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llvm-mirror/lib/CodeGen/AsmPrinter.cpp
Chris Lattner 05d5a44c02 Do not use .xword and friends to emit zeros on V9. Apparently there are issues
with emitting .xwords when not on an 8-byte boundary (.xword 0 is not the
same as 8 .byte 0's).  Because we do not know when or when we are not aligned,
just emit bytes like the old V9 asmprinter did.

llvm-svn: 16006
2004-08-24 00:26:11 +00:00

300 lines
10 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/CodeGen/AsmPrinter.h"
#include "llvm/Constants.h"
#include "llvm/Instruction.h"
#include "llvm/Support/Mangler.h"
#include "llvm/Target/TargetMachine.h"
using namespace llvm;
bool AsmPrinter::doInitialization(Module &M) {
Mang = new Mangler(M, GlobalPrefix);
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((Value*)MF.getFunction());
}
// emitAlignment - Emit an alignment directive to the specified power of two.
void AsmPrinter::emitAlignment(unsigned NumBits) const {
if (AlignmentIsInBytes) NumBits = 1 << NumBits;
O << AlignDirective << NumBits << "\n";
}
/// emitZeros - Emit a block of zeros.
///
void AsmPrinter::emitZeros(unsigned 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())
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 << (unsigned long long)CI->getValue();
else if (const ConstantUInt *CI = dyn_cast<ConstantUInt>(CV))
O << CI->getValue();
else if (isa<GlobalValue>((Value*)CV))
// This is a constant address for a global variable or function. Use the
// name of the variable or function as the address value.
O << Mang->getValueName(CV);
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 (unsigned Offset = TD.getIndexedOffset(ptrVal->getType(), idxVec)) {
O << "(";
emitConstantValueOnly(ptrVal);
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");
O << "(";
emitConstantValueOnly(Op);
O << ")";
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';
}
/// getAsCString - Return the specified array as a C compatible string, only if
/// the predicate isString is true.
///
static void printAsCString(std::ostream &O, const ConstantArray *CVA) {
assert(CVA->isString() && "Array is not string compatible!");
O << "\"";
for (unsigned i = 0; i != CVA->getNumOperands(); ++i) {
unsigned char C = 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()) {
emitZeros(TD.getTypeSize(CV->getType()));
return;
} else if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) {
if (CVA->isString()) {
O << AsciiDirective;
printAsCString(O, CVA);
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());
unsigned 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.
unsigned fieldSize = TD.getTypeSize(field->getType());
unsigned 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) {
union DU { // Abide by C TBAA rules
double FVal;
uint64_t UVal;
} U;
U.FVal = Val;
if (Data64bitsDirective)
O << Data64bitsDirective << U.UVal << "\t" << CommentString
<< " double value: " << Val << "\n";
else if (TD.isBigEndian()) {
O << Data32bitsDirective << unsigned(U.UVal >> 32)
<< "\t" << CommentString << " double most significant word "
<< Val << "\n";
O << Data32bitsDirective << unsigned(U.UVal)
<< "\t" << CommentString << " double least significant word "
<< Val << "\n";
} else {
O << Data32bitsDirective << unsigned(U.UVal)
<< "\t" << CommentString << " double least significant word " << Val
<< "\n";
O << Data32bitsDirective << unsigned(U.UVal >> 32)
<< "\t" << CommentString << " double most significant word " << Val
<< "\n";
}
return;
} else {
union FU { // Abide by C TBAA rules
float FVal;
int32_t UVal;
} U;
U.FVal = Val;
O << Data32bitsDirective << U.UVal << "\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;
}
}
const Type *type = CV->getType();
switch (type->getTypeID()) {
case Type::UByteTyID: case Type::SByteTyID:
O << Data8bitsDirective;
break;
case Type::UShortTyID: case Type::ShortTyID:
O << Data16bitsDirective;
break;
case Type::BoolTyID:
case Type::PointerTyID:
case Type::UIntTyID: case Type::IntTyID:
O << Data32bitsDirective;
break;
case Type::ULongTyID: case Type::LongTyID:
assert (0 && "Should have already output double-word constant.");
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";
}