mirror of
https://github.com/c64scene-ar/llvm-6502.git
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2ab36d3502
perform initialization without static constructors AND without explicit initialization by the client. For the moment, passes are required to initialize both their (potential) dependencies and any passes they preserve. I hope to be able to relax the latter requirement in the future. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116334 91177308-0d34-0410-b5e6-96231b3b80d8
828 lines
28 KiB
C++
828 lines
28 KiB
C++
//===-- llvm/CodeGen/Splitter.cpp - Splitter -----------------------------===//
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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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#define DEBUG_TYPE "loopsplitter"
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#include "Splitter.h"
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#include "SimpleRegisterCoalescing.h"
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#include "llvm/Module.h"
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#include "llvm/CodeGen/CalcSpillWeights.h"
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#include "llvm/CodeGen/LiveIntervalAnalysis.h"
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#include "llvm/CodeGen/LiveStackAnalysis.h"
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#include "llvm/CodeGen/MachineDominators.h"
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#include "llvm/CodeGen/MachineInstrBuilder.h"
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#include "llvm/CodeGen/MachineFunction.h"
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#include "llvm/CodeGen/MachineRegisterInfo.h"
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#include "llvm/CodeGen/SlotIndexes.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/Target/TargetMachine.h"
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#include "llvm/Target/TargetInstrInfo.h"
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using namespace llvm;
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char LoopSplitter::ID = 0;
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INITIALIZE_PASS_BEGIN(LoopSplitter, "loop-splitting",
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"Split virtual regists across loop boundaries.", false, false)
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INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
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INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
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INITIALIZE_PASS_DEPENDENCY(SlotIndexes)
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INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
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INITIALIZE_PASS_END(LoopSplitter, "loop-splitting",
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"Split virtual regists across loop boundaries.", false, false)
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namespace llvm {
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class StartSlotComparator {
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public:
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StartSlotComparator(LiveIntervals &lis) : lis(lis) {}
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bool operator()(const MachineBasicBlock *mbb1,
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const MachineBasicBlock *mbb2) const {
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return lis.getMBBStartIdx(mbb1) < lis.getMBBStartIdx(mbb2);
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}
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private:
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LiveIntervals &lis;
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};
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class LoopSplit {
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public:
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LoopSplit(LoopSplitter &ls, LiveInterval &li, MachineLoop &loop)
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: ls(ls), li(li), loop(loop), valid(true), inSplit(false), newLI(0) {
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assert(TargetRegisterInfo::isVirtualRegister(li.reg) &&
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"Cannot split physical registers.");
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}
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LiveInterval& getLI() const { return li; }
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MachineLoop& getLoop() const { return loop; }
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bool isValid() const { return valid; }
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bool isWorthwhile() const { return valid && (inSplit || !outSplits.empty()); }
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void invalidate() { valid = false; }
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void splitIncoming() { inSplit = true; }
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void splitOutgoing(MachineLoop::Edge &edge) { outSplits.insert(edge); }
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void addLoopInstr(MachineInstr *i) { loopInstrs.push_back(i); }
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void apply() {
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assert(valid && "Attempt to apply invalid split.");
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applyIncoming();
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applyOutgoing();
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copyRanges();
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renameInside();
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}
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private:
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LoopSplitter &ls;
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LiveInterval &li;
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MachineLoop &loop;
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bool valid, inSplit;
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std::set<MachineLoop::Edge> outSplits;
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std::vector<MachineInstr*> loopInstrs;
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LiveInterval *newLI;
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std::map<VNInfo*, VNInfo*> vniMap;
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LiveInterval* getNewLI() {
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if (newLI == 0) {
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const TargetRegisterClass *trc = ls.mri->getRegClass(li.reg);
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unsigned vreg = ls.mri->createVirtualRegister(trc);
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newLI = &ls.lis->getOrCreateInterval(vreg);
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}
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return newLI;
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}
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VNInfo* getNewVNI(VNInfo *oldVNI) {
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VNInfo *newVNI = vniMap[oldVNI];
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if (newVNI == 0) {
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newVNI = getNewLI()->createValueCopy(oldVNI,
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ls.lis->getVNInfoAllocator());
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vniMap[oldVNI] = newVNI;
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}
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return newVNI;
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}
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void applyIncoming() {
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if (!inSplit) {
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return;
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}
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MachineBasicBlock *preHeader = loop.getLoopPreheader();
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if (preHeader == 0) {
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assert(ls.canInsertPreHeader(loop) &&
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"Can't insert required preheader.");
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preHeader = &ls.insertPreHeader(loop);
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}
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LiveRange *preHeaderRange =
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ls.lis->findExitingRange(li, preHeader);
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assert(preHeaderRange != 0 && "Range not live into preheader.");
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// Insert the new copy.
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MachineInstr *copy = BuildMI(*preHeader,
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preHeader->getFirstTerminator(),
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DebugLoc(),
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ls.tii->get(TargetOpcode::COPY))
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.addReg(getNewLI()->reg, RegState::Define)
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.addReg(li.reg, RegState::Kill);
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ls.lis->InsertMachineInstrInMaps(copy);
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SlotIndex copyDefIdx = ls.lis->getInstructionIndex(copy).getDefIndex();
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VNInfo *newVal = getNewVNI(preHeaderRange->valno);
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newVal->def = copyDefIdx;
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newVal->setCopy(copy);
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li.removeRange(copyDefIdx, ls.lis->getMBBEndIdx(preHeader), true);
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getNewLI()->addRange(LiveRange(copyDefIdx,
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ls.lis->getMBBEndIdx(preHeader),
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newVal));
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}
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void applyOutgoing() {
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for (std::set<MachineLoop::Edge>::iterator osItr = outSplits.begin(),
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osEnd = outSplits.end();
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osItr != osEnd; ++osItr) {
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MachineLoop::Edge edge = *osItr;
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MachineBasicBlock *outBlock = edge.second;
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if (ls.isCriticalEdge(edge)) {
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assert(ls.canSplitEdge(edge) && "Unsplitable critical edge.");
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outBlock = &ls.splitEdge(edge, loop);
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}
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LiveRange *outRange = ls.lis->findEnteringRange(li, outBlock);
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assert(outRange != 0 && "No exiting range?");
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MachineInstr *copy = BuildMI(*outBlock, outBlock->begin(),
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DebugLoc(),
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ls.tii->get(TargetOpcode::COPY))
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.addReg(li.reg, RegState::Define)
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.addReg(getNewLI()->reg, RegState::Kill);
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ls.lis->InsertMachineInstrInMaps(copy);
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SlotIndex copyDefIdx = ls.lis->getInstructionIndex(copy).getDefIndex();
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// Blow away output range definition.
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outRange->valno->def = ls.lis->getInvalidIndex();
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li.removeRange(ls.lis->getMBBStartIdx(outBlock), copyDefIdx);
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SlotIndex newDefIdx = ls.lis->getMBBStartIdx(outBlock);
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assert(ls.lis->getInstructionFromIndex(newDefIdx) == 0 &&
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"PHI def index points at actual instruction.");
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VNInfo *newVal =
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getNewLI()->getNextValue(newDefIdx, 0, ls.lis->getVNInfoAllocator());
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getNewLI()->addRange(LiveRange(ls.lis->getMBBStartIdx(outBlock),
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copyDefIdx, newVal));
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}
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}
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void copyRange(LiveRange &lr) {
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std::pair<bool, LoopSplitter::SlotPair> lsr =
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ls.getLoopSubRange(lr, loop);
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if (!lsr.first)
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return;
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LiveRange loopRange(lsr.second.first, lsr.second.second,
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getNewVNI(lr.valno));
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li.removeRange(loopRange.start, loopRange.end, true);
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getNewLI()->addRange(loopRange);
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}
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void copyRanges() {
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for (std::vector<MachineInstr*>::iterator iItr = loopInstrs.begin(),
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iEnd = loopInstrs.end();
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iItr != iEnd; ++iItr) {
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MachineInstr &instr = **iItr;
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SlotIndex instrIdx = ls.lis->getInstructionIndex(&instr);
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if (instr.modifiesRegister(li.reg, 0)) {
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LiveRange *defRange =
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li.getLiveRangeContaining(instrIdx.getDefIndex());
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if (defRange != 0) // May have caught this already.
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copyRange(*defRange);
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}
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if (instr.readsRegister(li.reg, 0)) {
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LiveRange *useRange =
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li.getLiveRangeContaining(instrIdx.getUseIndex());
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if (useRange != 0) { // May have caught this already.
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copyRange(*useRange);
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}
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}
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}
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for (MachineLoop::block_iterator bbItr = loop.block_begin(),
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bbEnd = loop.block_end();
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bbItr != bbEnd; ++bbItr) {
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MachineBasicBlock &loopBlock = **bbItr;
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LiveRange *enteringRange =
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ls.lis->findEnteringRange(li, &loopBlock);
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if (enteringRange != 0) {
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copyRange(*enteringRange);
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}
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}
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}
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void renameInside() {
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for (std::vector<MachineInstr*>::iterator iItr = loopInstrs.begin(),
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iEnd = loopInstrs.end();
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iItr != iEnd; ++iItr) {
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MachineInstr &instr = **iItr;
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for (unsigned i = 0; i < instr.getNumOperands(); ++i) {
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MachineOperand &mop = instr.getOperand(i);
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if (mop.isReg() && mop.getReg() == li.reg) {
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mop.setReg(getNewLI()->reg);
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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 LoopSplitter::getAnalysisUsage(AnalysisUsage &au) const {
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au.addRequired<MachineDominatorTree>();
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au.addPreserved<MachineDominatorTree>();
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au.addRequired<MachineLoopInfo>();
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au.addPreserved<MachineLoopInfo>();
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au.addPreserved<RegisterCoalescer>();
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au.addPreserved<CalculateSpillWeights>();
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au.addPreserved<LiveStacks>();
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au.addRequired<SlotIndexes>();
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au.addPreserved<SlotIndexes>();
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au.addRequired<LiveIntervals>();
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au.addPreserved<LiveIntervals>();
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MachineFunctionPass::getAnalysisUsage(au);
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}
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bool LoopSplitter::runOnMachineFunction(MachineFunction &fn) {
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mf = &fn;
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mri = &mf->getRegInfo();
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tii = mf->getTarget().getInstrInfo();
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tri = mf->getTarget().getRegisterInfo();
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sis = &getAnalysis<SlotIndexes>();
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lis = &getAnalysis<LiveIntervals>();
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mli = &getAnalysis<MachineLoopInfo>();
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mdt = &getAnalysis<MachineDominatorTree>();
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fqn = mf->getFunction()->getParent()->getModuleIdentifier() + "." +
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mf->getFunction()->getName().str();
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dbgs() << "Splitting " << mf->getFunction()->getName() << ".";
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dumpOddTerminators();
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// dbgs() << "----------------------------------------\n";
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// lis->dump();
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// dbgs() << "----------------------------------------\n";
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// std::deque<MachineLoop*> loops;
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// std::copy(mli->begin(), mli->end(), std::back_inserter(loops));
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// dbgs() << "Loops:\n";
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// while (!loops.empty()) {
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// MachineLoop &loop = *loops.front();
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// loops.pop_front();
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// std::copy(loop.begin(), loop.end(), std::back_inserter(loops));
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// dumpLoopInfo(loop);
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// }
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//lis->dump();
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//exit(0);
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// Setup initial intervals.
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for (LiveIntervals::iterator liItr = lis->begin(), liEnd = lis->end();
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liItr != liEnd; ++liItr) {
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LiveInterval *li = liItr->second;
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if (TargetRegisterInfo::isVirtualRegister(li->reg) &&
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!lis->intervalIsInOneMBB(*li)) {
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intervals.push_back(li);
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}
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}
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processIntervals();
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intervals.clear();
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// dbgs() << "----------------------------------------\n";
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// lis->dump();
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// dbgs() << "----------------------------------------\n";
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dumpOddTerminators();
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//exit(1);
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return false;
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}
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void LoopSplitter::releaseMemory() {
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fqn.clear();
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intervals.clear();
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loopRangeMap.clear();
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}
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void LoopSplitter::dumpOddTerminators() {
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for (MachineFunction::iterator bbItr = mf->begin(), bbEnd = mf->end();
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bbItr != bbEnd; ++bbItr) {
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MachineBasicBlock *mbb = &*bbItr;
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MachineBasicBlock *a = 0, *b = 0;
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SmallVector<MachineOperand, 4> c;
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if (tii->AnalyzeBranch(*mbb, a, b, c)) {
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dbgs() << "MBB#" << mbb->getNumber() << " has multiway terminator.\n";
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dbgs() << " Terminators:\n";
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for (MachineBasicBlock::iterator iItr = mbb->begin(), iEnd = mbb->end();
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iItr != iEnd; ++iItr) {
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MachineInstr *instr= &*iItr;
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dbgs() << " " << *instr << "";
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}
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dbgs() << "\n Listed successors: [ ";
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for (MachineBasicBlock::succ_iterator sItr = mbb->succ_begin(), sEnd = mbb->succ_end();
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sItr != sEnd; ++sItr) {
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MachineBasicBlock *succMBB = *sItr;
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dbgs() << succMBB->getNumber() << " ";
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}
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dbgs() << "]\n\n";
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}
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}
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}
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void LoopSplitter::dumpLoopInfo(MachineLoop &loop) {
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MachineBasicBlock &headerBlock = *loop.getHeader();
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typedef SmallVector<MachineLoop::Edge, 8> ExitEdgesList;
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ExitEdgesList exitEdges;
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loop.getExitEdges(exitEdges);
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dbgs() << " Header: BB#" << headerBlock.getNumber() << ", Contains: [ ";
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for (std::vector<MachineBasicBlock*>::const_iterator
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subBlockItr = loop.getBlocks().begin(),
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subBlockEnd = loop.getBlocks().end();
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subBlockItr != subBlockEnd; ++subBlockItr) {
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MachineBasicBlock &subBlock = **subBlockItr;
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dbgs() << "BB#" << subBlock.getNumber() << " ";
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}
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dbgs() << "], Exit edges: [ ";
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for (ExitEdgesList::iterator exitEdgeItr = exitEdges.begin(),
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exitEdgeEnd = exitEdges.end();
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exitEdgeItr != exitEdgeEnd; ++exitEdgeItr) {
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MachineLoop::Edge &exitEdge = *exitEdgeItr;
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dbgs() << "(MBB#" << exitEdge.first->getNumber()
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<< ", MBB#" << exitEdge.second->getNumber() << ") ";
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}
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dbgs() << "], Sub-Loop Headers: [ ";
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for (MachineLoop::iterator subLoopItr = loop.begin(),
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subLoopEnd = loop.end();
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subLoopItr != subLoopEnd; ++subLoopItr) {
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MachineLoop &subLoop = **subLoopItr;
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MachineBasicBlock &subLoopBlock = *subLoop.getHeader();
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dbgs() << "BB#" << subLoopBlock.getNumber() << " ";
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}
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dbgs() << "]\n";
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}
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void LoopSplitter::updateTerminators(MachineBasicBlock &mbb) {
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mbb.updateTerminator();
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for (MachineBasicBlock::iterator miItr = mbb.begin(), miEnd = mbb.end();
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miItr != miEnd; ++miItr) {
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if (lis->isNotInMIMap(miItr)) {
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lis->InsertMachineInstrInMaps(miItr);
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}
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}
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}
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bool LoopSplitter::canInsertPreHeader(MachineLoop &loop) {
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MachineBasicBlock *header = loop.getHeader();
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MachineBasicBlock *a = 0, *b = 0;
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SmallVector<MachineOperand, 4> c;
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for (MachineBasicBlock::pred_iterator pbItr = header->pred_begin(),
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pbEnd = header->pred_end();
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pbItr != pbEnd; ++pbItr) {
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MachineBasicBlock *predBlock = *pbItr;
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if (!!tii->AnalyzeBranch(*predBlock, a, b, c)) {
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return false;
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}
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}
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MachineFunction::iterator headerItr(header);
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if (headerItr == mf->begin())
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return true;
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MachineBasicBlock *headerLayoutPred = llvm::prior(headerItr);
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assert(headerLayoutPred != 0 && "Header should have layout pred.");
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return (!tii->AnalyzeBranch(*headerLayoutPred, a, b, c));
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}
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MachineBasicBlock& LoopSplitter::insertPreHeader(MachineLoop &loop) {
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assert(loop.getLoopPreheader() == 0 && "Loop already has preheader.");
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MachineBasicBlock &header = *loop.getHeader();
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// Save the preds - we'll need to update them once we insert the preheader.
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typedef std::set<MachineBasicBlock*> HeaderPreds;
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HeaderPreds headerPreds;
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for (MachineBasicBlock::pred_iterator predItr = header.pred_begin(),
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predEnd = header.pred_end();
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predItr != predEnd; ++predItr) {
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if (!loop.contains(*predItr))
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headerPreds.insert(*predItr);
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}
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assert(!headerPreds.empty() && "No predecessors for header?");
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//dbgs() << fqn << " MBB#" << header.getNumber() << " inserting preheader...";
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MachineBasicBlock *preHeader =
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mf->CreateMachineBasicBlock(header.getBasicBlock());
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assert(preHeader != 0 && "Failed to create pre-header.");
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mf->insert(header, preHeader);
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for (HeaderPreds::iterator hpItr = headerPreds.begin(),
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hpEnd = headerPreds.end();
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hpItr != hpEnd; ++hpItr) {
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assert(*hpItr != 0 && "How'd a null predecessor get into this set?");
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MachineBasicBlock &hp = **hpItr;
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hp.ReplaceUsesOfBlockWith(&header, preHeader);
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}
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preHeader->addSuccessor(&header);
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MachineBasicBlock *oldLayoutPred =
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llvm::prior(MachineFunction::iterator(preHeader));
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if (oldLayoutPred != 0) {
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updateTerminators(*oldLayoutPred);
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}
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lis->InsertMBBInMaps(preHeader);
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if (MachineLoop *parentLoop = loop.getParentLoop()) {
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assert(parentLoop->getHeader() != loop.getHeader() &&
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"Parent loop has same header?");
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parentLoop->addBasicBlockToLoop(preHeader, mli->getBase());
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// Invalidate all parent loop ranges.
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while (parentLoop != 0) {
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loopRangeMap.erase(parentLoop);
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parentLoop = parentLoop->getParentLoop();
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}
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}
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for (LiveIntervals::iterator liItr = lis->begin(),
|
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liEnd = lis->end();
|
|
liItr != liEnd; ++liItr) {
|
|
LiveInterval &li = *liItr->second;
|
|
|
|
// Is this safe for physregs?
|
|
// TargetRegisterInfo::isPhysicalRegister(li.reg) ||
|
|
if (!lis->isLiveInToMBB(li, &header))
|
|
continue;
|
|
|
|
if (lis->isLiveInToMBB(li, preHeader)) {
|
|
assert(lis->isLiveOutOfMBB(li, preHeader) &&
|
|
"Range terminates in newly added preheader?");
|
|
continue;
|
|
}
|
|
|
|
bool insertRange = false;
|
|
|
|
for (MachineBasicBlock::pred_iterator predItr = preHeader->pred_begin(),
|
|
predEnd = preHeader->pred_end();
|
|
predItr != predEnd; ++predItr) {
|
|
MachineBasicBlock *predMBB = *predItr;
|
|
if (lis->isLiveOutOfMBB(li, predMBB)) {
|
|
insertRange = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!insertRange)
|
|
continue;
|
|
|
|
SlotIndex newDefIdx = lis->getMBBStartIdx(preHeader);
|
|
assert(lis->getInstructionFromIndex(newDefIdx) == 0 &&
|
|
"PHI def index points at actual instruction.");
|
|
VNInfo *newVal = li.getNextValue(newDefIdx, 0, lis->getVNInfoAllocator());
|
|
li.addRange(LiveRange(lis->getMBBStartIdx(preHeader),
|
|
lis->getMBBEndIdx(preHeader),
|
|
newVal));
|
|
}
|
|
|
|
|
|
//dbgs() << "Dumping SlotIndexes:\n";
|
|
//sis->dump();
|
|
|
|
//dbgs() << "done. (Added MBB#" << preHeader->getNumber() << ")\n";
|
|
|
|
return *preHeader;
|
|
}
|
|
|
|
bool LoopSplitter::isCriticalEdge(MachineLoop::Edge &edge) {
|
|
assert(edge.first->succ_size() > 1 && "Non-sensical edge.");
|
|
if (edge.second->pred_size() > 1)
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
bool LoopSplitter::canSplitEdge(MachineLoop::Edge &edge) {
|
|
MachineFunction::iterator outBlockItr(edge.second);
|
|
if (outBlockItr == mf->begin())
|
|
return true;
|
|
MachineBasicBlock *outBlockLayoutPred = llvm::prior(outBlockItr);
|
|
assert(outBlockLayoutPred != 0 && "Should have a layout pred if out!=begin.");
|
|
MachineBasicBlock *a = 0, *b = 0;
|
|
SmallVector<MachineOperand, 4> c;
|
|
return (!tii->AnalyzeBranch(*outBlockLayoutPred, a, b, c) &&
|
|
!tii->AnalyzeBranch(*edge.first, a, b, c));
|
|
}
|
|
|
|
MachineBasicBlock& LoopSplitter::splitEdge(MachineLoop::Edge &edge,
|
|
MachineLoop &loop) {
|
|
|
|
MachineBasicBlock &inBlock = *edge.first;
|
|
MachineBasicBlock &outBlock = *edge.second;
|
|
|
|
assert((inBlock.succ_size() > 1) && (outBlock.pred_size() > 1) &&
|
|
"Splitting non-critical edge?");
|
|
|
|
//dbgs() << fqn << " Splitting edge (MBB#" << inBlock.getNumber()
|
|
// << " -> MBB#" << outBlock.getNumber() << ")...";
|
|
|
|
MachineBasicBlock *splitBlock =
|
|
mf->CreateMachineBasicBlock();
|
|
|
|
assert(splitBlock != 0 && "Failed to create split block.");
|
|
|
|
mf->insert(&outBlock, splitBlock);
|
|
|
|
inBlock.ReplaceUsesOfBlockWith(&outBlock, splitBlock);
|
|
splitBlock->addSuccessor(&outBlock);
|
|
|
|
MachineBasicBlock *oldLayoutPred =
|
|
llvm::prior(MachineFunction::iterator(splitBlock));
|
|
if (oldLayoutPred != 0) {
|
|
updateTerminators(*oldLayoutPred);
|
|
}
|
|
|
|
lis->InsertMBBInMaps(splitBlock);
|
|
|
|
loopRangeMap.erase(&loop);
|
|
|
|
MachineLoop *splitParentLoop = loop.getParentLoop();
|
|
while (splitParentLoop != 0 &&
|
|
!splitParentLoop->contains(&outBlock)) {
|
|
splitParentLoop = splitParentLoop->getParentLoop();
|
|
}
|
|
|
|
if (splitParentLoop != 0) {
|
|
assert(splitParentLoop->contains(&loop) &&
|
|
"Split-block parent doesn't contain original loop?");
|
|
splitParentLoop->addBasicBlockToLoop(splitBlock, mli->getBase());
|
|
|
|
// Invalidate all parent loop ranges.
|
|
while (splitParentLoop != 0) {
|
|
loopRangeMap.erase(splitParentLoop);
|
|
splitParentLoop = splitParentLoop->getParentLoop();
|
|
}
|
|
}
|
|
|
|
|
|
for (LiveIntervals::iterator liItr = lis->begin(),
|
|
liEnd = lis->end();
|
|
liItr != liEnd; ++liItr) {
|
|
LiveInterval &li = *liItr->second;
|
|
bool intersects = lis->isLiveOutOfMBB(li, &inBlock) &&
|
|
lis->isLiveInToMBB(li, &outBlock);
|
|
if (lis->isLiveInToMBB(li, splitBlock)) {
|
|
if (!intersects) {
|
|
li.removeRange(lis->getMBBStartIdx(splitBlock),
|
|
lis->getMBBEndIdx(splitBlock), true);
|
|
}
|
|
} else if (intersects) {
|
|
SlotIndex newDefIdx = lis->getMBBStartIdx(splitBlock);
|
|
assert(lis->getInstructionFromIndex(newDefIdx) == 0 &&
|
|
"PHI def index points at actual instruction.");
|
|
VNInfo *newVal = li.getNextValue(newDefIdx, 0,
|
|
lis->getVNInfoAllocator());
|
|
li.addRange(LiveRange(lis->getMBBStartIdx(splitBlock),
|
|
lis->getMBBEndIdx(splitBlock),
|
|
newVal));
|
|
}
|
|
}
|
|
|
|
//dbgs() << "done. (Added MBB#" << splitBlock->getNumber() << ")\n";
|
|
|
|
return *splitBlock;
|
|
}
|
|
|
|
LoopSplitter::LoopRanges& LoopSplitter::getLoopRanges(MachineLoop &loop) {
|
|
typedef std::set<MachineBasicBlock*, StartSlotComparator> LoopMBBSet;
|
|
LoopRangeMap::iterator lrItr = loopRangeMap.find(&loop);
|
|
if (lrItr == loopRangeMap.end()) {
|
|
LoopMBBSet loopMBBs((StartSlotComparator(*lis)));
|
|
std::copy(loop.block_begin(), loop.block_end(),
|
|
std::inserter(loopMBBs, loopMBBs.begin()));
|
|
|
|
assert(!loopMBBs.empty() && "No blocks in loop?");
|
|
|
|
LoopRanges &loopRanges = loopRangeMap[&loop];
|
|
assert(loopRanges.empty() && "Loop encountered but not processed?");
|
|
SlotIndex oldEnd = lis->getMBBEndIdx(*loopMBBs.begin());
|
|
loopRanges.push_back(
|
|
std::make_pair(lis->getMBBStartIdx(*loopMBBs.begin()),
|
|
lis->getInvalidIndex()));
|
|
for (LoopMBBSet::iterator curBlockItr = llvm::next(loopMBBs.begin()),
|
|
curBlockEnd = loopMBBs.end();
|
|
curBlockItr != curBlockEnd; ++curBlockItr) {
|
|
SlotIndex newStart = lis->getMBBStartIdx(*curBlockItr);
|
|
if (newStart != oldEnd) {
|
|
loopRanges.back().second = oldEnd;
|
|
loopRanges.push_back(std::make_pair(newStart,
|
|
lis->getInvalidIndex()));
|
|
}
|
|
oldEnd = lis->getMBBEndIdx(*curBlockItr);
|
|
}
|
|
|
|
loopRanges.back().second =
|
|
lis->getMBBEndIdx(*llvm::prior(loopMBBs.end()));
|
|
|
|
return loopRanges;
|
|
}
|
|
return lrItr->second;
|
|
}
|
|
|
|
std::pair<bool, LoopSplitter::SlotPair> LoopSplitter::getLoopSubRange(
|
|
const LiveRange &lr,
|
|
MachineLoop &loop) {
|
|
LoopRanges &loopRanges = getLoopRanges(loop);
|
|
LoopRanges::iterator lrItr = loopRanges.begin(),
|
|
lrEnd = loopRanges.end();
|
|
while (lrItr != lrEnd && lr.start >= lrItr->second) {
|
|
++lrItr;
|
|
}
|
|
|
|
if (lrItr == lrEnd) {
|
|
SlotIndex invalid = lis->getInvalidIndex();
|
|
return std::make_pair(false, SlotPair(invalid, invalid));
|
|
}
|
|
|
|
SlotIndex srStart(lr.start < lrItr->first ? lrItr->first : lr.start);
|
|
SlotIndex srEnd(lr.end > lrItr->second ? lrItr->second : lr.end);
|
|
|
|
return std::make_pair(true, SlotPair(srStart, srEnd));
|
|
}
|
|
|
|
void LoopSplitter::dumpLoopRanges(MachineLoop &loop) {
|
|
LoopRanges &loopRanges = getLoopRanges(loop);
|
|
dbgs() << "For loop MBB#" << loop.getHeader()->getNumber() << ", subranges are: [ ";
|
|
for (LoopRanges::iterator lrItr = loopRanges.begin(), lrEnd = loopRanges.end();
|
|
lrItr != lrEnd; ++lrItr) {
|
|
dbgs() << "[" << lrItr->first << ", " << lrItr->second << ") ";
|
|
}
|
|
dbgs() << "]\n";
|
|
}
|
|
|
|
void LoopSplitter::processHeader(LoopSplit &split) {
|
|
MachineBasicBlock &header = *split.getLoop().getHeader();
|
|
//dbgs() << " Processing loop header BB#" << header.getNumber() << "\n";
|
|
|
|
if (!lis->isLiveInToMBB(split.getLI(), &header))
|
|
return; // Not live in, but nothing wrong so far.
|
|
|
|
MachineBasicBlock *preHeader = split.getLoop().getLoopPreheader();
|
|
if (!preHeader) {
|
|
|
|
if (!canInsertPreHeader(split.getLoop())) {
|
|
split.invalidate();
|
|
return; // Couldn't insert a pre-header. Bail on this interval.
|
|
}
|
|
|
|
for (MachineBasicBlock::pred_iterator predItr = header.pred_begin(),
|
|
predEnd = header.pred_end();
|
|
predItr != predEnd; ++predItr) {
|
|
if (lis->isLiveOutOfMBB(split.getLI(), *predItr)) {
|
|
split.splitIncoming();
|
|
break;
|
|
}
|
|
}
|
|
} else if (lis->isLiveOutOfMBB(split.getLI(), preHeader)) {
|
|
split.splitIncoming();
|
|
}
|
|
}
|
|
|
|
void LoopSplitter::processLoopExits(LoopSplit &split) {
|
|
typedef SmallVector<MachineLoop::Edge, 8> ExitEdgesList;
|
|
ExitEdgesList exitEdges;
|
|
split.getLoop().getExitEdges(exitEdges);
|
|
|
|
//dbgs() << " Processing loop exits:\n";
|
|
|
|
for (ExitEdgesList::iterator exitEdgeItr = exitEdges.begin(),
|
|
exitEdgeEnd = exitEdges.end();
|
|
exitEdgeItr != exitEdgeEnd; ++exitEdgeItr) {
|
|
MachineLoop::Edge exitEdge = *exitEdgeItr;
|
|
|
|
LiveRange *outRange =
|
|
split.getLI().getLiveRangeContaining(lis->getMBBStartIdx(exitEdge.second));
|
|
|
|
if (outRange != 0) {
|
|
if (isCriticalEdge(exitEdge) && !canSplitEdge(exitEdge)) {
|
|
split.invalidate();
|
|
return;
|
|
}
|
|
|
|
split.splitOutgoing(exitEdge);
|
|
}
|
|
}
|
|
}
|
|
|
|
void LoopSplitter::processLoopUses(LoopSplit &split) {
|
|
std::set<MachineInstr*> processed;
|
|
|
|
for (MachineRegisterInfo::reg_iterator
|
|
rItr = mri->reg_begin(split.getLI().reg),
|
|
rEnd = mri->reg_end();
|
|
rItr != rEnd; ++rItr) {
|
|
MachineInstr &instr = *rItr;
|
|
if (split.getLoop().contains(&instr) && processed.count(&instr) == 0) {
|
|
split.addLoopInstr(&instr);
|
|
processed.insert(&instr);
|
|
}
|
|
}
|
|
|
|
//dbgs() << " Rewriting reg" << li.reg << " to reg" << newLI->reg
|
|
// << " in blocks [ ";
|
|
//dbgs() << "]\n";
|
|
}
|
|
|
|
bool LoopSplitter::splitOverLoop(LiveInterval &li, MachineLoop &loop) {
|
|
assert(TargetRegisterInfo::isVirtualRegister(li.reg) &&
|
|
"Attempt to split physical register.");
|
|
|
|
LoopSplit split(*this, li, loop);
|
|
processHeader(split);
|
|
if (split.isValid())
|
|
processLoopExits(split);
|
|
if (split.isValid())
|
|
processLoopUses(split);
|
|
if (split.isValid() /* && split.isWorthwhile() */) {
|
|
split.apply();
|
|
DEBUG(dbgs() << "Success.\n");
|
|
return true;
|
|
}
|
|
DEBUG(dbgs() << "Failed.\n");
|
|
return false;
|
|
}
|
|
|
|
void LoopSplitter::processInterval(LiveInterval &li) {
|
|
std::deque<MachineLoop*> loops;
|
|
std::copy(mli->begin(), mli->end(), std::back_inserter(loops));
|
|
|
|
while (!loops.empty()) {
|
|
MachineLoop &loop = *loops.front();
|
|
loops.pop_front();
|
|
DEBUG(
|
|
dbgs() << fqn << " reg" << li.reg << " " << li.weight << " BB#"
|
|
<< loop.getHeader()->getNumber() << " ";
|
|
);
|
|
if (!splitOverLoop(li, loop)) {
|
|
// Couldn't split over outer loop, schedule sub-loops to be checked.
|
|
std::copy(loop.begin(), loop.end(), std::back_inserter(loops));
|
|
}
|
|
}
|
|
}
|
|
|
|
void LoopSplitter::processIntervals() {
|
|
while (!intervals.empty()) {
|
|
LiveInterval &li = *intervals.front();
|
|
intervals.pop_front();
|
|
|
|
assert(!lis->intervalIsInOneMBB(li) &&
|
|
"Single interval in process worklist.");
|
|
|
|
processInterval(li);
|
|
}
|
|
}
|
|
|
|
}
|