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Diffstat (limited to 'lib/Bytecode/Writer/Writer.cpp')
| -rw-r--r-- | lib/Bytecode/Writer/Writer.cpp | 1175 |
1 files changed, 1175 insertions, 0 deletions
diff --git a/lib/Bytecode/Writer/Writer.cpp b/lib/Bytecode/Writer/Writer.cpp new file mode 100644 index 0000000000..b1f2634296 --- /dev/null +++ b/lib/Bytecode/Writer/Writer.cpp @@ -0,0 +1,1175 @@ +//===-- Writer.cpp - Library for writing LLVM bytecode files --------------===// +// +// The LLVM Compiler Infrastructure +// +// This file was developed by the LLVM research group and is distributed under +// the University of Illinois Open Source License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This library implements the functionality defined in llvm/Bytecode/Writer.h +// +// Note that this file uses an unusual technique of outputting all the bytecode +// to a vector of unsigned char, then copies the vector to an ostream. The +// reason for this is that we must do "seeking" in the stream to do back- +// patching, and some very important ostreams that we want to support (like +// pipes) do not support seeking. :( :( :( +// +//===----------------------------------------------------------------------===// + +#include "WriterInternals.h" +#include "llvm/Bytecode/WriteBytecodePass.h" +#include "llvm/CallingConv.h" +#include "llvm/Constants.h" +#include "llvm/DerivedTypes.h" +#include "llvm/Instructions.h" +#include "llvm/Module.h" +#include "llvm/SymbolTable.h" +#include "llvm/Support/GetElementPtrTypeIterator.h" +#include "llvm/Support/Compressor.h" +#include "llvm/Support/MathExtras.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/Statistic.h" +#include <cstring> +#include <algorithm> +using namespace llvm; + +/// This value needs to be incremented every time the bytecode format changes +/// so that the reader can distinguish which format of the bytecode file has +/// been written. +/// @brief The bytecode version number +const unsigned BCVersionNum = 5; + +static RegisterPass<WriteBytecodePass> X("emitbytecode", "Bytecode Writer"); + +static Statistic<> +BytesWritten("bytecodewriter", "Number of bytecode bytes written"); + +//===----------------------------------------------------------------------===// +//=== Output Primitives ===// +//===----------------------------------------------------------------------===// + +// output - If a position is specified, it must be in the valid portion of the +// string... note that this should be inlined always so only the relevant IF +// body should be included. +inline void BytecodeWriter::output(unsigned i, int pos) { + if (pos == -1) { // Be endian clean, little endian is our friend + Out.push_back((unsigned char)i); + Out.push_back((unsigned char)(i >> 8)); + Out.push_back((unsigned char)(i >> 16)); + Out.push_back((unsigned char)(i >> 24)); + } else { + Out[pos ] = (unsigned char)i; + Out[pos+1] = (unsigned char)(i >> 8); + Out[pos+2] = (unsigned char)(i >> 16); + Out[pos+3] = (unsigned char)(i >> 24); + } +} + +inline void BytecodeWriter::output(int i) { + output((unsigned)i); +} + +/// output_vbr - Output an unsigned value, by using the least number of bytes +/// possible. This is useful because many of our "infinite" values are really +/// very small most of the time; but can be large a few times. +/// Data format used: If you read a byte with the high bit set, use the low +/// seven bits as data and then read another byte. +inline void BytecodeWriter::output_vbr(uint64_t i) { + while (1) { + if (i < 0x80) { // done? + Out.push_back((unsigned char)i); // We know the high bit is clear... + return; + } + + // Nope, we are bigger than a character, output the next 7 bits and set the + // high bit to say that there is more coming... + Out.push_back(0x80 | ((unsigned char)i & 0x7F)); + i >>= 7; // Shift out 7 bits now... + } +} + +inline void BytecodeWriter::output_vbr(unsigned i) { + while (1) { + if (i < 0x80) { // done? + Out.push_back((unsigned char)i); // We know the high bit is clear... + return; + } + + // Nope, we are bigger than a character, output the next 7 bits and set the + // high bit to say that there is more coming... + Out.push_back(0x80 | ((unsigned char)i & 0x7F)); + i >>= 7; // Shift out 7 bits now... + } +} + +inline void BytecodeWriter::output_typeid(unsigned i) { + if (i <= 0x00FFFFFF) + this->output_vbr(i); + else { + this->output_vbr(0x00FFFFFF); + this->output_vbr(i); + } +} + +inline void BytecodeWriter::output_vbr(int64_t i) { + if (i < 0) + output_vbr(((uint64_t)(-i) << 1) | 1); // Set low order sign bit... + else + output_vbr((uint64_t)i << 1); // Low order bit is clear. +} + + +inline void BytecodeWriter::output_vbr(int i) { + if (i < 0) + output_vbr(((unsigned)(-i) << 1) | 1); // Set low order sign bit... + else + output_vbr((unsigned)i << 1); // Low order bit is clear. +} + +inline void BytecodeWriter::output(const std::string &s) { + unsigned Len = s.length(); + output_vbr(Len ); // Strings may have an arbitrary length... + Out.insert(Out.end(), s.begin(), s.end()); +} + +inline void BytecodeWriter::output_data(const void *Ptr, const void *End) { + Out.insert(Out.end(), (const unsigned char*)Ptr, (const unsigned char*)End); +} + +inline void BytecodeWriter::output_float(float& FloatVal) { + /// FIXME: This isn't optimal, it has size problems on some platforms + /// where FP is not IEEE. + uint32_t i = FloatToBits(FloatVal); + Out.push_back( static_cast<unsigned char>( (i & 0xFF ))); + Out.push_back( static_cast<unsigned char>( (i >> 8) & 0xFF)); + Out.push_back( static_cast<unsigned char>( (i >> 16) & 0xFF)); + Out.push_back( static_cast<unsigned char>( (i >> 24) & 0xFF)); +} + +inline void BytecodeWriter::output_double(double& DoubleVal) { + /// FIXME: This isn't optimal, it has size problems on some platforms + /// where FP is not IEEE. + uint64_t i = DoubleToBits(DoubleVal); + Out.push_back( static_cast<unsigned char>( (i & 0xFF ))); + Out.push_back( static_cast<unsigned char>( (i >> 8) & 0xFF)); + Out.push_back( static_cast<unsigned char>( (i >> 16) & 0xFF)); + Out.push_back( static_cast<unsigned char>( (i >> 24) & 0xFF)); + Out.push_back( static_cast<unsigned char>( (i >> 32) & 0xFF)); + Out.push_back( static_cast<unsigned char>( (i >> 40) & 0xFF)); + Out.push_back( static_cast<unsigned char>( (i >> 48) & 0xFF)); + Out.push_back( static_cast<unsigned char>( (i >> 56) & 0xFF)); +} + +inline BytecodeBlock::BytecodeBlock(unsigned ID, BytecodeWriter& w, + bool elideIfEmpty, bool hasLongFormat ) + : Id(ID), Writer(w), ElideIfEmpty(elideIfEmpty), HasLongFormat(hasLongFormat){ + + if (HasLongFormat) { + w.output(ID); + w.output(0U); // For length in long format + } else { + w.output(0U); /// Place holder for ID and length for this block + } + Loc = w.size(); +} + +inline BytecodeBlock::~BytecodeBlock() { // Do backpatch when block goes out + // of scope... + if (Loc == Writer.size() && ElideIfEmpty) { + // If the block is empty, and we are allowed to, do not emit the block at + // all! + Writer.resize(Writer.size()-(HasLongFormat?8:4)); + return; + } + + if (HasLongFormat) + Writer.output(unsigned(Writer.size()-Loc), int(Loc-4)); + else + Writer.output(unsigned(Writer.size()-Loc) << 5 | (Id & 0x1F), int(Loc-4)); +} + +//===----------------------------------------------------------------------===// +//=== Constant Output ===// +//===----------------------------------------------------------------------===// + +void BytecodeWriter::outputType(const Type *T) { + output_vbr((unsigned)T->getTypeID()); + + // That's all there is to handling primitive types... + if (T->isPrimitiveType()) { + return; // We might do this if we alias a prim type: %x = type int + } + + switch (T->getTypeID()) { // Handle derived types now. + case Type::FunctionTyID: { + const FunctionType *MT = cast<FunctionType>(T); + int Slot = Table.getSlot(MT->getReturnType()); + assert(Slot != -1 && "Type used but not available!!"); + output_typeid((unsigned)Slot); + + // Output the number of arguments to function (+1 if varargs): + output_vbr((unsigned)MT->getNumParams()+MT->isVarArg()); + + // Output all of the arguments... + FunctionType::param_iterator I = MT->param_begin(); + for (; I != MT->param_end(); ++I) { + Slot = Table.getSlot(*I); + assert(Slot != -1 && "Type used but not available!!"); + output_typeid((unsigned)Slot); + } + + // Terminate list with VoidTy if we are a varargs function... + if (MT->isVarArg()) + output_typeid((unsigned)Type::VoidTyID); + break; + } + + case Type::ArrayTyID: { + const ArrayType *AT = cast<ArrayType>(T); + int Slot = Table.getSlot(AT->getElementType()); + assert(Slot != -1 && "Type used but not available!!"); + output_typeid((unsigned)Slot); + output_vbr(AT->getNumElements()); + break; + } + + case Type::PackedTyID: { + const PackedType *PT = cast<PackedType>(T); + int Slot = Table.getSlot(PT->getElementType()); + assert(Slot != -1 && "Type used but not available!!"); + output_typeid((unsigned)Slot); + output_vbr(PT->getNumElements()); + break; + } + + + case Type::StructTyID: { + const StructType *ST = cast<StructType>(T); + + // Output all of the element types... + for (StructType::element_iterator I = ST->element_begin(), + E = ST->element_end(); I != E; ++I) { + int Slot = Table.getSlot(*I); + assert(Slot != -1 && "Type used but not available!!"); + output_typeid((unsigned)Slot); + } + + // Terminate list with VoidTy + output_typeid((unsigned)Type::VoidTyID); + break; + } + + case Type::PointerTyID: { + const PointerType *PT = cast<PointerType>(T); + int Slot = Table.getSlot(PT->getElementType()); + assert(Slot != -1 && "Type used but not available!!"); + output_typeid((unsigned)Slot); + break; + } + + case Type::OpaqueTyID: + // No need to emit anything, just the count of opaque types is enough. + break; + + default: + std::cerr << __FILE__ << ":" << __LINE__ << ": Don't know how to serialize" + << " Type '" << T->getDescription() << "'\n"; + break; + } +} + +void BytecodeWriter::outputConstant(const Constant *CPV) { + assert((CPV->getType()->isPrimitiveType() || !CPV->isNullValue()) && + "Shouldn't output null constants!"); + + // We must check for a ConstantExpr before switching by type because + // a ConstantExpr can be of any type, and has no explicit value. + // + if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CPV)) { + // FIXME: Encoding of constant exprs could be much more compact! + assert(CE->getNumOperands() > 0 && "ConstantExpr with 0 operands"); + assert(CE->getNumOperands() != 1 || CE->getOpcode() == Instruction::Cast); + output_vbr(1+CE->getNumOperands()); // flags as an expr + output_vbr(CE->getOpcode()); // flags as an expr + + for (User::const_op_iterator OI = CE->op_begin(); OI != CE->op_end(); ++OI){ + int Slot = Table.getSlot(*OI); + assert(Slot != -1 && "Unknown constant used in ConstantExpr!!"); + output_vbr((unsigned)Slot); + Slot = Table.getSlot((*OI)->getType()); + output_typeid((unsigned)Slot); + } + return; + } else if (isa<UndefValue>(CPV)) { + output_vbr(1U); // 1 -> UndefValue constant. + return; + } else { + output_vbr(0U); // flag as not a ConstantExpr + } + + switch (CPV->getType()->getTypeID()) { + case Type::BoolTyID: // Boolean Types + if (cast<ConstantBool>(CPV)->getValue()) + output_vbr(1U); + else + output_vbr(0U); + break; + + case Type::UByteTyID: // Unsigned integer types... + case Type::UShortTyID: + case Type::UIntTyID: + case Type::ULongTyID: + output_vbr(cast<ConstantUInt>(CPV)->getValue()); + break; + + case Type::SByteTyID: // Signed integer types... + case Type::ShortTyID: + case Type::IntTyID: + case Type::LongTyID: + output_vbr(cast<ConstantSInt>(CPV)->getValue()); + break; + + case Type::ArrayTyID: { + const ConstantArray *CPA = cast<ConstantArray>(CPV); + assert(!CPA->isString() && "Constant strings should be handled specially!"); + + for (unsigned i = 0, e = CPA->getNumOperands(); i != e; ++i) { + int Slot = Table.getSlot(CPA->getOperand(i)); + assert(Slot != -1 && "Constant used but not available!!"); + output_vbr((unsigned)Slot); + } + break; + } + + case Type::PackedTyID: { + const ConstantPacked *CP = cast<ConstantPacked>(CPV); + + for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i) { + int Slot = Table.getSlot(CP->getOperand(i)); + assert(Slot != -1 && "Constant used but not available!!"); + output_vbr((unsigned)Slot); + } + break; + } + + case Type::StructTyID: { + const ConstantStruct *CPS = cast<ConstantStruct>(CPV); + + for (unsigned i = 0, e = CPS->getNumOperands(); i != e; ++i) { + int Slot = Table.getSlot(CPS->getOperand(i)); + assert(Slot != -1 && "Constant used but not available!!"); + output_vbr((unsigned)Slot); + } + break; + } + + case Type::PointerTyID: + assert(0 && "No non-null, non-constant-expr constants allowed!"); + abort(); + + case Type::FloatTyID: { // Floating point types... + float Tmp = (float)cast<ConstantFP>(CPV)->getValue(); + output_float(Tmp); + break; + } + case Type::DoubleTyID: { + double Tmp = cast<ConstantFP>(CPV)->getValue(); + output_double(Tmp); + break; + } + + case Type::VoidTyID: + case Type::LabelTyID: + default: + std::cerr << __FILE__ << ":" << __LINE__ << ": Don't know how to serialize" + << " type '" << *CPV->getType() << "'\n"; + break; + } + return; +} + +void BytecodeWriter::outputConstantStrings() { + SlotCalculator::string_iterator I = Table.string_begin(); + SlotCalculator::string_iterator E = Table.string_end(); + if (I == E) return; // No strings to emit + + // If we have != 0 strings to emit, output them now. Strings are emitted into + // the 'void' type plane. + output_vbr(unsigned(E-I)); + output_typeid(Type::VoidTyID); + + // Emit all of the strings. + for (I = Table.string_begin(); I != E; ++I) { + const ConstantArray *Str = *I; + int Slot = Table.getSlot(Str->getType()); + assert(Slot != -1 && "Constant string of unknown type?"); + output_typeid((unsigned)Slot); + + // Now that we emitted the type (which indicates the size of the string), + // emit all of the characters. + std::string Val = Str->getAsString(); + output_data(Val.c_str(), Val.c_str()+Val.size()); + } +} + +//===----------------------------------------------------------------------===// +//=== Instruction Output ===// +//===----------------------------------------------------------------------===// +typedef unsigned char uchar; + +// outputInstructionFormat0 - Output those weird instructions that have a large +// number of operands or have large operands themselves. +// +// Format: [opcode] [type] [numargs] [arg0] [arg1] ... [arg<numargs-1>] +// +void BytecodeWriter::outputInstructionFormat0(const Instruction *I, + unsigned Opcode, + const SlotCalculator &Table, + unsigned Type) { + // Opcode must have top two bits clear... + output_vbr(Opcode << 2); // Instruction Opcode ID + output_typeid(Type); // Result type + + unsigned NumArgs = I->getNumOperands(); + output_vbr(NumArgs + (isa<CastInst>(I) || + isa<VAArgInst>(I) || Opcode == 56 || Opcode == 58)); + + if (!isa<GetElementPtrInst>(&I)) { + for (unsigned i = 0; i < NumArgs; ++i) { + int Slot = Table.getSlot(I->getOperand(i)); + assert(Slot >= 0 && "No slot number for value!?!?"); + output_vbr((unsigned)Slot); + } + + if (isa<CastInst>(I) || isa<VAArgInst>(I)) { + int Slot = Table.getSlot(I->getType()); + assert(Slot != -1 && "Cast return type unknown?"); + output_typeid((unsigned)Slot); + } else if (Opcode == 56) { // Invoke escape sequence + output_vbr(cast<InvokeInst>(I)->getCallingConv()); + } else if (Opcode == 58) { // Call escape sequence + output_vbr((cast<CallInst>(I)->getCallingConv() << 1) | + unsigned(cast<CallInst>(I)->isTailCall())); + } + } else { + int Slot = Table.getSlot(I->getOperand(0)); + assert(Slot >= 0 && "No slot number for value!?!?"); + output_vbr(unsigned(Slot)); + + // We need to encode the type of sequential type indices into their slot # + unsigned Idx = 1; + for (gep_type_iterator TI = gep_type_begin(I), E = gep_type_end(I); + Idx != NumArgs; ++TI, ++Idx) { + Slot = Table.getSlot(I->getOperand(Idx)); + assert(Slot >= 0 && "No slot number for value!?!?"); + + if (isa<SequentialType>(*TI)) { + unsigned IdxId; + switch (I->getOperand(Idx)->getType()->getTypeID()) { + default: assert(0 && "Unknown index type!"); + case Type::UIntTyID: IdxId = 0; break; + case Type::IntTyID: IdxId = 1; break; + case Type::ULongTyID: IdxId = 2; break; + case Type::LongTyID: IdxId = 3; break; + } + Slot = (Slot << 2) | IdxId; + } + output_vbr(unsigned(Slot)); + } + } +} + + +// outputInstrVarArgsCall - Output the absurdly annoying varargs function calls. +// This are more annoying than most because the signature of the call does not +// tell us anything about the types of the arguments in the varargs portion. +// Because of this, we encode (as type 0) all of the argument types explicitly +// before the argument value. This really sucks, but you shouldn't be using +// varargs functions in your code! *death to printf*! +// +// Format: [opcode] [type] [numargs] [arg0] [arg1] ... [arg<numargs-1>] +// +void BytecodeWriter::outputInstrVarArgsCall(const Instruction *I, + unsigned Opcode, + const SlotCalculator &Table, + unsigned Type) { + assert(isa<CallInst>(I) || isa<InvokeInst>(I)); + // Opcode must have top two bits clear... + output_vbr(Opcode << 2); // Instruction Opcode ID + output_typeid(Type); // Result type (varargs type) + + const PointerType *PTy = cast<PointerType>(I->getOperand(0)->getType()); + const FunctionType *FTy = cast<FunctionType>(PTy->getElementType()); + unsigned NumParams = FTy->getNumParams(); + + unsigned NumFixedOperands; + if (isa<CallInst>(I)) { + // Output an operand for the callee and each fixed argument, then two for + // each variable argument. + NumFixedOperands = 1+NumParams; + } else { + assert(isa<InvokeInst>(I) && "Not call or invoke??"); + // Output an operand for the callee and destinations, then two for each + // variable argument. + NumFixedOperands = 3+NumParams; + } + output_vbr(2 * I->getNumOperands()-NumFixedOperands); + + // The type for the function has already been emitted in the type field of the + // instruction. Just emit the slot # now. + for (unsigned i = 0; i != NumFixedOperands; ++i) { + int Slot = Table.getSlot(I->getOperand(i)); + assert(Slot >= 0 && "No slot number for value!?!?"); + output_vbr((unsigned)Slot); + } + + for (unsigned i = NumFixedOperands, e = I->getNumOperands(); i != e; ++i) { + // Output Arg Type ID + int Slot = Table.getSlot(I->getOperand(i)->getType()); + assert(Slot >= 0 && "No slot number for value!?!?"); + output_typeid((unsigned)Slot); + + // Output arg ID itself + Slot = Table.getSlot(I->getOperand(i)); + assert(Slot >= 0 && "No slot number for value!?!?"); + output_vbr((unsigned)Slot); + } +} + + +// outputInstructionFormat1 - Output one operand instructions, knowing that no +// operand index is >= 2^12. +// +inline void BytecodeWriter::outputInstructionFormat1(const Instruction *I, + unsigned Opcode, + unsigned *Slots, + unsigned Type) { + // bits Instruction format: + // -------------------------- + // 01-00: Opcode type, fixed to 1. + // 07-02: Opcode + // 19-08: Resulting type plane + // 31-20: Operand #1 (if set to (2^12-1), then zero operands) + // + output(1 | (Opcode << 2) | (Type << 8) | (Slots[0] << 20)); +} + + +// outputInstructionFormat2 - Output two operand instructions, knowing that no +// operand index is >= 2^8. +// +inline void BytecodeWriter::outputInstructionFormat2(const Instruction *I, + unsigned Opcode, + unsigned *Slots, + unsigned Type) { + // bits Instruction format: + // -------------------------- + // 01-00: Opcode type, fixed to 2. + // 07-02: Opcode + // 15-08: Resulting type plane + // 23-16: Operand #1 + // 31-24: Operand #2 + // + output(2 | (Opcode << 2) | (Type << 8) | (Slots[0] << 16) | (Slots[1] << 24)); +} + + +// outputInstructionFormat3 - Output three operand instructions, knowing that no +// operand index is >= 2^6. +// +inline void BytecodeWriter::outputInstructionFormat3(const Instruction *I, + unsigned Opcode, + unsigned *Slots, + unsigned Type) { + // bits Instruction format: + // -------------------------- + // 01-00: Opcode type, fixed to 3. + // 07-02: Opcode + // 13-08: Resulting type plane + // 19-14: Operand #1 + // 25-20: Operand #2 + // 31-26: Operand #3 + // + output(3 | (Opcode << 2) | (Type << 8) | + (Slots[0] << 14) | (Slots[1] << 20) | (Slots[2] << 26)); +} + +void BytecodeWriter::outputInstruction(const Instruction &I) { + assert(I.getOpcode() < 56 && "Opcode too big???"); + unsigned Opcode = I.getOpcode(); + unsigned NumOperands = I.getNumOperands(); + + // Encode 'tail call' as 61, 'volatile load' as 62, and 'volatile store' as + // 63. + if (const CallInst *CI = dyn_cast<CallInst>(&I)) { + if (CI->getCallingConv() == CallingConv::C) { + if (CI->isTailCall()) + Opcode = 61; // CCC + Tail Call + else + ; // Opcode = Instruction::Call + } else if (CI->getCallingConv() == CallingConv::Fast) { + if (CI->isTailCall()) + Opcode = 59; // FastCC + TailCall + else + Opcode = 60; // FastCC + Not Tail Call + } else { + Opcode = 58; // Call escape sequence. + } + } else if (const InvokeInst *II = dyn_cast<InvokeInst>(&I)) { + if (II->getCallingConv() == CallingConv::Fast) + Opcode = 57; // FastCC invoke. + else if (II->getCallingConv() != CallingConv::C) + Opcode = 56; // Invoke escape sequence. + + } else if (isa<LoadInst>(I) && cast<LoadInst>(I).isVolatile()) { + Opcode = 62; + } else if (isa<StoreInst>(I) && cast<StoreInst>(I).isVolatile()) { + Opcode = 63; + } + + // Figure out which type to encode with the instruction. Typically we want + // the type of the first parameter, as opposed to the type of the instruction + // (for example, with setcc, we always know it returns bool, but the type of + // the first param is actually interesting). But if we have no arguments + // we take the type of the instruction itself. + // + const Type *Ty; + switch (I.getOpcode()) { + case Instruction::Select: + case Instruction::Malloc: + case Instruction::Alloca: + Ty = I.getType(); // These ALWAYS want to encode the return type + break; + case Instruction::Store: + Ty = I.getOperand(1)->getType(); // Encode the pointer type... + assert(isa<PointerType>(Ty) && "Store to nonpointer type!?!?"); + break; + default: // Otherwise use the default behavior... + Ty = NumOperands ? I.getOperand(0)->getType() : I.getType(); + break; + } + + unsigned Type; + int Slot = Table.getSlot(Ty); + assert(Slot != -1 && "Type not available!!?!"); + Type = (unsigned)Slot; + + // Varargs calls and invokes are encoded entirely different from any other + // instructions. + if (const CallInst *CI = dyn_cast<CallInst>(&I)){ + const PointerType *Ty =cast<PointerType>(CI->getCalledValue()->getType()); + if (cast<FunctionType>(Ty->getElementType())->isVarArg()) { + outputInstrVarArgsCall(CI, Opcode, Table, Type); + return; + } + } else if (const InvokeInst *II = dyn_cast<InvokeInst>(&I)) { + const PointerType *Ty =cast<PointerType>(II->getCalledValue()->getType()); + if (cast<FunctionType>(Ty->getElementType())->isVarArg()) { + outputInstrVarArgsCall(II, Opcode, Table, Type); + return; + } + } + + if (NumOperands <= 3) { + // Make sure that we take the type number into consideration. We don't want + // to overflow the field size for the instruction format we select. + // + unsigned MaxOpSlot = Type; + unsigned Slots[3]; Slots[0] = (1 << 12)-1; // Marker to signify 0 operands + + for (unsigned i = 0; i != NumOperands; ++i) { + int slot = Table.getSlot(I.getOperand(i)); + assert(slot != -1 && "Broken bytecode!"); + if (unsigned(slot) > MaxOpSlot) MaxOpSlot = unsigned(slot); + Slots[i] = unsigned(slot); + } + + // Handle the special cases for various instructions... + if (isa<CastInst>(I) || isa<VAArgInst>(I)) { + // Cast has to encode the destination type as the second argument in the + // packet, or else we won't know what type to cast to! + Slots[1] = Table.getSlot(I.getType()); + assert(Slots[1] != ~0U && "Cast return type unknown?"); + if (Slots[1] > MaxOpSlot) MaxOpSlot = Slots[1]; + NumOperands++; + } else if (const GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(&I)) { + // We need to encode the type of sequential type indices into their slot # + unsigned Idx = 1; + for (gep_type_iterator I = gep_type_begin(GEP), E = gep_type_end(GEP); + I != E; ++I, ++Idx) + if (isa<SequentialType>(*I)) { + unsigned IdxId; + switch (GEP->getOperand(Idx)->getType()->getTypeID()) { + default: assert(0 && "Unknown index type!"); + case Type::UIntTyID: IdxId = 0; break; + case Type::IntTyID: IdxId = 1; break; + case Type::ULongTyID: IdxId = 2; break; + case Type::LongTyID: IdxId = 3; break; + } + Slots[Idx] = (Slots[Idx] << 2) | IdxId; + if (Slots[Idx] > MaxOpSlot) MaxOpSlot = Slots[Idx]; + } + } else if (Opcode == 58) { + // If this is the escape sequence for call, emit the tailcall/cc info. + const CallInst &CI = cast<CallInst>(I); + ++NumOperands; + if (NumOperands < 3) { + Slots[NumOperands-1] = (CI.getCallingConv() << 1)|unsigned(CI.isTailCall()); + if (Slots[NumOperands-1] > MaxOpSlot) + MaxOpSlot = Slots[NumOperands-1]; + } + } else if (Opcode == 56) { + // Invoke escape seq has at least 4 operands to encode. + ++NumOperands; + } + + // Decide which instruction encoding to use. This is determined primarily + // by the number of operands, and secondarily by whether or not the max + // operand will fit into the instruction encoding. More operands == fewer + // bits per operand. + // + switch (NumOperands) { + case 0: + case 1: + if (MaxOpSlot < (1 << 12)-1) { // -1 because we use 4095 to indicate 0 ops + outputInstructionFormat1(&I, Opcode, Slots, Type); + return; + } + break; + + case 2: + if (MaxOpSlot < (1 << 8)) { + outputInstructionFormat2(&I, Opcode, Slots, Type); + return; + } + break; + + case 3: + if (MaxOpSlot < (1 << 6)) { + outputInstructionFormat3(&I, Opcode, Slots, Type); + return; + } + break; + default: + break; + } + } + + // If we weren't handled before here, we either have a large number of + // operands or a large operand index that we are referring to. + outputInstructionFormat0(&I, Opcode, Table, Type); +} + +//===----------------------------------------------------------------------===// +//=== Block Output ===// +//===----------------------------------------------------------------------===// + +BytecodeWriter::BytecodeWriter(std::vector<unsigned char> &o, const Module *M) + : Out(o), Table(M) { + + // Emit the signature... + static const unsigned char *Sig = (const unsigned char*)"llvm"; + output_data(Sig, Sig+4); + + // Emit the top level CLASS block. + BytecodeBlock ModuleBlock(BytecodeFormat::ModuleBlockID, *this, false, true); + + bool isBigEndian = M->getEndianness() == Module::BigEndian; + bool hasLongPointers = M->getPointerSize() == Module::Pointer64; + bool hasNoEndianness = M->getEndianness() == Module::AnyEndianness; + bool hasNoPointerSize = M->getPointerSize() == Module::AnyPointerSize; + + // Output the version identifier and other information. + unsigned Version = (BCVersionNum << 4) | + (unsigned)isBigEndian | (hasLongPointers << 1) | + (hasNoEndianness << 2) | + (hasNoPointerSize << 3); + output_vbr(Version); + + // The Global type plane comes first + { + BytecodeBlock CPool(BytecodeFormat::GlobalTypePlaneBlockID, *this ); + outputTypes(Type::FirstDerivedTyID); + } + + // The ModuleInfoBlock follows directly after the type information + outputModuleInfoBlock(M); + + // Output module level constants, used for global variable initializers + outputConstants(false); + + // Do the whole module now! Process each function at a time... + for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) + outputFunction(I); + + // If needed, output the symbol table for the module... + outputSymbolTable(M->getSymbolTable()); +} + +void BytecodeWriter::outputTypes(unsigned TypeNum) { + // Write the type plane for types first because earlier planes (e.g. for a + // primitive type like float) may have constants constructed using types + // coming later (e.g., via getelementptr from a pointer type). The type + // plane is needed before types can be fwd or bkwd referenced. + const std::vector<const Type*>& Types = Table.getTypes(); + assert(!Types.empty() && "No types at all?"); + assert(TypeNum <= Types.size() && "Invalid TypeNo index"); + + unsigned NumEntries = Types.size() - TypeNum; + + // Output type header: [num entries] + output_vbr(NumEntries); + + for (unsigned i = TypeNum; i < TypeNum+NumEntries; ++i) + outputType(Types[i]); +} + +// Helper function for outputConstants(). +// Writes out all the constants in the plane Plane starting at entry StartNo. +// +void BytecodeWriter::outputConstantsInPlane(const std::vector<const Value*> + &Plane, unsigned StartNo) { + unsigned ValNo = StartNo; + + // Scan through and ignore function arguments, global values, and constant + // strings. + for (; ValNo < Plane.size() && + (isa<Argument>(Plane[ValNo]) || isa<GlobalValue>(Plane[ValNo]) || + (isa<ConstantArray>(Plane[ValNo]) && + cast<ConstantArray>(Plane[ValNo])->isString())); ValNo++) + /*empty*/; + + unsigned NC = ValNo; // Number of constants + for (; NC < Plane.size() && (isa<Constant>(Plane[NC])); NC++) + /*empty*/; + NC -= ValNo; // Convert from index into count + if (NC == 0) return; // Skip empty type planes... + + // FIXME: Most slabs only have 1 or 2 entries! We should encode this much + // more compactly. + + // Output type header: [num entries][type id number] + // + output_vbr(NC); + + // Output the Type ID Number... + int Slot = Table.getSlot(Plane.front()->getType()); + assert (Slot != -1 && "Type in constant pool but not in function!!"); + output_typeid((unsigned)Slot); + + for (unsigned i = ValNo; i < ValNo+NC; ++i) { + const Value *V = Plane[i]; + if (const Constant *C = dyn_cast<Constant>(V)) { + outputConstant(C); + } + } +} + +static inline bool hasNullValue(const Type *Ty) { + return Ty != Type::LabelTy && Ty != Type::VoidTy && !isa<OpaqueType>(Ty); +} + +void BytecodeWriter::outputConstants(bool isFunction) { + BytecodeBlock CPool(BytecodeFormat::ConstantPoolBlockID, *this, + true /* Elide block if empty */); + + unsigned NumPlanes = Table.getNumPlanes(); + + if (isFunction) + // Output the type plane before any constants! + outputTypes(Table.getModuleTypeLevel()); + else + // Output module-level string constants before any other constants. + outputConstantStrings(); + + for (unsigned pno = 0; pno != NumPlanes; pno++) { + const std::vector<const Value*> &Plane = Table.getPlane(pno); + if (!Plane.empty()) { // Skip empty type planes... + unsigned ValNo = 0; + if (isFunction) // Don't re-emit module constants + ValNo += Table.getModuleLevel(pno); + + if (hasNullValue(Plane[0]->getType())) { + // Skip zero initializer + if (ValNo == 0) + ValNo = 1; + } + + // Write out constants in the plane + outputConstantsInPlane(Plane, ValNo); + } + } +} + +static unsigned getEncodedLinkage(const GlobalValue *GV) { + switch (GV->getLinkage()) { + default: assert(0 && "Invalid linkage!"); + case GlobalValue::ExternalLinkage: return 0; + case GlobalValue::WeakLinkage: return 1; + case GlobalValue::AppendingLinkage: return 2; + case GlobalValue::InternalLinkage: return 3; + case GlobalValue::LinkOnceLinkage: return 4; + } +} + +void BytecodeWriter::outputModuleInfoBlock(const Module *M) { + BytecodeBlock ModuleInfoBlock(BytecodeFormat::ModuleGlobalInfoBlockID, *this); + + // Output the types for the global variables in the module... + for (Module::const_global_iterator I = M->global_begin(), + End = M->global_end(); I != End;++I) { + int Slot = Table.getSlot(I->getType()); + assert(Slot != -1 && "Module global vars is broken!"); + + // Fields: bit0 = isConstant, bit1 = hasInitializer, bit2-4=Linkage, + // bit5+ = Slot # for type + unsigned oSlot = ((unsigned)Slot << 5) | (getEncodedLinkage(I) << 2) | + (I->hasInitializer() << 1) | (unsigned)I->isConstant(); + output_vbr(oSlot); + + // If we have an initializer, output it now. + if (I->hasInitializer()) { + Slot = Table.getSlot((Value*)I->getInitializer()); + assert(Slot != -1 && "No slot for global var initializer!"); + output_vbr((unsigned)Slot); + } + } + output_typeid((unsigned)Table.getSlot(Type::VoidTy)); + + // Output the types of the functions in this module. + for (Module::const_iterator I = M->begin(), End = M->end(); I != End; ++I) { + int Slot = Table.getSlot(I->getType()); + assert(Slot != -1 && "Module slot calculator is broken!"); + assert(Slot >= Type::FirstDerivedTyID && "Derived type not in range!"); + assert(((Slot << 5) >> 5) == Slot && "Slot # too big!"); + unsigned ID = (Slot << 5); + + if (I->getCallingConv() < 15) + ID += I->getCallingConv()+1; + + if (I->isExternal()) // If external, we don't have an FunctionInfo block. + ID |= 1 << 4; + output_vbr(ID); + + if (I->getCallingConv() >= 15) + output_vbr(I->getCallingConv()); + } + output_vbr((unsigned)Table.getSlot(Type::VoidTy) << 5); + + // Emit the list of dependent libraries for the Module. + Module::lib_iterator LI = M->lib_begin(); + Module::lib_iterator LE = M->lib_end(); + output_vbr(unsigned(LE - LI)); // Emit the number of dependent libraries. + for (; LI != LE; ++LI) + output(*LI); + + // Output the target triple from the module + output(M->getTargetTriple()); +} + +void BytecodeWriter::outputInstructions(const Function *F) { + BytecodeBlock ILBlock(BytecodeFormat::InstructionListBlockID, *this); + for (Function::const_iterator BB = F->begin(), E = F->end(); BB != E; ++BB) + for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I!=E; ++I) + outputInstruction(*I); +} + +void BytecodeWriter::outputFunction(const Function *F) { + // If this is an external function, there is nothing else to emit! + if (F->isExternal()) return; + + BytecodeBlock FunctionBlock(BytecodeFormat::FunctionBlockID, *this); + output_vbr(getEncodedLinkage(F)); + + // Get slot information about the function... + Table.incorporateFunction(F); + + if (Table.getCompactionTable().empty()) { + // Output information about the constants in the function if the compaction + // table is not being used. + outputConstants(true); + } else { + // Otherwise, emit the compaction table. + outputCompactionTable(); + } + + // Output all of the instructions in the body of the function + outputInstructions(F); + + // If needed, output the symbol table for the function... + outputSymbolTable(F->getSymbolTable()); + + Table.purgeFunction(); +} + +void BytecodeWriter::outputCompactionTablePlane(unsigned PlaneNo, + const std::vector<const Value*> &Plane, + unsigned StartNo) { + unsigned End = Table.getModuleLevel(PlaneNo); + if (Plane.empty() || StartNo == End || End == 0) return; // Nothing to emit + assert(StartNo < End && "Cannot emit negative range!"); + assert(StartNo < Plane.size() && End <= Plane.size()); + + // Do not emit the null initializer! + ++StartNo; + + // Figure out which encoding to use. By far the most common case we have is + // to emit 0-2 entries in a compaction table plane. + switch (End-StartNo) { + case 0: // Avoid emitting two vbr's if possible. + case 1: + case 2: + output_vbr((PlaneNo << 2) | End-StartNo); + break; + default: + // Output the number of things. + output_vbr((unsigned(End-StartNo) << 2) | 3); + output_typeid(PlaneNo); // Emit the type plane this is + break; + } + + for (unsigned i = StartNo; i != End; ++i) + output_vbr(Table.getGlobalSlot(Plane[i])); +} + +void BytecodeWriter::outputCompactionTypes(unsigned StartNo) { + // Get the compaction type table from the slot calculator + const std::vector<const Type*> &CTypes = Table.getCompactionTypes(); + + // The compaction types may have been uncompactified back to the + // global types. If so, we just write an empty table + if (CTypes.size() == 0 ) { + output_vbr(0U); + return; + } + + assert(CTypes.size() >= StartNo && "Invalid compaction types start index"); + + // Determine how many types to write + unsigned NumTypes = CTypes.size() - StartNo; + + // Output the number of types. + output_vbr(NumTypes); + + for (unsigned i = StartNo; i < StartNo+NumTypes; ++i) + output_typeid(Table.getGlobalSlot(CTypes[i])); +} + +void BytecodeWriter::outputCompactionTable() { + // Avoid writing the compaction table at all if there is no content. + if (Table.getCompactionTypes().size() >= Type::FirstDerivedTyID || + (!Table.CompactionTableIsEmpty())) { + BytecodeBlock CTB(BytecodeFormat::CompactionTableBlockID, *this, + true/*ElideIfEmpty*/); + const std::vector<std::vector<const Value*> > &CT = + Table.getCompactionTable(); + + // First things first, emit the type compaction table if there is one. + outputCompactionTypes(Type::FirstDerivedTyID); + + for (unsigned i = 0, e = CT.size(); i != e; ++i) + outputCompactionTablePlane(i, CT[i], 0); + } +} + +void BytecodeWriter::outputSymbolTable(const SymbolTable &MST) { + // Do not output the Bytecode block for an empty symbol table, it just wastes + // space! + if (MST.isEmpty()) return; + + BytecodeBlock SymTabBlock(BytecodeFormat::SymbolTableBlockID, *this, + true/*ElideIfEmpty*/); + + // Write the number of types + output_vbr(MST.num_types()); + + // Write each of the types + for (SymbolTable::type_const_iterator TI = MST.type_begin(), + TE = MST.type_end(); TI != TE; ++TI ) { + // Symtab entry:[def slot #][name] + output_typeid((unsigned)Table.getSlot(TI->second)); + output(TI->first); + } + + // Now do each of the type planes in order. + for (SymbolTable::plane_const_iterator PI = MST.plane_begin(), + PE = MST.plane_end(); PI != PE; ++PI) { + SymbolTable::value_const_iterator I = MST.value_begin(PI->first); + SymbolTable::value_const_iterator End = MST.value_end(PI->first); + int Slot; + + if (I == End) continue; // Don't mess with an absent type... + + // Write the number of values in this plane + output_vbr((unsigned)PI->second.size()); + + // Write the slot number of the type for this plane + Slot = Table.getSlot(PI->first); + assert(Slot != -1 && "Type in symtab, but not in table!"); + output_typeid((unsigned)Slot); + + // Write each of the values in this plane + for (; I != End; ++I) { + // Symtab entry: [def slot #][name] + Slot = Table.getSlot(I->second); + assert(Slot != -1 && "Value in symtab but has no slot number!!"); + output_vbr((unsigned)Slot); + output(I->first); + } + } +} + +void llvm::WriteBytecodeToFile(const Module *M, std::ostream &Out, + bool compress ) { + assert(M && "You can't write a null module!!"); + + // Create a vector of unsigned char for the bytecode output. We + // reserve 256KBytes of space in the vector so that we avoid doing + // lots of little allocations. 256KBytes is sufficient for a large + // proportion of the bytecode files we will encounter. Larger files + // will be automatically doubled in size as needed (std::vector + // behavior). + std::vector<unsigned char> Buffer; + Buffer.reserve(256 * 1024); + + // The BytecodeWriter populates Buffer for us. + BytecodeWriter BCW(Buffer, M); + + // Keep track of how much we've written + BytesWritten += Buffer.size(); + + // Determine start and end points of the Buffer + const unsigned char *FirstByte = &Buffer.front(); + + // If we're supposed to compress this mess ... + if (compress) { + + // We signal compression by using an alternate magic number for the + // file. The compressed bytecode file's magic number is "llvc" instead + // of "llvm". + char compressed_magic[4]; + compressed_magic[0] = 'l'; + compressed_magic[1] = 'l'; + compressed_magic[2] = 'v'; + compressed_magic[3] = 'c'; + + Out.write(compressed_magic,4); + + // Compress everything after the magic number (which we altered) + uint64_t zipSize = Compressor::compressToStream( + (char*)(FirstByte+4), // Skip the magic number + Buffer.size()-4, // Skip the magic number + Out // Where to write compressed data + ); + + } else { + + // We're not compressing, so just write the entire block. + Out.write((char*)FirstByte, Buffer.size()); + } + + // make sure it hits disk now + Out.flush(); +} + |