llvm-6502/lib/Target/MBlaze/MCTargetDesc/MBlazeMCCodeEmitter.cpp
2011-07-25 20:18:18 +00:00

225 lines
7.1 KiB
C++

//===-- MBlazeMCCodeEmitter.cpp - Convert MBlaze code to machine code -----===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the MBlazeMCCodeEmitter class.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "mccodeemitter"
#include "MCTargetDesc/MBlazeBaseInfo.h"
#include "MCTargetDesc/MBlazeMCTargetDesc.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstrInfo.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCFixup.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
STATISTIC(MCNumEmitted, "Number of MC instructions emitted");
namespace {
class MBlazeMCCodeEmitter : public MCCodeEmitter {
MBlazeMCCodeEmitter(const MBlazeMCCodeEmitter &); // DO NOT IMPLEMENT
void operator=(const MBlazeMCCodeEmitter &); // DO NOT IMPLEMENT
const MCInstrInfo &MCII;
public:
MBlazeMCCodeEmitter(const MCInstrInfo &mcii, const MCSubtargetInfo &sti,
MCContext &ctx)
: MCII(mcii) {
}
~MBlazeMCCodeEmitter() {}
// getBinaryCodeForInstr - TableGen'erated function for getting the
// binary encoding for an instruction.
unsigned getBinaryCodeForInstr(const MCInst &MI) const;
/// getMachineOpValue - Return binary encoding of operand. If the machine
/// operand requires relocation, record the relocation and return zero.
unsigned getMachineOpValue(const MCInst &MI,const MCOperand &MO) const;
unsigned getMachineOpValue(const MCInst &MI, unsigned OpIdx) const {
return getMachineOpValue(MI, MI.getOperand(OpIdx));
}
static unsigned GetMBlazeRegNum(const MCOperand &MO) {
// FIXME: getMBlazeRegisterNumbering() is sufficient?
assert(0 && "MBlazeMCCodeEmitter::GetMBlazeRegNum() not yet implemented.");
return 0;
}
void EmitByte(unsigned char C, unsigned &CurByte, raw_ostream &OS) const {
// The MicroBlaze uses a bit reversed format so we need to reverse the
// order of the bits. Taken from:
// http://graphics.stanford.edu/~seander/bithacks.html
C = ((C * 0x80200802ULL) & 0x0884422110ULL) * 0x0101010101ULL >> 32;
OS << (char)C;
++CurByte;
}
void EmitRawByte(unsigned char C, unsigned &CurByte, raw_ostream &OS) const {
OS << (char)C;
++CurByte;
}
void EmitConstant(uint64_t Val, unsigned Size, unsigned &CurByte,
raw_ostream &OS) const {
assert(Size <= 8 && "size too big in emit constant");
for (unsigned i = 0; i != Size; ++i) {
EmitByte(Val & 255, CurByte, OS);
Val >>= 8;
}
}
void EmitIMM(const MCOperand &imm, unsigned &CurByte, raw_ostream &OS) const;
void EmitIMM(const MCInst &MI, unsigned &CurByte, raw_ostream &OS) const;
void EmitImmediate(const MCInst &MI, unsigned opNo, bool pcrel,
unsigned &CurByte, raw_ostream &OS,
SmallVectorImpl<MCFixup> &Fixups) const;
void EncodeInstruction(const MCInst &MI, raw_ostream &OS,
SmallVectorImpl<MCFixup> &Fixups) const;
};
} // end anonymous namespace
MCCodeEmitter *llvm::createMBlazeMCCodeEmitter(const MCInstrInfo &MCII,
const MCSubtargetInfo &STI,
MCContext &Ctx) {
return new MBlazeMCCodeEmitter(MCII, STI, Ctx);
}
/// getMachineOpValue - Return binary encoding of operand. If the machine
/// operand requires relocation, record the relocation and return zero.
unsigned MBlazeMCCodeEmitter::getMachineOpValue(const MCInst &MI,
const MCOperand &MO) const {
if (MO.isReg())
return getMBlazeRegisterNumbering(MO.getReg());
else if (MO.isImm())
return static_cast<unsigned>(MO.getImm());
else if (MO.isExpr())
return 0; // The relocation has already been recorded at this point.
else {
#ifndef NDEBUG
errs() << MO;
#endif
llvm_unreachable(0);
}
return 0;
}
void MBlazeMCCodeEmitter::
EmitIMM(const MCOperand &imm, unsigned &CurByte, raw_ostream &OS) const {
int32_t val = (int32_t)imm.getImm();
if (val > 32767 || val < -32768) {
EmitByte(0x0D, CurByte, OS);
EmitByte(0x00, CurByte, OS);
EmitRawByte((val >> 24) & 0xFF, CurByte, OS);
EmitRawByte((val >> 16) & 0xFF, CurByte, OS);
}
}
void MBlazeMCCodeEmitter::
EmitIMM(const MCInst &MI, unsigned &CurByte,raw_ostream &OS) const {
switch (MI.getOpcode()) {
default: break;
case MBlaze::ADDIK32:
case MBlaze::ORI32:
case MBlaze::BRLID32:
EmitByte(0x0D, CurByte, OS);
EmitByte(0x00, CurByte, OS);
EmitRawByte(0, CurByte, OS);
EmitRawByte(0, CurByte, OS);
}
}
void MBlazeMCCodeEmitter::
EmitImmediate(const MCInst &MI, unsigned opNo, bool pcrel, unsigned &CurByte,
raw_ostream &OS, SmallVectorImpl<MCFixup> &Fixups) const {
assert(MI.getNumOperands()>opNo && "Not enought operands for instruction");
MCOperand oper = MI.getOperand(opNo);
if (oper.isImm()) {
EmitIMM(oper, CurByte, OS);
} else if (oper.isExpr()) {
MCFixupKind FixupKind;
switch (MI.getOpcode()) {
default:
FixupKind = pcrel ? FK_PCRel_2 : FK_Data_2;
Fixups.push_back(MCFixup::Create(0,oper.getExpr(),FixupKind));
break;
case MBlaze::ORI32:
case MBlaze::ADDIK32:
case MBlaze::BRLID32:
FixupKind = pcrel ? FK_PCRel_4 : FK_Data_4;
Fixups.push_back(MCFixup::Create(0,oper.getExpr(),FixupKind));
break;
}
}
}
void MBlazeMCCodeEmitter::
EncodeInstruction(const MCInst &MI, raw_ostream &OS,
SmallVectorImpl<MCFixup> &Fixups) const {
unsigned Opcode = MI.getOpcode();
const MCInstrDesc &Desc = MCII.get(Opcode);
uint64_t TSFlags = Desc.TSFlags;
// Keep track of the current byte being emitted.
unsigned CurByte = 0;
// Emit an IMM instruction if the instruction we are encoding requires it
EmitIMM(MI,CurByte,OS);
switch ((TSFlags & MBlazeII::FormMask)) {
default: break;
case MBlazeII::FPseudo:
// Pseudo instructions don't get encoded.
return;
case MBlazeII::FRRI:
EmitImmediate(MI, 2, false, CurByte, OS, Fixups);
break;
case MBlazeII::FRIR:
EmitImmediate(MI, 1, false, CurByte, OS, Fixups);
break;
case MBlazeII::FCRI:
EmitImmediate(MI, 1, true, CurByte, OS, Fixups);
break;
case MBlazeII::FRCI:
EmitImmediate(MI, 1, true, CurByte, OS, Fixups);
case MBlazeII::FCCI:
EmitImmediate(MI, 0, true, CurByte, OS, Fixups);
break;
}
++MCNumEmitted; // Keep track of the # of mi's emitted
unsigned Value = getBinaryCodeForInstr(MI);
EmitConstant(Value, 4, CurByte, OS);
}
// FIXME: These #defines shouldn't be necessary. Instead, tblgen should
// be able to generate code emitter helpers for either variant, like it
// does for the AsmWriter.
#define MBlazeCodeEmitter MBlazeMCCodeEmitter
#define MachineInstr MCInst
#include "MBlazeGenCodeEmitter.inc"
#undef MBlazeCodeEmitter
#undef MachineInstr