llvm-6502/lib/Target/PowerPC/PPCCodeEmitter.cpp

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//===-- PPCCodeEmitter.cpp - JIT Code Emitter for PowerPC32 -------*- C++ -*-=//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the PowerPC 32-bit CodeEmitter and associated machinery to
// JIT-compile bitcode to native PowerPC.
//
//===----------------------------------------------------------------------===//
#include "PPCTargetMachine.h"
#include "PPCRelocations.h"
#include "PPC.h"
#include "llvm/Module.h"
#include "llvm/PassManager.h"
#include "llvm/CodeGen/MachineCodeEmitter.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
namespace {
class VISIBILITY_HIDDEN PPCCodeEmitter : public MachineFunctionPass {
TargetMachine &TM;
MachineCodeEmitter &MCE;
/// MovePCtoLROffset - When/if we see a MovePCtoLR instruction, we record
/// its address in the function into this pointer.
void *MovePCtoLROffset;
/// getMachineOpValue - evaluates the MachineOperand of a given MachineInstr
///
unsigned getMachineOpValue(const MachineInstr &MI, const MachineOperand &MO);
void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<MachineModuleInfo>();
MachineFunctionPass::getAnalysisUsage(AU);
}
public:
static char ID;
PPCCodeEmitter(TargetMachine &T, MachineCodeEmitter &M)
: MachineFunctionPass(&ID), TM(T), MCE(M) {}
const char *getPassName() const { return "PowerPC Machine Code Emitter"; }
/// runOnMachineFunction - emits the given MachineFunction to memory
///
bool runOnMachineFunction(MachineFunction &MF);
/// emitBasicBlock - emits the given MachineBasicBlock to memory
///
void emitBasicBlock(MachineBasicBlock &MBB);
/// getValueBit - return the particular bit of Val
///
unsigned getValueBit(int64_t Val, unsigned bit) { return (Val >> bit) & 1; }
/// getBinaryCodeForInstr - This function, generated by the
/// CodeEmitterGenerator using TableGen, produces the binary encoding for
/// machine instructions.
///
unsigned getBinaryCodeForInstr(const MachineInstr &MI);
};
char PPCCodeEmitter::ID = 0;
}
/// createPPCCodeEmitterPass - Return a pass that emits the collected PPC code
/// to the specified MCE object.
FunctionPass *llvm::createPPCCodeEmitterPass(PPCTargetMachine &TM,
MachineCodeEmitter &MCE) {
return new PPCCodeEmitter(TM, MCE);
}
bool PPCCodeEmitter::runOnMachineFunction(MachineFunction &MF) {
assert((MF.getTarget().getRelocationModel() != Reloc::Default ||
MF.getTarget().getRelocationModel() != Reloc::Static) &&
"JIT relocation model must be set to static or default!");
MCE.setModuleInfo(&getAnalysis<MachineModuleInfo>());
do {
MovePCtoLROffset = 0;
MCE.startFunction(MF);
for (MachineFunction::iterator BB = MF.begin(), E = MF.end(); BB != E; ++BB)
emitBasicBlock(*BB);
} while (MCE.finishFunction(MF));
return false;
}
void PPCCodeEmitter::emitBasicBlock(MachineBasicBlock &MBB) {
MCE.StartMachineBasicBlock(&MBB);
for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); I != E; ++I){
const MachineInstr &MI = *I;
switch (MI.getOpcode()) {
default:
MCE.emitWordBE(getBinaryCodeForInstr(MI));
break;
case TargetInstrInfo::DBG_LABEL:
case TargetInstrInfo::EH_LABEL:
MCE.emitLabel(MI.getOperand(0).getImm());
break;
case TargetInstrInfo::IMPLICIT_DEF:
break; // pseudo opcode, no side effects
case PPC::MovePCtoLR:
case PPC::MovePCtoLR8:
assert(TM.getRelocationModel() == Reloc::PIC_);
MovePCtoLROffset = (void*)MCE.getCurrentPCValue();
MCE.emitWordBE(0x48000005); // bl 1
break;
}
}
}
unsigned PPCCodeEmitter::getMachineOpValue(const MachineInstr &MI,
const MachineOperand &MO) {
unsigned rv = 0; // Return value; defaults to 0 for unhandled cases
// or things that get fixed up later by the JIT.
if (MO.isReg()) {
rv = PPCRegisterInfo::getRegisterNumbering(MO.getReg());
// Special encoding for MTCRF and MFOCRF, which uses a bit mask for the
// register, not the register number directly.
if ((MI.getOpcode() == PPC::MTCRF || MI.getOpcode() == PPC::MFOCRF) &&
(MO.getReg() >= PPC::CR0 && MO.getReg() <= PPC::CR7)) {
rv = 0x80 >> rv;
}
} else if (MO.isImm()) {
rv = MO.getImm();
} else if (MO.isGlobal() || MO.isSymbol() ||
MO.isCPI() || MO.isJTI()) {
unsigned Reloc = 0;
if (MI.getOpcode() == PPC::BL_Macho || MI.getOpcode() == PPC::BL8_Macho ||
MI.getOpcode() == PPC::BL_ELF || MI.getOpcode() == PPC::BL8_ELF ||
MI.getOpcode() == PPC::TAILB || MI.getOpcode() == PPC::TAILB8)
Reloc = PPC::reloc_pcrel_bx;
else {
if (TM.getRelocationModel() == Reloc::PIC_) {
assert(MovePCtoLROffset && "MovePCtoLR not seen yet?");
}
switch (MI.getOpcode()) {
default: MI.dump(); assert(0 && "Unknown instruction for relocation!");
case PPC::LIS:
case PPC::LIS8:
case PPC::ADDIS:
case PPC::ADDIS8:
Reloc = PPC::reloc_absolute_high; // Pointer to symbol
break;
case PPC::LI:
case PPC::LI8:
case PPC::LA:
// Loads.
case PPC::LBZ:
case PPC::LBZ8:
case PPC::LHA:
case PPC::LHA8:
case PPC::LHZ:
case PPC::LHZ8:
case PPC::LWZ:
case PPC::LWZ8:
case PPC::LFS:
case PPC::LFD:
// Stores.
case PPC::STB:
case PPC::STB8:
case PPC::STH:
case PPC::STH8:
case PPC::STW:
case PPC::STW8:
case PPC::STFS:
case PPC::STFD:
Reloc = PPC::reloc_absolute_low;
break;
case PPC::LWA:
case PPC::LD:
case PPC::STD:
case PPC::STD_32:
Reloc = PPC::reloc_absolute_low_ix;
break;
}
}
MachineRelocation R;
if (MO.isGlobal()) {
R = MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc,
MO.getGlobal(), 0,
isa<Function>(MO.getGlobal()));
} else if (MO.isSymbol()) {
R = MachineRelocation::getExtSym(MCE.getCurrentPCOffset(),
Reloc, MO.getSymbolName(), 0);
} else if (MO.isCPI()) {
R = MachineRelocation::getConstPool(MCE.getCurrentPCOffset(),
Reloc, MO.getIndex(), 0);
} else {
assert(MO.isJTI());
R = MachineRelocation::getJumpTable(MCE.getCurrentPCOffset(),
Reloc, MO.getIndex(), 0);
}
// If in PIC mode, we need to encode the negated address of the
// 'movepctolr' into the unrelocated field. After relocation, we'll have
// &gv-&movepctolr-4 in the imm field. Once &movepctolr is added to the imm
// field, we get &gv. This doesn't happen for branch relocations, which are
// always implicitly pc relative.
if (TM.getRelocationModel() == Reloc::PIC_ && Reloc != PPC::reloc_pcrel_bx){
assert(MovePCtoLROffset && "MovePCtoLR not seen yet?");
R.setConstantVal(-(intptr_t)MovePCtoLROffset - 4);
}
MCE.addRelocation(R);
} else if (MO.isMBB()) {
unsigned Reloc = 0;
unsigned Opcode = MI.getOpcode();
if (Opcode == PPC::B || Opcode == PPC::BL_Macho ||
Opcode == PPC::BLA_Macho || Opcode == PPC::BL_ELF ||
Opcode == PPC::BLA_ELF)
Reloc = PPC::reloc_pcrel_bx;
else // BCC instruction
Reloc = PPC::reloc_pcrel_bcx;
MCE.addRelocation(MachineRelocation::getBB(MCE.getCurrentPCOffset(),
Reloc, MO.getMBB()));
} else {
cerr << "ERROR: Unknown type of MachineOperand: " << MO << "\n";
abort();
}
return rv;
}
#include "PPCGenCodeEmitter.inc"