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llvm-6502/lib/Target/Mips/MipsAsmPrinter.cpp

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//===-- 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 "MipsInstrInfo.h"
#include "MipsTargetMachine.h"
#include "MipsMachineFunction.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/CodeGen/AsmPrinter.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/Support/Mangler.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/MathExtras.h"
#include <cctype>
using namespace llvm;
STATISTIC(EmittedInsts, "Number of machine instrs printed");
namespace {
struct VISIBILITY_HIDDEN MipsAsmPrinter : public AsmPrinter {
MipsAsmPrinter(std::ostream &O, MipsTargetMachine &TM,
const TargetAsmInfo *T):
AsmPrinter(O, TM, T) {}
virtual const char *getPassName() const {
return "Mips Assembly Printer";
}
enum SetDirectiveFlags {
REORDER, // enables instruction reordering.
NOREORDER, // disables instruction reordering.
MACRO, // enables GAS macros.
NOMACRO // disables GAS macros.
};
void printOperand(const MachineInstr *MI, int opNum);
void printMemOperand(const MachineInstr *MI, int opNum,
const char *Modifier = 0);
unsigned int getSavedRegsBitmask(bool isFloat, MachineFunction &MF);
void printHex32(unsigned int Value);
void emitFunctionStart(MachineFunction &MF);
void emitFunctionEnd(MachineFunction &MF);
void emitFrameDirective(MachineFunction &MF);
void emitMaskDirective(MachineFunction &MF);
void emitFMaskDirective(MachineFunction &MF);
void emitSetDirective(SetDirectiveFlags Flag);
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(std::ostream &o,
MipsTargetMachine &tm)
{
return new MipsAsmPrinter(o, tm, tm.getTargetAsmInfo());
}
//===----------------------------------------------------------------------===//
//
// 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 directive for GPR
void MipsAsmPrinter::
emitMaskDirective(MachineFunction &MF)
{
MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
int StackSize = MF.getFrameInfo()->getStackSize();
int Offset = (!MipsFI->getTopSavedRegOffset()) ? 0 :
(-(StackSize-MipsFI->getTopSavedRegOffset()));
#ifndef NDEBUG
DOUT << "--> emitMaskDirective" << "\n";
DOUT << "StackSize : " << StackSize << "\n";
DOUT << "getTopSavedReg : " << MipsFI->getTopSavedRegOffset() << "\n";
DOUT << "Offset : " << Offset << "\n\n";
#endif
unsigned int Bitmask = getSavedRegsBitmask(false, MF);
O << "\t.mask \t";
printHex32(Bitmask);
O << "," << Offset << "\n";
}
/// TODO: Mask Directive for Float Point
void MipsAsmPrinter::
emitFMaskDirective(MachineFunction &MF)
{
unsigned int Bitmask = getSavedRegsBitmask(true, MF);
O << "\t.fmask\t";
printHex32(Bitmask);
O << ",0" << "\n";
}
/// 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.
void MipsAsmPrinter::
emitSetDirective(SetDirectiveFlags Flag)
{
O << "\t.set\t";
switch(Flag) {
case REORDER: O << "reorder" << "\n"; break;
case NOREORDER: O << "noreorder" << "\n"; break;
case MACRO: O << "macro" << "\n"; break;
case NOMACRO: O << "nomacro" << "\n"; break;
default: break;
}
}
// Create a bitmask with all callee saved registers for CPU
// or Float Point registers. For CPU registers consider RA,
// GP and FP for saving if necessary.
unsigned int MipsAsmPrinter::
getSavedRegsBitmask(bool isFloat, MachineFunction &MF)
{
const TargetRegisterInfo &RI = *TM.getRegisterInfo();
// Float Point Registers, TODO
if (isFloat)
return 0;
// CPU Registers
unsigned int Bitmask = 0;
MachineFrameInfo *MFI = MF.getFrameInfo();
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
for (unsigned i = 0, e = CSI.size(); i != e; ++i)
Bitmask |= (1 << MipsRegisterInfo::getRegisterNumbering(CSI[i].getReg()));
if (RI.hasFP(MF))
Bitmask |= (1 << MipsRegisterInfo::
getRegisterNumbering(RI.getFrameRegister(MF)));
if (MF.getFrameInfo()->hasCalls())
Bitmask |= (1 << MipsRegisterInfo::
getRegisterNumbering(RI.getRARegister()));
return Bitmask;
}
// Print a 32 bit hex number with all numbers.
void MipsAsmPrinter::
printHex32(unsigned int Value)
{
O << "0x" << std::hex;
for (int i = 7; i >= 0; i--)
O << std::hex << ( (Value & (0xF << (i*4))) >> (i*4) );
O << std::dec;
}
/// 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();
SwitchToTextSection(getSectionForFunction(*F).c_str(), F);
// 2 bits aligned
EmitAlignment(2, F);
O << "\t.globl\t" << CurrentFnName << "\n";
O << "\t.ent\t" << CurrentFnName << "\n";
O << "\t.type\t" << CurrentFnName << ", @function\n";
O << CurrentFnName << ":\n";
emitFrameDirective(MF);
emitMaskDirective(MF);
emitFMaskDirective(MF);
if (TM.getRelocationModel() == Reloc::Static) {
emitSetDirective(NOREORDER);
emitSetDirective(NOMACRO);
}
O << "\n";
}
/// Emit the directives used by GAS on the end of functions
void MipsAsmPrinter::
emitFunctionEnd(MachineFunction &MF)
{
if (TM.getRelocationModel() == Reloc::Static) {
emitSetDirective(MACRO);
emitSetDirective(REORDER);
}
O << "\t.end\t" << CurrentFnName << "\n";
}
/// runOnMachineFunction - This uses the printMachineInstruction()
/// method to print assembly for each instruction.
bool MipsAsmPrinter::
runOnMachineFunction(MachineFunction &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";
// What's my mangled name?
CurrentFnName = Mang->getValueName(MF.getFunction());
// 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;
}
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.isRegister()
&& !MO.isImmediate()) {
if ((isPIC) && (isCodeLarge))
O << "%call_hi(";
else
O << "%hi(";
closeP = true;
} else if ((MI->getOpcode() == Mips::ADDiu) && !MO.isRegister()
&& !MO.isImmediate()) {
O << "%lo(";
closeP = true;
} else if ((isPIC) && (MI->getOpcode() == Mips::LW)
&& (!MO.isRegister()) && (!MO.isImmediate())) {
const MachineOperand &firstMO = MI->getOperand(opNum-1);
const MachineOperand &lastMO = MI->getOperand(opNum+1);
if ((firstMO.isRegister()) && (lastMO.isRegister())) {
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:
if ((MI->getOpcode() == Mips::SLTiu) || (MI->getOpcode() == Mips::ORi) ||
(MI->getOpcode() == Mips::LUi) || (MI->getOpcode() == Mips::ANDi))
O << (unsigned short int)MO.getImm();
else
O << (short int)MO.getImm();
break;
case MachineOperand::MO_MachineBasicBlock:
printBasicBlockLabel(MO.getMBB());
return;
case MachineOperand::MO_GlobalAddress:
O << Mang->getValueName(MO.getGlobal());
break;
case MachineOperand::MO_ExternalSymbol:
O << MO.getSymbolName();
break;
case MachineOperand::MO_JumpTableIndex:
O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
<< '_' << MO.getIndex();
break;
// FIXME: Verify correct
case MachineOperand::MO_ConstantPoolIndex:
O << TAI->getPrivateGlobalPrefix() << "CPI"
<< getFunctionNumber() << "_" << MO.getIndex();
break;
default:
O << "<unknown operand type>"; abort (); break;
}
if (closeP) O << ")";
}
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 << ")";
}
bool MipsAsmPrinter::
doInitialization(Module &M)
{
Mang = new Mangler(M);
return false; // success
}
bool MipsAsmPrinter::
doFinalization(Module &M)
{
const TargetData *TD = TM.getTargetData();
// Print out module-level global variables here.
for (Module::const_global_iterator I = M.global_begin(),
E = M.global_end(); I != E; ++I)
// External global require no code
if (I->hasInitializer()) {
// Check to see if this is a special global
// used by LLVM, if so, emit it.
if (EmitSpecialLLVMGlobal(I))
continue;
O << "\n\n";
std::string name = Mang->getValueName(I);
Constant *C = I->getInitializer();
unsigned Size = TD->getABITypeSize(C->getType());
unsigned Align = TD->getPreferredAlignmentLog(I);
// Is this correct ?
if (C->isNullValue() && (I->hasLinkOnceLinkage() ||
I->hasInternalLinkage() || I->hasWeakLinkage()))
{
if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
if (!NoZerosInBSS && TAI->getBSSSection())
SwitchToDataSection(TAI->getBSSSection(), I);
else
SwitchToDataSection(TAI->getDataSection(), I);
if (I->hasInternalLinkage()) {
if (TAI->getLCOMMDirective())
O << TAI->getLCOMMDirective() << name << "," << Size;
else
O << "\t.local\t" << name << "\n";
} else {
O << TAI->getCOMMDirective() << name << "," << Size;
// The .comm alignment in bytes.
if (TAI->getCOMMDirectiveTakesAlignment())
O << "," << (1 << Align);
}
} else {
switch (I->getLinkage())
{
case GlobalValue::LinkOnceLinkage:
case GlobalValue::WeakLinkage:
// FIXME: Verify correct for weak.
// Nonnull linkonce -> weak
O << "\t.weak " << name << "\n";
SwitchToDataSection("", I);
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 << TAI->getGlobalDirective() << name << "\n";
// Fall Through
case GlobalValue::InternalLinkage:
// FIXME: special handling for ".ctors" & ".dtors" sections
if (I->hasSection() && (I->getSection() == ".ctors" ||
I->getSection() == ".dtors")) {
std::string SectionName = ".section " + I->getSection();
SectionName += ",\"aw\",%progbits";
SwitchToDataSection(SectionName.c_str());
} else {
if (C->isNullValue() && !NoZerosInBSS && TAI->getBSSSection())
SwitchToDataSection(TAI->getBSSSection(), I);
else if (!I->isConstant())
SwitchToDataSection(TAI->getDataSection(), I);
else {
// Read-only data.
if (TAI->getReadOnlySection())
SwitchToDataSection(TAI->getReadOnlySection(), I);
else
SwitchToDataSection(TAI->getDataSection(), I);
}
}
break;
case GlobalValue::GhostLinkage:
cerr << "Should not have any unmaterialized functions!\n";
abort();
case GlobalValue::DLLImportLinkage:
cerr << "DLLImport linkage is not supported by this target!\n";
abort();
case GlobalValue::DLLExportLinkage:
cerr << "DLLExport linkage is not supported by this target!\n";
abort();
default:
assert(0 && "Unknown linkage type!");
}
O << "\t.align " << Align << "\n";
O << "\t.type " << name << ",@object\n";
O << "\t.size " << name << "," << Size << "\n";
O << name << ":\n";
EmitGlobalConstant(C);
}
}
return AsmPrinter::doFinalization(M);
}
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