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Diffstat (limited to 'contrib/llvm/lib/CodeGen/MachineFunction.cpp')
| -rw-r--r-- | contrib/llvm/lib/CodeGen/MachineFunction.cpp | 755 |
1 files changed, 755 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/MachineFunction.cpp b/contrib/llvm/lib/CodeGen/MachineFunction.cpp new file mode 100644 index 0000000..d8c2f6a --- /dev/null +++ b/contrib/llvm/lib/CodeGen/MachineFunction.cpp @@ -0,0 +1,755 @@ +//===-- MachineFunction.cpp -----------------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// Collect native machine code information for a function. This allows +// target-specific information about the generated code to be stored with each +// function. +// +//===----------------------------------------------------------------------===// + +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/Function.h" +#include "llvm/CodeGen/MachineConstantPool.h" +#include "llvm/CodeGen/MachineFunctionPass.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineInstr.h" +#include "llvm/CodeGen/MachineJumpTableInfo.h" +#include "llvm/CodeGen/MachineModuleInfo.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" +#include "llvm/CodeGen/Passes.h" +#include "llvm/MC/MCAsmInfo.h" +#include "llvm/MC/MCContext.h" +#include "llvm/Analysis/ConstantFolding.h" +#include "llvm/Analysis/DebugInfo.h" +#include "llvm/Support/Debug.h" +#include "llvm/Target/TargetData.h" +#include "llvm/Target/TargetLowering.h" +#include "llvm/Target/TargetMachine.h" +#include "llvm/Target/TargetFrameLowering.h" +#include "llvm/ADT/SmallString.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/Support/GraphWriter.h" +#include "llvm/Support/raw_ostream.h" +using namespace llvm; + +//===----------------------------------------------------------------------===// +// MachineFunction implementation +//===----------------------------------------------------------------------===// + +// Out of line virtual method. +MachineFunctionInfo::~MachineFunctionInfo() {} + +void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) { + MBB->getParent()->DeleteMachineBasicBlock(MBB); +} + +MachineFunction::MachineFunction(const Function *F, const TargetMachine &TM, + unsigned FunctionNum, MachineModuleInfo &mmi, + GCModuleInfo* gmi) + : Fn(F), Target(TM), Ctx(mmi.getContext()), MMI(mmi), GMI(gmi) { + if (TM.getRegisterInfo()) + RegInfo = new (Allocator) MachineRegisterInfo(*TM.getRegisterInfo()); + else + RegInfo = 0; + MFInfo = 0; + FrameInfo = new (Allocator) MachineFrameInfo(*TM.getFrameLowering()); + if (Fn->hasFnAttr(Attribute::StackAlignment)) + FrameInfo->setMaxAlignment(Attribute::getStackAlignmentFromAttrs( + Fn->getAttributes().getFnAttributes())); + ConstantPool = new (Allocator) MachineConstantPool(TM.getTargetData()); + Alignment = TM.getTargetLowering()->getMinFunctionAlignment(); + // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn. + if (!Fn->hasFnAttr(Attribute::OptimizeForSize)) + Alignment = std::max(Alignment, + TM.getTargetLowering()->getPrefFunctionAlignment()); + FunctionNumber = FunctionNum; + JumpTableInfo = 0; +} + +MachineFunction::~MachineFunction() { + BasicBlocks.clear(); + InstructionRecycler.clear(Allocator); + BasicBlockRecycler.clear(Allocator); + if (RegInfo) { + RegInfo->~MachineRegisterInfo(); + Allocator.Deallocate(RegInfo); + } + if (MFInfo) { + MFInfo->~MachineFunctionInfo(); + Allocator.Deallocate(MFInfo); + } + FrameInfo->~MachineFrameInfo(); Allocator.Deallocate(FrameInfo); + ConstantPool->~MachineConstantPool(); Allocator.Deallocate(ConstantPool); + + if (JumpTableInfo) { + JumpTableInfo->~MachineJumpTableInfo(); + Allocator.Deallocate(JumpTableInfo); + } +} + +/// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it +/// does already exist, allocate one. +MachineJumpTableInfo *MachineFunction:: +getOrCreateJumpTableInfo(unsigned EntryKind) { + if (JumpTableInfo) return JumpTableInfo; + + JumpTableInfo = new (Allocator) + MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind); + return JumpTableInfo; +} + +/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and +/// recomputes them. This guarantees that the MBB numbers are sequential, +/// dense, and match the ordering of the blocks within the function. If a +/// specific MachineBasicBlock is specified, only that block and those after +/// it are renumbered. +void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) { + if (empty()) { MBBNumbering.clear(); return; } + MachineFunction::iterator MBBI, E = end(); + if (MBB == 0) + MBBI = begin(); + else + MBBI = MBB; + + // Figure out the block number this should have. + unsigned BlockNo = 0; + if (MBBI != begin()) + BlockNo = prior(MBBI)->getNumber()+1; + + for (; MBBI != E; ++MBBI, ++BlockNo) { + if (MBBI->getNumber() != (int)BlockNo) { + // Remove use of the old number. + if (MBBI->getNumber() != -1) { + assert(MBBNumbering[MBBI->getNumber()] == &*MBBI && + "MBB number mismatch!"); + MBBNumbering[MBBI->getNumber()] = 0; + } + + // If BlockNo is already taken, set that block's number to -1. + if (MBBNumbering[BlockNo]) + MBBNumbering[BlockNo]->setNumber(-1); + + MBBNumbering[BlockNo] = MBBI; + MBBI->setNumber(BlockNo); + } + } + + // Okay, all the blocks are renumbered. If we have compactified the block + // numbering, shrink MBBNumbering now. + assert(BlockNo <= MBBNumbering.size() && "Mismatch!"); + MBBNumbering.resize(BlockNo); +} + +/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead +/// of `new MachineInstr'. +/// +MachineInstr * +MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID, + DebugLoc DL, bool NoImp) { + return new (InstructionRecycler.Allocate<MachineInstr>(Allocator)) + MachineInstr(MCID, DL, NoImp); +} + +/// CloneMachineInstr - Create a new MachineInstr which is a copy of the +/// 'Orig' instruction, identical in all ways except the instruction +/// has no parent, prev, or next. +/// +MachineInstr * +MachineFunction::CloneMachineInstr(const MachineInstr *Orig) { + return new (InstructionRecycler.Allocate<MachineInstr>(Allocator)) + MachineInstr(*this, *Orig); +} + +/// DeleteMachineInstr - Delete the given MachineInstr. +/// +void +MachineFunction::DeleteMachineInstr(MachineInstr *MI) { + MI->~MachineInstr(); + InstructionRecycler.Deallocate(Allocator, MI); +} + +/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this +/// instead of `new MachineBasicBlock'. +/// +MachineBasicBlock * +MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) { + return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator)) + MachineBasicBlock(*this, bb); +} + +/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock. +/// +void +MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) { + assert(MBB->getParent() == this && "MBB parent mismatch!"); + MBB->~MachineBasicBlock(); + BasicBlockRecycler.Deallocate(Allocator, MBB); +} + +MachineMemOperand * +MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f, + uint64_t s, unsigned base_alignment, + const MDNode *TBAAInfo, + const MDNode *Ranges) { + return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment, + TBAAInfo, Ranges); +} + +MachineMemOperand * +MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO, + int64_t Offset, uint64_t Size) { + return new (Allocator) + MachineMemOperand(MachinePointerInfo(MMO->getValue(), + MMO->getOffset()+Offset), + MMO->getFlags(), Size, + MMO->getBaseAlignment(), 0); +} + +MachineInstr::mmo_iterator +MachineFunction::allocateMemRefsArray(unsigned long Num) { + return Allocator.Allocate<MachineMemOperand *>(Num); +} + +std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator> +MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin, + MachineInstr::mmo_iterator End) { + // Count the number of load mem refs. + unsigned Num = 0; + for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) + if ((*I)->isLoad()) + ++Num; + + // Allocate a new array and populate it with the load information. + MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num); + unsigned Index = 0; + for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) { + if ((*I)->isLoad()) { + if (!(*I)->isStore()) + // Reuse the MMO. + Result[Index] = *I; + else { + // Clone the MMO and unset the store flag. + MachineMemOperand *JustLoad = + getMachineMemOperand((*I)->getPointerInfo(), + (*I)->getFlags() & ~MachineMemOperand::MOStore, + (*I)->getSize(), (*I)->getBaseAlignment(), + (*I)->getTBAAInfo()); + Result[Index] = JustLoad; + } + ++Index; + } + } + return std::make_pair(Result, Result + Num); +} + +std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator> +MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin, + MachineInstr::mmo_iterator End) { + // Count the number of load mem refs. + unsigned Num = 0; + for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) + if ((*I)->isStore()) + ++Num; + + // Allocate a new array and populate it with the store information. + MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num); + unsigned Index = 0; + for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) { + if ((*I)->isStore()) { + if (!(*I)->isLoad()) + // Reuse the MMO. + Result[Index] = *I; + else { + // Clone the MMO and unset the load flag. + MachineMemOperand *JustStore = + getMachineMemOperand((*I)->getPointerInfo(), + (*I)->getFlags() & ~MachineMemOperand::MOLoad, + (*I)->getSize(), (*I)->getBaseAlignment(), + (*I)->getTBAAInfo()); + Result[Index] = JustStore; + } + ++Index; + } + } + return std::make_pair(Result, Result + Num); +} + +void MachineFunction::dump() const { + print(dbgs()); +} + +void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const { + OS << "# Machine code for function " << Fn->getName() << ": "; + if (RegInfo) { + OS << (RegInfo->isSSA() ? "SSA" : "Post SSA"); + if (!RegInfo->tracksLiveness()) + OS << ", not tracking liveness"; + } + OS << '\n'; + + // Print Frame Information + FrameInfo->print(*this, OS); + + // Print JumpTable Information + if (JumpTableInfo) + JumpTableInfo->print(OS); + + // Print Constant Pool + ConstantPool->print(OS); + + const TargetRegisterInfo *TRI = getTarget().getRegisterInfo(); + + if (RegInfo && !RegInfo->livein_empty()) { + OS << "Function Live Ins: "; + for (MachineRegisterInfo::livein_iterator + I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) { + OS << PrintReg(I->first, TRI); + if (I->second) + OS << " in " << PrintReg(I->second, TRI); + if (llvm::next(I) != E) + OS << ", "; + } + OS << '\n'; + } + if (RegInfo && !RegInfo->liveout_empty()) { + OS << "Function Live Outs:"; + for (MachineRegisterInfo::liveout_iterator + I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I) + OS << ' ' << PrintReg(*I, TRI); + OS << '\n'; + } + + for (const_iterator BB = begin(), E = end(); BB != E; ++BB) { + OS << '\n'; + BB->print(OS, Indexes); + } + + OS << "\n# End machine code for function " << Fn->getName() << ".\n\n"; +} + +namespace llvm { + template<> + struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits { + + DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {} + + static std::string getGraphName(const MachineFunction *F) { + return "CFG for '" + F->getFunction()->getName().str() + "' function"; + } + + std::string getNodeLabel(const MachineBasicBlock *Node, + const MachineFunction *Graph) { + std::string OutStr; + { + raw_string_ostream OSS(OutStr); + + if (isSimple()) { + OSS << "BB#" << Node->getNumber(); + if (const BasicBlock *BB = Node->getBasicBlock()) + OSS << ": " << BB->getName(); + } else + Node->print(OSS); + } + + if (OutStr[0] == '\n') OutStr.erase(OutStr.begin()); + + // Process string output to make it nicer... + for (unsigned i = 0; i != OutStr.length(); ++i) + if (OutStr[i] == '\n') { // Left justify + OutStr[i] = '\\'; + OutStr.insert(OutStr.begin()+i+1, 'l'); + } + return OutStr; + } + }; +} + +void MachineFunction::viewCFG() const +{ +#ifndef NDEBUG + ViewGraph(this, "mf" + getFunction()->getName()); +#else + errs() << "MachineFunction::viewCFG is only available in debug builds on " + << "systems with Graphviz or gv!\n"; +#endif // NDEBUG +} + +void MachineFunction::viewCFGOnly() const +{ +#ifndef NDEBUG + ViewGraph(this, "mf" + getFunction()->getName(), true); +#else + errs() << "MachineFunction::viewCFGOnly is only available in debug builds on " + << "systems with Graphviz or gv!\n"; +#endif // NDEBUG +} + +/// addLiveIn - Add the specified physical register as a live-in value and +/// create a corresponding virtual register for it. +unsigned MachineFunction::addLiveIn(unsigned PReg, + const TargetRegisterClass *RC) { + MachineRegisterInfo &MRI = getRegInfo(); + unsigned VReg = MRI.getLiveInVirtReg(PReg); + if (VReg) { + assert(MRI.getRegClass(VReg) == RC && "Register class mismatch!"); + return VReg; + } + VReg = MRI.createVirtualRegister(RC); + MRI.addLiveIn(PReg, VReg); + return VReg; +} + +/// getJTISymbol - Return the MCSymbol for the specified non-empty jump table. +/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a +/// normal 'L' label is returned. +MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx, + bool isLinkerPrivate) const { + assert(JumpTableInfo && "No jump tables"); + + assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!"); + const MCAsmInfo &MAI = *getTarget().getMCAsmInfo(); + + const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() : + MAI.getPrivateGlobalPrefix(); + SmallString<60> Name; + raw_svector_ostream(Name) + << Prefix << "JTI" << getFunctionNumber() << '_' << JTI; + return Ctx.GetOrCreateSymbol(Name.str()); +} + +/// getPICBaseSymbol - Return a function-local symbol to represent the PIC +/// base. +MCSymbol *MachineFunction::getPICBaseSymbol() const { + const MCAsmInfo &MAI = *Target.getMCAsmInfo(); + return Ctx.GetOrCreateSymbol(Twine(MAI.getPrivateGlobalPrefix())+ + Twine(getFunctionNumber())+"$pb"); +} + +//===----------------------------------------------------------------------===// +// MachineFrameInfo implementation +//===----------------------------------------------------------------------===// + +/// CreateFixedObject - Create a new object at a fixed location on the stack. +/// All fixed objects should be created before other objects are created for +/// efficiency. By default, fixed objects are immutable. This returns an +/// index with a negative value. +/// +int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset, + bool Immutable) { + assert(Size != 0 && "Cannot allocate zero size fixed stack objects!"); + // The alignment of the frame index can be determined from its offset from + // the incoming frame position. If the frame object is at offset 32 and + // the stack is guaranteed to be 16-byte aligned, then we know that the + // object is 16-byte aligned. + unsigned StackAlign = TFI.getStackAlignment(); + unsigned Align = MinAlign(SPOffset, StackAlign); + Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable, + /*isSS*/false, false)); + return -++NumFixedObjects; +} + + +BitVector +MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const { + assert(MBB && "MBB must be valid"); + const MachineFunction *MF = MBB->getParent(); + assert(MF && "MBB must be part of a MachineFunction"); + const TargetMachine &TM = MF->getTarget(); + const TargetRegisterInfo *TRI = TM.getRegisterInfo(); + BitVector BV(TRI->getNumRegs()); + + // Before CSI is calculated, no registers are considered pristine. They can be + // freely used and PEI will make sure they are saved. + if (!isCalleeSavedInfoValid()) + return BV; + + for (const uint16_t *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR) + BV.set(*CSR); + + // The entry MBB always has all CSRs pristine. + if (MBB == &MF->front()) + return BV; + + // On other MBBs the saved CSRs are not pristine. + const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo(); + for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(), + E = CSI.end(); I != E; ++I) + BV.reset(I->getReg()); + + return BV; +} + + +void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{ + if (Objects.empty()) return; + + const TargetFrameLowering *FI = MF.getTarget().getFrameLowering(); + int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0); + + OS << "Frame Objects:\n"; + + for (unsigned i = 0, e = Objects.size(); i != e; ++i) { + const StackObject &SO = Objects[i]; + OS << " fi#" << (int)(i-NumFixedObjects) << ": "; + if (SO.Size == ~0ULL) { + OS << "dead\n"; + continue; + } + if (SO.Size == 0) + OS << "variable sized"; + else + OS << "size=" << SO.Size; + OS << ", align=" << SO.Alignment; + + if (i < NumFixedObjects) + OS << ", fixed"; + if (i < NumFixedObjects || SO.SPOffset != -1) { + int64_t Off = SO.SPOffset - ValOffset; + OS << ", at location [SP"; + if (Off > 0) + OS << "+" << Off; + else if (Off < 0) + OS << Off; + OS << "]"; + } + OS << "\n"; + } +} + +void MachineFrameInfo::dump(const MachineFunction &MF) const { + print(MF, dbgs()); +} + +//===----------------------------------------------------------------------===// +// MachineJumpTableInfo implementation +//===----------------------------------------------------------------------===// + +/// getEntrySize - Return the size of each entry in the jump table. +unsigned MachineJumpTableInfo::getEntrySize(const TargetData &TD) const { + // The size of a jump table entry is 4 bytes unless the entry is just the + // address of a block, in which case it is the pointer size. + switch (getEntryKind()) { + case MachineJumpTableInfo::EK_BlockAddress: + return TD.getPointerSize(); + case MachineJumpTableInfo::EK_GPRel64BlockAddress: + return 8; + case MachineJumpTableInfo::EK_GPRel32BlockAddress: + case MachineJumpTableInfo::EK_LabelDifference32: + case MachineJumpTableInfo::EK_Custom32: + return 4; + case MachineJumpTableInfo::EK_Inline: + return 0; + } + llvm_unreachable("Unknown jump table encoding!"); +} + +/// getEntryAlignment - Return the alignment of each entry in the jump table. +unsigned MachineJumpTableInfo::getEntryAlignment(const TargetData &TD) const { + // The alignment of a jump table entry is the alignment of int32 unless the + // entry is just the address of a block, in which case it is the pointer + // alignment. + switch (getEntryKind()) { + case MachineJumpTableInfo::EK_BlockAddress: + return TD.getPointerABIAlignment(); + case MachineJumpTableInfo::EK_GPRel64BlockAddress: + return TD.getABIIntegerTypeAlignment(64); + case MachineJumpTableInfo::EK_GPRel32BlockAddress: + case MachineJumpTableInfo::EK_LabelDifference32: + case MachineJumpTableInfo::EK_Custom32: + return TD.getABIIntegerTypeAlignment(32); + case MachineJumpTableInfo::EK_Inline: + return 1; + } + llvm_unreachable("Unknown jump table encoding!"); +} + +/// createJumpTableIndex - Create a new jump table entry in the jump table info. +/// +unsigned MachineJumpTableInfo::createJumpTableIndex( + const std::vector<MachineBasicBlock*> &DestBBs) { + assert(!DestBBs.empty() && "Cannot create an empty jump table!"); + JumpTables.push_back(MachineJumpTableEntry(DestBBs)); + return JumpTables.size()-1; +} + +/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update +/// the jump tables to branch to New instead. +bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old, + MachineBasicBlock *New) { + assert(Old != New && "Not making a change?"); + bool MadeChange = false; + for (size_t i = 0, e = JumpTables.size(); i != e; ++i) + ReplaceMBBInJumpTable(i, Old, New); + return MadeChange; +} + +/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update +/// the jump table to branch to New instead. +bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx, + MachineBasicBlock *Old, + MachineBasicBlock *New) { + assert(Old != New && "Not making a change?"); + bool MadeChange = false; + MachineJumpTableEntry &JTE = JumpTables[Idx]; + for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j) + if (JTE.MBBs[j] == Old) { + JTE.MBBs[j] = New; + MadeChange = true; + } + return MadeChange; +} + +void MachineJumpTableInfo::print(raw_ostream &OS) const { + if (JumpTables.empty()) return; + + OS << "Jump Tables:\n"; + + for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) { + OS << " jt#" << i << ": "; + for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j) + OS << " BB#" << JumpTables[i].MBBs[j]->getNumber(); + } + + OS << '\n'; +} + +void MachineJumpTableInfo::dump() const { print(dbgs()); } + + +//===----------------------------------------------------------------------===// +// MachineConstantPool implementation +//===----------------------------------------------------------------------===// + +void MachineConstantPoolValue::anchor() { } + +Type *MachineConstantPoolEntry::getType() const { + if (isMachineConstantPoolEntry()) + return Val.MachineCPVal->getType(); + return Val.ConstVal->getType(); +} + + +unsigned MachineConstantPoolEntry::getRelocationInfo() const { + if (isMachineConstantPoolEntry()) + return Val.MachineCPVal->getRelocationInfo(); + return Val.ConstVal->getRelocationInfo(); +} + +MachineConstantPool::~MachineConstantPool() { + for (unsigned i = 0, e = Constants.size(); i != e; ++i) + if (Constants[i].isMachineConstantPoolEntry()) + delete Constants[i].Val.MachineCPVal; + for (DenseSet<MachineConstantPoolValue*>::iterator I = + MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end(); + I != E; ++I) + delete *I; +} + +/// CanShareConstantPoolEntry - Test whether the given two constants +/// can be allocated the same constant pool entry. +static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B, + const TargetData *TD) { + // Handle the trivial case quickly. + if (A == B) return true; + + // If they have the same type but weren't the same constant, quickly + // reject them. + if (A->getType() == B->getType()) return false; + + // We can't handle structs or arrays. + if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) || + isa<StructType>(B->getType()) || isa<ArrayType>(B->getType())) + return false; + + // For now, only support constants with the same size. + uint64_t StoreSize = TD->getTypeStoreSize(A->getType()); + if (StoreSize != TD->getTypeStoreSize(B->getType()) || + StoreSize > 128) + return false; + + Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8); + + // Try constant folding a bitcast of both instructions to an integer. If we + // get two identical ConstantInt's, then we are good to share them. We use + // the constant folding APIs to do this so that we get the benefit of + // TargetData. + if (isa<PointerType>(A->getType())) + A = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy, + const_cast<Constant*>(A), TD); + else if (A->getType() != IntTy) + A = ConstantFoldInstOperands(Instruction::BitCast, IntTy, + const_cast<Constant*>(A), TD); + if (isa<PointerType>(B->getType())) + B = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy, + const_cast<Constant*>(B), TD); + else if (B->getType() != IntTy) + B = ConstantFoldInstOperands(Instruction::BitCast, IntTy, + const_cast<Constant*>(B), TD); + + return A == B; +} + +/// getConstantPoolIndex - Create a new entry in the constant pool or return +/// an existing one. User must specify the log2 of the minimum required +/// alignment for the object. +/// +unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C, + unsigned Alignment) { + assert(Alignment && "Alignment must be specified!"); + if (Alignment > PoolAlignment) PoolAlignment = Alignment; + + // Check to see if we already have this constant. + // + // FIXME, this could be made much more efficient for large constant pools. + for (unsigned i = 0, e = Constants.size(); i != e; ++i) + if (!Constants[i].isMachineConstantPoolEntry() && + CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) { + if ((unsigned)Constants[i].getAlignment() < Alignment) + Constants[i].Alignment = Alignment; + return i; + } + + Constants.push_back(MachineConstantPoolEntry(C, Alignment)); + return Constants.size()-1; +} + +unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V, + unsigned Alignment) { + assert(Alignment && "Alignment must be specified!"); + if (Alignment > PoolAlignment) PoolAlignment = Alignment; + + // Check to see if we already have this constant. + // + // FIXME, this could be made much more efficient for large constant pools. + int Idx = V->getExistingMachineCPValue(this, Alignment); + if (Idx != -1) { + MachineCPVsSharingEntries.insert(V); + return (unsigned)Idx; + } + + Constants.push_back(MachineConstantPoolEntry(V, Alignment)); + return Constants.size()-1; +} + +void MachineConstantPool::print(raw_ostream &OS) const { + if (Constants.empty()) return; + + OS << "Constant Pool:\n"; + for (unsigned i = 0, e = Constants.size(); i != e; ++i) { + OS << " cp#" << i << ": "; + if (Constants[i].isMachineConstantPoolEntry()) + Constants[i].Val.MachineCPVal->print(OS); + else + OS << *(Value*)Constants[i].Val.ConstVal; + OS << ", align=" << Constants[i].getAlignment(); + OS << "\n"; + } +} + +void MachineConstantPool::dump() const { print(dbgs()); } |
