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+//===-- llvm/CodeGen/Spiller.cpp - Spiller -------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "spiller"
+
+#include "Spiller.h"
+#include "VirtRegMap.h"
+#include "LiveRangeEdit.h"
+#include "llvm/CodeGen/LiveIntervalAnalysis.h"
+#include "llvm/CodeGen/LiveStackAnalysis.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineLoopInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+namespace {
+ enum SpillerName { trivial, standard, inline_ };
+}
+
+static cl::opt<SpillerName>
+spillerOpt("spiller",
+ cl::desc("Spiller to use: (default: standard)"),
+ cl::Prefix,
+ cl::values(clEnumVal(trivial, "trivial spiller"),
+ clEnumVal(standard, "default spiller"),
+ clEnumValN(inline_, "inline", "inline spiller"),
+ clEnumValEnd),
+ cl::init(standard));
+
+// Spiller virtual destructor implementation.
+Spiller::~Spiller() {}
+
+namespace {
+
+/// Utility class for spillers.
+class SpillerBase : public Spiller {
+protected:
+ MachineFunctionPass *pass;
+ MachineFunction *mf;
+ VirtRegMap *vrm;
+ LiveIntervals *lis;
+ MachineFrameInfo *mfi;
+ MachineRegisterInfo *mri;
+ const TargetInstrInfo *tii;
+ const TargetRegisterInfo *tri;
+
+ /// Construct a spiller base.
+ SpillerBase(MachineFunctionPass &pass, MachineFunction &mf, VirtRegMap &vrm)
+ : pass(&pass), mf(&mf), vrm(&vrm)
+ {
+ lis = &pass.getAnalysis<LiveIntervals>();
+ mfi = mf.getFrameInfo();
+ mri = &mf.getRegInfo();
+ tii = mf.getTarget().getInstrInfo();
+ tri = mf.getTarget().getRegisterInfo();
+ }
+
+ /// Add spill ranges for every use/def of the live interval, inserting loads
+ /// immediately before each use, and stores after each def. No folding or
+ /// remat is attempted.
+ void trivialSpillEverywhere(LiveInterval *li,
+ SmallVectorImpl<LiveInterval*> &newIntervals) {
+ DEBUG(dbgs() << "Spilling everywhere " << *li << "\n");
+
+ assert(li->weight != HUGE_VALF &&
+ "Attempting to spill already spilled value.");
+
+ assert(!TargetRegisterInfo::isStackSlot(li->reg) &&
+ "Trying to spill a stack slot.");
+
+ DEBUG(dbgs() << "Trivial spill everywhere of reg" << li->reg << "\n");
+
+ const TargetRegisterClass *trc = mri->getRegClass(li->reg);
+ unsigned ss = vrm->assignVirt2StackSlot(li->reg);
+
+ // Iterate over reg uses/defs.
+ for (MachineRegisterInfo::reg_iterator
+ regItr = mri->reg_begin(li->reg); regItr != mri->reg_end();) {
+
+ // Grab the use/def instr.
+ MachineInstr *mi = &*regItr;
+
+ DEBUG(dbgs() << " Processing " << *mi);
+
+ // Step regItr to the next use/def instr.
+ do {
+ ++regItr;
+ } while (regItr != mri->reg_end() && (&*regItr == mi));
+
+ // Collect uses & defs for this instr.
+ SmallVector<unsigned, 2> indices;
+ bool hasUse = false;
+ bool hasDef = false;
+ for (unsigned i = 0; i != mi->getNumOperands(); ++i) {
+ MachineOperand &op = mi->getOperand(i);
+ if (!op.isReg() || op.getReg() != li->reg)
+ continue;
+ hasUse |= mi->getOperand(i).isUse();
+ hasDef |= mi->getOperand(i).isDef();
+ indices.push_back(i);
+ }
+
+ // Create a new vreg & interval for this instr.
+ unsigned newVReg = mri->createVirtualRegister(trc);
+ vrm->grow();
+ vrm->assignVirt2StackSlot(newVReg, ss);
+ LiveInterval *newLI = &lis->getOrCreateInterval(newVReg);
+ newLI->weight = HUGE_VALF;
+
+ // Update the reg operands & kill flags.
+ for (unsigned i = 0; i < indices.size(); ++i) {
+ unsigned mopIdx = indices[i];
+ MachineOperand &mop = mi->getOperand(mopIdx);
+ mop.setReg(newVReg);
+ if (mop.isUse() && !mi->isRegTiedToDefOperand(mopIdx)) {
+ mop.setIsKill(true);
+ }
+ }
+ assert(hasUse || hasDef);
+
+ // Insert reload if necessary.
+ MachineBasicBlock::iterator miItr(mi);
+ if (hasUse) {
+ tii->loadRegFromStackSlot(*mi->getParent(), miItr, newVReg, ss, trc,
+ tri);
+ MachineInstr *loadInstr(prior(miItr));
+ SlotIndex loadIndex =
+ lis->InsertMachineInstrInMaps(loadInstr).getDefIndex();
+ vrm->addSpillSlotUse(ss, loadInstr);
+ SlotIndex endIndex = loadIndex.getNextIndex();
+ VNInfo *loadVNI =
+ newLI->getNextValue(loadIndex, 0, lis->getVNInfoAllocator());
+ newLI->addRange(LiveRange(loadIndex, endIndex, loadVNI));
+ }
+
+ // Insert store if necessary.
+ if (hasDef) {
+ tii->storeRegToStackSlot(*mi->getParent(), llvm::next(miItr), newVReg,
+ true, ss, trc, tri);
+ MachineInstr *storeInstr(llvm::next(miItr));
+ SlotIndex storeIndex =
+ lis->InsertMachineInstrInMaps(storeInstr).getDefIndex();
+ vrm->addSpillSlotUse(ss, storeInstr);
+ SlotIndex beginIndex = storeIndex.getPrevIndex();
+ VNInfo *storeVNI =
+ newLI->getNextValue(beginIndex, 0, lis->getVNInfoAllocator());
+ newLI->addRange(LiveRange(beginIndex, storeIndex, storeVNI));
+ }
+
+ newIntervals.push_back(newLI);
+ }
+ }
+};
+
+} // end anonymous namespace
+
+namespace {
+
+/// Spills any live range using the spill-everywhere method with no attempt at
+/// folding.
+class TrivialSpiller : public SpillerBase {
+public:
+
+ TrivialSpiller(MachineFunctionPass &pass, MachineFunction &mf,
+ VirtRegMap &vrm)
+ : SpillerBase(pass, mf, vrm) {}
+
+ void spill(LiveRangeEdit &LRE) {
+ // Ignore spillIs - we don't use it.
+ trivialSpillEverywhere(&LRE.getParent(), *LRE.getNewVRegs());
+ }
+};
+
+} // end anonymous namespace
+
+namespace {
+
+/// Falls back on LiveIntervals::addIntervalsForSpills.
+class StandardSpiller : public Spiller {
+protected:
+ MachineFunction *mf;
+ LiveIntervals *lis;
+ LiveStacks *lss;
+ MachineLoopInfo *loopInfo;
+ VirtRegMap *vrm;
+public:
+ StandardSpiller(MachineFunctionPass &pass, MachineFunction &mf,
+ VirtRegMap &vrm)
+ : mf(&mf),
+ lis(&pass.getAnalysis<LiveIntervals>()),
+ lss(&pass.getAnalysis<LiveStacks>()),
+ loopInfo(pass.getAnalysisIfAvailable<MachineLoopInfo>()),
+ vrm(&vrm) {}
+
+ /// Falls back on LiveIntervals::addIntervalsForSpills.
+ void spill(LiveRangeEdit &LRE) {
+ std::vector<LiveInterval*> added =
+ lis->addIntervalsForSpills(LRE.getParent(), LRE.getUselessVRegs(),
+ loopInfo, *vrm);
+ LRE.getNewVRegs()->insert(LRE.getNewVRegs()->end(),
+ added.begin(), added.end());
+
+ // Update LiveStacks.
+ int SS = vrm->getStackSlot(LRE.getReg());
+ if (SS == VirtRegMap::NO_STACK_SLOT)
+ return;
+ const TargetRegisterClass *RC = mf->getRegInfo().getRegClass(LRE.getReg());
+ LiveInterval &SI = lss->getOrCreateInterval(SS, RC);
+ if (!SI.hasAtLeastOneValue())
+ SI.getNextValue(SlotIndex(), 0, lss->getVNInfoAllocator());
+ SI.MergeRangesInAsValue(LRE.getParent(), SI.getValNumInfo(0));
+ }
+};
+
+} // end anonymous namespace
+
+llvm::Spiller* llvm::createSpiller(MachineFunctionPass &pass,
+ MachineFunction &mf,
+ VirtRegMap &vrm) {
+ switch (spillerOpt) {
+ default: assert(0 && "unknown spiller");
+ case trivial: return new TrivialSpiller(pass, mf, vrm);
+ case standard: return new StandardSpiller(pass, mf, vrm);
+ case inline_: return createInlineSpiller(pass, mf, vrm);
+ }
+}
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