//===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===// // // 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 file implements the AsmPrinter class. // //===----------------------------------------------------------------------===// #include "llvm/CodeGen/AsmPrinter.h" #include "llvm/Assembly/Writer.h" #include "llvm/DerivedTypes.h" #include "llvm/Constants.h" #include "llvm/Module.h" #include "llvm/CodeGen/MachineConstantPool.h" #include "llvm/Support/Mangler.h" #include "llvm/Support/MathExtras.h" #include "llvm/Target/TargetMachine.h" #include #include using namespace llvm; AsmPrinter::AsmPrinter(std::ostream &o, TargetMachine &tm) : FunctionNumber(0), O(o), TM(tm), CommentString("#"), GlobalPrefix(""), PrivateGlobalPrefix("."), GlobalVarAddrPrefix(""), GlobalVarAddrSuffix(""), FunctionAddrPrefix(""), FunctionAddrSuffix(""), InlineAsmStart("#APP\n"), InlineAsmEnd("#NO_APP\n"), ZeroDirective("\t.zero\t"), AsciiDirective("\t.ascii\t"), AscizDirective("\t.asciz\t"), Data8bitsDirective("\t.byte\t"), Data16bitsDirective("\t.short\t"), Data32bitsDirective("\t.long\t"), Data64bitsDirective("\t.quad\t"), AlignDirective("\t.align\t"), AlignmentIsInBytes(true), SwitchToSectionDirective("\t.section\t"), ConstantPoolSection("\t.section .rodata\n"), StaticCtorsSection("\t.section .ctors,\"aw\",@progbits"), StaticDtorsSection("\t.section .dtors,\"aw\",@progbits"), LCOMMDirective(0), COMMDirective("\t.comm\t"), COMMDirectiveTakesAlignment(true), HasDotTypeDotSizeDirective(true) { } /// SwitchSection - Switch to the specified section of the executable if we /// are not already in it! /// void AsmPrinter::SwitchSection(const char *NewSection, const GlobalValue *GV) { std::string NS; if (GV && GV->hasSection()) NS = SwitchToSectionDirective + GV->getSection(); else NS = std::string("\t")+NewSection; if (CurrentSection != NS) { CurrentSection = NS; if (!CurrentSection.empty()) O << CurrentSection << '\n'; } } bool AsmPrinter::doInitialization(Module &M) { Mang = new Mangler(M, GlobalPrefix); if (!M.getModuleInlineAsm().empty()) O << CommentString << " Start of file scope inline assembly\n" << M.getModuleInlineAsm() << "\n" << CommentString << " End of file scope inline assembly\n"; SwitchSection("", 0); // Reset back to no section. if (MachineDebugInfo *DebugInfo = getAnalysisToUpdate()) { DebugInfo->AnalyzeModule(M); } return false; } bool AsmPrinter::doFinalization(Module &M) { delete Mang; Mang = 0; return false; } void AsmPrinter::SetupMachineFunction(MachineFunction &MF) { // What's my mangled name? CurrentFnName = Mang->getValueName(MF.getFunction()); IncrementFunctionNumber(); } /// EmitConstantPool - Print to the current output stream assembly /// representations of the constants in the constant pool MCP. This is /// used to print out constants which have been "spilled to memory" by /// the code generator. /// void AsmPrinter::EmitConstantPool(MachineConstantPool *MCP) { const std::vector &CP = MCP->getConstants(); if (CP.empty()) return; const TargetData &TD = TM.getTargetData(); SwitchSection(ConstantPoolSection, 0); EmitAlignment(MCP->getConstantPoolAlignment()); for (unsigned i = 0, e = CP.size(); i != e; ++i) { O << PrivateGlobalPrefix << "CPI" << getFunctionNumber() << '_' << i << ":\t\t\t\t\t" << CommentString << " "; WriteTypeSymbolic(O, CP[i].Val->getType(), 0) << '\n'; EmitGlobalConstant(CP[i].Val); if (i != e-1) { unsigned EntSize = TM.getTargetData().getTypeSize(CP[i].Val->getType()); unsigned ValEnd = CP[i].Offset + EntSize; // Emit inter-object padding for alignment. EmitZeros(CP[i+1].Offset-ValEnd); } } } /// EmitSpecialLLVMGlobal - Check to see if the specified global is a /// special global used by LLVM. If so, emit it and return true, otherwise /// do nothing and return false. bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) { assert(GV->hasInitializer() && GV->hasAppendingLinkage() && "Not a special LLVM global!"); if (GV->getName() == "llvm.used") return true; // No need to emit this at all. if (GV->getName() == "llvm.global_ctors" && GV->use_empty()) { SwitchSection(StaticCtorsSection, 0); EmitAlignment(2, 0); EmitXXStructorList(GV->getInitializer()); return true; } if (GV->getName() == "llvm.global_dtors" && GV->use_empty()) { SwitchSection(StaticDtorsSection, 0); EmitAlignment(2, 0); EmitXXStructorList(GV->getInitializer()); return true; } return false; } /// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the /// function pointers, ignoring the init priority. void AsmPrinter::EmitXXStructorList(Constant *List) { // Should be an array of '{ int, void ()* }' structs. The first value is the // init priority, which we ignore. if (!isa(List)) return; ConstantArray *InitList = cast(List); for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) if (ConstantStruct *CS = dyn_cast(InitList->getOperand(i))){ if (CS->getNumOperands() != 2) return; // Not array of 2-element structs. if (CS->getOperand(1)->isNullValue()) return; // Found a null terminator, exit printing. // Emit the function pointer. EmitGlobalConstant(CS->getOperand(1)); } } /// getPreferredAlignmentLog - Return the preferred alignment of the /// specified global, returned in log form. This includes an explicitly /// requested alignment (if the global has one). unsigned AsmPrinter::getPreferredAlignmentLog(const GlobalVariable *GV) const { unsigned Alignment = TM.getTargetData().getTypeAlignmentShift(GV->getType()); if (GV->getAlignment() > (1U << Alignment)) Alignment = Log2_32(GV->getAlignment()); if (GV->hasInitializer()) { // Always round up alignment of global doubles to 8 bytes. if (GV->getType()->getElementType() == Type::DoubleTy && Alignment < 3) Alignment = 3; if (Alignment < 4) { // If the global is not external, see if it is large. If so, give it a // larger alignment. if (TM.getTargetData().getTypeSize(GV->getType()->getElementType()) > 128) Alignment = 4; // 16-byte alignment. } } return Alignment; } // EmitAlignment - Emit an alignment directive to the specified power of two. void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const { if (GV && GV->getAlignment()) NumBits = Log2_32(GV->getAlignment()); if (NumBits == 0) return; // No need to emit alignment. if (AlignmentIsInBytes) NumBits = 1 << NumBits; O << AlignDirective << NumBits << "\n"; } /// EmitZeros - Emit a block of zeros. /// void AsmPrinter::EmitZeros(uint64_t NumZeros) const { if (NumZeros) { if (ZeroDirective) O << ZeroDirective << NumZeros << "\n"; else { for (; NumZeros; --NumZeros) O << Data8bitsDirective << "0\n"; } } } // Print out the specified constant, without a storage class. Only the // constants valid in constant expressions can occur here. void AsmPrinter::EmitConstantValueOnly(const Constant *CV) { if (CV->isNullValue() || isa(CV)) O << "0"; else if (const ConstantBool *CB = dyn_cast(CV)) { assert(CB == ConstantBool::True); O << "1"; } else if (const ConstantSInt *CI = dyn_cast(CV)) if (((CI->getValue() << 32) >> 32) == CI->getValue()) O << CI->getValue(); else O << (uint64_t)CI->getValue(); else if (const ConstantUInt *CI = dyn_cast(CV)) O << CI->getValue(); else if (const GlobalValue *GV = dyn_cast(CV)) { // This is a constant address for a global variable or function. Use the // name of the variable or function as the address value, possibly // decorating it with GlobalVarAddrPrefix/Suffix or // FunctionAddrPrefix/Suffix (these all default to "" ) if (isa(GV)) O << FunctionAddrPrefix << Mang->getValueName(GV) << FunctionAddrSuffix; else O << GlobalVarAddrPrefix << Mang->getValueName(GV) << GlobalVarAddrSuffix; } else if (const ConstantExpr *CE = dyn_cast(CV)) { const TargetData &TD = TM.getTargetData(); switch(CE->getOpcode()) { case Instruction::GetElementPtr: { // generate a symbolic expression for the byte address const Constant *ptrVal = CE->getOperand(0); std::vector idxVec(CE->op_begin()+1, CE->op_end()); if (int64_t Offset = TD.getIndexedOffset(ptrVal->getType(), idxVec)) { if (Offset) O << "("; EmitConstantValueOnly(ptrVal); if (Offset > 0) O << ") + " << Offset; else if (Offset < 0) O << ") - " << -Offset; } else { EmitConstantValueOnly(ptrVal); } break; } case Instruction::Cast: { // Support only non-converting or widening casts for now, that is, ones // that do not involve a change in value. This assertion is really gross, // and may not even be a complete check. Constant *Op = CE->getOperand(0); const Type *OpTy = Op->getType(), *Ty = CE->getType(); // Remember, kids, pointers can be losslessly converted back and forth // into 32-bit or wider integers, regardless of signedness. :-P assert(((isa(OpTy) && (Ty == Type::LongTy || Ty == Type::ULongTy || Ty == Type::IntTy || Ty == Type::UIntTy)) || (isa(Ty) && (OpTy == Type::LongTy || OpTy == Type::ULongTy || OpTy == Type::IntTy || OpTy == Type::UIntTy)) || (((TD.getTypeSize(Ty) >= TD.getTypeSize(OpTy)) && OpTy->isLosslesslyConvertibleTo(Ty)))) && "FIXME: Don't yet support this kind of constant cast expr"); EmitConstantValueOnly(Op); break; } case Instruction::Add: O << "("; EmitConstantValueOnly(CE->getOperand(0)); O << ") + ("; EmitConstantValueOnly(CE->getOperand(1)); O << ")"; break; default: assert(0 && "Unsupported operator!"); } } else { assert(0 && "Unknown constant value!"); } } /// toOctal - Convert the low order bits of X into an octal digit. /// static inline char toOctal(int X) { return (X&7)+'0'; } /// printAsCString - Print the specified array as a C compatible string, only if /// the predicate isString is true. /// static void printAsCString(std::ostream &O, const ConstantArray *CVA, unsigned LastElt) { assert(CVA->isString() && "Array is not string compatible!"); O << "\""; for (unsigned i = 0; i != LastElt; ++i) { unsigned char C = (unsigned char)cast(CVA->getOperand(i))->getRawValue(); if (C == '"') { O << "\\\""; } else if (C == '\\') { O << "\\\\"; } else if (isprint(C)) { O << C; } else { switch(C) { case '\b': O << "\\b"; break; case '\f': O << "\\f"; break; case '\n': O << "\\n"; break; case '\r': O << "\\r"; break; case '\t': O << "\\t"; break; default: O << '\\'; O << toOctal(C >> 6); O << toOctal(C >> 3); O << toOctal(C >> 0); break; } } } O << "\""; } /// EmitGlobalConstant - Print a general LLVM constant to the .s file. /// void AsmPrinter::EmitGlobalConstant(const Constant *CV) { const TargetData &TD = TM.getTargetData(); if (CV->isNullValue() || isa(CV)) { EmitZeros(TD.getTypeSize(CV->getType())); return; } else if (const ConstantArray *CVA = dyn_cast(CV)) { if (CVA->isString()) { unsigned NumElts = CVA->getNumOperands(); if (AscizDirective && NumElts && cast(CVA->getOperand(NumElts-1))->getRawValue() == 0) { O << AscizDirective; printAsCString(O, CVA, NumElts-1); } else { O << AsciiDirective; printAsCString(O, CVA, NumElts); } O << "\n"; } else { // Not a string. Print the values in successive locations for (unsigned i = 0, e = CVA->getNumOperands(); i != e; ++i) EmitGlobalConstant(CVA->getOperand(i)); } return; } else if (const ConstantStruct *CVS = dyn_cast(CV)) { // Print the fields in successive locations. Pad to align if needed! const StructLayout *cvsLayout = TD.getStructLayout(CVS->getType()); uint64_t sizeSoFar = 0; for (unsigned i = 0, e = CVS->getNumOperands(); i != e; ++i) { const Constant* field = CVS->getOperand(i); // Check if padding is needed and insert one or more 0s. uint64_t fieldSize = TD.getTypeSize(field->getType()); uint64_t padSize = ((i == e-1? cvsLayout->StructSize : cvsLayout->MemberOffsets[i+1]) - cvsLayout->MemberOffsets[i]) - fieldSize; sizeSoFar += fieldSize + padSize; // Now print the actual field value EmitGlobalConstant(field); // Insert the field padding unless it's zero bytes... EmitZeros(padSize); } assert(sizeSoFar == cvsLayout->StructSize && "Layout of constant struct may be incorrect!"); return; } else if (const ConstantFP *CFP = dyn_cast(CV)) { // FP Constants are printed as integer constants to avoid losing // precision... double Val = CFP->getValue(); if (CFP->getType() == Type::DoubleTy) { if (Data64bitsDirective) O << Data64bitsDirective << DoubleToBits(Val) << "\t" << CommentString << " double value: " << Val << "\n"; else if (TD.isBigEndian()) { O << Data32bitsDirective << unsigned(DoubleToBits(Val) >> 32) << "\t" << CommentString << " double most significant word " << Val << "\n"; O << Data32bitsDirective << unsigned(DoubleToBits(Val)) << "\t" << CommentString << " double least significant word " << Val << "\n"; } else { O << Data32bitsDirective << unsigned(DoubleToBits(Val)) << "\t" << CommentString << " double least significant word " << Val << "\n"; O << Data32bitsDirective << unsigned(DoubleToBits(Val) >> 32) << "\t" << CommentString << " double most significant word " << Val << "\n"; } return; } else { O << Data32bitsDirective << FloatToBits(Val) << "\t" << CommentString << " float " << Val << "\n"; return; } } else if (CV->getType() == Type::ULongTy || CV->getType() == Type::LongTy) { if (const ConstantInt *CI = dyn_cast(CV)) { uint64_t Val = CI->getRawValue(); if (Data64bitsDirective) O << Data64bitsDirective << Val << "\n"; else if (TD.isBigEndian()) { O << Data32bitsDirective << unsigned(Val >> 32) << "\t" << CommentString << " Double-word most significant word " << Val << "\n"; O << Data32bitsDirective << unsigned(Val) << "\t" << CommentString << " Double-word least significant word " << Val << "\n"; } else { O << Data32bitsDirective << unsigned(Val) << "\t" << CommentString << " Double-word least significant word " << Val << "\n"; O << Data32bitsDirective << unsigned(Val >> 32) << "\t" << CommentString << " Double-word most significant word " << Val << "\n"; } return; } } else if (const ConstantPacked *CP = dyn_cast(CV)) { const PackedType *PTy = CP->getType(); for (unsigned I = 0, E = PTy->getNumElements(); I < E; ++I) EmitGlobalConstant(CP->getOperand(I)); return; } const Type *type = CV->getType(); switch (type->getTypeID()) { case Type::BoolTyID: case Type::UByteTyID: case Type::SByteTyID: O << Data8bitsDirective; break; case Type::UShortTyID: case Type::ShortTyID: O << Data16bitsDirective; break; case Type::PointerTyID: if (TD.getPointerSize() == 8) { O << Data64bitsDirective; break; } //Fall through for pointer size == int size case Type::UIntTyID: case Type::IntTyID: O << Data32bitsDirective; break; case Type::ULongTyID: case Type::LongTyID: assert(Data64bitsDirective &&"Target cannot handle 64-bit constant exprs!"); O << Data64bitsDirective; break; case Type::FloatTyID: case Type::DoubleTyID: assert (0 && "Should have already output floating point constant."); default: assert (0 && "Can't handle printing this type of thing"); break; } EmitConstantValueOnly(CV); O << "\n"; } /// printInlineAsm - This method formats and prints the specified machine /// instruction that is an inline asm. void AsmPrinter::printInlineAsm(const MachineInstr *MI) const { O << InlineAsmStart; unsigned NumOperands = MI->getNumOperands(); // Count the number of register definitions. unsigned NumDefs = 0; for (; MI->getOperand(NumDefs).isDef(); ++NumDefs) assert(NumDefs != NumOperands-1 && "No asm string?"); assert(MI->getOperand(NumDefs).isExternalSymbol() && "No asm string?"); // Disassemble the AsmStr, printing out the literal pieces, the operands, etc. const char *AsmStr = MI->getOperand(NumDefs).getSymbolName(); // The variant of the current asmprinter: FIXME: change. int AsmPrinterVariant = 0; int CurVariant = -1; // The number of the {.|.|.} region we are in. const char *LastEmitted = AsmStr; // One past the last character emitted. while (*LastEmitted) { switch (*LastEmitted) { default: { // Not a special case, emit the string section literally. const char *LiteralEnd = LastEmitted+1; while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' && *LiteralEnd != '}' && *LiteralEnd != '$') ++LiteralEnd; if (CurVariant == -1 || CurVariant == AsmPrinterVariant) O.write(LastEmitted, LiteralEnd-LastEmitted); LastEmitted = LiteralEnd; break; } case '$': { ++LastEmitted; // Consume '$' character. if (*LastEmitted == '$') { // $$ -> $ if (CurVariant == -1 || CurVariant == AsmPrinterVariant) O << '$'; ++LastEmitted; // Consume second '$' character. break; } bool HasCurlyBraces = false; if (*LastEmitted == '{') { // ${variable} ++LastEmitted; // Consume '{' character. HasCurlyBraces = true; } const char *IDStart = LastEmitted; char *IDEnd; long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs. if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) { std::cerr << "Bad $ operand number in inline asm string: '" << AsmStr << "'\n"; exit(1); } LastEmitted = IDEnd; char Modifier[2] = { 0, 0 }; if (HasCurlyBraces) { // If we have curly braces, check for a modifier character. This // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm. if (*LastEmitted == ':') { ++LastEmitted; // Consume ':' character. if (*LastEmitted == 0) { std::cerr << "Bad ${:} expression in inline asm string: '" << AsmStr << "'\n"; exit(1); } Modifier[0] = *LastEmitted; ++LastEmitted; // Consume modifier character. } if (*LastEmitted != '}') { std::cerr << "Bad ${} expression in inline asm string: '" << AsmStr << "'\n"; exit(1); } ++LastEmitted; // Consume '}' character. } if ((unsigned)Val >= NumOperands-1) { std::cerr << "Invalid $ operand number in inline asm string: '" << AsmStr << "'\n"; exit(1); } // Okay, we finally have a value number. Ask the target to print this // operand! if (CurVariant == -1 || CurVariant == AsmPrinterVariant) { unsigned OpNo = 1; // Scan to find the machine operand number for the operand. for (; Val; --Val) { unsigned OpFlags = MI->getOperand(OpNo).getImmedValue(); OpNo += (OpFlags >> 3) + 1; } unsigned OpFlags = MI->getOperand(OpNo).getImmedValue(); ++OpNo; // Skip over the ID number. bool Error; AsmPrinter *AP = const_cast(this); if ((OpFlags & 7) == 4 /*ADDR MODE*/) { Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant, Modifier[0] ? Modifier : 0); } else { Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant, Modifier[0] ? Modifier : 0); } if (Error) { std::cerr << "Invalid operand found in inline asm: '" << AsmStr << "'\n"; MI->dump(); exit(1); } } break; } case '{': ++LastEmitted; // Consume '{' character. if (CurVariant != -1) { std::cerr << "Nested variants found in inline asm string: '" << AsmStr << "'\n"; exit(1); } CurVariant = 0; // We're in the first variant now. break; case '|': ++LastEmitted; // consume '|' character. if (CurVariant == -1) { std::cerr << "Found '|' character outside of variant in inline asm " << "string: '" << AsmStr << "'\n"; exit(1); } ++CurVariant; // We're in the next variant. break; case '}': ++LastEmitted; // consume '}' character. if (CurVariant == -1) { std::cerr << "Found '}' character outside of variant in inline asm " << "string: '" << AsmStr << "'\n"; exit(1); } CurVariant = -1; break; } } O << "\n" << InlineAsmEnd; } /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM /// instruction, using the specified assembler variant. Targets should /// overried this to format as appropriate. bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo, unsigned AsmVariant, const char *ExtraCode) { // Target doesn't support this yet! return true; } bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo, unsigned AsmVariant, const char *ExtraCode) { // Target doesn't support this yet! return true; }