llvm-6502/lib/Target/X86/X86IntelAsmPrinter.cpp
Evan Cheng 8f7f7125e9 Better implementation of truncate. ISel matches it to a pseudo instruction
that gets emitted as movl (for r32 to i16, i8) or a movw (for r16 to i8). And
if the destination gets allocated a subregister of the source operand, then
the instruction will not be emitted at all.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28119 91177308-0d34-0410-b5e6-96231b3b80d8
2006-05-05 05:40:20 +00:00

438 lines
13 KiB
C++
Executable File

//===-- X86IntelAsmPrinter.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 format assembly language.
// This printer is the output mechanism used by `llc'.
//
//===----------------------------------------------------------------------===//
#include "X86IntelAsmPrinter.h"
#include "X86.h"
#include "llvm/Constants.h"
#include "llvm/Module.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/Support/Mangler.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
X86IntelAsmPrinter::X86IntelAsmPrinter(std::ostream &O, X86TargetMachine &TM)
: X86SharedAsmPrinter(O, TM) {
}
/// runOnMachineFunction - This uses the printMachineInstruction()
/// method to print assembly for each instruction.
///
bool X86IntelAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
if (forDarwin) {
// Let PassManager know we need debug information and relay
// the MachineDebugInfo address on to DwarfWriter.
DW.SetDebugInfo(&getAnalysis<MachineDebugInfo>());
}
SetupMachineFunction(MF);
O << "\n\n";
// Print out constants referenced by the function
EmitConstantPool(MF.getConstantPool());
// Print out labels for the function.
SwitchSection(".code", MF.getFunction());
EmitAlignment(4);
if (MF.getFunction()->getLinkage() == GlobalValue::ExternalLinkage)
O << "\tpublic " << CurrentFnName << "\n";
O << CurrentFnName << "\tproc near\n";
if (forDarwin) {
// Emit pre-function debug information.
DW.BeginFunction(&MF);
}
// 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()) {
printBasicBlockLabel(I, true);
O << '\n';
}
for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
II != E; ++II) {
// Print the assembly for the instruction.
O << "\t";
printMachineInstruction(II);
}
}
if (forDarwin) {
// Emit post-function debug information.
DW.EndFunction();
}
O << CurrentFnName << "\tendp\n";
// We didn't modify anything.
return false;
}
void X86IntelAsmPrinter::printSSECC(const MachineInstr *MI, unsigned Op) {
unsigned char value = MI->getOperand(Op).getImmedValue();
assert(value <= 7 && "Invalid ssecc argument!");
switch (value) {
case 0: O << "eq"; break;
case 1: O << "lt"; break;
case 2: O << "le"; break;
case 3: O << "unord"; break;
case 4: O << "neq"; break;
case 5: O << "nlt"; break;
case 6: O << "nle"; break;
case 7: O << "ord"; break;
}
}
void X86IntelAsmPrinter::printOp(const MachineOperand &MO,
const char *Modifier) {
const MRegisterInfo &RI = *TM.getRegisterInfo();
switch (MO.getType()) {
case MachineOperand::MO_Register:
if (MRegisterInfo::isPhysicalRegister(MO.getReg())) {
unsigned Reg = MO.getReg();
if (Modifier && strncmp(Modifier, "trunc", strlen("trunc")) == 0) {
MVT::ValueType VT = (strcmp(Modifier,"trunc16") == 0)
? MVT::i16 : MVT::i32;
Reg = getX86SubSuperRegister(Reg, VT);
}
O << RI.get(Reg).Name;
} else
O << "reg" << MO.getReg();
return;
case MachineOperand::MO_Immediate:
O << (int)MO.getImmedValue();
return;
case MachineOperand::MO_MachineBasicBlock:
printBasicBlockLabel(MO.getMachineBasicBlock());
return;
case MachineOperand::MO_ConstantPoolIndex: {
bool isMemOp = Modifier && !strcmp(Modifier, "mem");
if (!isMemOp) O << "OFFSET ";
O << "[" << PrivateGlobalPrefix << "CPI" << getFunctionNumber() << "_"
<< MO.getConstantPoolIndex();
if (forDarwin && TM.getRelocationModel() == Reloc::PIC)
O << "-\"L" << getFunctionNumber() << "$pb\"";
int Offset = MO.getOffset();
if (Offset > 0)
O << " + " << Offset;
else if (Offset < 0)
O << Offset;
O << "]";
return;
}
case MachineOperand::MO_GlobalAddress: {
bool isCallOp = Modifier && !strcmp(Modifier, "call");
bool isMemOp = Modifier && !strcmp(Modifier, "mem");
if (!isMemOp && !isCallOp) O << "OFFSET ";
if (forDarwin && TM.getRelocationModel() != Reloc::Static) {
GlobalValue *GV = MO.getGlobal();
std::string Name = Mang->getValueName(GV);
if (!isMemOp && !isCallOp) O << '$';
// Link-once, External, or Weakly-linked global variables need
// non-lazily-resolved stubs
if (GV->isExternal() || GV->hasWeakLinkage() ||
GV->hasLinkOnceLinkage()) {
// Dynamically-resolved functions need a stub for the function.
if (isCallOp && isa<Function>(GV) && cast<Function>(GV)->isExternal()) {
FnStubs.insert(Name);
O << "L" << Name << "$stub";
} else {
GVStubs.insert(Name);
O << "L" << Name << "$non_lazy_ptr";
}
} else {
O << Mang->getValueName(GV);
}
if (!isCallOp && TM.getRelocationModel() == Reloc::PIC)
O << "-\"L" << getFunctionNumber() << "$pb\"";
} else
O << Mang->getValueName(MO.getGlobal());
int Offset = MO.getOffset();
if (Offset > 0)
O << " + " << Offset;
else if (Offset < 0)
O << Offset;
return;
}
case MachineOperand::MO_ExternalSymbol: {
bool isCallOp = Modifier && !strcmp(Modifier, "call");
if (isCallOp && forDarwin && TM.getRelocationModel() != Reloc::Static) {
std::string Name(GlobalPrefix);
Name += MO.getSymbolName();
FnStubs.insert(Name);
O << "L" << Name << "$stub";
return;
}
if (!isCallOp) O << "OFFSET ";
O << GlobalPrefix << 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;
}
O << "[";
bool NeedPlus = false;
if (BaseReg.getReg()) {
printOp(BaseReg, "mem");
NeedPlus = true;
}
if (IndexReg.getReg()) {
if (NeedPlus) O << " + ";
if (ScaleVal != 1)
O << ScaleVal << "*";
printOp(IndexReg);
NeedPlus = true;
}
if (DispSpec.isGlobalAddress() || DispSpec.isConstantPoolIndex()) {
if (NeedPlus)
O << " + ";
printOp(DispSpec, "mem");
} else {
int DispVal = DispSpec.getImmedValue();
if (DispVal || (!BaseReg.getReg() && !IndexReg.getReg())) {
if (NeedPlus)
if (DispVal > 0)
O << " + ";
else {
O << " - ";
DispVal = -DispVal;
}
O << DispVal;
}
}
O << "]";
}
void X86IntelAsmPrinter::printPICLabel(const MachineInstr *MI, unsigned Op) {
O << "\"L" << getFunctionNumber() << "$pb\"\n";
O << "\"L" << getFunctionNumber() << "$pb\":";
}
bool X86IntelAsmPrinter::printAsmMRegister(const MachineOperand &MO,
const char Mode) {
const MRegisterInfo &RI = *TM.getRegisterInfo();
unsigned Reg = MO.getReg();
switch (Mode) {
default: return true; // Unknown mode.
case 'b': // Print QImode register
Reg = getX86SubSuperRegister(Reg, MVT::i8);
break;
case 'h': // Print QImode high register
Reg = getX86SubSuperRegister(Reg, MVT::i8, true);
break;
case 'w': // Print HImode register
Reg = getX86SubSuperRegister(Reg, MVT::i16);
break;
case 'k': // Print SImode register
Reg = getX86SubSuperRegister(Reg, MVT::i32);
break;
}
O << '%' << RI.get(Reg).Name;
return false;
}
/// PrintAsmOperand - Print out an operand for an inline asm expression.
///
bool X86IntelAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
unsigned AsmVariant,
const char *ExtraCode) {
// Does this asm operand have a single letter operand modifier?
if (ExtraCode && ExtraCode[0]) {
if (ExtraCode[1] != 0) return true; // Unknown modifier.
switch (ExtraCode[0]) {
default: return true; // Unknown modifier.
case 'b': // Print QImode register
case 'h': // Print QImode high register
case 'w': // Print HImode register
case 'k': // Print SImode register
return printAsmMRegister(MI->getOperand(OpNo), ExtraCode[0]);
}
}
printOperand(MI, OpNo);
return false;
}
bool X86IntelAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
unsigned OpNo,
unsigned AsmVariant,
const char *ExtraCode) {
if (ExtraCode && ExtraCode[0])
return true; // Unknown modifier.
printMemReference(MI, OpNo);
return false;
}
/// printMachineInstruction -- Print out a single X86 LLVM instruction
/// MI in Intel syntax to the current output stream.
///
void X86IntelAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
++EmittedInsts;
// See if a truncate instruction can be turned into a nop.
switch (MI->getOpcode()) {
default: break;
case X86::TRUNC_R32_R16:
case X86::TRUNC_R32_R8:
case X86::TRUNC_R16_R8: {
const MachineOperand &MO0 = MI->getOperand(0);
const MachineOperand &MO1 = MI->getOperand(1);
unsigned Reg0 = MO0.getReg();
unsigned Reg1 = MO1.getReg();
if (MI->getOpcode() == X86::TRUNC_R16_R8)
Reg0 = getX86SubSuperRegister(Reg0, MVT::i16);
else
Reg0 = getX86SubSuperRegister(Reg0, MVT::i32);
if (Reg0 == Reg1)
O << CommentString << " TRUNCATE ";
break;
}
}
// Call the autogenerated instruction printer routines.
printInstruction(MI);
}
bool X86IntelAsmPrinter::doInitialization(Module &M) {
X86SharedAsmPrinter::doInitialization(M);
CommentString = ";";
GlobalPrefix = "_";
PrivateGlobalPrefix = "$";
AlignDirective = "\talign\t";
MLSections = true;
ZeroDirective = "\tdb\t";
ZeroDirectiveSuffix = " dup(0)";
AsciiDirective = "\tdb\t";
AscizDirective = 0;
Data8bitsDirective = "\t.db\t";
Data16bitsDirective = "\t.dw\t";
Data32bitsDirective = "\t.dd\t";
Data64bitsDirective = "\t.dq\t";
HasDotTypeDotSizeDirective = false;
Mang->markCharUnacceptable('.');
O << "\t.686\n\t.model flat\n\n";
// Emit declarations for external functions.
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
if (I->isExternal())
O << "\textern " << Mang->getValueName(I) << ":near\n";
// Emit declarations for external globals.
for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I) {
if (I->isExternal())
O << "\textern " << Mang->getValueName(I) << ":byte\n";
else if (I->getLinkage() == GlobalValue::ExternalLinkage)
O << "\tpublic " << Mang->getValueName(I) << "\n";
}
return false;
}
bool X86IntelAsmPrinter::doFinalization(Module &M) {
X86SharedAsmPrinter::doFinalization(M);
SwitchSection("", 0);
O << "\tend\n";
return false;
}
void X86IntelAsmPrinter::EmitString(const ConstantArray *CVA) const {
unsigned NumElts = CVA->getNumOperands();
if (NumElts) {
// ML does not have escape sequences except '' for '. It also has a maximum
// string length of 255.
unsigned len = 0;
bool inString = false;
for (unsigned i = 0; i < NumElts; i++) {
int n = cast<ConstantInt>(CVA->getOperand(i))->getRawValue() & 255;
if (len == 0)
O << "\tdb ";
if (n >= 32 && n <= 127) {
if (!inString) {
if (len > 0) {
O << ",'";
len += 2;
} else {
O << "'";
len++;
}
inString = true;
}
if (n == '\'') {
O << "'";
len++;
}
O << char(n);
} else {
if (inString) {
O << "'";
len++;
inString = false;
}
if (len > 0) {
O << ",";
len++;
}
O << n;
len += 1 + (n > 9) + (n > 99);
}
if (len > 60) {
if (inString) {
O << "'";
inString = false;
}
O << "\n";
len = 0;
}
}
if (len > 0) {
if (inString)
O << "'";
O << "\n";
}
}
}
// Include the auto-generated portion of the assembly writer.
#include "X86GenAsmWriter1.inc"