llvm-6502/lib/Target/Mips/AsmPrinter/MipsAsmPrinter.cpp
2009-07-18 23:03:22 +00:00

586 lines
18 KiB
C++

//===-- MipsAsmPrinter.cpp - Mips LLVM assembly writer --------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file 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 GAS-format MIPS assembly language.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "mips-asm-printer"
#include "Mips.h"
#include "MipsSubtarget.h"
#include "MipsInstrInfo.h"
#include "MipsTargetMachine.h"
#include "MipsMachineFunction.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/MDNode.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/DwarfWriter.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/Target/TargetAsmInfo.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetRegistry.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Mangler.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Support/MathExtras.h"
#include <cctype>
using namespace llvm;
STATISTIC(EmittedInsts, "Number of machine instrs printed");
namespace {
class VISIBILITY_HIDDEN MipsAsmPrinter : public AsmPrinter {
const MipsSubtarget *Subtarget;
public:
explicit MipsAsmPrinter(formatted_raw_ostream &O, TargetMachine &TM,
const TargetAsmInfo *T, bool V)
: AsmPrinter(O, TM, T, V) {
Subtarget = &TM.getSubtarget<MipsSubtarget>();
}
virtual const char *getPassName() const {
return "Mips Assembly Printer";
}
bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
unsigned AsmVariant, const char *ExtraCode);
void printOperand(const MachineInstr *MI, int opNum);
void printUnsignedImm(const MachineInstr *MI, int opNum);
void printMemOperand(const MachineInstr *MI, int opNum,
const char *Modifier = 0);
void printFCCOperand(const MachineInstr *MI, int opNum,
const char *Modifier = 0);
void printModuleLevelGV(const GlobalVariable* GVar);
void printSavedRegsBitmask(MachineFunction &MF);
void printHex32(unsigned int Value);
const char *emitCurrentABIString(void);
void emitFunctionStart(MachineFunction &MF);
void emitFunctionEnd(MachineFunction &MF);
void emitFrameDirective(MachineFunction &MF);
bool printInstruction(const MachineInstr *MI); // autogenerated.
bool runOnMachineFunction(MachineFunction &F);
bool doInitialization(Module &M);
bool doFinalization(Module &M);
};
} // end of anonymous namespace
#include "MipsGenAsmWriter.inc"
/// createMipsCodePrinterPass - Returns a pass that prints the MIPS
/// assembly code for a MachineFunction to the given output stream,
/// using the given target machine description. This should work
/// regardless of whether the function is in SSA form.
FunctionPass *llvm::createMipsCodePrinterPass(formatted_raw_ostream &o,
TargetMachine &tm,
bool verbose) {
return new MipsAsmPrinter(o, tm, tm.getTargetAsmInfo(), verbose);
}
//===----------------------------------------------------------------------===//
//
// Mips Asm Directives
//
// -- Frame directive "frame Stackpointer, Stacksize, RARegister"
// Describe the stack frame.
//
// -- Mask directives "(f)mask bitmask, offset"
// Tells the assembler which registers are saved and where.
// bitmask - contain a little endian bitset indicating which registers are
// saved on function prologue (e.g. with a 0x80000000 mask, the
// assembler knows the register 31 (RA) is saved at prologue.
// offset - the position before stack pointer subtraction indicating where
// the first saved register on prologue is located. (e.g. with a
//
// Consider the following function prologue:
//
// .frame $fp,48,$ra
// .mask 0xc0000000,-8
// addiu $sp, $sp, -48
// sw $ra, 40($sp)
// sw $fp, 36($sp)
//
// With a 0xc0000000 mask, the assembler knows the register 31 (RA) and
// 30 (FP) are saved at prologue. As the save order on prologue is from
// left to right, RA is saved first. A -8 offset means that after the
// stack pointer subtration, the first register in the mask (RA) will be
// saved at address 48-8=40.
//
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
// Mask directives
//===----------------------------------------------------------------------===//
// Create a bitmask with all callee saved registers for CPU or Floating Point
// registers. For CPU registers consider RA, GP and FP for saving if necessary.
void MipsAsmPrinter::
printSavedRegsBitmask(MachineFunction &MF)
{
const TargetRegisterInfo &RI = *TM.getRegisterInfo();
MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
// CPU and FPU Saved Registers Bitmasks
unsigned int CPUBitmask = 0;
unsigned int FPUBitmask = 0;
// Set the CPU and FPU Bitmasks
MachineFrameInfo *MFI = MF.getFrameInfo();
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
unsigned RegNum = MipsRegisterInfo::getRegisterNumbering(CSI[i].getReg());
if (CSI[i].getRegClass() == Mips::CPURegsRegisterClass)
CPUBitmask |= (1 << RegNum);
else
FPUBitmask |= (1 << RegNum);
}
// Return Address and Frame registers must also be set in CPUBitmask.
if (RI.hasFP(MF))
CPUBitmask |= (1 << MipsRegisterInfo::
getRegisterNumbering(RI.getFrameRegister(MF)));
if (MF.getFrameInfo()->hasCalls())
CPUBitmask |= (1 << MipsRegisterInfo::
getRegisterNumbering(RI.getRARegister()));
// Print CPUBitmask
O << "\t.mask \t"; printHex32(CPUBitmask); O << ','
<< MipsFI->getCPUTopSavedRegOff() << '\n';
// Print FPUBitmask
O << "\t.fmask\t"; printHex32(FPUBitmask); O << ","
<< MipsFI->getFPUTopSavedRegOff() << '\n';
}
// Print a 32 bit hex number with all numbers.
void MipsAsmPrinter::
printHex32(unsigned int Value)
{
O << "0x";
for (int i = 7; i >= 0; i--)
O << utohexstr( (Value & (0xF << (i*4))) >> (i*4) );
}
//===----------------------------------------------------------------------===//
// Frame and Set directives
//===----------------------------------------------------------------------===//
/// Frame Directive
void MipsAsmPrinter::
emitFrameDirective(MachineFunction &MF)
{
const TargetRegisterInfo &RI = *TM.getRegisterInfo();
unsigned stackReg = RI.getFrameRegister(MF);
unsigned returnReg = RI.getRARegister();
unsigned stackSize = MF.getFrameInfo()->getStackSize();
O << "\t.frame\t" << '$' << LowercaseString(RI.get(stackReg).AsmName)
<< ',' << stackSize << ','
<< '$' << LowercaseString(RI.get(returnReg).AsmName)
<< '\n';
}
/// Emit Set directives.
const char * MipsAsmPrinter::
emitCurrentABIString(void)
{
switch(Subtarget->getTargetABI()) {
case MipsSubtarget::O32: return "abi32";
case MipsSubtarget::O64: return "abiO64";
case MipsSubtarget::N32: return "abiN32";
case MipsSubtarget::N64: return "abi64";
case MipsSubtarget::EABI: return "eabi32"; // TODO: handle eabi64
default: break;
}
llvm_unreachable("Unknown Mips ABI");
return NULL;
}
/// Emit the directives used by GAS on the start of functions
void MipsAsmPrinter::
emitFunctionStart(MachineFunction &MF)
{
// Print out the label for the function.
const Function *F = MF.getFunction();
SwitchToSection(TAI->SectionForGlobal(F));
// 2 bits aligned
EmitAlignment(MF.getAlignment(), F);
O << "\t.globl\t" << CurrentFnName << '\n';
O << "\t.ent\t" << CurrentFnName << '\n';
printVisibility(CurrentFnName, F->getVisibility());
if ((TAI->hasDotTypeDotSizeDirective()) && Subtarget->isLinux())
O << "\t.type\t" << CurrentFnName << ", @function\n";
O << CurrentFnName << ":\n";
emitFrameDirective(MF);
printSavedRegsBitmask(MF);
O << '\n';
}
/// Emit the directives used by GAS on the end of functions
void MipsAsmPrinter::
emitFunctionEnd(MachineFunction &MF)
{
// There are instruction for this macros, but they must
// always be at the function end, and we can't emit and
// break with BB logic.
O << "\t.set\tmacro\n";
O << "\t.set\treorder\n";
O << "\t.end\t" << CurrentFnName << '\n';
if (TAI->hasDotTypeDotSizeDirective() && !Subtarget->isLinux())
O << "\t.size\t" << CurrentFnName << ", .-" << CurrentFnName << '\n';
}
/// runOnMachineFunction - This uses the printMachineInstruction()
/// method to print assembly for each instruction.
bool MipsAsmPrinter::
runOnMachineFunction(MachineFunction &MF)
{
this->MF = &MF;
SetupMachineFunction(MF);
// Print out constants referenced by the function
EmitConstantPool(MF.getConstantPool());
// Print out jump tables referenced by the function
EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
O << "\n\n";
// Emit the function start directives
emitFunctionStart(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 (I != MF.begin()) {
printBasicBlockLabel(I, true, true);
O << '\n';
}
for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
II != E; ++II) {
// Print the assembly for the instruction.
printInstruction(II);
++EmittedInsts;
}
// Each Basic Block is separated by a newline
O << '\n';
}
// Emit function end directives
emitFunctionEnd(MF);
// We didn't modify anything.
return false;
}
// Print out an operand for an inline asm expression.
bool MipsAsmPrinter::
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])
return true; // Unknown modifier.
printOperand(MI, OpNo);
return false;
}
void MipsAsmPrinter::
printOperand(const MachineInstr *MI, int opNum)
{
const MachineOperand &MO = MI->getOperand(opNum);
const TargetRegisterInfo &RI = *TM.getRegisterInfo();
bool closeP = false;
bool isPIC = (TM.getRelocationModel() == Reloc::PIC_);
bool isCodeLarge = (TM.getCodeModel() == CodeModel::Large);
// %hi and %lo used on mips gas to load global addresses on
// static code. %got is used to load global addresses when
// using PIC_. %call16 is used to load direct call targets
// on PIC_ and small code size. %call_lo and %call_hi load
// direct call targets on PIC_ and large code size.
if (MI->getOpcode() == Mips::LUi && !MO.isReg() && !MO.isImm()) {
if ((isPIC) && (isCodeLarge))
O << "%call_hi(";
else
O << "%hi(";
closeP = true;
} else if ((MI->getOpcode() == Mips::ADDiu) && !MO.isReg() && !MO.isImm()) {
const MachineOperand &firstMO = MI->getOperand(opNum-1);
if (firstMO.getReg() == Mips::GP)
O << "%gp_rel(";
else
O << "%lo(";
closeP = true;
} else if ((isPIC) && (MI->getOpcode() == Mips::LW) &&
(!MO.isReg()) && (!MO.isImm())) {
const MachineOperand &firstMO = MI->getOperand(opNum-1);
const MachineOperand &lastMO = MI->getOperand(opNum+1);
if ((firstMO.isReg()) && (lastMO.isReg())) {
if ((firstMO.getReg() == Mips::T9) && (lastMO.getReg() == Mips::GP)
&& (!isCodeLarge))
O << "%call16(";
else if ((firstMO.getReg() != Mips::T9) && (lastMO.getReg() == Mips::GP))
O << "%got(";
else if ((firstMO.getReg() == Mips::T9) && (lastMO.getReg() != Mips::GP)
&& (isCodeLarge))
O << "%call_lo(";
closeP = true;
}
}
switch (MO.getType())
{
case MachineOperand::MO_Register:
if (TargetRegisterInfo::isPhysicalRegister(MO.getReg()))
O << '$' << LowercaseString (RI.get(MO.getReg()).AsmName);
else
O << '$' << MO.getReg();
break;
case MachineOperand::MO_Immediate:
O << (short int)MO.getImm();
break;
case MachineOperand::MO_MachineBasicBlock:
printBasicBlockLabel(MO.getMBB());
return;
case MachineOperand::MO_GlobalAddress:
O << Mang->getMangledName(MO.getGlobal());
break;
case MachineOperand::MO_ExternalSymbol:
O << MO.getSymbolName();
break;
case MachineOperand::MO_JumpTableIndex:
O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
<< '_' << MO.getIndex();
break;
case MachineOperand::MO_ConstantPoolIndex:
O << TAI->getPrivateGlobalPrefix() << "CPI"
<< getFunctionNumber() << "_" << MO.getIndex();
break;
default:
llvm_unreachable("<unknown operand type>");
}
if (closeP) O << ")";
}
void MipsAsmPrinter::
printUnsignedImm(const MachineInstr *MI, int opNum)
{
const MachineOperand &MO = MI->getOperand(opNum);
if (MO.getType() == MachineOperand::MO_Immediate)
O << (unsigned short int)MO.getImm();
else
printOperand(MI, opNum);
}
void MipsAsmPrinter::
printMemOperand(const MachineInstr *MI, int opNum, const char *Modifier)
{
// when using stack locations for not load/store instructions
// print the same way as all normal 3 operand instructions.
if (Modifier && !strcmp(Modifier, "stackloc")) {
printOperand(MI, opNum+1);
O << ", ";
printOperand(MI, opNum);
return;
}
// Load/Store memory operands -- imm($reg)
// If PIC target the target is loaded as the
// pattern lw $25,%call16($28)
printOperand(MI, opNum);
O << "(";
printOperand(MI, opNum+1);
O << ")";
}
void MipsAsmPrinter::
printFCCOperand(const MachineInstr *MI, int opNum, const char *Modifier)
{
const MachineOperand& MO = MI->getOperand(opNum);
O << Mips::MipsFCCToString((Mips::CondCode)MO.getImm());
}
bool MipsAsmPrinter::
doInitialization(Module &M)
{
Mang = new Mangler(M, "", TAI->getPrivateGlobalPrefix());
// Tell the assembler which ABI we are using
O << "\t.section .mdebug." << emitCurrentABIString() << '\n';
// TODO: handle O64 ABI
if (Subtarget->isABI_EABI())
O << "\t.section .gcc_compiled_long" <<
(Subtarget->isGP32bit() ? "32" : "64") << '\n';
// return to previous section
O << "\t.previous" << '\n';
return false; // success
}
void MipsAsmPrinter::
printModuleLevelGV(const GlobalVariable* GVar) {
const TargetData *TD = TM.getTargetData();
if (!GVar->hasInitializer())
return; // External global require no code
// Check to see if this is a special global used by LLVM, if so, emit it.
if (EmitSpecialLLVMGlobal(GVar))
return;
O << "\n\n";
std::string name = Mang->getMangledName(GVar);
Constant *C = GVar->getInitializer();
if (isa<MDNode>(C) || isa<MDString>(C))
return;
const Type *CTy = C->getType();
unsigned Size = TD->getTypeAllocSize(CTy);
const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
bool printSizeAndType = true;
// A data structure or array is aligned in memory to the largest
// alignment boundary required by any data type inside it (this matches
// the Preferred Type Alignment). For integral types, the alignment is
// the type size.
unsigned Align;
if (CTy->getTypeID() == Type::IntegerTyID ||
CTy->getTypeID() == Type::VoidTyID) {
assert(!(Size & (Size-1)) && "Alignment is not a power of two!");
Align = Log2_32(Size);
} else
Align = TD->getPreferredTypeAlignmentShift(CTy);
printVisibility(name, GVar->getVisibility());
SwitchToSection(TAI->SectionForGlobal(GVar));
if (C->isNullValue() && !GVar->hasSection()) {
if (!GVar->isThreadLocal() &&
(GVar->hasLocalLinkage() || GVar->isWeakForLinker())) {
if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
if (GVar->hasLocalLinkage())
O << "\t.local\t" << name << '\n';
O << TAI->getCOMMDirective() << name << ',' << Size;
if (TAI->getCOMMDirectiveTakesAlignment())
O << ',' << (1 << Align);
O << '\n';
return;
}
}
switch (GVar->getLinkage()) {
case GlobalValue::LinkOnceAnyLinkage:
case GlobalValue::LinkOnceODRLinkage:
case GlobalValue::CommonLinkage:
case GlobalValue::WeakAnyLinkage:
case GlobalValue::WeakODRLinkage:
// FIXME: Verify correct for weak.
// Nonnull linkonce -> weak
O << "\t.weak " << name << '\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 << TAI->getGlobalDirective() << name << '\n';
// Fall Through
case GlobalValue::PrivateLinkage:
case GlobalValue::InternalLinkage:
if (CVA && CVA->isCString())
printSizeAndType = false;
break;
case GlobalValue::GhostLinkage:
llvm_unreachable("Should not have any unmaterialized functions!");
case GlobalValue::DLLImportLinkage:
llvm_unreachable("DLLImport linkage is not supported by this target!");
case GlobalValue::DLLExportLinkage:
llvm_unreachable("DLLExport linkage is not supported by this target!");
default:
llvm_unreachable("Unknown linkage type!");
}
EmitAlignment(Align, GVar);
if (TAI->hasDotTypeDotSizeDirective() && printSizeAndType) {
O << "\t.type " << name << ",@object\n";
O << "\t.size " << name << ',' << Size << '\n';
}
O << name << ":\n";
EmitGlobalConstant(C);
}
bool MipsAsmPrinter::
doFinalization(Module &M)
{
// Print out module-level global variables here.
for (Module::const_global_iterator I = M.global_begin(),
E = M.global_end(); I != E; ++I)
printModuleLevelGV(I);
O << '\n';
return AsmPrinter::doFinalization(M);
}
// Force static initialization.
extern "C" void LLVMInitializeMipsAsmPrinter() {
TargetRegistry::RegisterAsmPrinter(TheMipsTarget, createMipsCodePrinterPass);
TargetRegistry::RegisterAsmPrinter(TheMipselTarget,
createMipsCodePrinterPass);
}