037ced5606d5cea8a1676b21eaf91d924deChris Lattner 699ba256037ced5606d5cea8a1676b21eaf91d924deChris Lattner // We are about to delete CopyMI, so need to remove it as the 'instruction 700ba256037ced5606d5cea8a1676b21eaf91d924deChris Lattner // that defines this value #'. 70191725b75852443923b419fd23215194cfc65dd88Chris Lattner IntB.setValueNumberInfo(BValNo, std::make_pair(~0U, 0)); 702ba256037ced5606d5cea8a1676b21eaf91d924deChris Lattner 703f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // Okay, we can merge them. We need to insert a new liverange: 704f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // [ValLR.end, BLR.begin) of either value number, then we merge the 705f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // two value numbers. 706c114b2cad7293d98686d380273085f5c32966b52Chris Lattner unsigned FillerStart = ValLR->end, FillerEnd = BLR->start; 707c114b2cad7293d98686d380273085f5c32966b52Chris Lattner IntB.addRange(LiveRange(FillerStart, FillerEnd, BValNo)); 708c114b2cad7293d98686d380273085f5c32966b52Chris Lattner 709c114b2cad7293d98686d380273085f5c32966b52Chris Lattner // If the IntB live range is assigned to a physical register, and if that 710c114b2cad7293d98686d380273085f5c32966b52Chris Lattner // physreg has aliases, 711c114b2cad7293d98686d380273085f5c32966b52Chris Lattner if (MRegisterInfo::isPhysicalRegister(IntB.reg)) { 712c114b2cad7293d98686d380273085f5c32966b52Chris Lattner for (const unsigned *AS = mri_->getAliasSet(IntB.reg); *AS; ++AS) { 713c114b2cad7293d98686d380273085f5c32966b52Chris Lattner LiveInterval &AliasLI = getInterval(*AS); 714c114b2cad7293d98686d380273085f5c32966b52Chris Lattner AliasLI.addRange(LiveRange(FillerStart, FillerEnd, 71591725b75852443923b419fd23215194cfc65dd88Chris Lattner AliasLI.getNextValue(~0U, 0))); 716c114b2cad7293d98686d380273085f5c32966b52Chris Lattner } 717c114b2cad7293d98686d380273085f5c32966b52Chris Lattner } 718f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 719f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // Okay, merge "B1" into the same value number as "B0". 720f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner if (BValNo != ValLR->ValId) 721f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner IntB.MergeValueNumberInto(BValNo, ValLR->ValId); 722f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << " result = "; IntB.print(std::cerr, mri_); 723f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner std::cerr << "\n"); 724f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 725f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // Finally, delete the copy instruction. 726f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner RemoveMachineInstrFromMaps(CopyMI); 727f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner CopyMI->eraseFromParent(); 728f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner ++numPeep; 729aa51a484e188ecb8d3e4b6ac852c553a4aacc89aChris Lattner return true; 730aa51a484e188ecb8d3e4b6ac852c553a4aacc89aChris Lattner} 731aa51a484e188ecb8d3e4b6ac852c553a4aacc89aChris Lattner 7327ac2d3146a196fa0120c579ecd2ddd69652ad230Chris Lattner 733f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// JoinCopy - Attempt to join intervals corresponding to SrcReg/DstReg, 734f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// which are the src/dst of the copy instruction CopyMI. This returns true 735f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// if the copy was successfully coallesced away, or if it is never possible 736f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// to coallesce these this copy, due to register constraints. It returns 737f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// false if it is not currently possible to coallesce this interval, but 738f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner/// it may be possible if other things get coallesced. 739f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattnerbool LiveIntervals::JoinCopy(MachineInstr *CopyMI, 740f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner unsigned SrcReg, unsigned DstReg) { 741f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 742f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 743f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << getInstructionIndex(CopyMI) << '\t' << *CopyMI); 744f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 745f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // Get representative registers. 746f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner SrcReg = rep(SrcReg); 747f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DstReg = rep(DstReg); 748f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 749f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // If they are already joined we continue. 750f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner if (SrcReg == DstReg) { 751f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << "\tCopy already coallesced.\n"); 752f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner return true; // Not coallescable. 753f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner } 754f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 755f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // If they are both physical registers, we cannot join them. 756f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner if (MRegisterInfo::isPhysicalRegister(SrcReg) && 757f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner MRegisterInfo::isPhysicalRegister(DstReg)) { 758f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << "\tCan not coallesce physregs.\n"); 759f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner return true; // Not coallescable. 7607ac2d3146a196fa0120c579ecd2ddd69652ad230Chris Lattner } 761f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 762f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // We only join virtual registers with allocatable physical registers. 763f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner if (MRegisterInfo::isPhysicalRegister(SrcReg) && !allocatableRegs_[SrcReg]){ 764f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << "\tSrc reg is unallocatable physreg.\n"); 765f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner return true; // Not coallescable. 766f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner } 767f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner if (MRegisterInfo::isPhysicalRegister(DstReg) && !allocatableRegs_[DstReg]){ 768f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << "\tDst reg is unallocatable physreg.\n"); 769f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner return true; // Not coallescable. 770f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner } 771f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 772f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // If they are not of the same register class, we cannot join them. 773f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner if (differingRegisterClasses(SrcReg, DstReg)) { 774f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << "\tSrc/Dest are different register classes.\n"); 775f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner return true; // Not coallescable. 776f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner } 777f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 778f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner LiveInterval &SrcInt = getInterval(SrcReg); 779f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner LiveInterval &DestInt = getInterval(DstReg); 780f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner assert(SrcInt.reg == SrcReg && DestInt.reg == DstReg && 781f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner "Register mapping is horribly broken!"); 782f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 783f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << "\t\tInspecting "; SrcInt.print(std::cerr, mri_); 784f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner std::cerr << " and "; DestInt.print(std::cerr, mri_); 785f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner std::cerr << ": "); 786f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 7876d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // Okay, attempt to join these two intervals. On failure, this returns false. 7886d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // Otherwise, if one of the intervals being joined is a physreg, this method 7896d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // always canonicalizes DestInt to be it. The output "SrcInt" will not have 7906d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // been modified, so we can use this information below to update aliases. 7916d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner if (!JoinIntervals(DestInt, SrcInt)) { 7926d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // Coallescing failed. 7936d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 7946d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // If we can eliminate the copy without merging the live ranges, do so now. 7956d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner if (AdjustCopiesBackFrom(SrcInt, DestInt, CopyMI)) 7966d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner return true; 797f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 7986d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // Otherwise, we are unable to join the intervals. 799f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << "Interference!\n"); 800f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner return false; 801f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner } 802f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 803e7f729b42b54fa751ba3524e1c597aad6d3ec3d7Chris Lattner bool Swapped = SrcReg == DestInt.reg; 804e7f729b42b54fa751ba3524e1c597aad6d3ec3d7Chris Lattner if (Swapped) 805e7f729b42b54fa751ba3524e1c597aad6d3ec3d7Chris Lattner std::swap(SrcReg, DstReg); 806e7f729b42b54fa751ba3524e1c597aad6d3ec3d7Chris Lattner assert(MRegisterInfo::isVirtualRegister(SrcReg) && 807e7f729b42b54fa751ba3524e1c597aad6d3ec3d7Chris Lattner "LiveInterval::join didn't work right!"); 808e7f729b42b54fa751ba3524e1c597aad6d3ec3d7Chris Lattner 809c114b2cad7293d98686d380273085f5c32966b52Chris Lattner // If we're about to merge live ranges into a physical register live range, 810c114b2cad7293d98686d380273085f5c32966b52Chris Lattner // we have to update any aliased register's live ranges to indicate that they 811c114b2cad7293d98686d380273085f5c32966b52Chris Lattner // have clobbered values for this range. 812e7f729b42b54fa751ba3524e1c597aad6d3ec3d7Chris Lattner if (MRegisterInfo::isPhysicalRegister(DstReg)) { 813e7f729b42b54fa751ba3524e1c597aad6d3ec3d7Chris Lattner for (const unsigned *AS = mri_->getAliasSet(DstReg); *AS; ++AS) 814e7f729b42b54fa751ba3524e1c597aad6d3ec3d7Chris Lattner getInterval(*AS).MergeInClobberRanges(SrcInt); 815c114b2cad7293d98686d380273085f5c32966b52Chris Lattner } 816c114b2cad7293d98686d380273085f5c32966b52Chris Lattner 817f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << "\n\t\tJoined. Result = "; DestInt.print(std::cerr, mri_); 818f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner std::cerr << "\n"); 819e7f729b42b54fa751ba3524e1c597aad6d3ec3d7Chris Lattner 820e7f729b42b54fa751ba3524e1c597aad6d3ec3d7Chris Lattner // If the intervals were swapped by Join, swap them back so that the register 821e7f729b42b54fa751ba3524e1c597aad6d3ec3d7Chris Lattner // mapping (in the r2i map) is correct. 822e7f729b42b54fa751ba3524e1c597aad6d3ec3d7Chris Lattner if (Swapped) SrcInt.swap(DestInt); 823e7f729b42b54fa751ba3524e1c597aad6d3ec3d7Chris Lattner r2iMap_.erase(SrcReg); 824e7f729b42b54fa751ba3524e1c597aad6d3ec3d7Chris Lattner r2rMap_[SrcReg] = DstReg; 825e7f729b42b54fa751ba3524e1c597aad6d3ec3d7Chris Lattner 826bfe180af9eef1cf767f61f501ca325fcce2ae7ceChris Lattner // Finally, delete the copy instruction. 827bfe180af9eef1cf767f61f501ca325fcce2ae7ceChris Lattner RemoveMachineInstrFromMaps(CopyMI); 828bfe180af9eef1cf767f61f501ca325fcce2ae7ceChris Lattner CopyMI->eraseFromParent(); 829bfe180af9eef1cf767f61f501ca325fcce2ae7ceChris Lattner ++numPeep; 830f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner ++numJoins; 831f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner return true; 832dd2cc65f34f9b7bfda1cd0c42becedfc361d46f8Alkis Evlogimenos} 833dd2cc65f34f9b7bfda1cd0c42becedfc361d46f8Alkis Evlogimenos 8346d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// ComputeUltimateVN - Assuming we are going to join two live intervals, 8356d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// compute what the resultant value numbers for each value in the input two 8366d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// ranges will be. This is complicated by copies between the two which can 8376d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// and will commonly cause multiple value numbers to be merged into one. 8386d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// 8396d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// VN is the value number that we're trying to resolve. InstDefiningValue 8406d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// keeps track of the new InstDefiningValue assignment for the result 8416d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// LiveInterval. ThisFromOther/OtherFromThis are sets that keep track of 8426d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// whether a value in this or other is a copy from the opposite set. 8436d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// ThisValNoAssignments/OtherValNoAssignments keep track of value #'s that have 8446d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// already been assigned. 8456d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// 8466d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// ThisFromOther[x] - If x is defined as a copy from the other interval, this 8476d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// contains the value number the copy is from. 8486d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// 8496d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattnerstatic unsigned ComputeUltimateVN(unsigned VN, 85091725b75852443923b419fd23215194cfc65dd88Chris Lattner SmallVector<std::pair<unsigned, 85191725b75852443923b419fd23215194cfc65dd88Chris Lattner unsigned>, 16> &ValueNumberInfo, 8526d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner SmallVector<int, 16> &ThisFromOther, 8536d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner SmallVector<int, 16> &OtherFromThis, 8546d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner SmallVector<int, 16> &ThisValNoAssignments, 8556d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner SmallVector<int, 16> &OtherValNoAssignments, 8566d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner LiveInterval &ThisLI, LiveInterval &OtherLI) { 8576d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // If the VN has already been computed, just return it. 8586d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner if (ThisValNoAssignments[VN] >= 0) 8596d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner return ThisValNoAssignments[VN]; 8606d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner assert(ThisValNoAssignments[VN] != -2 && "FIXME: Cyclic case, handle it!"); 8616d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 8626d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // If this val is not a copy from the other val, then it must be a new value 8636d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // number in the destination. 8646d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner int OtherValNo = ThisFromOther[VN]; 8656d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner if (OtherValNo == -1) { 86691725b75852443923b419fd23215194cfc65dd88Chris Lattner ValueNumberInfo.push_back(ThisLI.getValNumInfo(VN)); 86791725b75852443923b419fd23215194cfc65dd88Chris Lattner return ThisValNoAssignments[VN] = ValueNumberInfo.size()-1; 8686d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner } 8696d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 8706d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // Otherwise, this *is* a copy from the RHS. Mark this value number as 8716d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // currently being computed, then ask what the ultimate value # of the other 8726d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // value is. 8736d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner ThisValNoAssignments[VN] = -2; 8746d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner unsigned UltimateVN = 87591725b75852443923b419fd23215194cfc65dd88Chris Lattner ComputeUltimateVN(OtherValNo, ValueNumberInfo, 8766d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner OtherFromThis, ThisFromOther, 8776d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner OtherValNoAssignments, ThisValNoAssignments, 8786d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner OtherLI, ThisLI); 8796d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner return ThisValNoAssignments[VN] = UltimateVN; 8806d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner} 8816d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 8826d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 8836d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// JoinIntervals - Attempt to join these two intervals. On failure, this 8846d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// returns false. Otherwise, if one of the intervals being joined is a 8856d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// physreg, this method always canonicalizes LHS to be it. The output 8866d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// "RHS" will not have been modified, so we can use this information 8876d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner/// below to update aliases. 8886d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattnerbool LiveIntervals::JoinIntervals(LiveInterval &LHS, LiveInterval &RHS) { 8896d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // Loop over the value numbers of the LHS, seeing if any are defined from the 8906d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // RHS. 8916d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner SmallVector<int, 16> LHSValsDefinedFromRHS; 8926d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner LHSValsDefinedFromRHS.resize(LHS.getNumValNums(), -1); 8936d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner for (unsigned VN = 0, e = LHS.getNumValNums(); VN != e; ++VN) { 89491725b75852443923b419fd23215194cfc65dd88Chris Lattner unsigned ValSrcReg = LHS.getSrcRegForValNum(VN); 89591725b75852443923b419fd23215194cfc65dd88Chris Lattner if (ValSrcReg == 0) // Src not defined by a copy? 8966d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner continue; 89791725b75852443923b419fd23215194cfc65dd88Chris Lattner 8986d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // DstReg is known to be a register in the LHS interval. If the src is from 8996d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // the RHS interval, we can use its value #. 90091725b75852443923b419fd23215194cfc65dd88Chris Lattner if (rep(ValSrcReg) != RHS.reg) 9016d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner continue; 90291725b75852443923b419fd23215194cfc65dd88Chris Lattner 9036d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // Figure out the value # from the RHS. 90491725b75852443923b419fd23215194cfc65dd88Chris Lattner unsigned ValInst = LHS.getInstForValNum(VN); 9056d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner LHSValsDefinedFromRHS[VN] = RHS.getLiveRangeContaining(ValInst-1)->ValId; 9066d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner } 9076d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 9086d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // Loop over the value numbers of the RHS, seeing if any are defined from the 9096d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // LHS. 9106d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner SmallVector<int, 16> RHSValsDefinedFromLHS; 9116d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner RHSValsDefinedFromLHS.resize(RHS.getNumValNums(), -1); 9126d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner for (unsigned VN = 0, e = RHS.getNumValNums(); VN != e; ++VN) { 91391725b75852443923b419fd23215194cfc65dd88Chris Lattner unsigned ValSrcReg = RHS.getSrcRegForValNum(VN); 91491725b75852443923b419fd23215194cfc65dd88Chris Lattner if (ValSrcReg == 0) // Src not defined by a copy? 9156d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner continue; 9166d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 9176d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // DstReg is known to be a register in the RHS interval. If the src is from 9186d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // the LHS interval, we can use its value #. 91991725b75852443923b419fd23215194cfc65dd88Chris Lattner if (rep(ValSrcReg) != LHS.reg) 9206d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner continue; 9216d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 9226d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // Figure out the value # from the LHS. 92391725b75852443923b419fd23215194cfc65dd88Chris Lattner unsigned ValInst = RHS.getInstForValNum(VN); 9246d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner RHSValsDefinedFromLHS[VN] = LHS.getLiveRangeContaining(ValInst-1)->ValId; 9256d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner } 9266d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 9276d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // Now that we know the value mapping, compute the final value assignment, 9286d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // assuming that the live ranges can be coallesced. 9296d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner SmallVector<int, 16> LHSValNoAssignments; 9306d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner SmallVector<int, 16> RHSValNoAssignments; 93191725b75852443923b419fd23215194cfc65dd88Chris Lattner SmallVector<std::pair<unsigned,unsigned>, 16> ValueNumberInfo; 9326d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner LHSValNoAssignments.resize(LHS.getNumValNums(), -1); 9336d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner RHSValNoAssignments.resize(RHS.getNumValNums(), -1); 9346d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 9356d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // Compute ultimate value numbers for the LHS and RHS values. 9366d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner for (unsigned VN = 0, e = LHS.getNumValNums(); VN != e; ++VN) { 9376d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner if (LHS.getInstForValNum(VN) == ~2U) continue; 93891725b75852443923b419fd23215194cfc65dd88Chris Lattner ComputeUltimateVN(VN, ValueNumberInfo, 9396d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner LHSValsDefinedFromRHS, RHSValsDefinedFromLHS, 9406d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner LHSValNoAssignments, RHSValNoAssignments, LHS, RHS); 9416d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner } 9426d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner for (unsigned VN = 0, e = RHS.getNumValNums(); VN != e; ++VN) { 9436d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner if (RHS.getInstForValNum(VN) == ~2U) continue; 94491725b75852443923b419fd23215194cfc65dd88Chris Lattner ComputeUltimateVN(VN, ValueNumberInfo, 9456d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner RHSValsDefinedFromLHS, LHSValsDefinedFromRHS, 9466d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner RHSValNoAssignments, LHSValNoAssignments, RHS, LHS); 9476d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner } 9486d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 9496d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // Armed with the mappings of LHS/RHS values to ultimate values, walk the 9506d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // interval lists to see if these intervals are coallescable. 9516d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner LiveInterval::const_iterator I = LHS.begin(); 9526d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner LiveInterval::const_iterator IE = LHS.end(); 9536d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner LiveInterval::const_iterator J = RHS.begin(); 9546d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner LiveInterval::const_iterator JE = RHS.end(); 9556d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 9566d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // Skip ahead until the first place of potential sharing. 9576d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner if (I->start < J->start) { 9586d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner I = std::upper_bound(I, IE, J->start); 9596d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner if (I != LHS.begin()) --I; 9606d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner } else if (J->start < I->start) { 9616d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner J = std::upper_bound(J, JE, I->start); 9626d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner if (J != RHS.begin()) --J; 9636d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner } 9646d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 9656d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner while (1) { 9666d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // Determine if these two live ranges overlap. 9676d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner bool Overlaps; 9686d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner if (I->start < J->start) { 9696d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner Overlaps = I->end > J->start; 9706d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner } else { 9716d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner Overlaps = J->end > I->start; 9726d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner } 9736d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 9746d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // If so, check value # info to determine if they are really different. 9756d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner if (Overlaps) { 9766d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // If the live range overlap will map to the same value number in the 9776d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // result liverange, we can still coallesce them. If not, we can't. 9786d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner if (LHSValNoAssignments[I->ValId] != RHSValNoAssignments[J->ValId]) 9796d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner return false; 9806d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner } 9816d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 9826d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner if (I->end < J->end) { 9836d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner ++I; 9846d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner if (I == IE) break; 9856d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner } else { 9866d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner ++J; 9876d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner if (J == JE) break; 9886d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner } 9896d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner } 9906d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner 9916d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // If we get here, we know that we can coallesce the live ranges. Ask the 9926d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner // intervals to coallesce themselves now. 9936d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner LHS.join(RHS, &LHSValNoAssignments[0], &RHSValNoAssignments[0], 99491725b75852443923b419fd23215194cfc65dd88Chris Lattner ValueNumberInfo); 9956d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner return true; 9966d8fbef015ff836bcb8f64f52c49805e43f8ea9fChris Lattner} 997f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 998f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 999cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattnernamespace { 1000cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner // DepthMBBCompare - Comparison predicate that sort first based on the loop 1001cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner // depth of the basic block (the unsigned), and then on the MBB number. 1002cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner struct DepthMBBCompare { 1003cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner typedef std::pair<unsigned, MachineBasicBlock*> DepthMBBPair; 1004cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner bool operator()(const DepthMBBPair &LHS, const DepthMBBPair &RHS) const { 1005cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner if (LHS.first > RHS.first) return true; // Deeper loops first 1006706515727c6d024015fffded2b3109a4f0ac5299Alkis Evlogimenos return LHS.first == RHS.first && 10071a8ea01f01b30e28e4e3ac0e3a344c4a4d579270Alkis Evlogimenos LHS.second->getNumber() < RHS.second->getNumber(); 1008cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner } 1009cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner }; 1010cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner} 1011cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner 1012f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 1013f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattnervoid LiveIntervals::CopyCoallesceInMBB(MachineBasicBlock *MBB, 1014f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner std::vector<CopyRec> &TryAgain) { 1015f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner DEBUG(std::cerr << ((Value*)MBB->getBasicBlock())->getName() << ":\n"); 1016f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 1017f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner for (MachineBasicBlock::iterator MII = MBB->begin(), E = MBB->end(); 1018f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner MII != E;) { 1019f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner MachineInstr *Inst = MII++; 1020f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 1021f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // If this isn't a copy, we can't join intervals. 1022f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner unsigned SrcReg, DstReg; 1023f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner if (!tii_->isMoveInstr(*Inst, SrcReg, DstReg)) continue; 1024f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 1025f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner if (!JoinCopy(Inst, SrcReg, DstReg)) 1026f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner TryAgain.push_back(getCopyRec(Inst, SrcReg, DstReg)); 1027f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner } 1028f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner} 1029f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 1030f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 1031cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattnervoid LiveIntervals::joinIntervals() { 1032cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner DEBUG(std::cerr << "********** JOINING INTERVALS ***********\n"); 10331c5c0444f1326b58cf05015651f36f2b04ca322dChris Lattner 1034f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner std::vector<CopyRec> TryAgainList; 1035f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 1036cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner const LoopInfo &LI = getAnalysis<LoopInfo>(); 1037cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner if (LI.begin() == LI.end()) { 1038cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner // If there are no loops in the function, join intervals in function order. 10391c5c0444f1326b58cf05015651f36f2b04ca322dChris Lattner for (MachineFunction::iterator I = mf_->begin(), E = mf_->end(); 10401c5c0444f1326b58cf05015651f36f2b04ca322dChris Lattner I != E; ++I) 1041f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner CopyCoallesceInMBB(I, TryAgainList); 1042cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner } else { 1043cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner // Otherwise, join intervals in inner loops before other intervals. 1044cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner // Unfortunately we can't just iterate over loop hierarchy here because 1045cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner // there may be more MBB's than BB's. Collect MBB's for sorting. 1046cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner std::vector<std::pair<unsigned, MachineBasicBlock*> > MBBs; 1047cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner for (MachineFunction::iterator I = mf_->begin(), E = mf_->end(); 1048cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner I != E; ++I) 1049cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner MBBs.push_back(std::make_pair(LI.getLoopDepth(I->getBasicBlock()), I)); 1050cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner 1051cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner // Sort by loop depth. 1052cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner std::sort(MBBs.begin(), MBBs.end(), DepthMBBCompare()); 1053cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner 1054706515727c6d024015fffded2b3109a4f0ac5299Alkis Evlogimenos // Finally, join intervals in loop nest order. 1055cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner for (unsigned i = 0, e = MBBs.size(); i != e; ++i) 1056f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner CopyCoallesceInMBB(MBBs[i].second, TryAgainList); 1057cc0d156f7bca0811aade0a95b0e7419176383c90Chris Lattner } 1058c83e40d1b6582155286f1044623d544dea20202eChris Lattner 1059f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // Joining intervals can allow other intervals to be joined. Iteratively join 1060f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner // until we make no progress. 1061f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner bool ProgressMade = true; 1062f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner while (ProgressMade) { 1063f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner ProgressMade = false; 1064f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 1065f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner for (unsigned i = 0, e = TryAgainList.size(); i != e; ++i) { 1066f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner CopyRec &TheCopy = TryAgainList[i]; 1067f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner if (TheCopy.MI && 1068f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner JoinCopy(TheCopy.MI, TheCopy.SrcReg, TheCopy.DstReg)) { 1069f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner TheCopy.MI = 0; // Mark this one as done. 1070f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner ProgressMade = true; 1071f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner } 1072f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner } 1073f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner } 1074f7da2c7b0c6293c268881628fc351bed7763f1f4Chris Lattner 1075c83e40d1b6582155286f1044623d544dea20202eChris Lattner DEBUG(std::cerr << "*** Register mapping ***\n"); 10765d0d1e350a30772fd70798b5733bb060febd7b0dAlkis Evlogimenos DEBUG(for (int i = 0, e = r2rMap_.size(); i != e; ++i) 10777c10b0d2c9b4d637edf27548c104b7199b0e3578Chris Lattner if (r2rMap_[i]) { 10787c10b0d2c9b4d637edf27548c104b7199b0e3578Chris Lattner std::cerr << " reg " << i << " -> "; 10797c10b0d2c9b4d637edf27548c104b7199b0e3578Chris Lattner printRegName(r2rMap_[i]); 10807c10b0d2c9b4d637edf27548c104b7199b0e3578Chris Lattner std::cerr << "\n"; 10817c10b0d2c9b4d637edf27548c104b7199b0e3578Chris Lattner }); 10821c5c0444f1326b58cf05015651f36f2b04ca322dChris Lattner} 10831c5c0444f1326b58cf05015651f36f2b04ca322dChris Lattner 1084647c15e58ed4c3fda81041d401ca7547639958dcEvan Cheng/// Return true if the two specified registers belong to different register 1085647c15e58ed4c3fda81041d401ca7547639958dcEvan Cheng/// classes. The registers may be either phys or virt regs. 1086647c15e58ed4c3fda81041d401ca7547639958dcEvan Chengbool LiveIntervals::differingRegisterClasses(unsigned RegA, 1087647c15e58ed4c3fda81041d401ca7547639958dcEvan Cheng unsigned RegB) const { 10887ac2d3146a196fa0120c579ecd2ddd69652ad230Chris Lattner 10897ac2d3146a196fa0120c579ecd2ddd69652ad230Chris Lattner // Get the register classes for the first reg. 1090ad3c74fc9b52b652859807580c8e40b67394d689Chris Lattner if (MRegisterInfo::isPhysicalRegister(RegA)) { 1091edf128a7fa90f2b0b7ee24741a04a7ae1ecd6f7eMisha Brukman assert(MRegisterInfo::isVirtualRegister(RegB) && 1092ad3c74fc9b52b652859807580c8e40b67394d689Chris Lattner "Shouldn't consider two physregs!"); 1093647c15e58ed4c3fda81041d401ca7547639958dcEvan Cheng return !mf_->getSSARegMap()->getRegClass(RegB)->contains(RegA); 1094ad3c74fc9b52b652859807580c8e40b67394d689Chris Lattner } 10957ac2d3146a196fa0120c579ecd2ddd69652ad230Chris Lattner 10967ac2d3146a196fa0120c579ecd2ddd69652ad230Chris Lattner // Compare against the regclass for the second reg. 1097647c15e58ed4c3fda81041d401ca7547639958dcEvan Cheng const TargetRegisterClass *RegClass = mf_->getSSARegMap()->getRegClass(RegA); 1098647c15e58ed4c3fda81041d401ca7547639958dcEvan Cheng if (MRegisterInfo::isVirtualRegister(RegB)) 1099647c15e58ed4c3fda81041d401ca7547639958dcEvan Cheng return RegClass != mf_->getSSARegMap()->getRegClass(RegB); 1100647c15e58ed4c3fda81041d401ca7547639958dcEvan Cheng else 1101647c15e58ed4c3fda81041d401ca7547639958dcEvan Cheng return !RegClass->contains(RegB); 11027ac2d3146a196fa0120c579ecd2ddd69652ad230Chris Lattner} 11037ac2d3146a196fa0120c579ecd2ddd69652ad230Chris Lattner 1104a1613db62fec94845aa8306232fb665273615badAlkis EvlogimenosLiveInterval LiveIntervals::createInterval(unsigned reg) { 1105edf128a7fa90f2b0b7ee24741a04a7ae1ecd6f7eMisha Brukman float Weight = MRegisterInfo::isPhysicalRegister(reg) ? 1106c9d94d12900bd0d2bd482ef31f8f1deb3ffafa23Chris Lattner (float)HUGE_VAL : 0.0F; 1107a1613db62fec94845aa8306232fb665273615badAlkis Evlogimenos return LiveInterval(reg, Weight); 11089a8b490735d216435862a3d52e669357f165550fAlkis Evlogimenos} 1109