diff options
Diffstat (limited to 'contrib/llvm/lib/CodeGen/Spiller.cpp')
-rw-r--r-- | contrib/llvm/lib/CodeGen/Spiller.cpp | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/Spiller.cpp b/contrib/llvm/lib/CodeGen/Spiller.cpp new file mode 100644 index 0000000..4cd22eb --- /dev/null +++ b/contrib/llvm/lib/CodeGen/Spiller.cpp @@ -0,0 +1,194 @@ +//===-- 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 "llvm/CodeGen/LiveIntervalAnalysis.h" +#include "llvm/CodeGen/LiveRangeEdit.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, inline_ }; +} + +static cl::opt<SpillerName> +spillerOpt("spiller", + cl::desc("Spiller to use: (default: standard)"), + cl::Prefix, + cl::values(clEnumVal(trivial, "trivial spiller"), + clEnumValN(inline_, "inline", "inline spiller"), + clEnumValEnd), + cl::init(trivial)); + +// 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(LiveRangeEdit& LRE) { + LiveInterval* li = &LRE.getParent(); + + 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. + LiveInterval *newLI = &LRE.create(); + 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(newLI->reg); + 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, newLI->reg, ss, trc, + tri); + MachineInstr *loadInstr(prior(miItr)); + SlotIndex loadIndex = + lis->InsertMachineInstrInMaps(loadInstr).getRegSlot(); + SlotIndex endIndex = loadIndex.getNextIndex(); + VNInfo *loadVNI = + newLI->getNextValue(loadIndex, lis->getVNInfoAllocator()); + newLI->addRange(LiveRange(loadIndex, endIndex, loadVNI)); + } + + // Insert store if necessary. + if (hasDef) { + tii->storeRegToStackSlot(*mi->getParent(), llvm::next(miItr),newLI->reg, + true, ss, trc, tri); + MachineInstr *storeInstr(llvm::next(miItr)); + SlotIndex storeIndex = + lis->InsertMachineInstrInMaps(storeInstr).getRegSlot(); + SlotIndex beginIndex = storeIndex.getPrevIndex(); + VNInfo *storeVNI = + newLI->getNextValue(beginIndex, lis->getVNInfoAllocator()); + newLI->addRange(LiveRange(beginIndex, storeIndex, storeVNI)); + } + } + } +}; + +} // 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); + } +}; + +} // end anonymous namespace + +void Spiller::anchor() { } + +llvm::Spiller* llvm::createSpiller(MachineFunctionPass &pass, + MachineFunction &mf, + VirtRegMap &vrm) { + switch (spillerOpt) { + case trivial: return new TrivialSpiller(pass, mf, vrm); + case inline_: return createInlineSpiller(pass, mf, vrm); + } + llvm_unreachable("Invalid spiller optimization"); +} |