llvm-6502/lib/Target/X86/X86AsmPrinter.cpp
2004-11-14 21:03:49 +00:00

610 lines
20 KiB
C++

//===-- X86AsmPrinter.cpp - Convert X86 LLVM code to Intel assembly -------===//
//
// 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 contains a printer that converts from our internal representation
// of machine-dependent LLVM code to Intel and AT&T format assembly
// language. This printer is the output mechanism used by `llc' and `lli
// -print-machineinstrs' on X86.
//
//===----------------------------------------------------------------------===//
#include "X86.h"
#include "X86TargetMachine.h"
#include "llvm/Module.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Support/Mangler.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/CommandLine.h"
using namespace llvm;
namespace {
Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed");
enum AsmWriterFlavor { att, intel };
cl::opt<AsmWriterFlavor>
AsmWriterFlavor("x86-asm-syntax",
cl::desc("Choose style of code to emit from X86 backend:"),
cl::values(
clEnumVal(att, " Emit AT&T-style assembly"),
clEnumVal(intel, " Emit Intel-style assembly"),
clEnumValEnd),
cl::init(att));
struct X86SharedAsmPrinter : public AsmPrinter {
X86SharedAsmPrinter(std::ostream &O, TargetMachine &TM)
: AsmPrinter(O, TM) { }
void printConstantPool(MachineConstantPool *MCP);
bool doFinalization(Module &M);
};
}
static bool isScale(const MachineOperand &MO) {
return MO.isImmediate() &&
(MO.getImmedValue() == 1 || MO.getImmedValue() == 2 ||
MO.getImmedValue() == 4 || MO.getImmedValue() == 8);
}
static bool isMem(const MachineInstr *MI, unsigned Op) {
if (MI->getOperand(Op).isFrameIndex()) return true;
if (MI->getOperand(Op).isConstantPoolIndex()) return true;
return Op+4 <= MI->getNumOperands() &&
MI->getOperand(Op ).isRegister() && isScale(MI->getOperand(Op+1)) &&
MI->getOperand(Op+2).isRegister() && (MI->getOperand(Op+3).isImmediate() ||
MI->getOperand(Op+3).isGlobalAddress());
}
// SwitchSection - Switch to the specified section of the executable if we are
// not already in it!
//
static void SwitchSection(std::ostream &OS, std::string &CurSection,
const char *NewSection) {
if (CurSection != NewSection) {
CurSection = NewSection;
if (!CurSection.empty())
OS << "\t" << NewSection << "\n";
}
}
/// printConstantPool - 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 X86SharedAsmPrinter::printConstantPool(MachineConstantPool *MCP) {
const std::vector<Constant*> &CP = MCP->getConstants();
const TargetData &TD = TM.getTargetData();
if (CP.empty()) return;
for (unsigned i = 0, e = CP.size(); i != e; ++i) {
O << "\t.section .rodata\n";
emitAlignment(TD.getTypeAlignmentShift(CP[i]->getType()));
O << ".CPI" << CurrentFnName << "_" << i << ":\t\t\t\t\t" << CommentString
<< *CP[i] << "\n";
emitGlobalConstant(CP[i]);
}
}
bool X86SharedAsmPrinter::doFinalization(Module &M) {
const TargetData &TD = TM.getTargetData();
std::string CurSection;
// Print out module-level global variables here.
for (Module::const_giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
if (I->hasInitializer()) { // External global require no code
O << "\n\n";
std::string name = Mang->getValueName(I);
Constant *C = I->getInitializer();
unsigned Size = TD.getTypeSize(C->getType());
unsigned Align = TD.getTypeAlignmentShift(C->getType());
if (C->isNullValue() &&
(I->hasLinkOnceLinkage() || I->hasInternalLinkage() ||
I->hasWeakLinkage() /* FIXME: Verify correct */)) {
SwitchSection(O, CurSection, ".data");
if (I->hasInternalLinkage())
O << "\t.local " << name << "\n";
O << "\t.comm " << name << "," << TD.getTypeSize(C->getType())
<< "," << (1 << Align);
O << "\t\t# ";
WriteAsOperand(O, I, true, true, &M);
O << "\n";
} else {
switch (I->getLinkage()) {
case GlobalValue::LinkOnceLinkage:
case GlobalValue::WeakLinkage: // FIXME: Verify correct for weak.
// Nonnull linkonce -> weak
O << "\t.weak " << name << "\n";
SwitchSection(O, CurSection, "");
O << "\t.section\t.llvm.linkonce.d." << name << ",\"aw\",@progbits\n";
break;
case GlobalValue::AppendingLinkage:
// FIXME: appending linkage variables should go into a section of
// their name or something. For now, just emit them as external.
case GlobalValue::ExternalLinkage:
// If external or appending, declare as a global symbol
O << "\t.globl " << name << "\n";
// FALL THROUGH
case GlobalValue::InternalLinkage:
if (C->isNullValue())
SwitchSection(O, CurSection, ".bss");
else
SwitchSection(O, CurSection, ".data");
break;
case GlobalValue::GhostLinkage:
std::cerr << "GhostLinkage cannot appear in X86AsmPrinter!\n";
abort();
}
emitAlignment(Align);
O << "\t.type " << name << ",@object\n";
O << "\t.size " << name << "," << Size << "\n";
O << name << ":\t\t\t\t# ";
WriteAsOperand(O, I, true, true, &M);
O << " = ";
WriteAsOperand(O, C, false, false, &M);
O << "\n";
emitGlobalConstant(C);
}
}
AsmPrinter::doFinalization(M);
return false; // success
}
namespace {
struct X86IntelAsmPrinter : public X86SharedAsmPrinter {
X86IntelAsmPrinter(std::ostream &O, TargetMachine &TM)
: X86SharedAsmPrinter(O, TM) { }
virtual const char *getPassName() const {
return "X86 Intel-Style Assembly Printer";
}
/// printInstruction - This method is automatically generated by tablegen
/// from the instruction set description. This method returns true if the
/// machine instruction was sufficiently described to print it, otherwise it
/// returns false.
bool printInstruction(const MachineInstr *MI);
// This method is used by the tablegen'erated instruction printer.
void printOperand(const MachineInstr *MI, unsigned OpNo, MVT::ValueType VT){
const MachineOperand &MO = MI->getOperand(OpNo);
if (MO.getType() == MachineOperand::MO_MachineRegister) {
assert(MRegisterInfo::isPhysicalRegister(MO.getReg())&&"Not physref??");
// Bug Workaround: See note in Printer::doInitialization about %.
O << "%" << TM.getRegisterInfo()->get(MO.getReg()).Name;
} else {
printOp(MO);
}
}
void printCallOperand(const MachineInstr *MI, unsigned OpNo,
MVT::ValueType VT) {
printOp(MI->getOperand(OpNo), true); // Don't print "OFFSET".
}
void printMemoryOperand(const MachineInstr *MI, unsigned OpNo,
MVT::ValueType VT) {
switch (VT) {
default: assert(0 && "Unknown arg size!");
case MVT::i8: O << "BYTE PTR "; break;
case MVT::i16: O << "WORD PTR "; break;
case MVT::i32:
case MVT::f32: O << "DWORD PTR "; break;
case MVT::i64:
case MVT::f64: O << "QWORD PTR "; break;
case MVT::f80: O << "XWORD PTR "; break;
}
printMemReference(MI, OpNo);
}
void printMachineInstruction(const MachineInstr *MI);
void printOp(const MachineOperand &MO, bool elideOffsetKeyword = false);
void printMemReference(const MachineInstr *MI, unsigned Op);
bool runOnMachineFunction(MachineFunction &F);
bool doInitialization(Module &M);
};
} // end of anonymous namespace
// Include the auto-generated portion of the assembly writer.
#include "X86GenIntelAsmWriter.inc"
/// runOnMachineFunction - This uses the printMachineInstruction()
/// method to print assembly for each instruction.
///
bool X86IntelAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
setupMachineFunction(MF);
O << "\n\n";
// Print out constants referenced by the function
printConstantPool(MF.getConstantPool());
// Print out labels for the function.
O << "\t.text\n";
emitAlignment(4);
O << "\t.globl\t" << CurrentFnName << "\n";
O << "\t.type\t" << CurrentFnName << ", @function\n";
O << CurrentFnName << ":\n";
// Print out code for the function.
for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
I != E; ++I) {
// Print a label for the basic block if there are any predecessors.
if (I->pred_begin() != I->pred_end())
O << ".LBB" << CurrentFnName << "_" << I->getNumber() << ":\t"
<< CommentString << " " << I->getBasicBlock()->getName() << "\n";
for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
II != E; ++II) {
// Print the assembly for the instruction.
O << "\t";
printMachineInstruction(II);
}
}
// We didn't modify anything.
return false;
}
void X86IntelAsmPrinter::printOp(const MachineOperand &MO,
bool elideOffsetKeyword /* = false */) {
const MRegisterInfo &RI = *TM.getRegisterInfo();
switch (MO.getType()) {
case MachineOperand::MO_VirtualRegister:
if (Value *V = MO.getVRegValueOrNull()) {
O << "<" << V->getName() << ">";
return;
}
// FALLTHROUGH
case MachineOperand::MO_MachineRegister:
if (MRegisterInfo::isPhysicalRegister(MO.getReg()))
// Bug Workaround: See note in Printer::doInitialization about %.
O << "%" << RI.get(MO.getReg()).Name;
else
O << "%reg" << MO.getReg();
return;
case MachineOperand::MO_SignExtendedImmed:
case MachineOperand::MO_UnextendedImmed:
O << (int)MO.getImmedValue();
return;
case MachineOperand::MO_MachineBasicBlock: {
MachineBasicBlock *MBBOp = MO.getMachineBasicBlock();
O << ".LBB" << Mang->getValueName(MBBOp->getParent()->getFunction())
<< "_" << MBBOp->getNumber () << "\t# "
<< MBBOp->getBasicBlock ()->getName ();
return;
}
case MachineOperand::MO_PCRelativeDisp:
std::cerr << "Shouldn't use addPCDisp() when building X86 MachineInstrs";
abort ();
return;
case MachineOperand::MO_GlobalAddress: {
if (!elideOffsetKeyword)
O << "OFFSET ";
O << Mang->getValueName(MO.getGlobal());
int Offset = MO.getOffset();
if (Offset > 0)
O << " + " << Offset;
else if (Offset < 0)
O << " - " << -Offset;
return;
}
case MachineOperand::MO_ExternalSymbol:
O << MO.getSymbolName();
return;
default:
O << "<unknown operand type>"; return;
}
}
void X86IntelAsmPrinter::printMemReference(const MachineInstr *MI, unsigned Op){
assert(isMem(MI, Op) && "Invalid memory reference!");
const MachineOperand &BaseReg = MI->getOperand(Op);
int ScaleVal = MI->getOperand(Op+1).getImmedValue();
const MachineOperand &IndexReg = MI->getOperand(Op+2);
const MachineOperand &DispSpec = MI->getOperand(Op+3);
if (BaseReg.isFrameIndex()) {
O << "[frame slot #" << BaseReg.getFrameIndex();
if (DispSpec.getImmedValue())
O << " + " << DispSpec.getImmedValue();
O << "]";
return;
} else if (BaseReg.isConstantPoolIndex()) {
O << "[.CPI" << CurrentFnName << "_"
<< BaseReg.getConstantPoolIndex();
if (IndexReg.getReg()) {
O << " + ";
if (ScaleVal != 1)
O << ScaleVal << "*";
printOp(IndexReg);
}
if (DispSpec.getImmedValue())
O << " + " << DispSpec.getImmedValue();
O << "]";
return;
}
O << "[";
bool NeedPlus = false;
if (BaseReg.getReg()) {
printOp(BaseReg, true);
NeedPlus = true;
}
if (IndexReg.getReg()) {
if (NeedPlus) O << " + ";
if (ScaleVal != 1)
O << ScaleVal << "*";
printOp(IndexReg);
NeedPlus = true;
}
if (DispSpec.isGlobalAddress()) {
if (NeedPlus)
O << " + ";
printOp(DispSpec, true);
} else {
int DispVal = DispSpec.getImmedValue();
if (DispVal) {
if (NeedPlus)
if (DispVal > 0)
O << " + ";
else {
O << " - ";
DispVal = -DispVal;
}
O << DispVal;
}
}
O << "]";
}
/// printMachineInstruction -- Print out a single X86 LLVM instruction
/// MI in Intel syntax to the current output stream.
///
void X86IntelAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
++EmittedInsts;
// Call the autogenerated instruction printer routines.
printInstruction(MI);
}
bool X86IntelAsmPrinter::doInitialization(Module &M) {
AsmPrinter::doInitialization(M);
// Tell gas we are outputting Intel syntax (not AT&T syntax) assembly.
//
// Bug: gas in `intel_syntax noprefix' mode interprets the symbol `Sp' in an
// instruction as a reference to the register named sp, and if you try to
// reference a symbol `Sp' (e.g. `mov ECX, OFFSET Sp') then it gets lowercased
// before being looked up in the symbol table. This creates spurious
// `undefined symbol' errors when linking. Workaround: Do not use `noprefix'
// mode, and decorate all register names with percent signs.
O << "\t.intel_syntax\n";
return false;
}
namespace {
struct X86ATTAsmPrinter : public X86SharedAsmPrinter {
X86ATTAsmPrinter(std::ostream &O, TargetMachine &TM)
: X86SharedAsmPrinter(O, TM) { }
virtual const char *getPassName() const {
return "X86 AT&T-Style Assembly Printer";
}
/// printInstruction - This method is automatically generated by tablegen
/// from the instruction set description. This method returns true if the
/// machine instruction was sufficiently described to print it, otherwise it
/// returns false.
bool printInstruction(const MachineInstr *MI);
// This method is used by the tablegen'erated instruction printer.
void printOperand(const MachineInstr *MI, unsigned OpNo, MVT::ValueType VT){
printOp(MI->getOperand(OpNo));
}
void printCallOperand(const MachineInstr *MI, unsigned OpNo,
MVT::ValueType VT) {
printOp(MI->getOperand(OpNo), true); // Don't print '$' prefix.
}
void printMemoryOperand(const MachineInstr *MI, unsigned OpNo,
MVT::ValueType VT) {
printMemReference(MI, OpNo);
}
void printMachineInstruction(const MachineInstr *MI);
void printOp(const MachineOperand &MO, bool isCallOperand = false);
void printMemReference(const MachineInstr *MI, unsigned Op);
bool runOnMachineFunction(MachineFunction &F);
};
} // end of anonymous namespace
// Include the auto-generated portion of the assembly writer.
#include "X86GenATTAsmWriter.inc"
/// runOnMachineFunction - This uses the printMachineInstruction()
/// method to print assembly for each instruction.
///
bool X86ATTAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
setupMachineFunction(MF);
O << "\n\n";
// Print out constants referenced by the function
printConstantPool(MF.getConstantPool());
// Print out labels for the function.
O << "\t.text\n";
emitAlignment(4);
O << "\t.globl\t" << CurrentFnName << "\n";
O << "\t.type\t" << CurrentFnName << ", @function\n";
O << CurrentFnName << ":\n";
// Print out code for the function.
for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
I != E; ++I) {
// Print a label for the basic block.
if (I->pred_begin() != I->pred_end())
O << ".LBB" << CurrentFnName << "_" << I->getNumber() << ":\t"
<< CommentString << " " << I->getBasicBlock()->getName() << "\n";
for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
II != E; ++II) {
// Print the assembly for the instruction.
O << "\t";
printMachineInstruction(II);
}
}
// We didn't modify anything.
return false;
}
void X86ATTAsmPrinter::printOp(const MachineOperand &MO, bool isCallOp) {
const MRegisterInfo &RI = *TM.getRegisterInfo();
switch (MO.getType()) {
case MachineOperand::MO_VirtualRegister:
case MachineOperand::MO_MachineRegister:
assert(MRegisterInfo::isPhysicalRegister(MO.getReg()) &&
"Virtual registers should not make it this far!");
O << '%';
for (const char *Name = RI.get(MO.getReg()).Name; *Name; ++Name)
O << (char)tolower(*Name);
return;
case MachineOperand::MO_SignExtendedImmed:
case MachineOperand::MO_UnextendedImmed:
O << '$' << (int)MO.getImmedValue();
return;
case MachineOperand::MO_MachineBasicBlock: {
MachineBasicBlock *MBBOp = MO.getMachineBasicBlock();
O << ".LBB" << Mang->getValueName(MBBOp->getParent()->getFunction())
<< "_" << MBBOp->getNumber () << "\t# "
<< MBBOp->getBasicBlock ()->getName ();
return;
}
case MachineOperand::MO_PCRelativeDisp:
std::cerr << "Shouldn't use addPCDisp() when building X86 MachineInstrs";
abort ();
return;
case MachineOperand::MO_GlobalAddress: {
if (!isCallOp) O << '$';
O << Mang->getValueName(MO.getGlobal());
int Offset = MO.getOffset();
if (Offset > 0)
O << "+" << Offset;
else if (Offset < 0)
O << Offset;
return;
}
case MachineOperand::MO_ExternalSymbol:
if (!isCallOp) O << '$';
O << MO.getSymbolName();
return;
default:
O << "<unknown operand type>"; return;
}
}
void X86ATTAsmPrinter::printMemReference(const MachineInstr *MI, unsigned Op){
assert(isMem(MI, Op) && "Invalid memory reference!");
const MachineOperand &BaseReg = MI->getOperand(Op);
int ScaleVal = MI->getOperand(Op+1).getImmedValue();
const MachineOperand &IndexReg = MI->getOperand(Op+2);
const MachineOperand &DispSpec = MI->getOperand(Op+3);
if (BaseReg.isFrameIndex()) {
O << "[frame slot #" << BaseReg.getFrameIndex();
if (DispSpec.getImmedValue())
O << " + " << DispSpec.getImmedValue();
O << "]";
return;
} else if (BaseReg.isConstantPoolIndex()) {
O << ".CPI" << CurrentFnName << "_"
<< BaseReg.getConstantPoolIndex();
if (DispSpec.getImmedValue())
O << "+" << DispSpec.getImmedValue();
if (IndexReg.getReg()) {
O << "(,";
printOp(IndexReg);
if (ScaleVal != 1)
O << "," << ScaleVal;
O << ")";
}
return;
}
if (DispSpec.isGlobalAddress()) {
printOp(DispSpec, true);
} else {
int DispVal = DispSpec.getImmedValue();
if (DispVal)
O << DispVal;
}
if (IndexReg.getReg() || BaseReg.getReg()) {
O << "(";
if (BaseReg.getReg())
printOp(BaseReg);
if (IndexReg.getReg()) {
O << ",";
printOp(IndexReg);
if (ScaleVal != 1)
O << "," << ScaleVal;
}
O << ")";
}
}
/// printMachineInstruction -- Print out a single X86 LLVM instruction
/// MI in Intel syntax to the current output stream.
///
void X86ATTAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
++EmittedInsts;
// Call the autogenerated instruction printer routines.
printInstruction(MI);
}
/// createX86CodePrinterPass - Returns a pass that prints the X86 assembly code
/// for a MachineFunction to the given output stream, using the given target
/// machine description.
///
FunctionPass *llvm::createX86CodePrinterPass(std::ostream &o,TargetMachine &tm){
switch (AsmWriterFlavor) {
default: assert(0 && "Unknown asm flavor!");
case intel:
return new X86IntelAsmPrinter(o, tm);
case att:
return new X86ATTAsmPrinter(o, tm);
}
}