mirror of
https://github.com/c64scene-ar/llvm-6502.git
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81909 91177308-0d34-0410-b5e6-96231b3b80d8
2720 lines
100 KiB
C++
2720 lines
100 KiB
C++
//===-- LiveIntervalAnalysis.cpp - Live Interval Analysis -----------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the LiveInterval analysis pass which is used
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// by the Linear Scan Register allocator. This pass linearizes the
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// basic blocks of the function in DFS order and uses the
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// LiveVariables pass to conservatively compute live intervals for
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// each virtual and physical register.
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//
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//===----------------------------------------------------------------------===//
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#define DEBUG_TYPE "liveintervals"
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#include "llvm/CodeGen/LiveIntervalAnalysis.h"
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#include "VirtRegMap.h"
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#include "llvm/Value.h"
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#include "llvm/Analysis/AliasAnalysis.h"
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#include "llvm/CodeGen/LiveVariables.h"
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#include "llvm/CodeGen/MachineFrameInfo.h"
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#include "llvm/CodeGen/MachineInstr.h"
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#include "llvm/CodeGen/MachineInstrBuilder.h"
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#include "llvm/CodeGen/MachineLoopInfo.h"
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#include "llvm/CodeGen/MachineRegisterInfo.h"
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#include "llvm/CodeGen/Passes.h"
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#include "llvm/CodeGen/PseudoSourceValue.h"
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#include "llvm/Target/TargetRegisterInfo.h"
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#include "llvm/Target/TargetInstrInfo.h"
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#include "llvm/Target/TargetMachine.h"
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#include "llvm/Target/TargetOptions.h"
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/ErrorHandling.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/ADT/DepthFirstIterator.h"
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#include "llvm/ADT/SmallSet.h"
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#include "llvm/ADT/Statistic.h"
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#include "llvm/ADT/STLExtras.h"
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#include <algorithm>
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#include <limits>
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#include <cmath>
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using namespace llvm;
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// Hidden options for help debugging.
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static cl::opt<bool> DisableReMat("disable-rematerialization",
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cl::init(false), cl::Hidden);
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static cl::opt<bool> EnableAggressiveRemat("aggressive-remat", cl::Hidden);
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static cl::opt<bool> EnableFastSpilling("fast-spill",
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cl::init(false), cl::Hidden);
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static cl::opt<bool> EarlyCoalescing("early-coalescing", cl::init(false));
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static cl::opt<int> CoalescingLimit("early-coalescing-limit",
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cl::init(-1), cl::Hidden);
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STATISTIC(numIntervals , "Number of original intervals");
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STATISTIC(numFolds , "Number of loads/stores folded into instructions");
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STATISTIC(numSplits , "Number of intervals split");
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STATISTIC(numCoalescing, "Number of early coalescing performed");
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char LiveIntervals::ID = 0;
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static RegisterPass<LiveIntervals> X("liveintervals", "Live Interval Analysis");
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void LiveIntervals::getAnalysisUsage(AnalysisUsage &AU) const {
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AU.setPreservesCFG();
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AU.addRequired<AliasAnalysis>();
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AU.addPreserved<AliasAnalysis>();
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AU.addPreserved<LiveVariables>();
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AU.addRequired<LiveVariables>();
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AU.addPreservedID(MachineLoopInfoID);
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AU.addPreservedID(MachineDominatorsID);
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if (!StrongPHIElim) {
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AU.addPreservedID(PHIEliminationID);
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AU.addRequiredID(PHIEliminationID);
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}
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AU.addRequiredID(TwoAddressInstructionPassID);
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MachineFunctionPass::getAnalysisUsage(AU);
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}
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void LiveIntervals::releaseMemory() {
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// Free the live intervals themselves.
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for (DenseMap<unsigned, LiveInterval*>::iterator I = r2iMap_.begin(),
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E = r2iMap_.end(); I != E; ++I)
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delete I->second;
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MBB2IdxMap.clear();
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Idx2MBBMap.clear();
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mi2iMap_.clear();
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i2miMap_.clear();
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r2iMap_.clear();
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terminatorGaps.clear();
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phiJoinCopies.clear();
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// Release VNInfo memroy regions after all VNInfo objects are dtor'd.
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VNInfoAllocator.Reset();
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while (!CloneMIs.empty()) {
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MachineInstr *MI = CloneMIs.back();
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CloneMIs.pop_back();
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mf_->DeleteMachineInstr(MI);
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}
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}
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static bool CanTurnIntoImplicitDef(MachineInstr *MI, unsigned Reg,
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const TargetInstrInfo *tii_) {
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unsigned SrcReg, DstReg, SrcSubReg, DstSubReg;
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if (tii_->isMoveInstr(*MI, SrcReg, DstReg, SrcSubReg, DstSubReg) &&
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Reg == SrcReg)
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return true;
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if ((MI->getOpcode() == TargetInstrInfo::INSERT_SUBREG ||
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MI->getOpcode() == TargetInstrInfo::SUBREG_TO_REG) &&
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MI->getOperand(2).getReg() == Reg)
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return true;
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if (MI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG &&
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MI->getOperand(1).getReg() == Reg)
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return true;
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return false;
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}
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/// processImplicitDefs - Process IMPLICIT_DEF instructions and make sure
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/// there is one implicit_def for each use. Add isUndef marker to
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/// implicit_def defs and their uses.
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void LiveIntervals::processImplicitDefs() {
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SmallSet<unsigned, 8> ImpDefRegs;
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SmallVector<MachineInstr*, 8> ImpDefMIs;
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MachineBasicBlock *Entry = mf_->begin();
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SmallPtrSet<MachineBasicBlock*,16> Visited;
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for (df_ext_iterator<MachineBasicBlock*, SmallPtrSet<MachineBasicBlock*,16> >
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DFI = df_ext_begin(Entry, Visited), E = df_ext_end(Entry, Visited);
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DFI != E; ++DFI) {
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MachineBasicBlock *MBB = *DFI;
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for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end();
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I != E; ) {
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MachineInstr *MI = &*I;
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++I;
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if (MI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF) {
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unsigned Reg = MI->getOperand(0).getReg();
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ImpDefRegs.insert(Reg);
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ImpDefMIs.push_back(MI);
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continue;
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}
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bool ChangedToImpDef = false;
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for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
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MachineOperand& MO = MI->getOperand(i);
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if (!MO.isReg() || !MO.isUse() || MO.isUndef())
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continue;
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unsigned Reg = MO.getReg();
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if (!Reg)
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continue;
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if (!ImpDefRegs.count(Reg))
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continue;
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// Use is a copy, just turn it into an implicit_def.
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if (CanTurnIntoImplicitDef(MI, Reg, tii_)) {
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bool isKill = MO.isKill();
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MI->setDesc(tii_->get(TargetInstrInfo::IMPLICIT_DEF));
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for (int j = MI->getNumOperands() - 1, ee = 0; j > ee; --j)
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MI->RemoveOperand(j);
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if (isKill)
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ImpDefRegs.erase(Reg);
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ChangedToImpDef = true;
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break;
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}
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MO.setIsUndef();
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if (MO.isKill() || MI->isRegTiedToDefOperand(i)) {
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// Make sure other uses of
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for (unsigned j = i+1; j != e; ++j) {
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MachineOperand &MOJ = MI->getOperand(j);
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if (MOJ.isReg() && MOJ.isUse() && MOJ.getReg() == Reg)
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MOJ.setIsUndef();
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}
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ImpDefRegs.erase(Reg);
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}
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}
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if (ChangedToImpDef) {
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// Backtrack to process this new implicit_def.
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--I;
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} else {
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for (unsigned i = 0; i != MI->getNumOperands(); ++i) {
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MachineOperand& MO = MI->getOperand(i);
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if (!MO.isReg() || !MO.isDef())
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continue;
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ImpDefRegs.erase(MO.getReg());
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}
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}
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}
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// Any outstanding liveout implicit_def's?
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for (unsigned i = 0, e = ImpDefMIs.size(); i != e; ++i) {
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MachineInstr *MI = ImpDefMIs[i];
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unsigned Reg = MI->getOperand(0).getReg();
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if (TargetRegisterInfo::isPhysicalRegister(Reg) ||
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!ImpDefRegs.count(Reg)) {
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// Delete all "local" implicit_def's. That include those which define
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// physical registers since they cannot be liveout.
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MI->eraseFromParent();
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continue;
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}
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// If there are multiple defs of the same register and at least one
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// is not an implicit_def, do not insert implicit_def's before the
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// uses.
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bool Skip = false;
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for (MachineRegisterInfo::def_iterator DI = mri_->def_begin(Reg),
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DE = mri_->def_end(); DI != DE; ++DI) {
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if (DI->getOpcode() != TargetInstrInfo::IMPLICIT_DEF) {
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Skip = true;
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break;
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}
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}
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if (Skip)
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continue;
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// The only implicit_def which we want to keep are those that are live
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// out of its block.
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MI->eraseFromParent();
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for (MachineRegisterInfo::use_iterator UI = mri_->use_begin(Reg),
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UE = mri_->use_end(); UI != UE; ) {
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MachineOperand &RMO = UI.getOperand();
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MachineInstr *RMI = &*UI;
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++UI;
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MachineBasicBlock *RMBB = RMI->getParent();
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if (RMBB == MBB)
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continue;
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// Turn a copy use into an implicit_def.
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unsigned SrcReg, DstReg, SrcSubReg, DstSubReg;
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if (tii_->isMoveInstr(*RMI, SrcReg, DstReg, SrcSubReg, DstSubReg) &&
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Reg == SrcReg) {
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RMI->setDesc(tii_->get(TargetInstrInfo::IMPLICIT_DEF));
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for (int j = RMI->getNumOperands() - 1, ee = 0; j > ee; --j)
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RMI->RemoveOperand(j);
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continue;
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}
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const TargetRegisterClass* RC = mri_->getRegClass(Reg);
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unsigned NewVReg = mri_->createVirtualRegister(RC);
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RMO.setReg(NewVReg);
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RMO.setIsUndef();
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RMO.setIsKill();
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}
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}
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ImpDefRegs.clear();
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ImpDefMIs.clear();
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}
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}
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void LiveIntervals::computeNumbering() {
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Index2MiMap OldI2MI = i2miMap_;
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std::vector<IdxMBBPair> OldI2MBB = Idx2MBBMap;
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Idx2MBBMap.clear();
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MBB2IdxMap.clear();
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mi2iMap_.clear();
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i2miMap_.clear();
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terminatorGaps.clear();
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phiJoinCopies.clear();
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FunctionSize = 0;
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// Number MachineInstrs and MachineBasicBlocks.
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// Initialize MBB indexes to a sentinal.
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MBB2IdxMap.resize(mf_->getNumBlockIDs(),
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std::make_pair(MachineInstrIndex(),MachineInstrIndex()));
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MachineInstrIndex MIIndex;
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for (MachineFunction::iterator MBB = mf_->begin(), E = mf_->end();
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MBB != E; ++MBB) {
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MachineInstrIndex StartIdx = MIIndex;
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// Insert an empty slot at the beginning of each block.
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MIIndex = getNextIndex(MIIndex);
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i2miMap_.push_back(0);
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for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end();
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I != E; ++I) {
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if (I == MBB->getFirstTerminator()) {
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// Leave a gap for before terminators, this is where we will point
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// PHI kills.
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MachineInstrIndex tGap(true, MIIndex);
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bool inserted =
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terminatorGaps.insert(std::make_pair(&*MBB, tGap)).second;
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assert(inserted &&
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"Multiple 'first' terminators encountered during numbering.");
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inserted = inserted; // Avoid compiler warning if assertions turned off.
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i2miMap_.push_back(0);
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MIIndex = getNextIndex(MIIndex);
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}
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bool inserted = mi2iMap_.insert(std::make_pair(I, MIIndex)).second;
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assert(inserted && "multiple MachineInstr -> index mappings");
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inserted = true;
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i2miMap_.push_back(I);
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MIIndex = getNextIndex(MIIndex);
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FunctionSize++;
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// Insert max(1, numdefs) empty slots after every instruction.
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unsigned Slots = I->getDesc().getNumDefs();
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if (Slots == 0)
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Slots = 1;
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while (Slots--) {
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MIIndex = getNextIndex(MIIndex);
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i2miMap_.push_back(0);
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}
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}
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if (MBB->getFirstTerminator() == MBB->end()) {
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// Leave a gap for before terminators, this is where we will point
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// PHI kills.
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MachineInstrIndex tGap(true, MIIndex);
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bool inserted =
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terminatorGaps.insert(std::make_pair(&*MBB, tGap)).second;
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assert(inserted &&
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"Multiple 'first' terminators encountered during numbering.");
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inserted = inserted; // Avoid compiler warning if assertions turned off.
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i2miMap_.push_back(0);
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MIIndex = getNextIndex(MIIndex);
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}
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// Set the MBB2IdxMap entry for this MBB.
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MBB2IdxMap[MBB->getNumber()] = std::make_pair(StartIdx, getPrevSlot(MIIndex));
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Idx2MBBMap.push_back(std::make_pair(StartIdx, MBB));
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}
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std::sort(Idx2MBBMap.begin(), Idx2MBBMap.end(), Idx2MBBCompare());
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if (!OldI2MI.empty())
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for (iterator OI = begin(), OE = end(); OI != OE; ++OI) {
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for (LiveInterval::iterator LI = OI->second->begin(),
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LE = OI->second->end(); LI != LE; ++LI) {
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// Remap the start index of the live range to the corresponding new
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// number, or our best guess at what it _should_ correspond to if the
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// original instruction has been erased. This is either the following
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// instruction or its predecessor.
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unsigned index = LI->start.getVecIndex();
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MachineInstrIndex::Slot offset = LI->start.getSlot();
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if (LI->start.isLoad()) {
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std::vector<IdxMBBPair>::const_iterator I =
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std::lower_bound(OldI2MBB.begin(), OldI2MBB.end(), LI->start);
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// Take the pair containing the index
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std::vector<IdxMBBPair>::const_iterator J =
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(I == OldI2MBB.end() && OldI2MBB.size()>0) ? (I-1): I;
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LI->start = getMBBStartIdx(J->second);
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} else {
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LI->start = MachineInstrIndex(
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MachineInstrIndex(mi2iMap_[OldI2MI[index]]),
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(MachineInstrIndex::Slot)offset);
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}
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// Remap the ending index in the same way that we remapped the start,
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// except for the final step where we always map to the immediately
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// following instruction.
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index = (getPrevSlot(LI->end)).getVecIndex();
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offset = LI->end.getSlot();
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if (LI->end.isLoad()) {
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// VReg dies at end of block.
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std::vector<IdxMBBPair>::const_iterator I =
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std::lower_bound(OldI2MBB.begin(), OldI2MBB.end(), LI->end);
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--I;
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LI->end = getNextSlot(getMBBEndIdx(I->second));
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} else {
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unsigned idx = index;
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while (index < OldI2MI.size() && !OldI2MI[index]) ++index;
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if (index != OldI2MI.size())
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LI->end =
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MachineInstrIndex(mi2iMap_[OldI2MI[index]],
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(idx == index ? offset : MachineInstrIndex::LOAD));
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else
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LI->end =
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MachineInstrIndex(MachineInstrIndex::NUM * i2miMap_.size());
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}
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}
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for (LiveInterval::vni_iterator VNI = OI->second->vni_begin(),
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VNE = OI->second->vni_end(); VNI != VNE; ++VNI) {
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VNInfo* vni = *VNI;
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// Remap the VNInfo def index, which works the same as the
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// start indices above. VN's with special sentinel defs
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// don't need to be remapped.
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if (vni->isDefAccurate() && !vni->isUnused()) {
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unsigned index = vni->def.getVecIndex();
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MachineInstrIndex::Slot offset = vni->def.getSlot();
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if (vni->def.isLoad()) {
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std::vector<IdxMBBPair>::const_iterator I =
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std::lower_bound(OldI2MBB.begin(), OldI2MBB.end(), vni->def);
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// Take the pair containing the index
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std::vector<IdxMBBPair>::const_iterator J =
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(I == OldI2MBB.end() && OldI2MBB.size()>0) ? (I-1): I;
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vni->def = getMBBStartIdx(J->second);
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} else {
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vni->def = MachineInstrIndex(mi2iMap_[OldI2MI[index]], offset);
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}
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}
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// Remap the VNInfo kill indices, which works the same as
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// the end indices above.
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for (size_t i = 0; i < vni->kills.size(); ++i) {
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unsigned index = getPrevSlot(vni->kills[i]).getVecIndex();
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MachineInstrIndex::Slot offset = vni->kills[i].getSlot();
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if (vni->kills[i].isLoad()) {
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assert("Value killed at a load slot.");
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/*std::vector<IdxMBBPair>::const_iterator I =
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std::lower_bound(OldI2MBB.begin(), OldI2MBB.end(), vni->kills[i]);
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--I;
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vni->kills[i] = getMBBEndIdx(I->second);*/
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} else {
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if (vni->kills[i].isPHIIndex()) {
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std::vector<IdxMBBPair>::const_iterator I =
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std::lower_bound(OldI2MBB.begin(), OldI2MBB.end(), vni->kills[i]);
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--I;
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vni->kills[i] = terminatorGaps[I->second];
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} else {
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assert(OldI2MI[index] != 0 &&
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"Kill refers to instruction not present in index maps.");
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vni->kills[i] = MachineInstrIndex(mi2iMap_[OldI2MI[index]], offset);
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}
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/*
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unsigned idx = index;
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while (index < OldI2MI.size() && !OldI2MI[index]) ++index;
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if (index != OldI2MI.size())
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vni->kills[i] = mi2iMap_[OldI2MI[index]] +
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(idx == index ? offset : 0);
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else
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vni->kills[i] = InstrSlots::NUM * i2miMap_.size();
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*/
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}
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}
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}
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}
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}
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void LiveIntervals::scaleNumbering(int factor) {
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// Need to
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// * scale MBB begin and end points
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// * scale all ranges.
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// * Update VNI structures.
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// * Scale instruction numberings
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// Scale the MBB indices.
|
|
Idx2MBBMap.clear();
|
|
for (MachineFunction::iterator MBB = mf_->begin(), MBBE = mf_->end();
|
|
MBB != MBBE; ++MBB) {
|
|
std::pair<MachineInstrIndex, MachineInstrIndex> &mbbIndices = MBB2IdxMap[MBB->getNumber()];
|
|
mbbIndices.first = mbbIndices.first.scale(factor);
|
|
mbbIndices.second = mbbIndices.second.scale(factor);
|
|
Idx2MBBMap.push_back(std::make_pair(mbbIndices.first, MBB));
|
|
}
|
|
std::sort(Idx2MBBMap.begin(), Idx2MBBMap.end(), Idx2MBBCompare());
|
|
|
|
// Scale terminator gaps.
|
|
for (DenseMap<MachineBasicBlock*, MachineInstrIndex>::iterator
|
|
TGI = terminatorGaps.begin(), TGE = terminatorGaps.end();
|
|
TGI != TGE; ++TGI) {
|
|
terminatorGaps[TGI->first] = TGI->second.scale(factor);
|
|
}
|
|
|
|
// Scale the intervals.
|
|
for (iterator LI = begin(), LE = end(); LI != LE; ++LI) {
|
|
LI->second->scaleNumbering(factor);
|
|
}
|
|
|
|
// Scale MachineInstrs.
|
|
Mi2IndexMap oldmi2iMap = mi2iMap_;
|
|
MachineInstrIndex highestSlot;
|
|
for (Mi2IndexMap::iterator MI = oldmi2iMap.begin(), ME = oldmi2iMap.end();
|
|
MI != ME; ++MI) {
|
|
MachineInstrIndex newSlot = MI->second.scale(factor);
|
|
mi2iMap_[MI->first] = newSlot;
|
|
highestSlot = std::max(highestSlot, newSlot);
|
|
}
|
|
|
|
unsigned highestVIndex = highestSlot.getVecIndex();
|
|
i2miMap_.clear();
|
|
i2miMap_.resize(highestVIndex + 1);
|
|
for (Mi2IndexMap::iterator MI = mi2iMap_.begin(), ME = mi2iMap_.end();
|
|
MI != ME; ++MI) {
|
|
i2miMap_[MI->second.getVecIndex()] = const_cast<MachineInstr *>(MI->first);
|
|
}
|
|
|
|
}
|
|
|
|
|
|
/// runOnMachineFunction - Register allocate the whole function
|
|
///
|
|
bool LiveIntervals::runOnMachineFunction(MachineFunction &fn) {
|
|
mf_ = &fn;
|
|
mri_ = &mf_->getRegInfo();
|
|
tm_ = &fn.getTarget();
|
|
tri_ = tm_->getRegisterInfo();
|
|
tii_ = tm_->getInstrInfo();
|
|
aa_ = &getAnalysis<AliasAnalysis>();
|
|
lv_ = &getAnalysis<LiveVariables>();
|
|
allocatableRegs_ = tri_->getAllocatableSet(fn);
|
|
|
|
processImplicitDefs();
|
|
computeNumbering();
|
|
computeIntervals();
|
|
performEarlyCoalescing();
|
|
|
|
numIntervals += getNumIntervals();
|
|
|
|
DEBUG(dump());
|
|
return true;
|
|
}
|
|
|
|
/// print - Implement the dump method.
|
|
void LiveIntervals::print(raw_ostream &OS, const Module* ) const {
|
|
OS << "********** INTERVALS **********\n";
|
|
for (const_iterator I = begin(), E = end(); I != E; ++I) {
|
|
I->second->print(OS, tri_);
|
|
OS << "\n";
|
|
}
|
|
|
|
printInstrs(OS);
|
|
}
|
|
|
|
void LiveIntervals::printInstrs(raw_ostream &OS) const {
|
|
OS << "********** MACHINEINSTRS **********\n";
|
|
|
|
for (MachineFunction::iterator mbbi = mf_->begin(), mbbe = mf_->end();
|
|
mbbi != mbbe; ++mbbi) {
|
|
OS << ((Value*)mbbi->getBasicBlock())->getName() << ":\n";
|
|
for (MachineBasicBlock::iterator mii = mbbi->begin(),
|
|
mie = mbbi->end(); mii != mie; ++mii) {
|
|
OS << getInstructionIndex(mii) << '\t' << *mii;
|
|
}
|
|
}
|
|
}
|
|
|
|
void LiveIntervals::dumpInstrs() const {
|
|
printInstrs(errs());
|
|
}
|
|
|
|
/// conflictsWithPhysRegDef - Returns true if the specified register
|
|
/// is defined during the duration of the specified interval.
|
|
bool LiveIntervals::conflictsWithPhysRegDef(const LiveInterval &li,
|
|
VirtRegMap &vrm, unsigned reg) {
|
|
for (LiveInterval::Ranges::const_iterator
|
|
I = li.ranges.begin(), E = li.ranges.end(); I != E; ++I) {
|
|
for (MachineInstrIndex index = getBaseIndex(I->start),
|
|
end = getNextIndex(getBaseIndex(getPrevSlot(I->end))); index != end;
|
|
index = getNextIndex(index)) {
|
|
// skip deleted instructions
|
|
while (index != end && !getInstructionFromIndex(index))
|
|
index = getNextIndex(index);
|
|
if (index == end) break;
|
|
|
|
MachineInstr *MI = getInstructionFromIndex(index);
|
|
unsigned SrcReg, DstReg, SrcSubReg, DstSubReg;
|
|
if (tii_->isMoveInstr(*MI, SrcReg, DstReg, SrcSubReg, DstSubReg))
|
|
if (SrcReg == li.reg || DstReg == li.reg)
|
|
continue;
|
|
for (unsigned i = 0; i != MI->getNumOperands(); ++i) {
|
|
MachineOperand& mop = MI->getOperand(i);
|
|
if (!mop.isReg())
|
|
continue;
|
|
unsigned PhysReg = mop.getReg();
|
|
if (PhysReg == 0 || PhysReg == li.reg)
|
|
continue;
|
|
if (TargetRegisterInfo::isVirtualRegister(PhysReg)) {
|
|
if (!vrm.hasPhys(PhysReg))
|
|
continue;
|
|
PhysReg = vrm.getPhys(PhysReg);
|
|
}
|
|
if (PhysReg && tri_->regsOverlap(PhysReg, reg))
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/// conflictsWithPhysRegRef - Similar to conflictsWithPhysRegRef except
|
|
/// it can check use as well.
|
|
bool LiveIntervals::conflictsWithPhysRegRef(LiveInterval &li,
|
|
unsigned Reg, bool CheckUse,
|
|
SmallPtrSet<MachineInstr*,32> &JoinedCopies) {
|
|
for (LiveInterval::Ranges::const_iterator
|
|
I = li.ranges.begin(), E = li.ranges.end(); I != E; ++I) {
|
|
for (MachineInstrIndex index = getBaseIndex(I->start),
|
|
end = getNextIndex(getBaseIndex(getPrevSlot(I->end))); index != end;
|
|
index = getNextIndex(index)) {
|
|
// Skip deleted instructions.
|
|
MachineInstr *MI = 0;
|
|
while (index != end) {
|
|
MI = getInstructionFromIndex(index);
|
|
if (MI)
|
|
break;
|
|
index = getNextIndex(index);
|
|
}
|
|
if (index == end) break;
|
|
|
|
if (JoinedCopies.count(MI))
|
|
continue;
|
|
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
|
|
MachineOperand& MO = MI->getOperand(i);
|
|
if (!MO.isReg())
|
|
continue;
|
|
if (MO.isUse() && !CheckUse)
|
|
continue;
|
|
unsigned PhysReg = MO.getReg();
|
|
if (PhysReg == 0 || TargetRegisterInfo::isVirtualRegister(PhysReg))
|
|
continue;
|
|
if (tri_->isSubRegister(Reg, PhysReg))
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
#ifndef NDEBUG
|
|
static void printRegName(unsigned reg, const TargetRegisterInfo* tri_) {
|
|
if (TargetRegisterInfo::isPhysicalRegister(reg))
|
|
errs() << tri_->getName(reg);
|
|
else
|
|
errs() << "%reg" << reg;
|
|
}
|
|
#endif
|
|
|
|
void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb,
|
|
MachineBasicBlock::iterator mi,
|
|
MachineInstrIndex MIIdx,
|
|
MachineOperand& MO,
|
|
unsigned MOIdx,
|
|
LiveInterval &interval) {
|
|
DEBUG({
|
|
errs() << "\t\tregister: ";
|
|
printRegName(interval.reg, tri_);
|
|
});
|
|
|
|
// Virtual registers may be defined multiple times (due to phi
|
|
// elimination and 2-addr elimination). Much of what we do only has to be
|
|
// done once for the vreg. We use an empty interval to detect the first
|
|
// time we see a vreg.
|
|
LiveVariables::VarInfo& vi = lv_->getVarInfo(interval.reg);
|
|
if (interval.empty()) {
|
|
// Get the Idx of the defining instructions.
|
|
MachineInstrIndex defIndex = getDefIndex(MIIdx);
|
|
// Earlyclobbers move back one.
|
|
if (MO.isEarlyClobber())
|
|
defIndex = getUseIndex(MIIdx);
|
|
VNInfo *ValNo;
|
|
MachineInstr *CopyMI = NULL;
|
|
unsigned SrcReg, DstReg, SrcSubReg, DstSubReg;
|
|
if (mi->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG ||
|
|
mi->getOpcode() == TargetInstrInfo::INSERT_SUBREG ||
|
|
mi->getOpcode() == TargetInstrInfo::SUBREG_TO_REG ||
|
|
tii_->isMoveInstr(*mi, SrcReg, DstReg, SrcSubReg, DstSubReg))
|
|
CopyMI = mi;
|
|
// Earlyclobbers move back one.
|
|
ValNo = interval.getNextValue(defIndex, CopyMI, true, VNInfoAllocator);
|
|
|
|
assert(ValNo->id == 0 && "First value in interval is not 0?");
|
|
|
|
// Loop over all of the blocks that the vreg is defined in. There are
|
|
// two cases we have to handle here. The most common case is a vreg
|
|
// whose lifetime is contained within a basic block. In this case there
|
|
// will be a single kill, in MBB, which comes after the definition.
|
|
if (vi.Kills.size() == 1 && vi.Kills[0]->getParent() == mbb) {
|
|
// FIXME: what about dead vars?
|
|
MachineInstrIndex killIdx;
|
|
if (vi.Kills[0] != mi)
|
|
killIdx = getNextSlot(getUseIndex(getInstructionIndex(vi.Kills[0])));
|
|
else
|
|
killIdx = getNextSlot(defIndex);
|
|
|
|
// If the kill happens after the definition, we have an intra-block
|
|
// live range.
|
|
if (killIdx > defIndex) {
|
|
assert(vi.AliveBlocks.empty() &&
|
|
"Shouldn't be alive across any blocks!");
|
|
LiveRange LR(defIndex, killIdx, ValNo);
|
|
interval.addRange(LR);
|
|
DEBUG(errs() << " +" << LR << "\n");
|
|
ValNo->addKill(killIdx);
|
|
return;
|
|
}
|
|
}
|
|
|
|
// The other case we handle is when a virtual register lives to the end
|
|
// of the defining block, potentially live across some blocks, then is
|
|
// live into some number of blocks, but gets killed. Start by adding a
|
|
// range that goes from this definition to the end of the defining block.
|
|
LiveRange NewLR(defIndex, getNextSlot(getMBBEndIdx(mbb)), ValNo);
|
|
DEBUG(errs() << " +" << NewLR);
|
|
interval.addRange(NewLR);
|
|
|
|
// Iterate over all of the blocks that the variable is completely
|
|
// live in, adding [insrtIndex(begin), instrIndex(end)+4) to the
|
|
// live interval.
|
|
for (SparseBitVector<>::iterator I = vi.AliveBlocks.begin(),
|
|
E = vi.AliveBlocks.end(); I != E; ++I) {
|
|
LiveRange LR(getMBBStartIdx(*I),
|
|
getNextSlot(getMBBEndIdx(*I)), // MBB ends at -1.
|
|
ValNo);
|
|
interval.addRange(LR);
|
|
DEBUG(errs() << " +" << LR);
|
|
}
|
|
|
|
// Finally, this virtual register is live from the start of any killing
|
|
// block to the 'use' slot of the killing instruction.
|
|
for (unsigned i = 0, e = vi.Kills.size(); i != e; ++i) {
|
|
MachineInstr *Kill = vi.Kills[i];
|
|
MachineInstrIndex killIdx =
|
|
getNextSlot(getUseIndex(getInstructionIndex(Kill)));
|
|
LiveRange LR(getMBBStartIdx(Kill->getParent()),
|
|
killIdx, ValNo);
|
|
interval.addRange(LR);
|
|
ValNo->addKill(killIdx);
|
|
DEBUG(errs() << " +" << LR);
|
|
}
|
|
|
|
} else {
|
|
// If this is the second time we see a virtual register definition, it
|
|
// must be due to phi elimination or two addr elimination. If this is
|
|
// the result of two address elimination, then the vreg is one of the
|
|
// def-and-use register operand.
|
|
if (mi->isRegTiedToUseOperand(MOIdx)) {
|
|
// If this is a two-address definition, then we have already processed
|
|
// the live range. The only problem is that we didn't realize there
|
|
// are actually two values in the live interval. Because of this we
|
|
// need to take the LiveRegion that defines this register and split it
|
|
// into two values.
|
|
assert(interval.containsOneValue());
|
|
MachineInstrIndex DefIndex = getDefIndex(interval.getValNumInfo(0)->def);
|
|
MachineInstrIndex RedefIndex = getDefIndex(MIIdx);
|
|
if (MO.isEarlyClobber())
|
|
RedefIndex = getUseIndex(MIIdx);
|
|
|
|
const LiveRange *OldLR =
|
|
interval.getLiveRangeContaining(getPrevSlot(RedefIndex));
|
|
VNInfo *OldValNo = OldLR->valno;
|
|
|
|
// Delete the initial value, which should be short and continuous,
|
|
// because the 2-addr copy must be in the same MBB as the redef.
|
|
interval.removeRange(DefIndex, RedefIndex);
|
|
|
|
// Two-address vregs should always only be redefined once. This means
|
|
// that at this point, there should be exactly one value number in it.
|
|
assert(interval.containsOneValue() && "Unexpected 2-addr liveint!");
|
|
|
|
// The new value number (#1) is defined by the instruction we claimed
|
|
// defined value #0.
|
|
VNInfo *ValNo = interval.getNextValue(OldValNo->def, OldValNo->getCopy(),
|
|
false, // update at *
|
|
VNInfoAllocator);
|
|
ValNo->setFlags(OldValNo->getFlags()); // * <- updating here
|
|
|
|
// Value#0 is now defined by the 2-addr instruction.
|
|
OldValNo->def = RedefIndex;
|
|
OldValNo->setCopy(0);
|
|
if (MO.isEarlyClobber())
|
|
OldValNo->setHasRedefByEC(true);
|
|
|
|
// Add the new live interval which replaces the range for the input copy.
|
|
LiveRange LR(DefIndex, RedefIndex, ValNo);
|
|
DEBUG(errs() << " replace range with " << LR);
|
|
interval.addRange(LR);
|
|
ValNo->addKill(RedefIndex);
|
|
|
|
// If this redefinition is dead, we need to add a dummy unit live
|
|
// range covering the def slot.
|
|
if (MO.isDead())
|
|
interval.addRange(
|
|
LiveRange(RedefIndex, getNextSlot(RedefIndex), OldValNo));
|
|
|
|
DEBUG({
|
|
errs() << " RESULT: ";
|
|
interval.print(errs(), tri_);
|
|
});
|
|
} else {
|
|
// Otherwise, this must be because of phi elimination. If this is the
|
|
// first redefinition of the vreg that we have seen, go back and change
|
|
// the live range in the PHI block to be a different value number.
|
|
if (interval.containsOneValue()) {
|
|
// Remove the old range that we now know has an incorrect number.
|
|
VNInfo *VNI = interval.getValNumInfo(0);
|
|
MachineInstr *Killer = vi.Kills[0];
|
|
phiJoinCopies.push_back(Killer);
|
|
MachineInstrIndex Start = getMBBStartIdx(Killer->getParent());
|
|
MachineInstrIndex End =
|
|
getNextSlot(getUseIndex(getInstructionIndex(Killer)));
|
|
DEBUG({
|
|
errs() << " Removing [" << Start << "," << End << "] from: ";
|
|
interval.print(errs(), tri_);
|
|
errs() << "\n";
|
|
});
|
|
interval.removeRange(Start, End);
|
|
assert(interval.ranges.size() == 1 &&
|
|
"Newly discovered PHI interval has >1 ranges.");
|
|
MachineBasicBlock *killMBB = getMBBFromIndex(interval.endIndex());
|
|
VNI->addKill(terminatorGaps[killMBB]);
|
|
VNI->setHasPHIKill(true);
|
|
DEBUG({
|
|
errs() << " RESULT: ";
|
|
interval.print(errs(), tri_);
|
|
});
|
|
|
|
// Replace the interval with one of a NEW value number. Note that this
|
|
// value number isn't actually defined by an instruction, weird huh? :)
|
|
LiveRange LR(Start, End,
|
|
interval.getNextValue(MachineInstrIndex(mbb->getNumber()),
|
|
0, false, VNInfoAllocator));
|
|
LR.valno->setIsPHIDef(true);
|
|
DEBUG(errs() << " replace range with " << LR);
|
|
interval.addRange(LR);
|
|
LR.valno->addKill(End);
|
|
DEBUG({
|
|
errs() << " RESULT: ";
|
|
interval.print(errs(), tri_);
|
|
});
|
|
}
|
|
|
|
// In the case of PHI elimination, each variable definition is only
|
|
// live until the end of the block. We've already taken care of the
|
|
// rest of the live range.
|
|
MachineInstrIndex defIndex = getDefIndex(MIIdx);
|
|
if (MO.isEarlyClobber())
|
|
defIndex = getUseIndex(MIIdx);
|
|
|
|
VNInfo *ValNo;
|
|
MachineInstr *CopyMI = NULL;
|
|
unsigned SrcReg, DstReg, SrcSubReg, DstSubReg;
|
|
if (mi->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG ||
|
|
mi->getOpcode() == TargetInstrInfo::INSERT_SUBREG ||
|
|
mi->getOpcode() == TargetInstrInfo::SUBREG_TO_REG ||
|
|
tii_->isMoveInstr(*mi, SrcReg, DstReg, SrcSubReg, DstSubReg))
|
|
CopyMI = mi;
|
|
ValNo = interval.getNextValue(defIndex, CopyMI, true, VNInfoAllocator);
|
|
|
|
MachineInstrIndex killIndex = getNextSlot(getMBBEndIdx(mbb));
|
|
LiveRange LR(defIndex, killIndex, ValNo);
|
|
interval.addRange(LR);
|
|
ValNo->addKill(terminatorGaps[mbb]);
|
|
ValNo->setHasPHIKill(true);
|
|
DEBUG(errs() << " +" << LR);
|
|
}
|
|
}
|
|
|
|
DEBUG(errs() << '\n');
|
|
}
|
|
|
|
void LiveIntervals::handlePhysicalRegisterDef(MachineBasicBlock *MBB,
|
|
MachineBasicBlock::iterator mi,
|
|
MachineInstrIndex MIIdx,
|
|
MachineOperand& MO,
|
|
LiveInterval &interval,
|
|
MachineInstr *CopyMI) {
|
|
// A physical register cannot be live across basic block, so its
|
|
// lifetime must end somewhere in its defining basic block.
|
|
DEBUG({
|
|
errs() << "\t\tregister: ";
|
|
printRegName(interval.reg, tri_);
|
|
});
|
|
|
|
MachineInstrIndex baseIndex = MIIdx;
|
|
MachineInstrIndex start = getDefIndex(baseIndex);
|
|
// Earlyclobbers move back one.
|
|
if (MO.isEarlyClobber())
|
|
start = getUseIndex(MIIdx);
|
|
MachineInstrIndex end = start;
|
|
|
|
// If it is not used after definition, it is considered dead at
|
|
// the instruction defining it. Hence its interval is:
|
|
// [defSlot(def), defSlot(def)+1)
|
|
if (MO.isDead()) {
|
|
DEBUG(errs() << " dead");
|
|
end = getNextSlot(start);
|
|
goto exit;
|
|
}
|
|
|
|
// If it is not dead on definition, it must be killed by a
|
|
// subsequent instruction. Hence its interval is:
|
|
// [defSlot(def), useSlot(kill)+1)
|
|
baseIndex = getNextIndex(baseIndex);
|
|
while (++mi != MBB->end()) {
|
|
while (baseIndex.getVecIndex() < i2miMap_.size() &&
|
|
getInstructionFromIndex(baseIndex) == 0)
|
|
baseIndex = getNextIndex(baseIndex);
|
|
if (mi->killsRegister(interval.reg, tri_)) {
|
|
DEBUG(errs() << " killed");
|
|
end = getNextSlot(getUseIndex(baseIndex));
|
|
goto exit;
|
|
} else {
|
|
int DefIdx = mi->findRegisterDefOperandIdx(interval.reg, false, tri_);
|
|
if (DefIdx != -1) {
|
|
if (mi->isRegTiedToUseOperand(DefIdx)) {
|
|
// Two-address instruction.
|
|
end = getDefIndex(baseIndex);
|
|
if (mi->getOperand(DefIdx).isEarlyClobber())
|
|
end = getUseIndex(baseIndex);
|
|
} else {
|
|
// Another instruction redefines the register before it is ever read.
|
|
// Then the register is essentially dead at the instruction that defines
|
|
// it. Hence its interval is:
|
|
// [defSlot(def), defSlot(def)+1)
|
|
DEBUG(errs() << " dead");
|
|
end = getNextSlot(start);
|
|
}
|
|
goto exit;
|
|
}
|
|
}
|
|
|
|
baseIndex = getNextIndex(baseIndex);
|
|
}
|
|
|
|
// The only case we should have a dead physreg here without a killing or
|
|
// instruction where we know it's dead is if it is live-in to the function
|
|
// and never used. Another possible case is the implicit use of the
|
|
// physical register has been deleted by two-address pass.
|
|
end = getNextSlot(start);
|
|
|
|
exit:
|
|
assert(start < end && "did not find end of interval?");
|
|
|
|
// Already exists? Extend old live interval.
|
|
LiveInterval::iterator OldLR = interval.FindLiveRangeContaining(start);
|
|
bool Extend = OldLR != interval.end();
|
|
VNInfo *ValNo = Extend
|
|
? OldLR->valno : interval.getNextValue(start, CopyMI, true, VNInfoAllocator);
|
|
if (MO.isEarlyClobber() && Extend)
|
|
ValNo->setHasRedefByEC(true);
|
|
LiveRange LR(start, end, ValNo);
|
|
interval.addRange(LR);
|
|
LR.valno->addKill(end);
|
|
DEBUG(errs() << " +" << LR << '\n');
|
|
}
|
|
|
|
void LiveIntervals::handleRegisterDef(MachineBasicBlock *MBB,
|
|
MachineBasicBlock::iterator MI,
|
|
MachineInstrIndex MIIdx,
|
|
MachineOperand& MO,
|
|
unsigned MOIdx) {
|
|
if (TargetRegisterInfo::isVirtualRegister(MO.getReg()))
|
|
handleVirtualRegisterDef(MBB, MI, MIIdx, MO, MOIdx,
|
|
getOrCreateInterval(MO.getReg()));
|
|
else if (allocatableRegs_[MO.getReg()]) {
|
|
MachineInstr *CopyMI = NULL;
|
|
unsigned SrcReg, DstReg, SrcSubReg, DstSubReg;
|
|
if (MI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG ||
|
|
MI->getOpcode() == TargetInstrInfo::INSERT_SUBREG ||
|
|
MI->getOpcode() == TargetInstrInfo::SUBREG_TO_REG ||
|
|
tii_->isMoveInstr(*MI, SrcReg, DstReg, SrcSubReg, DstSubReg))
|
|
CopyMI = MI;
|
|
handlePhysicalRegisterDef(MBB, MI, MIIdx, MO,
|
|
getOrCreateInterval(MO.getReg()), CopyMI);
|
|
// Def of a register also defines its sub-registers.
|
|
for (const unsigned* AS = tri_->getSubRegisters(MO.getReg()); *AS; ++AS)
|
|
// If MI also modifies the sub-register explicitly, avoid processing it
|
|
// more than once. Do not pass in TRI here so it checks for exact match.
|
|
if (!MI->modifiesRegister(*AS))
|
|
handlePhysicalRegisterDef(MBB, MI, MIIdx, MO,
|
|
getOrCreateInterval(*AS), 0);
|
|
}
|
|
}
|
|
|
|
void LiveIntervals::handleLiveInRegister(MachineBasicBlock *MBB,
|
|
MachineInstrIndex MIIdx,
|
|
LiveInterval &interval, bool isAlias) {
|
|
DEBUG({
|
|
errs() << "\t\tlivein register: ";
|
|
printRegName(interval.reg, tri_);
|
|
});
|
|
|
|
// Look for kills, if it reaches a def before it's killed, then it shouldn't
|
|
// be considered a livein.
|
|
MachineBasicBlock::iterator mi = MBB->begin();
|
|
MachineInstrIndex baseIndex = MIIdx;
|
|
MachineInstrIndex start = baseIndex;
|
|
while (baseIndex.getVecIndex() < i2miMap_.size() &&
|
|
getInstructionFromIndex(baseIndex) == 0)
|
|
baseIndex = getNextIndex(baseIndex);
|
|
MachineInstrIndex end = baseIndex;
|
|
bool SeenDefUse = false;
|
|
|
|
while (mi != MBB->end()) {
|
|
if (mi->killsRegister(interval.reg, tri_)) {
|
|
DEBUG(errs() << " killed");
|
|
end = getNextSlot(getUseIndex(baseIndex));
|
|
SeenDefUse = true;
|
|
break;
|
|
} else if (mi->modifiesRegister(interval.reg, tri_)) {
|
|
// Another instruction redefines the register before it is ever read.
|
|
// Then the register is essentially dead at the instruction that defines
|
|
// it. Hence its interval is:
|
|
// [defSlot(def), defSlot(def)+1)
|
|
DEBUG(errs() << " dead");
|
|
end = getNextSlot(getDefIndex(start));
|
|
SeenDefUse = true;
|
|
break;
|
|
}
|
|
|
|
baseIndex = getNextIndex(baseIndex);
|
|
++mi;
|
|
if (mi != MBB->end()) {
|
|
while (baseIndex.getVecIndex() < i2miMap_.size() &&
|
|
getInstructionFromIndex(baseIndex) == 0)
|
|
baseIndex = getNextIndex(baseIndex);
|
|
}
|
|
}
|
|
|
|
// Live-in register might not be used at all.
|
|
if (!SeenDefUse) {
|
|
if (isAlias) {
|
|
DEBUG(errs() << " dead");
|
|
end = getNextSlot(getDefIndex(MIIdx));
|
|
} else {
|
|
DEBUG(errs() << " live through");
|
|
end = baseIndex;
|
|
}
|
|
}
|
|
|
|
VNInfo *vni =
|
|
interval.getNextValue(MachineInstrIndex(MBB->getNumber()),
|
|
0, false, VNInfoAllocator);
|
|
vni->setIsPHIDef(true);
|
|
LiveRange LR(start, end, vni);
|
|
|
|
interval.addRange(LR);
|
|
LR.valno->addKill(end);
|
|
DEBUG(errs() << " +" << LR << '\n');
|
|
}
|
|
|
|
bool
|
|
LiveIntervals::isProfitableToCoalesce(LiveInterval &DstInt, LiveInterval &SrcInt,
|
|
SmallVector<MachineInstr*,16> &IdentCopies,
|
|
SmallVector<MachineInstr*,16> &OtherCopies) {
|
|
bool HaveConflict = false;
|
|
unsigned NumIdent = 0;
|
|
for (MachineRegisterInfo::reg_iterator ri = mri_->reg_begin(SrcInt.reg),
|
|
re = mri_->reg_end(); ri != re; ++ri) {
|
|
MachineOperand &O = ri.getOperand();
|
|
if (!O.isDef())
|
|
continue;
|
|
|
|
MachineInstr *MI = &*ri;
|
|
unsigned SrcReg, DstReg, SrcSubReg, DstSubReg;
|
|
if (!tii_->isMoveInstr(*MI, SrcReg, DstReg, SrcSubReg, DstSubReg))
|
|
return false;
|
|
if (SrcReg != DstInt.reg) {
|
|
OtherCopies.push_back(MI);
|
|
HaveConflict |= DstInt.liveAt(getInstructionIndex(MI));
|
|
} else {
|
|
IdentCopies.push_back(MI);
|
|
++NumIdent;
|
|
}
|
|
}
|
|
|
|
if (!HaveConflict)
|
|
return false; // Let coalescer handle it
|
|
return IdentCopies.size() > OtherCopies.size();
|
|
}
|
|
|
|
void LiveIntervals::performEarlyCoalescing() {
|
|
if (!EarlyCoalescing)
|
|
return;
|
|
|
|
/// Perform early coalescing: eliminate copies which feed into phi joins
|
|
/// and whose sources are defined by the phi joins.
|
|
for (unsigned i = 0, e = phiJoinCopies.size(); i != e; ++i) {
|
|
MachineInstr *Join = phiJoinCopies[i];
|
|
if (CoalescingLimit != -1 && (int)numCoalescing == CoalescingLimit)
|
|
break;
|
|
|
|
unsigned PHISrc, PHIDst, SrcSubReg, DstSubReg;
|
|
bool isMove= tii_->isMoveInstr(*Join, PHISrc, PHIDst, SrcSubReg, DstSubReg);
|
|
#ifndef NDEBUG
|
|
assert(isMove && "PHI join instruction must be a move!");
|
|
#else
|
|
isMove = isMove;
|
|
#endif
|
|
|
|
LiveInterval &DstInt = getInterval(PHIDst);
|
|
LiveInterval &SrcInt = getInterval(PHISrc);
|
|
SmallVector<MachineInstr*, 16> IdentCopies;
|
|
SmallVector<MachineInstr*, 16> OtherCopies;
|
|
if (!isProfitableToCoalesce(DstInt, SrcInt, IdentCopies, OtherCopies))
|
|
continue;
|
|
|
|
DEBUG(errs() << "PHI Join: " << *Join);
|
|
assert(DstInt.containsOneValue() && "PHI join should have just one val#!");
|
|
VNInfo *VNI = DstInt.getValNumInfo(0);
|
|
|
|
// Change the non-identity copies to directly target the phi destination.
|
|
for (unsigned i = 0, e = OtherCopies.size(); i != e; ++i) {
|
|
MachineInstr *PHICopy = OtherCopies[i];
|
|
DEBUG(errs() << "Moving: " << *PHICopy);
|
|
|
|
MachineInstrIndex MIIndex = getInstructionIndex(PHICopy);
|
|
MachineInstrIndex DefIndex = getDefIndex(MIIndex);
|
|
LiveRange *SLR = SrcInt.getLiveRangeContaining(DefIndex);
|
|
MachineInstrIndex StartIndex = SLR->start;
|
|
MachineInstrIndex EndIndex = SLR->end;
|
|
|
|
// Delete val# defined by the now identity copy and add the range from
|
|
// beginning of the mbb to the end of the range.
|
|
SrcInt.removeValNo(SLR->valno);
|
|
DEBUG(errs() << " added range [" << StartIndex << ','
|
|
<< EndIndex << "] to reg" << DstInt.reg << '\n');
|
|
if (DstInt.liveAt(StartIndex))
|
|
DstInt.removeRange(StartIndex, EndIndex);
|
|
VNInfo *NewVNI = DstInt.getNextValue(DefIndex, PHICopy, true,
|
|
VNInfoAllocator);
|
|
NewVNI->setHasPHIKill(true);
|
|
DstInt.addRange(LiveRange(StartIndex, EndIndex, NewVNI));
|
|
for (unsigned j = 0, ee = PHICopy->getNumOperands(); j != ee; ++j) {
|
|
MachineOperand &MO = PHICopy->getOperand(j);
|
|
if (!MO.isReg() || MO.getReg() != PHISrc)
|
|
continue;
|
|
MO.setReg(PHIDst);
|
|
}
|
|
}
|
|
|
|
// Now let's eliminate all the would-be identity copies.
|
|
for (unsigned i = 0, e = IdentCopies.size(); i != e; ++i) {
|
|
MachineInstr *PHICopy = IdentCopies[i];
|
|
DEBUG(errs() << "Coalescing: " << *PHICopy);
|
|
|
|
MachineInstrIndex MIIndex = getInstructionIndex(PHICopy);
|
|
MachineInstrIndex DefIndex = getDefIndex(MIIndex);
|
|
LiveRange *SLR = SrcInt.getLiveRangeContaining(DefIndex);
|
|
MachineInstrIndex StartIndex = SLR->start;
|
|
MachineInstrIndex EndIndex = SLR->end;
|
|
|
|
// Delete val# defined by the now identity copy and add the range from
|
|
// beginning of the mbb to the end of the range.
|
|
SrcInt.removeValNo(SLR->valno);
|
|
RemoveMachineInstrFromMaps(PHICopy);
|
|
PHICopy->eraseFromParent();
|
|
DEBUG(errs() << " added range [" << StartIndex << ','
|
|
<< EndIndex << "] to reg" << DstInt.reg << '\n');
|
|
DstInt.addRange(LiveRange(StartIndex, EndIndex, VNI));
|
|
}
|
|
|
|
// Remove the phi join and update the phi block liveness.
|
|
MachineInstrIndex MIIndex = getInstructionIndex(Join);
|
|
MachineInstrIndex UseIndex = getUseIndex(MIIndex);
|
|
MachineInstrIndex DefIndex = getDefIndex(MIIndex);
|
|
LiveRange *SLR = SrcInt.getLiveRangeContaining(UseIndex);
|
|
LiveRange *DLR = DstInt.getLiveRangeContaining(DefIndex);
|
|
DLR->valno->setCopy(0);
|
|
DLR->valno->setIsDefAccurate(false);
|
|
DstInt.addRange(LiveRange(SLR->start, SLR->end, DLR->valno));
|
|
SrcInt.removeRange(SLR->start, SLR->end);
|
|
assert(SrcInt.empty());
|
|
removeInterval(PHISrc);
|
|
RemoveMachineInstrFromMaps(Join);
|
|
Join->eraseFromParent();
|
|
|
|
++numCoalescing;
|
|
}
|
|
}
|
|
|
|
/// computeIntervals - computes the live intervals for virtual
|
|
/// registers. for some ordering of the machine instructions [1,N] a
|
|
/// live interval is an interval [i, j) where 1 <= i <= j < N for
|
|
/// which a variable is live
|
|
void LiveIntervals::computeIntervals() {
|
|
DEBUG(errs() << "********** COMPUTING LIVE INTERVALS **********\n"
|
|
<< "********** Function: "
|
|
<< ((Value*)mf_->getFunction())->getName() << '\n');
|
|
|
|
SmallVector<unsigned, 8> UndefUses;
|
|
for (MachineFunction::iterator MBBI = mf_->begin(), E = mf_->end();
|
|
MBBI != E; ++MBBI) {
|
|
MachineBasicBlock *MBB = MBBI;
|
|
// Track the index of the current machine instr.
|
|
MachineInstrIndex MIIndex = getMBBStartIdx(MBB);
|
|
DEBUG(errs() << ((Value*)MBB->getBasicBlock())->getName() << ":\n");
|
|
|
|
MachineBasicBlock::iterator MI = MBB->begin(), miEnd = MBB->end();
|
|
|
|
// Create intervals for live-ins to this BB first.
|
|
for (MachineBasicBlock::const_livein_iterator LI = MBB->livein_begin(),
|
|
LE = MBB->livein_end(); LI != LE; ++LI) {
|
|
handleLiveInRegister(MBB, MIIndex, getOrCreateInterval(*LI));
|
|
// Multiple live-ins can alias the same register.
|
|
for (const unsigned* AS = tri_->getSubRegisters(*LI); *AS; ++AS)
|
|
if (!hasInterval(*AS))
|
|
handleLiveInRegister(MBB, MIIndex, getOrCreateInterval(*AS),
|
|
true);
|
|
}
|
|
|
|
// Skip over empty initial indices.
|
|
while (MIIndex.getVecIndex() < i2miMap_.size() &&
|
|
getInstructionFromIndex(MIIndex) == 0)
|
|
MIIndex = getNextIndex(MIIndex);
|
|
|
|
for (; MI != miEnd; ++MI) {
|
|
DEBUG(errs() << MIIndex << "\t" << *MI);
|
|
|
|
// Handle defs.
|
|
for (int i = MI->getNumOperands() - 1; i >= 0; --i) {
|
|
MachineOperand &MO = MI->getOperand(i);
|
|
if (!MO.isReg() || !MO.getReg())
|
|
continue;
|
|
|
|
// handle register defs - build intervals
|
|
if (MO.isDef())
|
|
handleRegisterDef(MBB, MI, MIIndex, MO, i);
|
|
else if (MO.isUndef())
|
|
UndefUses.push_back(MO.getReg());
|
|
}
|
|
|
|
// Skip over the empty slots after each instruction.
|
|
unsigned Slots = MI->getDesc().getNumDefs();
|
|
if (Slots == 0)
|
|
Slots = 1;
|
|
|
|
while (Slots--)
|
|
MIIndex = getNextIndex(MIIndex);
|
|
|
|
// Skip over empty indices.
|
|
while (MIIndex.getVecIndex() < i2miMap_.size() &&
|
|
getInstructionFromIndex(MIIndex) == 0)
|
|
MIIndex = getNextIndex(MIIndex);
|
|
}
|
|
}
|
|
|
|
// Create empty intervals for registers defined by implicit_def's (except
|
|
// for those implicit_def that define values which are liveout of their
|
|
// blocks.
|
|
for (unsigned i = 0, e = UndefUses.size(); i != e; ++i) {
|
|
unsigned UndefReg = UndefUses[i];
|
|
(void)getOrCreateInterval(UndefReg);
|
|
}
|
|
}
|
|
|
|
bool LiveIntervals::findLiveInMBBs(
|
|
MachineInstrIndex Start, MachineInstrIndex End,
|
|
SmallVectorImpl<MachineBasicBlock*> &MBBs) const {
|
|
std::vector<IdxMBBPair>::const_iterator I =
|
|
std::lower_bound(Idx2MBBMap.begin(), Idx2MBBMap.end(), Start);
|
|
|
|
bool ResVal = false;
|
|
while (I != Idx2MBBMap.end()) {
|
|
if (I->first >= End)
|
|
break;
|
|
MBBs.push_back(I->second);
|
|
ResVal = true;
|
|
++I;
|
|
}
|
|
return ResVal;
|
|
}
|
|
|
|
bool LiveIntervals::findReachableMBBs(
|
|
MachineInstrIndex Start, MachineInstrIndex End,
|
|
SmallVectorImpl<MachineBasicBlock*> &MBBs) const {
|
|
std::vector<IdxMBBPair>::const_iterator I =
|
|
std::lower_bound(Idx2MBBMap.begin(), Idx2MBBMap.end(), Start);
|
|
|
|
bool ResVal = false;
|
|
while (I != Idx2MBBMap.end()) {
|
|
if (I->first > End)
|
|
break;
|
|
MachineBasicBlock *MBB = I->second;
|
|
if (getMBBEndIdx(MBB) > End)
|
|
break;
|
|
for (MachineBasicBlock::succ_iterator SI = MBB->succ_begin(),
|
|
SE = MBB->succ_end(); SI != SE; ++SI)
|
|
MBBs.push_back(*SI);
|
|
ResVal = true;
|
|
++I;
|
|
}
|
|
return ResVal;
|
|
}
|
|
|
|
LiveInterval* LiveIntervals::createInterval(unsigned reg) {
|
|
float Weight = TargetRegisterInfo::isPhysicalRegister(reg) ? HUGE_VALF : 0.0F;
|
|
return new LiveInterval(reg, Weight);
|
|
}
|
|
|
|
/// dupInterval - Duplicate a live interval. The caller is responsible for
|
|
/// managing the allocated memory.
|
|
LiveInterval* LiveIntervals::dupInterval(LiveInterval *li) {
|
|
LiveInterval *NewLI = createInterval(li->reg);
|
|
NewLI->Copy(*li, mri_, getVNInfoAllocator());
|
|
return NewLI;
|
|
}
|
|
|
|
/// getVNInfoSourceReg - Helper function that parses the specified VNInfo
|
|
/// copy field and returns the source register that defines it.
|
|
unsigned LiveIntervals::getVNInfoSourceReg(const VNInfo *VNI) const {
|
|
if (!VNI->getCopy())
|
|
return 0;
|
|
|
|
if (VNI->getCopy()->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG) {
|
|
// If it's extracting out of a physical register, return the sub-register.
|
|
unsigned Reg = VNI->getCopy()->getOperand(1).getReg();
|
|
if (TargetRegisterInfo::isPhysicalRegister(Reg))
|
|
Reg = tri_->getSubReg(Reg, VNI->getCopy()->getOperand(2).getImm());
|
|
return Reg;
|
|
} else if (VNI->getCopy()->getOpcode() == TargetInstrInfo::INSERT_SUBREG ||
|
|
VNI->getCopy()->getOpcode() == TargetInstrInfo::SUBREG_TO_REG)
|
|
return VNI->getCopy()->getOperand(2).getReg();
|
|
|
|
unsigned SrcReg, DstReg, SrcSubReg, DstSubReg;
|
|
if (tii_->isMoveInstr(*VNI->getCopy(), SrcReg, DstReg, SrcSubReg, DstSubReg))
|
|
return SrcReg;
|
|
llvm_unreachable("Unrecognized copy instruction!");
|
|
return 0;
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Register allocator hooks.
|
|
//
|
|
|
|
/// getReMatImplicitUse - If the remat definition MI has one (for now, we only
|
|
/// allow one) virtual register operand, then its uses are implicitly using
|
|
/// the register. Returns the virtual register.
|
|
unsigned LiveIntervals::getReMatImplicitUse(const LiveInterval &li,
|
|
MachineInstr *MI) const {
|
|
unsigned RegOp = 0;
|
|
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
|
|
MachineOperand &MO = MI->getOperand(i);
|
|
if (!MO.isReg() || !MO.isUse())
|
|
continue;
|
|
unsigned Reg = MO.getReg();
|
|
if (Reg == 0 || Reg == li.reg)
|
|
continue;
|
|
|
|
if (TargetRegisterInfo::isPhysicalRegister(Reg) &&
|
|
!allocatableRegs_[Reg])
|
|
continue;
|
|
// FIXME: For now, only remat MI with at most one register operand.
|
|
assert(!RegOp &&
|
|
"Can't rematerialize instruction with multiple register operand!");
|
|
RegOp = MO.getReg();
|
|
#ifndef NDEBUG
|
|
break;
|
|
#endif
|
|
}
|
|
return RegOp;
|
|
}
|
|
|
|
/// isValNoAvailableAt - Return true if the val# of the specified interval
|
|
/// which reaches the given instruction also reaches the specified use index.
|
|
bool LiveIntervals::isValNoAvailableAt(const LiveInterval &li, MachineInstr *MI,
|
|
MachineInstrIndex UseIdx) const {
|
|
MachineInstrIndex Index = getInstructionIndex(MI);
|
|
VNInfo *ValNo = li.FindLiveRangeContaining(Index)->valno;
|
|
LiveInterval::const_iterator UI = li.FindLiveRangeContaining(UseIdx);
|
|
return UI != li.end() && UI->valno == ValNo;
|
|
}
|
|
|
|
/// isReMaterializable - Returns true if the definition MI of the specified
|
|
/// val# of the specified interval is re-materializable.
|
|
bool LiveIntervals::isReMaterializable(const LiveInterval &li,
|
|
const VNInfo *ValNo, MachineInstr *MI,
|
|
SmallVectorImpl<LiveInterval*> &SpillIs,
|
|
bool &isLoad) {
|
|
if (DisableReMat)
|
|
return false;
|
|
|
|
if (MI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF)
|
|
return true;
|
|
|
|
int FrameIdx = 0;
|
|
if (tii_->isLoadFromStackSlot(MI, FrameIdx) &&
|
|
mf_->getFrameInfo()->isImmutableObjectIndex(FrameIdx))
|
|
// FIXME: Let target specific isReallyTriviallyReMaterializable determines
|
|
// this but remember this is not safe to fold into a two-address
|
|
// instruction.
|
|
// This is a load from fixed stack slot. It can be rematerialized.
|
|
return true;
|
|
|
|
// If the target-specific rules don't identify an instruction as
|
|
// being trivially rematerializable, use some target-independent
|
|
// rules.
|
|
if (!MI->getDesc().isRematerializable() ||
|
|
!tii_->isTriviallyReMaterializable(MI)) {
|
|
if (!EnableAggressiveRemat)
|
|
return false;
|
|
|
|
// If the instruction accesses memory but the memoperands have been lost,
|
|
// we can't analyze it.
|
|
const TargetInstrDesc &TID = MI->getDesc();
|
|
if ((TID.mayLoad() || TID.mayStore()) && MI->memoperands_empty())
|
|
return false;
|
|
|
|
// Avoid instructions obviously unsafe for remat.
|
|
if (TID.hasUnmodeledSideEffects() || TID.isNotDuplicable())
|
|
return false;
|
|
|
|
// If the instruction accesses memory and the memory could be non-constant,
|
|
// assume the instruction is not rematerializable.
|
|
for (std::list<MachineMemOperand>::const_iterator
|
|
I = MI->memoperands_begin(), E = MI->memoperands_end(); I != E; ++I){
|
|
const MachineMemOperand &MMO = *I;
|
|
if (MMO.isVolatile() || MMO.isStore())
|
|
return false;
|
|
const Value *V = MMO.getValue();
|
|
if (!V)
|
|
return false;
|
|
if (const PseudoSourceValue *PSV = dyn_cast<PseudoSourceValue>(V)) {
|
|
if (!PSV->isConstant(mf_->getFrameInfo()))
|
|
return false;
|
|
} else if (!aa_->pointsToConstantMemory(V))
|
|
return false;
|
|
}
|
|
|
|
// If any of the registers accessed are non-constant, conservatively assume
|
|
// the instruction is not rematerializable.
|
|
unsigned ImpUse = 0;
|
|
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
|
|
const MachineOperand &MO = MI->getOperand(i);
|
|
if (MO.isReg()) {
|
|
unsigned Reg = MO.getReg();
|
|
if (Reg == 0)
|
|
continue;
|
|
if (TargetRegisterInfo::isPhysicalRegister(Reg))
|
|
return false;
|
|
|
|
// Only allow one def, and that in the first operand.
|
|
if (MO.isDef() != (i == 0))
|
|
return false;
|
|
|
|
// Only allow constant-valued registers.
|
|
bool IsLiveIn = mri_->isLiveIn(Reg);
|
|
MachineRegisterInfo::def_iterator I = mri_->def_begin(Reg),
|
|
E = mri_->def_end();
|
|
|
|
// For the def, it should be the only def of that register.
|
|
if (MO.isDef() && (next(I) != E || IsLiveIn))
|
|
return false;
|
|
|
|
if (MO.isUse()) {
|
|
// Only allow one use other register use, as that's all the
|
|
// remat mechanisms support currently.
|
|
if (Reg != li.reg) {
|
|
if (ImpUse == 0)
|
|
ImpUse = Reg;
|
|
else if (Reg != ImpUse)
|
|
return false;
|
|
}
|
|
// For the use, there should be only one associated def.
|
|
if (I != E && (next(I) != E || IsLiveIn))
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
unsigned ImpUse = getReMatImplicitUse(li, MI);
|
|
if (ImpUse) {
|
|
const LiveInterval &ImpLi = getInterval(ImpUse);
|
|
for (MachineRegisterInfo::use_iterator ri = mri_->use_begin(li.reg),
|
|
re = mri_->use_end(); ri != re; ++ri) {
|
|
MachineInstr *UseMI = &*ri;
|
|
MachineInstrIndex UseIdx = getInstructionIndex(UseMI);
|
|
if (li.FindLiveRangeContaining(UseIdx)->valno != ValNo)
|
|
continue;
|
|
if (!isValNoAvailableAt(ImpLi, MI, UseIdx))
|
|
return false;
|
|
}
|
|
|
|
// If a register operand of the re-materialized instruction is going to
|
|
// be spilled next, then it's not legal to re-materialize this instruction.
|
|
for (unsigned i = 0, e = SpillIs.size(); i != e; ++i)
|
|
if (ImpUse == SpillIs[i]->reg)
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/// isReMaterializable - Returns true if the definition MI of the specified
|
|
/// val# of the specified interval is re-materializable.
|
|
bool LiveIntervals::isReMaterializable(const LiveInterval &li,
|
|
const VNInfo *ValNo, MachineInstr *MI) {
|
|
SmallVector<LiveInterval*, 4> Dummy1;
|
|
bool Dummy2;
|
|
return isReMaterializable(li, ValNo, MI, Dummy1, Dummy2);
|
|
}
|
|
|
|
/// isReMaterializable - Returns true if every definition of MI of every
|
|
/// val# of the specified interval is re-materializable.
|
|
bool LiveIntervals::isReMaterializable(const LiveInterval &li,
|
|
SmallVectorImpl<LiveInterval*> &SpillIs,
|
|
bool &isLoad) {
|
|
isLoad = false;
|
|
for (LiveInterval::const_vni_iterator i = li.vni_begin(), e = li.vni_end();
|
|
i != e; ++i) {
|
|
const VNInfo *VNI = *i;
|
|
if (VNI->isUnused())
|
|
continue; // Dead val#.
|
|
// Is the def for the val# rematerializable?
|
|
if (!VNI->isDefAccurate())
|
|
return false;
|
|
MachineInstr *ReMatDefMI = getInstructionFromIndex(VNI->def);
|
|
bool DefIsLoad = false;
|
|
if (!ReMatDefMI ||
|
|
!isReMaterializable(li, VNI, ReMatDefMI, SpillIs, DefIsLoad))
|
|
return false;
|
|
isLoad |= DefIsLoad;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/// FilterFoldedOps - Filter out two-address use operands. Return
|
|
/// true if it finds any issue with the operands that ought to prevent
|
|
/// folding.
|
|
static bool FilterFoldedOps(MachineInstr *MI,
|
|
SmallVector<unsigned, 2> &Ops,
|
|
unsigned &MRInfo,
|
|
SmallVector<unsigned, 2> &FoldOps) {
|
|
MRInfo = 0;
|
|
for (unsigned i = 0, e = Ops.size(); i != e; ++i) {
|
|
unsigned OpIdx = Ops[i];
|
|
MachineOperand &MO = MI->getOperand(OpIdx);
|
|
// FIXME: fold subreg use.
|
|
if (MO.getSubReg())
|
|
return true;
|
|
if (MO.isDef())
|
|
MRInfo |= (unsigned)VirtRegMap::isMod;
|
|
else {
|
|
// Filter out two-address use operand(s).
|
|
if (MI->isRegTiedToDefOperand(OpIdx)) {
|
|
MRInfo = VirtRegMap::isModRef;
|
|
continue;
|
|
}
|
|
MRInfo |= (unsigned)VirtRegMap::isRef;
|
|
}
|
|
FoldOps.push_back(OpIdx);
|
|
}
|
|
return false;
|
|
}
|
|
|
|
|
|
/// tryFoldMemoryOperand - Attempts to fold either a spill / restore from
|
|
/// slot / to reg or any rematerialized load into ith operand of specified
|
|
/// MI. If it is successul, MI is updated with the newly created MI and
|
|
/// returns true.
|
|
bool LiveIntervals::tryFoldMemoryOperand(MachineInstr* &MI,
|
|
VirtRegMap &vrm, MachineInstr *DefMI,
|
|
MachineInstrIndex InstrIdx,
|
|
SmallVector<unsigned, 2> &Ops,
|
|
bool isSS, int Slot, unsigned Reg) {
|
|
// If it is an implicit def instruction, just delete it.
|
|
if (MI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF) {
|
|
RemoveMachineInstrFromMaps(MI);
|
|
vrm.RemoveMachineInstrFromMaps(MI);
|
|
MI->eraseFromParent();
|
|
++numFolds;
|
|
return true;
|
|
}
|
|
|
|
// Filter the list of operand indexes that are to be folded. Abort if
|
|
// any operand will prevent folding.
|
|
unsigned MRInfo = 0;
|
|
SmallVector<unsigned, 2> FoldOps;
|
|
if (FilterFoldedOps(MI, Ops, MRInfo, FoldOps))
|
|
return false;
|
|
|
|
// The only time it's safe to fold into a two address instruction is when
|
|
// it's folding reload and spill from / into a spill stack slot.
|
|
if (DefMI && (MRInfo & VirtRegMap::isMod))
|
|
return false;
|
|
|
|
MachineInstr *fmi = isSS ? tii_->foldMemoryOperand(*mf_, MI, FoldOps, Slot)
|
|
: tii_->foldMemoryOperand(*mf_, MI, FoldOps, DefMI);
|
|
if (fmi) {
|
|
// Remember this instruction uses the spill slot.
|
|
if (isSS) vrm.addSpillSlotUse(Slot, fmi);
|
|
|
|
// Attempt to fold the memory reference into the instruction. If
|
|
// we can do this, we don't need to insert spill code.
|
|
MachineBasicBlock &MBB = *MI->getParent();
|
|
if (isSS && !mf_->getFrameInfo()->isImmutableObjectIndex(Slot))
|
|
vrm.virtFolded(Reg, MI, fmi, (VirtRegMap::ModRef)MRInfo);
|
|
vrm.transferSpillPts(MI, fmi);
|
|
vrm.transferRestorePts(MI, fmi);
|
|
vrm.transferEmergencySpills(MI, fmi);
|
|
mi2iMap_.erase(MI);
|
|
i2miMap_[InstrIdx.getVecIndex()] = fmi;
|
|
mi2iMap_[fmi] = InstrIdx;
|
|
MI = MBB.insert(MBB.erase(MI), fmi);
|
|
++numFolds;
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/// canFoldMemoryOperand - Returns true if the specified load / store
|
|
/// folding is possible.
|
|
bool LiveIntervals::canFoldMemoryOperand(MachineInstr *MI,
|
|
SmallVector<unsigned, 2> &Ops,
|
|
bool ReMat) const {
|
|
// Filter the list of operand indexes that are to be folded. Abort if
|
|
// any operand will prevent folding.
|
|
unsigned MRInfo = 0;
|
|
SmallVector<unsigned, 2> FoldOps;
|
|
if (FilterFoldedOps(MI, Ops, MRInfo, FoldOps))
|
|
return false;
|
|
|
|
// It's only legal to remat for a use, not a def.
|
|
if (ReMat && (MRInfo & VirtRegMap::isMod))
|
|
return false;
|
|
|
|
return tii_->canFoldMemoryOperand(MI, FoldOps);
|
|
}
|
|
|
|
bool LiveIntervals::intervalIsInOneMBB(const LiveInterval &li) const {
|
|
SmallPtrSet<MachineBasicBlock*, 4> MBBs;
|
|
for (LiveInterval::Ranges::const_iterator
|
|
I = li.ranges.begin(), E = li.ranges.end(); I != E; ++I) {
|
|
std::vector<IdxMBBPair>::const_iterator II =
|
|
std::lower_bound(Idx2MBBMap.begin(), Idx2MBBMap.end(), I->start);
|
|
if (II == Idx2MBBMap.end())
|
|
continue;
|
|
if (I->end > II->first) // crossing a MBB.
|
|
return false;
|
|
MBBs.insert(II->second);
|
|
if (MBBs.size() > 1)
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/// rewriteImplicitOps - Rewrite implicit use operands of MI (i.e. uses of
|
|
/// interval on to-be re-materialized operands of MI) with new register.
|
|
void LiveIntervals::rewriteImplicitOps(const LiveInterval &li,
|
|
MachineInstr *MI, unsigned NewVReg,
|
|
VirtRegMap &vrm) {
|
|
// There is an implicit use. That means one of the other operand is
|
|
// being remat'ed and the remat'ed instruction has li.reg as an
|
|
// use operand. Make sure we rewrite that as well.
|
|
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
|
|
MachineOperand &MO = MI->getOperand(i);
|
|
if (!MO.isReg())
|
|
continue;
|
|
unsigned Reg = MO.getReg();
|
|
if (Reg == 0 || TargetRegisterInfo::isPhysicalRegister(Reg))
|
|
continue;
|
|
if (!vrm.isReMaterialized(Reg))
|
|
continue;
|
|
MachineInstr *ReMatMI = vrm.getReMaterializedMI(Reg);
|
|
MachineOperand *UseMO = ReMatMI->findRegisterUseOperand(li.reg);
|
|
if (UseMO)
|
|
UseMO->setReg(NewVReg);
|
|
}
|
|
}
|
|
|
|
/// rewriteInstructionForSpills, rewriteInstructionsForSpills - Helper functions
|
|
/// for addIntervalsForSpills to rewrite uses / defs for the given live range.
|
|
bool LiveIntervals::
|
|
rewriteInstructionForSpills(const LiveInterval &li, const VNInfo *VNI,
|
|
bool TrySplit, MachineInstrIndex index, MachineInstrIndex end,
|
|
MachineInstr *MI,
|
|
MachineInstr *ReMatOrigDefMI, MachineInstr *ReMatDefMI,
|
|
unsigned Slot, int LdSlot,
|
|
bool isLoad, bool isLoadSS, bool DefIsReMat, bool CanDelete,
|
|
VirtRegMap &vrm,
|
|
const TargetRegisterClass* rc,
|
|
SmallVector<int, 4> &ReMatIds,
|
|
const MachineLoopInfo *loopInfo,
|
|
unsigned &NewVReg, unsigned ImpUse, bool &HasDef, bool &HasUse,
|
|
DenseMap<unsigned,unsigned> &MBBVRegsMap,
|
|
std::vector<LiveInterval*> &NewLIs) {
|
|
bool CanFold = false;
|
|
RestartInstruction:
|
|
for (unsigned i = 0; i != MI->getNumOperands(); ++i) {
|
|
MachineOperand& mop = MI->getOperand(i);
|
|
if (!mop.isReg())
|
|
continue;
|
|
unsigned Reg = mop.getReg();
|
|
unsigned RegI = Reg;
|
|
if (Reg == 0 || TargetRegisterInfo::isPhysicalRegister(Reg))
|
|
continue;
|
|
if (Reg != li.reg)
|
|
continue;
|
|
|
|
bool TryFold = !DefIsReMat;
|
|
bool FoldSS = true; // Default behavior unless it's a remat.
|
|
int FoldSlot = Slot;
|
|
if (DefIsReMat) {
|
|
// If this is the rematerializable definition MI itself and
|
|
// all of its uses are rematerialized, simply delete it.
|
|
if (MI == ReMatOrigDefMI && CanDelete) {
|
|
DEBUG(errs() << "\t\t\t\tErasing re-materlizable def: "
|
|
<< MI << '\n');
|
|
RemoveMachineInstrFromMaps(MI);
|
|
vrm.RemoveMachineInstrFromMaps(MI);
|
|
MI->eraseFromParent();
|
|
break;
|
|
}
|
|
|
|
// If def for this use can't be rematerialized, then try folding.
|
|
// If def is rematerializable and it's a load, also try folding.
|
|
TryFold = !ReMatDefMI || (ReMatDefMI && (MI == ReMatOrigDefMI || isLoad));
|
|
if (isLoad) {
|
|
// Try fold loads (from stack slot, constant pool, etc.) into uses.
|
|
FoldSS = isLoadSS;
|
|
FoldSlot = LdSlot;
|
|
}
|
|
}
|
|
|
|
// Scan all of the operands of this instruction rewriting operands
|
|
// to use NewVReg instead of li.reg as appropriate. We do this for
|
|
// two reasons:
|
|
//
|
|
// 1. If the instr reads the same spilled vreg multiple times, we
|
|
// want to reuse the NewVReg.
|
|
// 2. If the instr is a two-addr instruction, we are required to
|
|
// keep the src/dst regs pinned.
|
|
//
|
|
// Keep track of whether we replace a use and/or def so that we can
|
|
// create the spill interval with the appropriate range.
|
|
|
|
HasUse = mop.isUse();
|
|
HasDef = mop.isDef();
|
|
SmallVector<unsigned, 2> Ops;
|
|
Ops.push_back(i);
|
|
for (unsigned j = i+1, e = MI->getNumOperands(); j != e; ++j) {
|
|
const MachineOperand &MOj = MI->getOperand(j);
|
|
if (!MOj.isReg())
|
|
continue;
|
|
unsigned RegJ = MOj.getReg();
|
|
if (RegJ == 0 || TargetRegisterInfo::isPhysicalRegister(RegJ))
|
|
continue;
|
|
if (RegJ == RegI) {
|
|
Ops.push_back(j);
|
|
if (!MOj.isUndef()) {
|
|
HasUse |= MOj.isUse();
|
|
HasDef |= MOj.isDef();
|
|
}
|
|
}
|
|
}
|
|
|
|
// Create a new virtual register for the spill interval.
|
|
// Create the new register now so we can map the fold instruction
|
|
// to the new register so when it is unfolded we get the correct
|
|
// answer.
|
|
bool CreatedNewVReg = false;
|
|
if (NewVReg == 0) {
|
|
NewVReg = mri_->createVirtualRegister(rc);
|
|
vrm.grow();
|
|
CreatedNewVReg = true;
|
|
}
|
|
|
|
if (!TryFold)
|
|
CanFold = false;
|
|
else {
|
|
// Do not fold load / store here if we are splitting. We'll find an
|
|
// optimal point to insert a load / store later.
|
|
if (!TrySplit) {
|
|
if (tryFoldMemoryOperand(MI, vrm, ReMatDefMI, index,
|
|
Ops, FoldSS, FoldSlot, NewVReg)) {
|
|
// Folding the load/store can completely change the instruction in
|
|
// unpredictable ways, rescan it from the beginning.
|
|
|
|
if (FoldSS) {
|
|
// We need to give the new vreg the same stack slot as the
|
|
// spilled interval.
|
|
vrm.assignVirt2StackSlot(NewVReg, FoldSlot);
|
|
}
|
|
|
|
HasUse = false;
|
|
HasDef = false;
|
|
CanFold = false;
|
|
if (isNotInMIMap(MI))
|
|
break;
|
|
goto RestartInstruction;
|
|
}
|
|
} else {
|
|
// We'll try to fold it later if it's profitable.
|
|
CanFold = canFoldMemoryOperand(MI, Ops, DefIsReMat);
|
|
}
|
|
}
|
|
|
|
mop.setReg(NewVReg);
|
|
if (mop.isImplicit())
|
|
rewriteImplicitOps(li, MI, NewVReg, vrm);
|
|
|
|
// Reuse NewVReg for other reads.
|
|
for (unsigned j = 0, e = Ops.size(); j != e; ++j) {
|
|
MachineOperand &mopj = MI->getOperand(Ops[j]);
|
|
mopj.setReg(NewVReg);
|
|
if (mopj.isImplicit())
|
|
rewriteImplicitOps(li, MI, NewVReg, vrm);
|
|
}
|
|
|
|
if (CreatedNewVReg) {
|
|
if (DefIsReMat) {
|
|
vrm.setVirtIsReMaterialized(NewVReg, ReMatDefMI);
|
|
if (ReMatIds[VNI->id] == VirtRegMap::MAX_STACK_SLOT) {
|
|
// Each valnum may have its own remat id.
|
|
ReMatIds[VNI->id] = vrm.assignVirtReMatId(NewVReg);
|
|
} else {
|
|
vrm.assignVirtReMatId(NewVReg, ReMatIds[VNI->id]);
|
|
}
|
|
if (!CanDelete || (HasUse && HasDef)) {
|
|
// If this is a two-addr instruction then its use operands are
|
|
// rematerializable but its def is not. It should be assigned a
|
|
// stack slot.
|
|
vrm.assignVirt2StackSlot(NewVReg, Slot);
|
|
}
|
|
} else {
|
|
vrm.assignVirt2StackSlot(NewVReg, Slot);
|
|
}
|
|
} else if (HasUse && HasDef &&
|
|
vrm.getStackSlot(NewVReg) == VirtRegMap::NO_STACK_SLOT) {
|
|
// If this interval hasn't been assigned a stack slot (because earlier
|
|
// def is a deleted remat def), do it now.
|
|
assert(Slot != VirtRegMap::NO_STACK_SLOT);
|
|
vrm.assignVirt2StackSlot(NewVReg, Slot);
|
|
}
|
|
|
|
// Re-matting an instruction with virtual register use. Add the
|
|
// register as an implicit use on the use MI.
|
|
if (DefIsReMat && ImpUse)
|
|
MI->addOperand(MachineOperand::CreateReg(ImpUse, false, true));
|
|
|
|
// Create a new register interval for this spill / remat.
|
|
LiveInterval &nI = getOrCreateInterval(NewVReg);
|
|
if (CreatedNewVReg) {
|
|
NewLIs.push_back(&nI);
|
|
MBBVRegsMap.insert(std::make_pair(MI->getParent()->getNumber(), NewVReg));
|
|
if (TrySplit)
|
|
vrm.setIsSplitFromReg(NewVReg, li.reg);
|
|
}
|
|
|
|
if (HasUse) {
|
|
if (CreatedNewVReg) {
|
|
LiveRange LR(getLoadIndex(index), getNextSlot(getUseIndex(index)),
|
|
nI.getNextValue(MachineInstrIndex(), 0, false,
|
|
VNInfoAllocator));
|
|
DEBUG(errs() << " +" << LR);
|
|
nI.addRange(LR);
|
|
} else {
|
|
// Extend the split live interval to this def / use.
|
|
MachineInstrIndex End = getNextSlot(getUseIndex(index));
|
|
LiveRange LR(nI.ranges[nI.ranges.size()-1].end, End,
|
|
nI.getValNumInfo(nI.getNumValNums()-1));
|
|
DEBUG(errs() << " +" << LR);
|
|
nI.addRange(LR);
|
|
}
|
|
}
|
|
if (HasDef) {
|
|
LiveRange LR(getDefIndex(index), getStoreIndex(index),
|
|
nI.getNextValue(MachineInstrIndex(), 0, false,
|
|
VNInfoAllocator));
|
|
DEBUG(errs() << " +" << LR);
|
|
nI.addRange(LR);
|
|
}
|
|
|
|
DEBUG({
|
|
errs() << "\t\t\t\tAdded new interval: ";
|
|
nI.print(errs(), tri_);
|
|
errs() << '\n';
|
|
});
|
|
}
|
|
return CanFold;
|
|
}
|
|
bool LiveIntervals::anyKillInMBBAfterIdx(const LiveInterval &li,
|
|
const VNInfo *VNI,
|
|
MachineBasicBlock *MBB,
|
|
MachineInstrIndex Idx) const {
|
|
MachineInstrIndex End = getMBBEndIdx(MBB);
|
|
for (unsigned j = 0, ee = VNI->kills.size(); j != ee; ++j) {
|
|
if (VNI->kills[j].isPHIIndex())
|
|
continue;
|
|
|
|
MachineInstrIndex KillIdx = VNI->kills[j];
|
|
if (KillIdx > Idx && KillIdx < End)
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/// RewriteInfo - Keep track of machine instrs that will be rewritten
|
|
/// during spilling.
|
|
namespace {
|
|
struct RewriteInfo {
|
|
MachineInstrIndex Index;
|
|
MachineInstr *MI;
|
|
bool HasUse;
|
|
bool HasDef;
|
|
RewriteInfo(MachineInstrIndex i, MachineInstr *mi, bool u, bool d)
|
|
: Index(i), MI(mi), HasUse(u), HasDef(d) {}
|
|
};
|
|
|
|
struct RewriteInfoCompare {
|
|
bool operator()(const RewriteInfo &LHS, const RewriteInfo &RHS) const {
|
|
return LHS.Index < RHS.Index;
|
|
}
|
|
};
|
|
}
|
|
|
|
void LiveIntervals::
|
|
rewriteInstructionsForSpills(const LiveInterval &li, bool TrySplit,
|
|
LiveInterval::Ranges::const_iterator &I,
|
|
MachineInstr *ReMatOrigDefMI, MachineInstr *ReMatDefMI,
|
|
unsigned Slot, int LdSlot,
|
|
bool isLoad, bool isLoadSS, bool DefIsReMat, bool CanDelete,
|
|
VirtRegMap &vrm,
|
|
const TargetRegisterClass* rc,
|
|
SmallVector<int, 4> &ReMatIds,
|
|
const MachineLoopInfo *loopInfo,
|
|
BitVector &SpillMBBs,
|
|
DenseMap<unsigned, std::vector<SRInfo> > &SpillIdxes,
|
|
BitVector &RestoreMBBs,
|
|
DenseMap<unsigned, std::vector<SRInfo> > &RestoreIdxes,
|
|
DenseMap<unsigned,unsigned> &MBBVRegsMap,
|
|
std::vector<LiveInterval*> &NewLIs) {
|
|
bool AllCanFold = true;
|
|
unsigned NewVReg = 0;
|
|
MachineInstrIndex start = getBaseIndex(I->start);
|
|
MachineInstrIndex end = getNextIndex(getBaseIndex(getPrevSlot(I->end)));
|
|
|
|
// First collect all the def / use in this live range that will be rewritten.
|
|
// Make sure they are sorted according to instruction index.
|
|
std::vector<RewriteInfo> RewriteMIs;
|
|
for (MachineRegisterInfo::reg_iterator ri = mri_->reg_begin(li.reg),
|
|
re = mri_->reg_end(); ri != re; ) {
|
|
MachineInstr *MI = &*ri;
|
|
MachineOperand &O = ri.getOperand();
|
|
++ri;
|
|
assert(!O.isImplicit() && "Spilling register that's used as implicit use?");
|
|
MachineInstrIndex index = getInstructionIndex(MI);
|
|
if (index < start || index >= end)
|
|
continue;
|
|
|
|
if (O.isUndef())
|
|
// Must be defined by an implicit def. It should not be spilled. Note,
|
|
// this is for correctness reason. e.g.
|
|
// 8 %reg1024<def> = IMPLICIT_DEF
|
|
// 12 %reg1024<def> = INSERT_SUBREG %reg1024<kill>, %reg1025, 2
|
|
// The live range [12, 14) are not part of the r1024 live interval since
|
|
// it's defined by an implicit def. It will not conflicts with live
|
|
// interval of r1025. Now suppose both registers are spilled, you can
|
|
// easily see a situation where both registers are reloaded before
|
|
// the INSERT_SUBREG and both target registers that would overlap.
|
|
continue;
|
|
RewriteMIs.push_back(RewriteInfo(index, MI, O.isUse(), O.isDef()));
|
|
}
|
|
std::sort(RewriteMIs.begin(), RewriteMIs.end(), RewriteInfoCompare());
|
|
|
|
unsigned ImpUse = DefIsReMat ? getReMatImplicitUse(li, ReMatDefMI) : 0;
|
|
// Now rewrite the defs and uses.
|
|
for (unsigned i = 0, e = RewriteMIs.size(); i != e; ) {
|
|
RewriteInfo &rwi = RewriteMIs[i];
|
|
++i;
|
|
MachineInstrIndex index = rwi.Index;
|
|
bool MIHasUse = rwi.HasUse;
|
|
bool MIHasDef = rwi.HasDef;
|
|
MachineInstr *MI = rwi.MI;
|
|
// If MI def and/or use the same register multiple times, then there
|
|
// are multiple entries.
|
|
unsigned NumUses = MIHasUse;
|
|
while (i != e && RewriteMIs[i].MI == MI) {
|
|
assert(RewriteMIs[i].Index == index);
|
|
bool isUse = RewriteMIs[i].HasUse;
|
|
if (isUse) ++NumUses;
|
|
MIHasUse |= isUse;
|
|
MIHasDef |= RewriteMIs[i].HasDef;
|
|
++i;
|
|
}
|
|
MachineBasicBlock *MBB = MI->getParent();
|
|
|
|
if (ImpUse && MI != ReMatDefMI) {
|
|
// Re-matting an instruction with virtual register use. Update the
|
|
// register interval's spill weight to HUGE_VALF to prevent it from
|
|
// being spilled.
|
|
LiveInterval &ImpLi = getInterval(ImpUse);
|
|
ImpLi.weight = HUGE_VALF;
|
|
}
|
|
|
|
unsigned MBBId = MBB->getNumber();
|
|
unsigned ThisVReg = 0;
|
|
if (TrySplit) {
|
|
DenseMap<unsigned,unsigned>::iterator NVI = MBBVRegsMap.find(MBBId);
|
|
if (NVI != MBBVRegsMap.end()) {
|
|
ThisVReg = NVI->second;
|
|
// One common case:
|
|
// x = use
|
|
// ...
|
|
// ...
|
|
// def = ...
|
|
// = use
|
|
// It's better to start a new interval to avoid artifically
|
|
// extend the new interval.
|
|
if (MIHasDef && !MIHasUse) {
|
|
MBBVRegsMap.erase(MBB->getNumber());
|
|
ThisVReg = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
bool IsNew = ThisVReg == 0;
|
|
if (IsNew) {
|
|
// This ends the previous live interval. If all of its def / use
|
|
// can be folded, give it a low spill weight.
|
|
if (NewVReg && TrySplit && AllCanFold) {
|
|
LiveInterval &nI = getOrCreateInterval(NewVReg);
|
|
nI.weight /= 10.0F;
|
|
}
|
|
AllCanFold = true;
|
|
}
|
|
NewVReg = ThisVReg;
|
|
|
|
bool HasDef = false;
|
|
bool HasUse = false;
|
|
bool CanFold = rewriteInstructionForSpills(li, I->valno, TrySplit,
|
|
index, end, MI, ReMatOrigDefMI, ReMatDefMI,
|
|
Slot, LdSlot, isLoad, isLoadSS, DefIsReMat,
|
|
CanDelete, vrm, rc, ReMatIds, loopInfo, NewVReg,
|
|
ImpUse, HasDef, HasUse, MBBVRegsMap, NewLIs);
|
|
if (!HasDef && !HasUse)
|
|
continue;
|
|
|
|
AllCanFold &= CanFold;
|
|
|
|
// Update weight of spill interval.
|
|
LiveInterval &nI = getOrCreateInterval(NewVReg);
|
|
if (!TrySplit) {
|
|
// The spill weight is now infinity as it cannot be spilled again.
|
|
nI.weight = HUGE_VALF;
|
|
continue;
|
|
}
|
|
|
|
// Keep track of the last def and first use in each MBB.
|
|
if (HasDef) {
|
|
if (MI != ReMatOrigDefMI || !CanDelete) {
|
|
bool HasKill = false;
|
|
if (!HasUse)
|
|
HasKill = anyKillInMBBAfterIdx(li, I->valno, MBB, getDefIndex(index));
|
|
else {
|
|
// If this is a two-address code, then this index starts a new VNInfo.
|
|
const VNInfo *VNI = li.findDefinedVNInfoForRegInt(getDefIndex(index));
|
|
if (VNI)
|
|
HasKill = anyKillInMBBAfterIdx(li, VNI, MBB, getDefIndex(index));
|
|
}
|
|
DenseMap<unsigned, std::vector<SRInfo> >::iterator SII =
|
|
SpillIdxes.find(MBBId);
|
|
if (!HasKill) {
|
|
if (SII == SpillIdxes.end()) {
|
|
std::vector<SRInfo> S;
|
|
S.push_back(SRInfo(index, NewVReg, true));
|
|
SpillIdxes.insert(std::make_pair(MBBId, S));
|
|
} else if (SII->second.back().vreg != NewVReg) {
|
|
SII->second.push_back(SRInfo(index, NewVReg, true));
|
|
} else if (index > SII->second.back().index) {
|
|
// If there is an earlier def and this is a two-address
|
|
// instruction, then it's not possible to fold the store (which
|
|
// would also fold the load).
|
|
SRInfo &Info = SII->second.back();
|
|
Info.index = index;
|
|
Info.canFold = !HasUse;
|
|
}
|
|
SpillMBBs.set(MBBId);
|
|
} else if (SII != SpillIdxes.end() &&
|
|
SII->second.back().vreg == NewVReg &&
|
|
index > SII->second.back().index) {
|
|
// There is an earlier def that's not killed (must be two-address).
|
|
// The spill is no longer needed.
|
|
SII->second.pop_back();
|
|
if (SII->second.empty()) {
|
|
SpillIdxes.erase(MBBId);
|
|
SpillMBBs.reset(MBBId);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (HasUse) {
|
|
DenseMap<unsigned, std::vector<SRInfo> >::iterator SII =
|
|
SpillIdxes.find(MBBId);
|
|
if (SII != SpillIdxes.end() &&
|
|
SII->second.back().vreg == NewVReg &&
|
|
index > SII->second.back().index)
|
|
// Use(s) following the last def, it's not safe to fold the spill.
|
|
SII->second.back().canFold = false;
|
|
DenseMap<unsigned, std::vector<SRInfo> >::iterator RII =
|
|
RestoreIdxes.find(MBBId);
|
|
if (RII != RestoreIdxes.end() && RII->second.back().vreg == NewVReg)
|
|
// If we are splitting live intervals, only fold if it's the first
|
|
// use and there isn't another use later in the MBB.
|
|
RII->second.back().canFold = false;
|
|
else if (IsNew) {
|
|
// Only need a reload if there isn't an earlier def / use.
|
|
if (RII == RestoreIdxes.end()) {
|
|
std::vector<SRInfo> Infos;
|
|
Infos.push_back(SRInfo(index, NewVReg, true));
|
|
RestoreIdxes.insert(std::make_pair(MBBId, Infos));
|
|
} else {
|
|
RII->second.push_back(SRInfo(index, NewVReg, true));
|
|
}
|
|
RestoreMBBs.set(MBBId);
|
|
}
|
|
}
|
|
|
|
// Update spill weight.
|
|
unsigned loopDepth = loopInfo->getLoopDepth(MBB);
|
|
nI.weight += getSpillWeight(HasDef, HasUse, loopDepth);
|
|
}
|
|
|
|
if (NewVReg && TrySplit && AllCanFold) {
|
|
// If all of its def / use can be folded, give it a low spill weight.
|
|
LiveInterval &nI = getOrCreateInterval(NewVReg);
|
|
nI.weight /= 10.0F;
|
|
}
|
|
}
|
|
|
|
bool LiveIntervals::alsoFoldARestore(int Id, MachineInstrIndex index,
|
|
unsigned vr, BitVector &RestoreMBBs,
|
|
DenseMap<unsigned,std::vector<SRInfo> > &RestoreIdxes) {
|
|
if (!RestoreMBBs[Id])
|
|
return false;
|
|
std::vector<SRInfo> &Restores = RestoreIdxes[Id];
|
|
for (unsigned i = 0, e = Restores.size(); i != e; ++i)
|
|
if (Restores[i].index == index &&
|
|
Restores[i].vreg == vr &&
|
|
Restores[i].canFold)
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
void LiveIntervals::eraseRestoreInfo(int Id, MachineInstrIndex index,
|
|
unsigned vr, BitVector &RestoreMBBs,
|
|
DenseMap<unsigned,std::vector<SRInfo> > &RestoreIdxes) {
|
|
if (!RestoreMBBs[Id])
|
|
return;
|
|
std::vector<SRInfo> &Restores = RestoreIdxes[Id];
|
|
for (unsigned i = 0, e = Restores.size(); i != e; ++i)
|
|
if (Restores[i].index == index && Restores[i].vreg)
|
|
Restores[i].index = MachineInstrIndex();
|
|
}
|
|
|
|
/// handleSpilledImpDefs - Remove IMPLICIT_DEF instructions which are being
|
|
/// spilled and create empty intervals for their uses.
|
|
void
|
|
LiveIntervals::handleSpilledImpDefs(const LiveInterval &li, VirtRegMap &vrm,
|
|
const TargetRegisterClass* rc,
|
|
std::vector<LiveInterval*> &NewLIs) {
|
|
for (MachineRegisterInfo::reg_iterator ri = mri_->reg_begin(li.reg),
|
|
re = mri_->reg_end(); ri != re; ) {
|
|
MachineOperand &O = ri.getOperand();
|
|
MachineInstr *MI = &*ri;
|
|
++ri;
|
|
if (O.isDef()) {
|
|
assert(MI->getOpcode() == TargetInstrInfo::IMPLICIT_DEF &&
|
|
"Register def was not rewritten?");
|
|
RemoveMachineInstrFromMaps(MI);
|
|
vrm.RemoveMachineInstrFromMaps(MI);
|
|
MI->eraseFromParent();
|
|
} else {
|
|
// This must be an use of an implicit_def so it's not part of the live
|
|
// interval. Create a new empty live interval for it.
|
|
// FIXME: Can we simply erase some of the instructions? e.g. Stores?
|
|
unsigned NewVReg = mri_->createVirtualRegister(rc);
|
|
vrm.grow();
|
|
vrm.setIsImplicitlyDefined(NewVReg);
|
|
NewLIs.push_back(&getOrCreateInterval(NewVReg));
|
|
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
|
|
MachineOperand &MO = MI->getOperand(i);
|
|
if (MO.isReg() && MO.getReg() == li.reg) {
|
|
MO.setReg(NewVReg);
|
|
MO.setIsUndef();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
std::vector<LiveInterval*> LiveIntervals::
|
|
addIntervalsForSpillsFast(const LiveInterval &li,
|
|
const MachineLoopInfo *loopInfo,
|
|
VirtRegMap &vrm) {
|
|
unsigned slot = vrm.assignVirt2StackSlot(li.reg);
|
|
|
|
std::vector<LiveInterval*> added;
|
|
|
|
assert(li.weight != HUGE_VALF &&
|
|
"attempt to spill already spilled interval!");
|
|
|
|
DEBUG({
|
|
errs() << "\t\t\t\tadding intervals for spills for interval: ";
|
|
li.dump();
|
|
errs() << '\n';
|
|
});
|
|
|
|
const TargetRegisterClass* rc = mri_->getRegClass(li.reg);
|
|
|
|
MachineRegisterInfo::reg_iterator RI = mri_->reg_begin(li.reg);
|
|
while (RI != mri_->reg_end()) {
|
|
MachineInstr* MI = &*RI;
|
|
|
|
SmallVector<unsigned, 2> Indices;
|
|
bool HasUse = false;
|
|
bool HasDef = false;
|
|
|
|
for (unsigned i = 0; i != MI->getNumOperands(); ++i) {
|
|
MachineOperand& mop = MI->getOperand(i);
|
|
if (!mop.isReg() || mop.getReg() != li.reg) continue;
|
|
|
|
HasUse |= MI->getOperand(i).isUse();
|
|
HasDef |= MI->getOperand(i).isDef();
|
|
|
|
Indices.push_back(i);
|
|
}
|
|
|
|
if (!tryFoldMemoryOperand(MI, vrm, NULL, getInstructionIndex(MI),
|
|
Indices, true, slot, li.reg)) {
|
|
unsigned NewVReg = mri_->createVirtualRegister(rc);
|
|
vrm.grow();
|
|
vrm.assignVirt2StackSlot(NewVReg, slot);
|
|
|
|
// create a new register for this spill
|
|
LiveInterval &nI = getOrCreateInterval(NewVReg);
|
|
|
|
// the spill weight is now infinity as it
|
|
// cannot be spilled again
|
|
nI.weight = HUGE_VALF;
|
|
|
|
// Rewrite register operands to use the new vreg.
|
|
for (SmallVectorImpl<unsigned>::iterator I = Indices.begin(),
|
|
E = Indices.end(); I != E; ++I) {
|
|
MI->getOperand(*I).setReg(NewVReg);
|
|
|
|
if (MI->getOperand(*I).isUse())
|
|
MI->getOperand(*I).setIsKill(true);
|
|
}
|
|
|
|
// Fill in the new live interval.
|
|
MachineInstrIndex index = getInstructionIndex(MI);
|
|
if (HasUse) {
|
|
LiveRange LR(getLoadIndex(index), getUseIndex(index),
|
|
nI.getNextValue(MachineInstrIndex(), 0, false,
|
|
getVNInfoAllocator()));
|
|
DEBUG(errs() << " +" << LR);
|
|
nI.addRange(LR);
|
|
vrm.addRestorePoint(NewVReg, MI);
|
|
}
|
|
if (HasDef) {
|
|
LiveRange LR(getDefIndex(index), getStoreIndex(index),
|
|
nI.getNextValue(MachineInstrIndex(), 0, false,
|
|
getVNInfoAllocator()));
|
|
DEBUG(errs() << " +" << LR);
|
|
nI.addRange(LR);
|
|
vrm.addSpillPoint(NewVReg, true, MI);
|
|
}
|
|
|
|
added.push_back(&nI);
|
|
|
|
DEBUG({
|
|
errs() << "\t\t\t\tadded new interval: ";
|
|
nI.dump();
|
|
errs() << '\n';
|
|
});
|
|
}
|
|
|
|
|
|
RI = mri_->reg_begin(li.reg);
|
|
}
|
|
|
|
return added;
|
|
}
|
|
|
|
std::vector<LiveInterval*> LiveIntervals::
|
|
addIntervalsForSpills(const LiveInterval &li,
|
|
SmallVectorImpl<LiveInterval*> &SpillIs,
|
|
const MachineLoopInfo *loopInfo, VirtRegMap &vrm) {
|
|
|
|
if (EnableFastSpilling)
|
|
return addIntervalsForSpillsFast(li, loopInfo, vrm);
|
|
|
|
assert(li.weight != HUGE_VALF &&
|
|
"attempt to spill already spilled interval!");
|
|
|
|
DEBUG({
|
|
errs() << "\t\t\t\tadding intervals for spills for interval: ";
|
|
li.print(errs(), tri_);
|
|
errs() << '\n';
|
|
});
|
|
|
|
// Each bit specify whether a spill is required in the MBB.
|
|
BitVector SpillMBBs(mf_->getNumBlockIDs());
|
|
DenseMap<unsigned, std::vector<SRInfo> > SpillIdxes;
|
|
BitVector RestoreMBBs(mf_->getNumBlockIDs());
|
|
DenseMap<unsigned, std::vector<SRInfo> > RestoreIdxes;
|
|
DenseMap<unsigned,unsigned> MBBVRegsMap;
|
|
std::vector<LiveInterval*> NewLIs;
|
|
const TargetRegisterClass* rc = mri_->getRegClass(li.reg);
|
|
|
|
unsigned NumValNums = li.getNumValNums();
|
|
SmallVector<MachineInstr*, 4> ReMatDefs;
|
|
ReMatDefs.resize(NumValNums, NULL);
|
|
SmallVector<MachineInstr*, 4> ReMatOrigDefs;
|
|
ReMatOrigDefs.resize(NumValNums, NULL);
|
|
SmallVector<int, 4> ReMatIds;
|
|
ReMatIds.resize(NumValNums, VirtRegMap::MAX_STACK_SLOT);
|
|
BitVector ReMatDelete(NumValNums);
|
|
unsigned Slot = VirtRegMap::MAX_STACK_SLOT;
|
|
|
|
// Spilling a split live interval. It cannot be split any further. Also,
|
|
// it's also guaranteed to be a single val# / range interval.
|
|
if (vrm.getPreSplitReg(li.reg)) {
|
|
vrm.setIsSplitFromReg(li.reg, 0);
|
|
// Unset the split kill marker on the last use.
|
|
MachineInstrIndex KillIdx = vrm.getKillPoint(li.reg);
|
|
if (KillIdx != MachineInstrIndex()) {
|
|
MachineInstr *KillMI = getInstructionFromIndex(KillIdx);
|
|
assert(KillMI && "Last use disappeared?");
|
|
int KillOp = KillMI->findRegisterUseOperandIdx(li.reg, true);
|
|
assert(KillOp != -1 && "Last use disappeared?");
|
|
KillMI->getOperand(KillOp).setIsKill(false);
|
|
}
|
|
vrm.removeKillPoint(li.reg);
|
|
bool DefIsReMat = vrm.isReMaterialized(li.reg);
|
|
Slot = vrm.getStackSlot(li.reg);
|
|
assert(Slot != VirtRegMap::MAX_STACK_SLOT);
|
|
MachineInstr *ReMatDefMI = DefIsReMat ?
|
|
vrm.getReMaterializedMI(li.reg) : NULL;
|
|
int LdSlot = 0;
|
|
bool isLoadSS = DefIsReMat && tii_->isLoadFromStackSlot(ReMatDefMI, LdSlot);
|
|
bool isLoad = isLoadSS ||
|
|
(DefIsReMat && (ReMatDefMI->getDesc().canFoldAsLoad()));
|
|
bool IsFirstRange = true;
|
|
for (LiveInterval::Ranges::const_iterator
|
|
I = li.ranges.begin(), E = li.ranges.end(); I != E; ++I) {
|
|
// If this is a split live interval with multiple ranges, it means there
|
|
// are two-address instructions that re-defined the value. Only the
|
|
// first def can be rematerialized!
|
|
if (IsFirstRange) {
|
|
// Note ReMatOrigDefMI has already been deleted.
|
|
rewriteInstructionsForSpills(li, false, I, NULL, ReMatDefMI,
|
|
Slot, LdSlot, isLoad, isLoadSS, DefIsReMat,
|
|
false, vrm, rc, ReMatIds, loopInfo,
|
|
SpillMBBs, SpillIdxes, RestoreMBBs, RestoreIdxes,
|
|
MBBVRegsMap, NewLIs);
|
|
} else {
|
|
rewriteInstructionsForSpills(li, false, I, NULL, 0,
|
|
Slot, 0, false, false, false,
|
|
false, vrm, rc, ReMatIds, loopInfo,
|
|
SpillMBBs, SpillIdxes, RestoreMBBs, RestoreIdxes,
|
|
MBBVRegsMap, NewLIs);
|
|
}
|
|
IsFirstRange = false;
|
|
}
|
|
|
|
handleSpilledImpDefs(li, vrm, rc, NewLIs);
|
|
return NewLIs;
|
|
}
|
|
|
|
bool TrySplit = !intervalIsInOneMBB(li);
|
|
if (TrySplit)
|
|
++numSplits;
|
|
bool NeedStackSlot = false;
|
|
for (LiveInterval::const_vni_iterator i = li.vni_begin(), e = li.vni_end();
|
|
i != e; ++i) {
|
|
const VNInfo *VNI = *i;
|
|
unsigned VN = VNI->id;
|
|
if (VNI->isUnused())
|
|
continue; // Dead val#.
|
|
// Is the def for the val# rematerializable?
|
|
MachineInstr *ReMatDefMI = VNI->isDefAccurate()
|
|
? getInstructionFromIndex(VNI->def) : 0;
|
|
bool dummy;
|
|
if (ReMatDefMI && isReMaterializable(li, VNI, ReMatDefMI, SpillIs, dummy)) {
|
|
// Remember how to remat the def of this val#.
|
|
ReMatOrigDefs[VN] = ReMatDefMI;
|
|
// Original def may be modified so we have to make a copy here.
|
|
MachineInstr *Clone = mf_->CloneMachineInstr(ReMatDefMI);
|
|
CloneMIs.push_back(Clone);
|
|
ReMatDefs[VN] = Clone;
|
|
|
|
bool CanDelete = true;
|
|
if (VNI->hasPHIKill()) {
|
|
// A kill is a phi node, not all of its uses can be rematerialized.
|
|
// It must not be deleted.
|
|
CanDelete = false;
|
|
// Need a stack slot if there is any live range where uses cannot be
|
|
// rematerialized.
|
|
NeedStackSlot = true;
|
|
}
|
|
if (CanDelete)
|
|
ReMatDelete.set(VN);
|
|
} else {
|
|
// Need a stack slot if there is any live range where uses cannot be
|
|
// rematerialized.
|
|
NeedStackSlot = true;
|
|
}
|
|
}
|
|
|
|
// One stack slot per live interval.
|
|
if (NeedStackSlot && vrm.getPreSplitReg(li.reg) == 0) {
|
|
if (vrm.getStackSlot(li.reg) == VirtRegMap::NO_STACK_SLOT)
|
|
Slot = vrm.assignVirt2StackSlot(li.reg);
|
|
|
|
// This case only occurs when the prealloc splitter has already assigned
|
|
// a stack slot to this vreg.
|
|
else
|
|
Slot = vrm.getStackSlot(li.reg);
|
|
}
|
|
|
|
// Create new intervals and rewrite defs and uses.
|
|
for (LiveInterval::Ranges::const_iterator
|
|
I = li.ranges.begin(), E = li.ranges.end(); I != E; ++I) {
|
|
MachineInstr *ReMatDefMI = ReMatDefs[I->valno->id];
|
|
MachineInstr *ReMatOrigDefMI = ReMatOrigDefs[I->valno->id];
|
|
bool DefIsReMat = ReMatDefMI != NULL;
|
|
bool CanDelete = ReMatDelete[I->valno->id];
|
|
int LdSlot = 0;
|
|
bool isLoadSS = DefIsReMat && tii_->isLoadFromStackSlot(ReMatDefMI, LdSlot);
|
|
bool isLoad = isLoadSS ||
|
|
(DefIsReMat && ReMatDefMI->getDesc().canFoldAsLoad());
|
|
rewriteInstructionsForSpills(li, TrySplit, I, ReMatOrigDefMI, ReMatDefMI,
|
|
Slot, LdSlot, isLoad, isLoadSS, DefIsReMat,
|
|
CanDelete, vrm, rc, ReMatIds, loopInfo,
|
|
SpillMBBs, SpillIdxes, RestoreMBBs, RestoreIdxes,
|
|
MBBVRegsMap, NewLIs);
|
|
}
|
|
|
|
// Insert spills / restores if we are splitting.
|
|
if (!TrySplit) {
|
|
handleSpilledImpDefs(li, vrm, rc, NewLIs);
|
|
return NewLIs;
|
|
}
|
|
|
|
SmallPtrSet<LiveInterval*, 4> AddedKill;
|
|
SmallVector<unsigned, 2> Ops;
|
|
if (NeedStackSlot) {
|
|
int Id = SpillMBBs.find_first();
|
|
while (Id != -1) {
|
|
std::vector<SRInfo> &spills = SpillIdxes[Id];
|
|
for (unsigned i = 0, e = spills.size(); i != e; ++i) {
|
|
MachineInstrIndex index = spills[i].index;
|
|
unsigned VReg = spills[i].vreg;
|
|
LiveInterval &nI = getOrCreateInterval(VReg);
|
|
bool isReMat = vrm.isReMaterialized(VReg);
|
|
MachineInstr *MI = getInstructionFromIndex(index);
|
|
bool CanFold = false;
|
|
bool FoundUse = false;
|
|
Ops.clear();
|
|
if (spills[i].canFold) {
|
|
CanFold = true;
|
|
for (unsigned j = 0, ee = MI->getNumOperands(); j != ee; ++j) {
|
|
MachineOperand &MO = MI->getOperand(j);
|
|
if (!MO.isReg() || MO.getReg() != VReg)
|
|
continue;
|
|
|
|
Ops.push_back(j);
|
|
if (MO.isDef())
|
|
continue;
|
|
if (isReMat ||
|
|
(!FoundUse && !alsoFoldARestore(Id, index, VReg,
|
|
RestoreMBBs, RestoreIdxes))) {
|
|
// MI has two-address uses of the same register. If the use
|
|
// isn't the first and only use in the BB, then we can't fold
|
|
// it. FIXME: Move this to rewriteInstructionsForSpills.
|
|
CanFold = false;
|
|
break;
|
|
}
|
|
FoundUse = true;
|
|
}
|
|
}
|
|
// Fold the store into the def if possible.
|
|
bool Folded = false;
|
|
if (CanFold && !Ops.empty()) {
|
|
if (tryFoldMemoryOperand(MI, vrm, NULL, index, Ops, true, Slot,VReg)){
|
|
Folded = true;
|
|
if (FoundUse) {
|
|
// Also folded uses, do not issue a load.
|
|
eraseRestoreInfo(Id, index, VReg, RestoreMBBs, RestoreIdxes);
|
|
nI.removeRange(getLoadIndex(index), getNextSlot(getUseIndex(index)));
|
|
}
|
|
nI.removeRange(getDefIndex(index), getStoreIndex(index));
|
|
}
|
|
}
|
|
|
|
// Otherwise tell the spiller to issue a spill.
|
|
if (!Folded) {
|
|
LiveRange *LR = &nI.ranges[nI.ranges.size()-1];
|
|
bool isKill = LR->end == getStoreIndex(index);
|
|
if (!MI->registerDefIsDead(nI.reg))
|
|
// No need to spill a dead def.
|
|
vrm.addSpillPoint(VReg, isKill, MI);
|
|
if (isKill)
|
|
AddedKill.insert(&nI);
|
|
}
|
|
}
|
|
Id = SpillMBBs.find_next(Id);
|
|
}
|
|
}
|
|
|
|
int Id = RestoreMBBs.find_first();
|
|
while (Id != -1) {
|
|
std::vector<SRInfo> &restores = RestoreIdxes[Id];
|
|
for (unsigned i = 0, e = restores.size(); i != e; ++i) {
|
|
MachineInstrIndex index = restores[i].index;
|
|
if (index == MachineInstrIndex())
|
|
continue;
|
|
unsigned VReg = restores[i].vreg;
|
|
LiveInterval &nI = getOrCreateInterval(VReg);
|
|
bool isReMat = vrm.isReMaterialized(VReg);
|
|
MachineInstr *MI = getInstructionFromIndex(index);
|
|
bool CanFold = false;
|
|
Ops.clear();
|
|
if (restores[i].canFold) {
|
|
CanFold = true;
|
|
for (unsigned j = 0, ee = MI->getNumOperands(); j != ee; ++j) {
|
|
MachineOperand &MO = MI->getOperand(j);
|
|
if (!MO.isReg() || MO.getReg() != VReg)
|
|
continue;
|
|
|
|
if (MO.isDef()) {
|
|
// If this restore were to be folded, it would have been folded
|
|
// already.
|
|
CanFold = false;
|
|
break;
|
|
}
|
|
Ops.push_back(j);
|
|
}
|
|
}
|
|
|
|
// Fold the load into the use if possible.
|
|
bool Folded = false;
|
|
if (CanFold && !Ops.empty()) {
|
|
if (!isReMat)
|
|
Folded = tryFoldMemoryOperand(MI, vrm, NULL,index,Ops,true,Slot,VReg);
|
|
else {
|
|
MachineInstr *ReMatDefMI = vrm.getReMaterializedMI(VReg);
|
|
int LdSlot = 0;
|
|
bool isLoadSS = tii_->isLoadFromStackSlot(ReMatDefMI, LdSlot);
|
|
// If the rematerializable def is a load, also try to fold it.
|
|
if (isLoadSS || ReMatDefMI->getDesc().canFoldAsLoad())
|
|
Folded = tryFoldMemoryOperand(MI, vrm, ReMatDefMI, index,
|
|
Ops, isLoadSS, LdSlot, VReg);
|
|
if (!Folded) {
|
|
unsigned ImpUse = getReMatImplicitUse(li, ReMatDefMI);
|
|
if (ImpUse) {
|
|
// Re-matting an instruction with virtual register use. Add the
|
|
// register as an implicit use on the use MI and update the register
|
|
// interval's spill weight to HUGE_VALF to prevent it from being
|
|
// spilled.
|
|
LiveInterval &ImpLi = getInterval(ImpUse);
|
|
ImpLi.weight = HUGE_VALF;
|
|
MI->addOperand(MachineOperand::CreateReg(ImpUse, false, true));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
// If folding is not possible / failed, then tell the spiller to issue a
|
|
// load / rematerialization for us.
|
|
if (Folded)
|
|
nI.removeRange(getLoadIndex(index), getNextSlot(getUseIndex(index)));
|
|
else
|
|
vrm.addRestorePoint(VReg, MI);
|
|
}
|
|
Id = RestoreMBBs.find_next(Id);
|
|
}
|
|
|
|
// Finalize intervals: add kills, finalize spill weights, and filter out
|
|
// dead intervals.
|
|
std::vector<LiveInterval*> RetNewLIs;
|
|
for (unsigned i = 0, e = NewLIs.size(); i != e; ++i) {
|
|
LiveInterval *LI = NewLIs[i];
|
|
if (!LI->empty()) {
|
|
LI->weight /= InstrSlots::NUM * getApproximateInstructionCount(*LI);
|
|
if (!AddedKill.count(LI)) {
|
|
LiveRange *LR = &LI->ranges[LI->ranges.size()-1];
|
|
MachineInstrIndex LastUseIdx = getBaseIndex(LR->end);
|
|
MachineInstr *LastUse = getInstructionFromIndex(LastUseIdx);
|
|
int UseIdx = LastUse->findRegisterUseOperandIdx(LI->reg, false);
|
|
assert(UseIdx != -1);
|
|
if (!LastUse->isRegTiedToDefOperand(UseIdx)) {
|
|
LastUse->getOperand(UseIdx).setIsKill();
|
|
vrm.addKillPoint(LI->reg, LastUseIdx);
|
|
}
|
|
}
|
|
RetNewLIs.push_back(LI);
|
|
}
|
|
}
|
|
|
|
handleSpilledImpDefs(li, vrm, rc, RetNewLIs);
|
|
return RetNewLIs;
|
|
}
|
|
|
|
/// hasAllocatableSuperReg - Return true if the specified physical register has
|
|
/// any super register that's allocatable.
|
|
bool LiveIntervals::hasAllocatableSuperReg(unsigned Reg) const {
|
|
for (const unsigned* AS = tri_->getSuperRegisters(Reg); *AS; ++AS)
|
|
if (allocatableRegs_[*AS] && hasInterval(*AS))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
/// getRepresentativeReg - Find the largest super register of the specified
|
|
/// physical register.
|
|
unsigned LiveIntervals::getRepresentativeReg(unsigned Reg) const {
|
|
// Find the largest super-register that is allocatable.
|
|
unsigned BestReg = Reg;
|
|
for (const unsigned* AS = tri_->getSuperRegisters(Reg); *AS; ++AS) {
|
|
unsigned SuperReg = *AS;
|
|
if (!hasAllocatableSuperReg(SuperReg) && hasInterval(SuperReg)) {
|
|
BestReg = SuperReg;
|
|
break;
|
|
}
|
|
}
|
|
return BestReg;
|
|
}
|
|
|
|
/// getNumConflictsWithPhysReg - Return the number of uses and defs of the
|
|
/// specified interval that conflicts with the specified physical register.
|
|
unsigned LiveIntervals::getNumConflictsWithPhysReg(const LiveInterval &li,
|
|
unsigned PhysReg) const {
|
|
unsigned NumConflicts = 0;
|
|
const LiveInterval &pli = getInterval(getRepresentativeReg(PhysReg));
|
|
for (MachineRegisterInfo::reg_iterator I = mri_->reg_begin(li.reg),
|
|
E = mri_->reg_end(); I != E; ++I) {
|
|
MachineOperand &O = I.getOperand();
|
|
MachineInstr *MI = O.getParent();
|
|
MachineInstrIndex Index = getInstructionIndex(MI);
|
|
if (pli.liveAt(Index))
|
|
++NumConflicts;
|
|
}
|
|
return NumConflicts;
|
|
}
|
|
|
|
/// spillPhysRegAroundRegDefsUses - Spill the specified physical register
|
|
/// around all defs and uses of the specified interval. Return true if it
|
|
/// was able to cut its interval.
|
|
bool LiveIntervals::spillPhysRegAroundRegDefsUses(const LiveInterval &li,
|
|
unsigned PhysReg, VirtRegMap &vrm) {
|
|
unsigned SpillReg = getRepresentativeReg(PhysReg);
|
|
|
|
for (const unsigned *AS = tri_->getAliasSet(PhysReg); *AS; ++AS)
|
|
// If there are registers which alias PhysReg, but which are not a
|
|
// sub-register of the chosen representative super register. Assert
|
|
// since we can't handle it yet.
|
|
assert(*AS == SpillReg || !allocatableRegs_[*AS] || !hasInterval(*AS) ||
|
|
tri_->isSuperRegister(*AS, SpillReg));
|
|
|
|
bool Cut = false;
|
|
LiveInterval &pli = getInterval(SpillReg);
|
|
SmallPtrSet<MachineInstr*, 8> SeenMIs;
|
|
for (MachineRegisterInfo::reg_iterator I = mri_->reg_begin(li.reg),
|
|
E = mri_->reg_end(); I != E; ++I) {
|
|
MachineOperand &O = I.getOperand();
|
|
MachineInstr *MI = O.getParent();
|
|
if (SeenMIs.count(MI))
|
|
continue;
|
|
SeenMIs.insert(MI);
|
|
MachineInstrIndex Index = getInstructionIndex(MI);
|
|
if (pli.liveAt(Index)) {
|
|
vrm.addEmergencySpill(SpillReg, MI);
|
|
MachineInstrIndex StartIdx = getLoadIndex(Index);
|
|
MachineInstrIndex EndIdx = getNextSlot(getStoreIndex(Index));
|
|
if (pli.isInOneLiveRange(StartIdx, EndIdx)) {
|
|
pli.removeRange(StartIdx, EndIdx);
|
|
Cut = true;
|
|
} else {
|
|
std::string msg;
|
|
raw_string_ostream Msg(msg);
|
|
Msg << "Ran out of registers during register allocation!";
|
|
if (MI->getOpcode() == TargetInstrInfo::INLINEASM) {
|
|
Msg << "\nPlease check your inline asm statement for invalid "
|
|
<< "constraints:\n";
|
|
MI->print(Msg, tm_);
|
|
}
|
|
llvm_report_error(Msg.str());
|
|
}
|
|
for (const unsigned* AS = tri_->getSubRegisters(SpillReg); *AS; ++AS) {
|
|
if (!hasInterval(*AS))
|
|
continue;
|
|
LiveInterval &spli = getInterval(*AS);
|
|
if (spli.liveAt(Index))
|
|
spli.removeRange(getLoadIndex(Index), getNextSlot(getStoreIndex(Index)));
|
|
}
|
|
}
|
|
}
|
|
return Cut;
|
|
}
|
|
|
|
LiveRange LiveIntervals::addLiveRangeToEndOfBlock(unsigned reg,
|
|
MachineInstr* startInst) {
|
|
LiveInterval& Interval = getOrCreateInterval(reg);
|
|
VNInfo* VN = Interval.getNextValue(
|
|
MachineInstrIndex(getInstructionIndex(startInst), MachineInstrIndex::DEF),
|
|
startInst, true, getVNInfoAllocator());
|
|
VN->setHasPHIKill(true);
|
|
VN->kills.push_back(terminatorGaps[startInst->getParent()]);
|
|
LiveRange LR(
|
|
MachineInstrIndex(getInstructionIndex(startInst), MachineInstrIndex::DEF),
|
|
getNextSlot(getMBBEndIdx(startInst->getParent())), VN);
|
|
Interval.addRange(LR);
|
|
|
|
return LR;
|
|
}
|
|
|