| //===-- 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. :( :( :( |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #define DEBUG_TYPE "bytecodewriter" |
| #include "WriterInternals.h" |
| #include "llvm/Bytecode/WriteBytecodePass.h" |
| #include "llvm/CallingConv.h" |
| #include "llvm/Constants.h" |
| #include "llvm/DerivedTypes.h" |
| #include "llvm/InlineAsm.h" |
| #include "llvm/Instructions.h" |
| #include "llvm/Module.h" |
| #include "llvm/TypeSymbolTable.h" |
| #include "llvm/ValueSymbolTable.h" |
| #include "llvm/Support/GetElementPtrTypeIterator.h" |
| #include "llvm/Support/Compressor.h" |
| #include "llvm/Support/MathExtras.h" |
| #include "llvm/Support/Streams.h" |
| #include "llvm/System/Program.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 = 7; |
| |
| static RegisterPass<WriteBytecodePass> X("emitbytecode", "Bytecode Writer"); |
| |
| STATISTIC(BytesWritten, "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) { |
| const StructType* STy = dyn_cast<StructType>(T); |
| if(STy && STy->isPacked()) |
| output_vbr((unsigned)Type::PackedStructTyID); |
| else |
| 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::IntegerTyID: |
| output_vbr(cast<IntegerType>(T)->getBitWidth()); |
| break; |
| 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_vbr(unsigned(MT->getParamAttrs(0))); |
| |
| // 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(); |
| unsigned Idx = 1; |
| for (; I != MT->param_end(); ++I) { |
| Slot = Table.getSlot(*I); |
| assert(Slot != -1 && "Type used but not available!!"); |
| output_typeid((unsigned)Slot); |
| output_vbr(unsigned(MT->getParamAttrs(Idx))); |
| Idx++; |
| } |
| |
| // 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: |
| 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->getType()->isInteger()) || |
| !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->isCast()); |
| output_vbr(1+CE->getNumOperands()); // flags as an expr |
| output_vbr(CE->getOpcode()); // Put out the CE op code |
| |
| 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); |
| } |
| if (CE->isCompare()) |
| output_vbr((unsigned)CE->getPredicate()); |
| return; |
| } else if (isa<UndefValue>(CPV)) { |
| output_vbr(1U); // 1 -> UndefValue constant. |
| return; |
| } else { |
| output_vbr(0U); // flag as not a ConstantExpr (i.e. 0 operands) |
| } |
| |
| switch (CPV->getType()->getTypeID()) { |
| case Type::IntegerTyID: { // Integer types... |
| unsigned NumBits = cast<IntegerType>(CPV->getType())->getBitWidth(); |
| if (NumBits <= 32) |
| output_vbr(uint32_t(cast<ConstantInt>(CPV)->getZExtValue())); |
| else if (NumBits <= 64) |
| output_vbr(uint64_t(cast<ConstantInt>(CPV)->getZExtValue())); |
| else |
| assert("Integer types > 64 bits not supported."); |
| 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: |
| cerr << __FILE__ << ":" << __LINE__ << ": Don't know how to serialize" |
| << " type '" << *CPV->getType() << "'\n"; |
| break; |
| } |
| return; |
| } |
| |
| /// outputInlineAsm - InlineAsm's get emitted to the constant pool, so they can |
| /// be shared by multiple uses. |
| void BytecodeWriter::outputInlineAsm(const InlineAsm *IA) { |
| // Output a marker, so we know when we have one one parsing the constant pool. |
| // Note that this encoding is 5 bytes: not very efficient for a marker. Since |
| // unique inline asms are rare, this should hardly matter. |
| output_vbr(~0U); |
| |
| output(IA->getAsmString()); |
| output(IA->getConstraintString()); |
| output_vbr(unsigned(IA->hasSideEffects())); |
| } |
| |
| 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 ===// |
| //===----------------------------------------------------------------------===// |
| |
| // 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<InvokeInst>(I) || |
| isa<CmpInst>(I) || isa<VAArgInst>(I) || 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 (isa<CmpInst>(I)) { |
| output_vbr(unsigned(cast<CmpInst>(I)->getPredicate())); |
| } else if (isa<InvokeInst>(I)) { |
| 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)) { |
| // These should be either 32-bits or 64-bits, however, with bit |
| // accurate types we just distinguish between less than or equal to |
| // 32-bits or greater than 32-bits. |
| unsigned BitWidth = |
| cast<IntegerType>(I->getOperand(Idx)->getType())->getBitWidth(); |
| assert(BitWidth == 32 || BitWidth == 64 && |
| "Invalid bitwidth for GEP index"); |
| unsigned IdxId = BitWidth == 32 ? 0 : 1; |
| Slot = (Slot << 1) | 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 + |
| unsigned(Opcode == 58 || isa<InvokeInst>(I))); |
| |
| // 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); |
| } |
| |
| if (isa<InvokeInst>(I)) { |
| // Emit the tail call/calling conv for invoke instructions |
| output_vbr(cast<InvokeInst>(I)->getCallingConv()); |
| } else if (Opcode == 58) { |
| const CallInst *CI = cast<CallInst>(I); |
| output_vbr((CI->getCallingConv() << 1) | unsigned(CI->isTailCall())); |
| } |
| } |
| |
| |
| // 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() < 57 && "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 (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 AllocationInst *AI = dyn_cast<AllocationInst>(&I)) { |
| assert(NumOperands == 1 && "Bogus allocation!"); |
| if (AI->getAlignment()) { |
| Slots[1] = Log2_32(AI->getAlignment())+1; |
| if (Slots[1] > MaxOpSlot) MaxOpSlot = Slots[1]; |
| NumOperands = 2; |
| } |
| } else if (isa<ICmpInst>(I) || isa<FCmpInst>(I)) { |
| // We need to encode the compare instruction's predicate as the third |
| // operand. Its not really a slot, but we don't want to break the |
| // instruction format for these instructions. |
| NumOperands++; |
| assert(NumOperands == 3 && "CmpInst with wrong number of operands?"); |
| Slots[2] = unsigned(cast<CmpInst>(&I)->getPredicate()); |
| if (Slots[2] > MaxOpSlot) |
| MaxOpSlot = Slots[2]; |
| } 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)) { |
| // These should be either 32-bits or 64-bits, however, with bit |
| // accurate types we just distinguish between less than or equal to |
| // 32-bits or greater than 32-bits. |
| unsigned BitWidth = |
| cast<IntegerType>(GEP->getOperand(Idx)->getType())->getBitWidth(); |
| assert(BitWidth == 32 || BitWidth == 64 && |
| "Invalid bitwidth for GEP index"); |
| unsigned IdxId = BitWidth == 32 ? 0 : 1; |
| Slots[Idx] = (Slots[Idx] << 1) | 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 (isa<InvokeInst>(I)) { |
| // 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); |
| |
| // Output the version identifier |
| output_vbr(BCVersionNum); |
| |
| // 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(); |
| |
| // 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); |
| |
| // Output the symbole table for types |
| outputTypeSymbolTable(M->getTypeSymbolTable()); |
| |
| // Output the symbol table for values |
| outputValueSymbolTable(M->getValueSymbolTable()); |
| } |
| |
| 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]) || |
| isa<InlineAsm>(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. |
| |
| // Put out type header: [num entries][type id number] |
| // |
| output_vbr(NC); |
| |
| // Put out 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); |
| else |
| outputInlineAsm(cast<InlineAsm>(V)); |
| } |
| } |
| |
| static inline bool hasNullValue(const Type *Ty) { |
| return Ty != Type::LabelTy && Ty != Type::VoidTy && !isa<OpaqueType>(Ty); |
| } |
| |
| void BytecodeWriter::outputConstants() { |
| BytecodeBlock CPool(BytecodeFormat::ConstantPoolBlockID, *this, |
| true /* Elide block if empty */); |
| |
| unsigned NumPlanes = Table.getNumPlanes(); |
| |
| // 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 (hasNullValue(Plane[0]->getType())) { |
| // Skip zero initializer |
| 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; |
| case GlobalValue::DLLImportLinkage: return 5; |
| case GlobalValue::DLLExportLinkage: return 6; |
| case GlobalValue::ExternalWeakLinkage: return 7; |
| } |
| } |
| |
| static unsigned getEncodedVisibility(const GlobalValue *GV) { |
| switch (GV->getVisibility()) { |
| default: assert(0 && "Invalid visibility!"); |
| case GlobalValue::DefaultVisibility: return 0; |
| case GlobalValue::HiddenVisibility: return 1; |
| } |
| } |
| |
| void BytecodeWriter::outputModuleInfoBlock(const Module *M) { |
| BytecodeBlock ModuleInfoBlock(BytecodeFormat::ModuleGlobalInfoBlockID, *this); |
| |
| // Give numbers to sections as we encounter them. |
| unsigned SectionIDCounter = 0; |
| std::vector<std::string> SectionNames; |
| std::map<std::string, unsigned> SectionID; |
| |
| // 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!"); |
| |
| assert((I->hasInitializer() || !I->hasInternalLinkage()) && |
| "Global must have an initializer or have external linkage!"); |
| |
| // Fields: bit0 = isConstant, bit1 = hasInitializer, bit2-4=Linkage, |
| // bit5+ = Slot # for type. |
| bool HasExtensionWord = (I->getAlignment() != 0) || |
| I->hasSection() || |
| (I->getVisibility() != GlobalValue::DefaultVisibility); |
| |
| // If we need to use the extension byte, set linkage=3(internal) and |
| // initializer = 0 (impossible!). |
| if (!HasExtensionWord) { |
| unsigned oSlot = ((unsigned)Slot << 5) | (getEncodedLinkage(I) << 2) | |
| (I->hasInitializer() << 1) | (unsigned)I->isConstant(); |
| output_vbr(oSlot); |
| } else { |
| unsigned oSlot = ((unsigned)Slot << 5) | (3 << 2) | |
| (0 << 1) | (unsigned)I->isConstant(); |
| output_vbr(oSlot); |
| |
| // The extension word has this format: bit 0 = has initializer, bit 1-3 = |
| // linkage, bit 4-8 = alignment (log2), bit 9 = has SectionID, |
| // bits 10-12 = visibility, bits 13+ = future use. |
| unsigned ExtWord = (unsigned)I->hasInitializer() | |
| (getEncodedLinkage(I) << 1) | |
| ((Log2_32(I->getAlignment())+1) << 4) | |
| ((unsigned)I->hasSection() << 9) | |
| (getEncodedVisibility(I) << 10); |
| output_vbr(ExtWord); |
| if (I->hasSection()) { |
| // Give section names unique ID's. |
| unsigned &Entry = SectionID[I->getSection()]; |
| if (Entry == 0) { |
| Entry = ++SectionIDCounter; |
| SectionNames.push_back(I->getSection()); |
| } |
| output_vbr(Entry); |
| } |
| } |
| |
| // 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 << 6) >> 6) == Slot && "Slot # too big!"); |
| unsigned CC = I->getCallingConv()+1; |
| unsigned ID = (Slot << 5) | (CC & 15); |
| |
| if (I->isDeclaration()) // If external, we don't have an FunctionInfo block. |
| ID |= 1 << 4; |
| |
| if (I->getAlignment() || I->hasSection() || (CC & ~15) != 0 || |
| (I->isDeclaration() && I->hasDLLImportLinkage()) || |
| (I->isDeclaration() && I->hasExternalWeakLinkage()) |
| ) |
| ID |= 1 << 31; // Do we need an extension word? |
| |
| output_vbr(ID); |
| |
| if (ID & (1 << 31)) { |
| // Extension byte: bits 0-4 = alignment, bits 5-9 = top nibble of calling |
| // convention, bit 10 = hasSectionID., bits 11-12 = external linkage type |
| unsigned extLinkage = 0; |
| |
| if (I->isDeclaration()) { |
| if (I->hasDLLImportLinkage()) { |
| extLinkage = 1; |
| } else if (I->hasExternalWeakLinkage()) { |
| extLinkage = 2; |
| } |
| } |
| |
| ID = (Log2_32(I->getAlignment())+1) | ((CC >> 4) << 5) | |
| (I->hasSection() << 10) | |
| ((extLinkage & 3) << 11); |
| output_vbr(ID); |
| |
| // Give section names unique ID's. |
| if (I->hasSection()) { |
| unsigned &Entry = SectionID[I->getSection()]; |
| if (Entry == 0) { |
| Entry = ++SectionIDCounter; |
| SectionNames.push_back(I->getSection()); |
| } |
| output_vbr(Entry); |
| } |
| } |
| } |
| 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()); |
| |
| // Output the data layout from the module |
| output(M->getDataLayout()); |
| |
| // Emit the table of section names. |
| output_vbr((unsigned)SectionNames.size()); |
| for (unsigned i = 0, e = SectionNames.size(); i != e; ++i) |
| output(SectionNames[i]); |
| |
| // Output the inline asm string. |
| output(M->getModuleInlineAsm()); |
| } |
| |
| 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->isDeclaration()) return; |
| |
| BytecodeBlock FunctionBlock(BytecodeFormat::FunctionBlockID, *this); |
| unsigned rWord = (getEncodedVisibility(F) << 16) | getEncodedLinkage(F); |
| output_vbr(rWord); |
| |
| // Get slot information about the function... |
| Table.incorporateFunction(F); |
| |
| // Output all of the instructions in the body of the function |
| outputInstructions(F); |
| |
| // If needed, output the symbol table for the function... |
| outputValueSymbolTable(F->getValueSymbolTable()); |
| |
| Table.purgeFunction(); |
| } |
| |
| |
| void BytecodeWriter::outputTypeSymbolTable(const TypeSymbolTable &TST) { |
| // Do not output the block for an empty symbol table, it just wastes |
| // space! |
| if (TST.empty()) return; |
| |
| // Create a header for the symbol table |
| BytecodeBlock SymTabBlock(BytecodeFormat::TypeSymbolTableBlockID, *this, |
| true/*ElideIfEmpty*/); |
| // Write the number of types |
| output_vbr(TST.size()); |
| |
| // Write each of the types |
| for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end(); |
| TI != TE; ++TI) { |
| // Symtab entry:[def slot #][name] |
| output_typeid((unsigned)Table.getSlot(TI->second)); |
| output(TI->first); |
| } |
| } |
| |
| void BytecodeWriter::outputValueSymbolTable(const ValueSymbolTable &VST) { |
| // Do not output the Bytecode block for an empty symbol table, it just wastes |
| // space! |
| if (VST.empty()) return; |
| |
| BytecodeBlock SymTabBlock(BytecodeFormat::ValueSymbolTableBlockID, *this, |
| true/*ElideIfEmpty*/); |
| |
| // Organize the symbol table by type |
| typedef std::pair<std::string, const Value*> PlaneMapEntry; |
| typedef std::vector<PlaneMapEntry> PlaneMapVector; |
| typedef std::map<const Type*, PlaneMapVector > PlaneMap; |
| PlaneMap Planes; |
| for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end(); |
| SI != SE; ++SI) |
| Planes[SI->second->getType()].push_back( |
| std::make_pair(SI->first,SI->second)); |
| |
| for (PlaneMap::const_iterator PI = Planes.begin(), PE = Planes.end(); |
| PI != PE; ++PI) { |
| int Slot; |
| |
| PlaneMapVector::const_iterator I = PI->second.begin(); |
| PlaneMapVector::const_iterator End = PI->second.end(); |
| |
| 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, OStream &Out, |
| bool compress) { |
| assert(M && "You can't write a null module!!"); |
| |
| // Make sure that std::cout is put into binary mode for systems |
| // that care. |
| if (Out == cout) |
| sys::Program::ChangeStdoutToBinary(); |
| |
| // 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.stream()->write(compressed_magic,4); |
| |
| // Compress everything after the magic number (which we altered) |
| Compressor::compressToStream( |
| (char*)(FirstByte+4), // Skip the magic number |
| Buffer.size()-4, // Skip the magic number |
| *Out.stream() // Where to write compressed data |
| ); |
| |
| } else { |
| |
| // We're not compressing, so just write the entire block. |
| Out.stream()->write((char*)FirstByte, Buffer.size()); |
| } |
| |
| // make sure it hits disk now |
| Out.stream()->flush(); |
| } |