llvm/lib/CodeGen/AsmPrinter.cpp
Chris Lattner 3e2fa7a746 rename method
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25572 91177308-0d34-0410-b5e6-96231b3b80d8
2006-01-24 04:16:34 +00:00

450 lines
16 KiB
C++

//===-- 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/DerivedTypes.h"
#include "llvm/CodeGen/AsmPrinter.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 <iostream>
using namespace llvm;
AsmPrinter::AsmPrinter(std::ostream &o, TargetMachine &tm)
: FunctionNumber(0), O(o), TM(tm),
CommentString("#"),
GlobalPrefix(""),
PrivateGlobalPrefix("."),
GlobalVarAddrPrefix(""),
GlobalVarAddrSuffix(""),
FunctionAddrPrefix(""),
FunctionAddrSuffix(""),
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.
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<Constant*> &CP = MCP->getConstants();
if (CP.empty()) return;
const TargetData &TD = TM.getTargetData();
SwitchSection(ConstantPoolSection, 0);
for (unsigned i = 0, e = CP.size(); i != e; ++i) {
// FIXME: force doubles to be naturally aligned. We should handle this
// more correctly in the future.
unsigned Alignment = TD.getTypeAlignmentShift(CP[i]->getType());
if (CP[i]->getType() == Type::DoubleTy && Alignment < 3) Alignment = 3;
EmitAlignment(Alignment);
O << PrivateGlobalPrefix << "CPI" << getFunctionNumber() << '_' << i
<< ":\t\t\t\t\t" << CommentString << *CP[i] << '\n';
EmitGlobalConstant(CP[i]);
}
}
/// 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<ConstantArray>(List)) return;
ConstantArray *InitList = cast<ConstantArray>(List);
for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
if (ConstantStruct *CS = dyn_cast<ConstantStruct>(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));
}
}
// 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<UndefValue>(CV))
O << "0";
else if (const ConstantBool *CB = dyn_cast<ConstantBool>(CV)) {
assert(CB == ConstantBool::True);
O << "1";
} else if (const ConstantSInt *CI = dyn_cast<ConstantSInt>(CV))
if (((CI->getValue() << 32) >> 32) == CI->getValue())
O << CI->getValue();
else
O << (uint64_t)CI->getValue();
else if (const ConstantUInt *CI = dyn_cast<ConstantUInt>(CV))
O << CI->getValue();
else if (const GlobalValue *GV = dyn_cast<GlobalValue>(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<Function>(GV))
O << FunctionAddrPrefix << Mang->getValueName(GV) << FunctionAddrSuffix;
else
O << GlobalVarAddrPrefix << Mang->getValueName(GV) << GlobalVarAddrSuffix;
} else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(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<Value*> 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<PointerType>(OpTy)
&& (Ty == Type::LongTy || Ty == Type::ULongTy
|| Ty == Type::IntTy || Ty == Type::UIntTy))
|| (isa<PointerType>(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<ConstantInt>(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<UndefValue>(CV)) {
EmitZeros(TD.getTypeSize(CV->getType()));
return;
} else if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) {
if (CVA->isString()) {
unsigned NumElts = CVA->getNumOperands();
if (AscizDirective && NumElts &&
cast<ConstantInt>(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<ConstantStruct>(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<ConstantFP>(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<ConstantInt>(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<ConstantPacked>(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";
}