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llvm-mirror/lib/CodeGen/AsmPrinter.cpp
Nate Begeman 0e92042770 Emit .set directives for jump table entries when possible, which reduces 
the number of relocations in object files, shrinkifying them.

llvm-svn: 29650
2006-08-12 21:29:52 +00:00

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//===-- 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/CodeGen/MachineJumpTableInfo.h"
#include "llvm/Support/Mangler.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include <iostream>
#include <cerrno>
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"),
InlineAsmEnd("#NO_APP"),
ZeroDirective("\t.zero\t"),
ZeroDirectiveSuffix(0),
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"),
TextSectionStartSuffix(""),
DataSectionStartSuffix(""),
SectionEndDirectiveSuffix(0),
ConstantPoolSection("\t.section .rodata\n"),
JumpTableDataSection("\t.section .rodata\n"),
JumpTableTextSection("\t.text\n"),
StaticCtorsSection("\t.section .ctors,\"aw\",@progbits"),
StaticDtorsSection("\t.section .dtors,\"aw\",@progbits"),
FourByteConstantSection(0),
EightByteConstantSection(0),
SixteenByteConstantSection(0),
SetDirective(0),
LCOMMDirective(0),
COMMDirective("\t.comm\t"),
COMMDirectiveTakesAlignment(true),
HasDotTypeDotSizeDirective(true) {
}
/// SwitchToTextSection - Switch to the specified text section of the executable
/// if we are not already in it!
///
void AsmPrinter::SwitchToTextSection(const char *NewSection,
const GlobalValue *GV) {
std::string NS;
if (GV && GV->hasSection())
NS = SwitchToSectionDirective + GV->getSection();
else
NS = NewSection;
// If we're already in this section, we're done.
if (CurrentSection == NS) return;
// Close the current section, if applicable.
if (SectionEndDirectiveSuffix && !CurrentSection.empty())
O << CurrentSection << SectionEndDirectiveSuffix << "\n";
CurrentSection = NS;
if (!CurrentSection.empty())
O << CurrentSection << TextSectionStartSuffix << '\n';
}
/// SwitchToDataSection - Switch to the specified data section of the executable
/// if we are not already in it!
///
void AsmPrinter::SwitchToDataSection(const char *NewSection,
const GlobalValue *GV) {
std::string NS;
if (GV && GV->hasSection())
NS = SwitchToSectionDirective + GV->getSection();
else
NS = NewSection;
// If we're already in this section, we're done.
if (CurrentSection == NS) return;
// Close the current section, if applicable.
if (SectionEndDirectiveSuffix && !CurrentSection.empty())
O << CurrentSection << SectionEndDirectiveSuffix << "\n";
CurrentSection = NS;
if (!CurrentSection.empty())
O << CurrentSection << DataSectionStartSuffix << '\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";
SwitchToDataSection("", 0); // Reset back to no section.
if (MachineDebugInfo *DebugInfo = getAnalysisToUpdate<MachineDebugInfo>()) {
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<MachineConstantPoolEntry> &CP = MCP->getConstants();
if (CP.empty()) return;
// Some targets require 4-, 8-, and 16- byte constant literals to be placed
// in special sections.
std::vector<std::pair<MachineConstantPoolEntry,unsigned> > FourByteCPs;
std::vector<std::pair<MachineConstantPoolEntry,unsigned> > EightByteCPs;
std::vector<std::pair<MachineConstantPoolEntry,unsigned> > SixteenByteCPs;
std::vector<std::pair<MachineConstantPoolEntry,unsigned> > OtherCPs;
for (unsigned i = 0, e = CP.size(); i != e; ++i) {
MachineConstantPoolEntry CPE = CP[i];
const Constant *CV = CPE.Val;
const Type *Ty = CV->getType();
if (FourByteConstantSection &&
TM.getTargetData()->getTypeSize(Ty) == 4)
FourByteCPs.push_back(std::make_pair(CPE, i));
else if (EightByteConstantSection &&
TM.getTargetData()->getTypeSize(Ty) == 8)
EightByteCPs.push_back(std::make_pair(CPE, i));
else if (SixteenByteConstantSection &&
TM.getTargetData()->getTypeSize(Ty) == 16)
SixteenByteCPs.push_back(std::make_pair(CPE, i));
else
OtherCPs.push_back(std::make_pair(CPE, i));
}
unsigned Alignment = MCP->getConstantPoolAlignment();
EmitConstantPool(Alignment, FourByteConstantSection, FourByteCPs);
EmitConstantPool(Alignment, EightByteConstantSection, EightByteCPs);
EmitConstantPool(Alignment, SixteenByteConstantSection, SixteenByteCPs);
EmitConstantPool(Alignment, ConstantPoolSection, OtherCPs);
}
void AsmPrinter::EmitConstantPool(unsigned Alignment, const char *Section,
std::vector<std::pair<MachineConstantPoolEntry,unsigned> > &CP) {
if (CP.empty()) return;
SwitchToDataSection(Section, 0);
EmitAlignment(Alignment);
for (unsigned i = 0, e = CP.size(); i != e; ++i) {
O << PrivateGlobalPrefix << "CPI" << getFunctionNumber() << '_'
<< CP[i].second << ":\t\t\t\t\t" << CommentString << " ";
WriteTypeSymbolic(O, CP[i].first.Val->getType(), 0) << '\n';
EmitGlobalConstant(CP[i].first.Val);
if (i != e-1) {
unsigned EntSize =
TM.getTargetData()->getTypeSize(CP[i].first.Val->getType());
unsigned ValEnd = CP[i].first.Offset + EntSize;
// Emit inter-object padding for alignment.
EmitZeros(CP[i+1].first.Offset-ValEnd);
}
}
}
/// EmitJumpTableInfo - Print assembly representations of the jump tables used
/// by the current function to the current output stream.
///
void AsmPrinter::EmitJumpTableInfo(MachineJumpTableInfo *MJTI) {
const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
if (JT.empty()) return;
const TargetData *TD = TM.getTargetData();
// JTEntryDirective is a string to print sizeof(ptr) for non-PIC jump tables,
// and 32 bits for PIC since PIC jump table entries are differences, not
// pointers to blocks.
const char *JTEntryDirective = Data32bitsDirective;
// Pick the directive to use to print the jump table entries, and switch to
// the appropriate section.
if (TM.getRelocationModel() == Reloc::PIC_) {
SwitchToTextSection(JumpTableTextSection, 0);
} else {
SwitchToDataSection(JumpTableDataSection, 0);
if (TD->getPointerSize() == 8)
JTEntryDirective = Data64bitsDirective;
}
EmitAlignment(Log2_32(TD->getPointerAlignment()));
for (unsigned i = 0, e = JT.size(); i != e; ++i) {
const std::vector<MachineBasicBlock*> &JTBBs = JT[i].MBBs;
// For PIC codegen, if possible we want to use the SetDirective to reduce
// the number of relocations the assembler will generate for the jump table.
// Set directives are all printed before the jump table itself.
std::set<MachineBasicBlock*> EmittedSets;
if (SetDirective && TM.getRelocationModel() == Reloc::PIC_)
for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
if (EmittedSets.insert(JTBBs[ii]).second)
printSetLabel(i, JTBBs[ii]);
O << PrivateGlobalPrefix << "JTI" << getFunctionNumber() << '_' << i
<< ":\n";
for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
O << JTEntryDirective << ' ';
// If we have emitted set directives for the jump table entries, print
// them rather than the entries themselves. If we're emitting PIC, then
// emit the table entries as differences between two text section labels.
// If we're emitting non-PIC code, then emit the entries as direct
// references to the target basic blocks.
if (!EmittedSets.empty()) {
O << PrivateGlobalPrefix << getFunctionNumber() << '_' << i << "_set_"
<< JTBBs[ii]->getNumber();
} else if (TM.getRelocationModel() == Reloc::PIC_) {
printBasicBlockLabel(JTBBs[ii], false, false);
O << '-' << PrivateGlobalPrefix << "JTI" << getFunctionNumber()
<< '_' << i;
} else {
printBasicBlockLabel(JTBBs[ii], false, false);
}
O << '\n';
}
}
}
/// 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) {
// Ignore debug and non-emitted data.
if (GV->getSection() == "llvm.metadata") return true;
if (!GV->hasAppendingLinkage()) return false;
assert(GV->hasInitializer() && "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()) {
SwitchToDataSection(StaticCtorsSection, 0);
EmitAlignment(2, 0);
EmitXXStructorList(GV->getInitializer());
return true;
}
if (GV->getName() == "llvm.global_dtors" && GV->use_empty()) {
SwitchToDataSection(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));
}
}
/// 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 {
const Type *ElemType = GV->getType()->getElementType();
unsigned Alignment = TM.getTargetData()->getTypeAlignmentShift(ElemType);
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(ElemType) > 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;
if (ZeroDirectiveSuffix)
O << ZeroDirectiveSuffix;
O << "\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 foldable casts to/from pointers that can be eliminated by
// changing the pointer to the appropriately sized integer type.
Constant *Op = CE->getOperand(0);
const Type *OpTy = Op->getType(), *Ty = CE->getType();
// Handle casts to pointers by changing them into casts to the appropriate
// integer type. This promotes constant folding and simplifies this code.
if (isa<PointerType>(Ty)) {
const Type *IntPtrTy = TD->getIntPtrType();
Op = ConstantExpr::getCast(Op, IntPtrTy);
return EmitConstantValueOnly(Op);
}
// We know the dest type is not a pointer. Is the src value a pointer or
// integral?
if (isa<PointerType>(OpTy) || OpTy->isIntegral()) {
// We can emit the pointer value into this slot if the slot is an
// integer slot greater or equal to the size of the pointer.
if (Ty->isIntegral() && TD->getTypeSize(Ty) >= TD->getTypeSize(OpTy))
return EmitConstantValueOnly(Op);
}
assert(0 && "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 << "\"";
}
/// EmitString - Emit a zero-byte-terminated string constant.
///
void AsmPrinter::EmitString(const ConstantArray *CVA) const {
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";
}
/// 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()) {
EmitString(CVA);
} 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) {
assert(Data64bitsDirective &&
"Target cannot handle 64-bit pointer exprs!");
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 {
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();
// If this asmstr is empty, don't bother printing the #APP/#NOAPP markers.
if (AsmStr[0] == 0) {
O << "\n"; // Tab already printed, avoid double indenting next instr.
return;
}
O << InlineAsmStart << "\n\t";
// 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 != '$' && *LiteralEnd != '\n')
++LiteralEnd;
if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
O.write(LastEmitted, LiteralEnd-LastEmitted);
LastEmitted = LiteralEnd;
break;
}
case '\n':
++LastEmitted; // Consume newline character.
O << "\n\t"; // Indent code with newline.
break;
case '$': {
++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;
bool Error = false;
// Scan to find the machine operand number for the operand.
for (; Val; --Val) {
if (OpNo >= MI->getNumOperands()) break;
unsigned OpFlags = MI->getOperand(OpNo).getImmedValue();
OpNo += (OpFlags >> 3) + 1;
}
if (OpNo >= MI->getNumOperands()) {
Error = true;
} else {
unsigned OpFlags = MI->getOperand(OpNo).getImmedValue();
++OpNo; // Skip over the ID number.
AsmPrinter *AP = const_cast<AsmPrinter*>(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\t" << InlineAsmEnd << "\n";
}
/// 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;
}
/// printBasicBlockLabel - This method prints the label for the specified
/// MachineBasicBlock
void AsmPrinter::printBasicBlockLabel(const MachineBasicBlock *MBB,
bool printColon,
bool printComment) const {
O << PrivateGlobalPrefix << "BB" << FunctionNumber << "_"
<< MBB->getNumber();
if (printColon)
O << ':';
if (printComment)
O << '\t' << CommentString << MBB->getBasicBlock()->getName();
}
/// printSetLabel - This method prints a set label for the specified
/// MachineBasicBlock
void AsmPrinter::printSetLabel(unsigned uid,
const MachineBasicBlock *MBB) const {
if (!SetDirective)
return;
O << SetDirective << ' ' << PrivateGlobalPrefix << getFunctionNumber()
<< '_' << uid << "_set_" << MBB->getNumber() << ',';
printBasicBlockLabel(MBB, false, false);
O << '-' << PrivateGlobalPrefix << "JTI" << getFunctionNumber()
<< '_' << uid << '\n';
}
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