llvm-6502/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
Bill Wendling 99cb622041 Use pointers to the MCAsmInfo and MCRegInfo.
Someone may want to do something crazy, like replace these objects if they
change or something.

No functionality change intended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184175 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-18 07:20:20 +00:00

432 lines
14 KiB
C++

//===-- MipsMCCodeEmitter.cpp - Convert Mips 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 MipsMCCodeEmitter class.
//
//===----------------------------------------------------------------------===//
//
#define DEBUG_TYPE "mccodeemitter"
#include "MCTargetDesc/MipsBaseInfo.h"
#include "MCTargetDesc/MipsFixupKinds.h"
#include "MCTargetDesc/MipsMCTargetDesc.h"
#include "llvm/ADT/APFloat.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstrInfo.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/Support/raw_ostream.h"
#define GET_INSTRMAP_INFO
#include "MipsGenInstrInfo.inc"
using namespace llvm;
namespace {
class MipsMCCodeEmitter : public MCCodeEmitter {
MipsMCCodeEmitter(const MipsMCCodeEmitter &) LLVM_DELETED_FUNCTION;
void operator=(const MipsMCCodeEmitter &) LLVM_DELETED_FUNCTION;
const MCInstrInfo &MCII;
MCContext &Ctx;
const MCSubtargetInfo &STI;
bool IsLittleEndian;
public:
MipsMCCodeEmitter(const MCInstrInfo &mcii, MCContext &Ctx_,
const MCSubtargetInfo &sti, bool IsLittle) :
MCII(mcii), Ctx(Ctx_), STI (sti), IsLittleEndian(IsLittle) {}
~MipsMCCodeEmitter() {}
void EmitByte(unsigned char C, raw_ostream &OS) const {
OS << (char)C;
}
void EmitInstruction(uint64_t Val, unsigned Size, raw_ostream &OS) const {
// Output the instruction encoding in little endian byte order.
for (unsigned i = 0; i < Size; ++i) {
unsigned Shift = IsLittleEndian ? i * 8 : (Size - 1 - i) * 8;
EmitByte((Val >> Shift) & 0xff, OS);
}
}
void EncodeInstruction(const MCInst &MI, raw_ostream &OS,
SmallVectorImpl<MCFixup> &Fixups) const;
// getBinaryCodeForInstr - TableGen'erated function for getting the
// binary encoding for an instruction.
uint64_t getBinaryCodeForInstr(const MCInst &MI,
SmallVectorImpl<MCFixup> &Fixups) const;
// getBranchJumpOpValue - Return binary encoding of the jump
// target operand. If the machine operand requires relocation,
// record the relocation and return zero.
unsigned getJumpTargetOpValue(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const;
// getBranchTargetOpValue - Return binary encoding of the branch
// target operand. If the machine operand requires relocation,
// record the relocation and return zero.
unsigned getBranchTargetOpValue(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const;
// getMachineOpValue - Return binary encoding of operand. If the machin
// operand requires relocation, record the relocation and return zero.
unsigned getMachineOpValue(const MCInst &MI,const MCOperand &MO,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned getMemEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned getSizeExtEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned getSizeInsEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned
getExprOpValue(const MCExpr *Expr,SmallVectorImpl<MCFixup> &Fixups) const;
}; // class MipsMCCodeEmitter
} // namespace
MCCodeEmitter *llvm::createMipsMCCodeEmitterEB(const MCInstrInfo &MCII,
const MCRegisterInfo &MRI,
const MCSubtargetInfo &STI,
MCContext &Ctx)
{
return new MipsMCCodeEmitter(MCII, Ctx, STI, false);
}
MCCodeEmitter *llvm::createMipsMCCodeEmitterEL(const MCInstrInfo &MCII,
const MCRegisterInfo &MRI,
const MCSubtargetInfo &STI,
MCContext &Ctx)
{
return new MipsMCCodeEmitter(MCII, Ctx, STI, true);
}
// If the D<shift> instruction has a shift amount that is greater
// than 31 (checked in calling routine), lower it to a D<shift>32 instruction
static void LowerLargeShift(MCInst& Inst) {
assert(Inst.getNumOperands() == 3 && "Invalid no. of operands for shift!");
assert(Inst.getOperand(2).isImm());
int64_t Shift = Inst.getOperand(2).getImm();
if (Shift <= 31)
return; // Do nothing
Shift -= 32;
// saminus32
Inst.getOperand(2).setImm(Shift);
switch (Inst.getOpcode()) {
default:
// Calling function is not synchronized
llvm_unreachable("Unexpected shift instruction");
case Mips::DSLL:
Inst.setOpcode(Mips::DSLL32);
return;
case Mips::DSRL:
Inst.setOpcode(Mips::DSRL32);
return;
case Mips::DSRA:
Inst.setOpcode(Mips::DSRA32);
return;
}
}
// Pick a DEXT or DINS instruction variant based on the pos and size operands
static void LowerDextDins(MCInst& InstIn) {
int Opcode = InstIn.getOpcode();
if (Opcode == Mips::DEXT)
assert(InstIn.getNumOperands() == 4 &&
"Invalid no. of machine operands for DEXT!");
else // Only DEXT and DINS are possible
assert(InstIn.getNumOperands() == 5 &&
"Invalid no. of machine operands for DINS!");
assert(InstIn.getOperand(2).isImm());
int64_t pos = InstIn.getOperand(2).getImm();
assert(InstIn.getOperand(3).isImm());
int64_t size = InstIn.getOperand(3).getImm();
if (size <= 32) {
if (pos < 32) // DEXT/DINS, do nothing
return;
// DEXTU/DINSU
InstIn.getOperand(2).setImm(pos - 32);
InstIn.setOpcode((Opcode == Mips::DEXT) ? Mips::DEXTU : Mips::DINSU);
return;
}
// DEXTM/DINSM
assert(pos < 32 && "DEXT/DINS cannot have both size and pos > 32");
InstIn.getOperand(3).setImm(size - 32);
InstIn.setOpcode((Opcode == Mips::DEXT) ? Mips::DEXTM : Mips::DINSM);
return;
}
/// EncodeInstruction - Emit the instruction.
/// Size the instruction (currently only 4 bytes
void MipsMCCodeEmitter::
EncodeInstruction(const MCInst &MI, raw_ostream &OS,
SmallVectorImpl<MCFixup> &Fixups) const
{
// Non-pseudo instructions that get changed for direct object
// only based on operand values.
// If this list of instructions get much longer we will move
// the check to a function call. Until then, this is more efficient.
MCInst TmpInst = MI;
switch (MI.getOpcode()) {
// If shift amount is >= 32 it the inst needs to be lowered further
case Mips::DSLL:
case Mips::DSRL:
case Mips::DSRA:
LowerLargeShift(TmpInst);
break;
// Double extract instruction is chosen by pos and size operands
case Mips::DEXT:
case Mips::DINS:
LowerDextDins(TmpInst);
}
uint32_t Binary = getBinaryCodeForInstr(TmpInst, Fixups);
// Check for unimplemented opcodes.
// Unfortunately in MIPS both NOP and SLL will come in with Binary == 0
// so we have to special check for them.
unsigned Opcode = TmpInst.getOpcode();
if ((Opcode != Mips::NOP) && (Opcode != Mips::SLL) && !Binary)
llvm_unreachable("unimplemented opcode in EncodeInstruction()");
if (STI.getFeatureBits() & Mips::FeatureMicroMips) {
int NewOpcode = Mips::Std2MicroMips (Opcode, Mips::Arch_micromips);
if (NewOpcode != -1) {
Opcode = NewOpcode;
TmpInst.setOpcode (NewOpcode);
Binary = getBinaryCodeForInstr(TmpInst, Fixups);
}
}
const MCInstrDesc &Desc = MCII.get(TmpInst.getOpcode());
// Get byte count of instruction
unsigned Size = Desc.getSize();
if (!Size)
llvm_unreachable("Desc.getSize() returns 0");
EmitInstruction(Binary, Size, OS);
}
/// getBranchTargetOpValue - Return binary encoding of the branch
/// target operand. If the machine operand requires relocation,
/// record the relocation and return zero.
unsigned MipsMCCodeEmitter::
getBranchTargetOpValue(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const {
const MCOperand &MO = MI.getOperand(OpNo);
// If the destination is an immediate, divide by 4.
if (MO.isImm()) return MO.getImm() >> 2;
assert(MO.isExpr() &&
"getBranchTargetOpValue expects only expressions or immediates");
const MCExpr *Expr = MO.getExpr();
Fixups.push_back(MCFixup::Create(0, Expr,
MCFixupKind(Mips::fixup_Mips_PC16)));
return 0;
}
/// getJumpTargetOpValue - Return binary encoding of the jump
/// target operand. If the machine operand requires relocation,
/// record the relocation and return zero.
unsigned MipsMCCodeEmitter::
getJumpTargetOpValue(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const {
const MCOperand &MO = MI.getOperand(OpNo);
// If the destination is an immediate, divide by 4.
if (MO.isImm()) return MO.getImm()>>2;
assert(MO.isExpr() &&
"getJumpTargetOpValue expects only expressions or an immediate");
const MCExpr *Expr = MO.getExpr();
Fixups.push_back(MCFixup::Create(0, Expr,
MCFixupKind(Mips::fixup_Mips_26)));
return 0;
}
unsigned MipsMCCodeEmitter::
getExprOpValue(const MCExpr *Expr,SmallVectorImpl<MCFixup> &Fixups) const {
int64_t Res;
if (Expr->EvaluateAsAbsolute(Res))
return Res;
MCExpr::ExprKind Kind = Expr->getKind();
if (Kind == MCExpr::Constant) {
return cast<MCConstantExpr>(Expr)->getValue();
}
if (Kind == MCExpr::Binary) {
unsigned Res = getExprOpValue(cast<MCBinaryExpr>(Expr)->getLHS(), Fixups);
Res += getExprOpValue(cast<MCBinaryExpr>(Expr)->getRHS(), Fixups);
return Res;
}
if (Kind == MCExpr::SymbolRef) {
Mips::Fixups FixupKind = Mips::Fixups(0);
switch(cast<MCSymbolRefExpr>(Expr)->getKind()) {
default: llvm_unreachable("Unknown fixup kind!");
break;
case MCSymbolRefExpr::VK_Mips_GPOFF_HI :
FixupKind = Mips::fixup_Mips_GPOFF_HI;
break;
case MCSymbolRefExpr::VK_Mips_GPOFF_LO :
FixupKind = Mips::fixup_Mips_GPOFF_LO;
break;
case MCSymbolRefExpr::VK_Mips_GOT_PAGE :
FixupKind = Mips::fixup_Mips_GOT_PAGE;
break;
case MCSymbolRefExpr::VK_Mips_GOT_OFST :
FixupKind = Mips::fixup_Mips_GOT_OFST;
break;
case MCSymbolRefExpr::VK_Mips_GOT_DISP :
FixupKind = Mips::fixup_Mips_GOT_DISP;
break;
case MCSymbolRefExpr::VK_Mips_GPREL:
FixupKind = Mips::fixup_Mips_GPREL16;
break;
case MCSymbolRefExpr::VK_Mips_GOT_CALL:
FixupKind = Mips::fixup_Mips_CALL16;
break;
case MCSymbolRefExpr::VK_Mips_GOT16:
FixupKind = Mips::fixup_Mips_GOT_Global;
break;
case MCSymbolRefExpr::VK_Mips_GOT:
FixupKind = Mips::fixup_Mips_GOT_Local;
break;
case MCSymbolRefExpr::VK_Mips_ABS_HI:
FixupKind = Mips::fixup_Mips_HI16;
break;
case MCSymbolRefExpr::VK_Mips_ABS_LO:
FixupKind = Mips::fixup_Mips_LO16;
break;
case MCSymbolRefExpr::VK_Mips_TLSGD:
FixupKind = Mips::fixup_Mips_TLSGD;
break;
case MCSymbolRefExpr::VK_Mips_TLSLDM:
FixupKind = Mips::fixup_Mips_TLSLDM;
break;
case MCSymbolRefExpr::VK_Mips_DTPREL_HI:
FixupKind = Mips::fixup_Mips_DTPREL_HI;
break;
case MCSymbolRefExpr::VK_Mips_DTPREL_LO:
FixupKind = Mips::fixup_Mips_DTPREL_LO;
break;
case MCSymbolRefExpr::VK_Mips_GOTTPREL:
FixupKind = Mips::fixup_Mips_GOTTPREL;
break;
case MCSymbolRefExpr::VK_Mips_TPREL_HI:
FixupKind = Mips::fixup_Mips_TPREL_HI;
break;
case MCSymbolRefExpr::VK_Mips_TPREL_LO:
FixupKind = Mips::fixup_Mips_TPREL_LO;
break;
case MCSymbolRefExpr::VK_Mips_HIGHER:
FixupKind = Mips::fixup_Mips_HIGHER;
break;
case MCSymbolRefExpr::VK_Mips_HIGHEST:
FixupKind = Mips::fixup_Mips_HIGHEST;
break;
case MCSymbolRefExpr::VK_Mips_GOT_HI16:
FixupKind = Mips::fixup_Mips_GOT_HI16;
break;
case MCSymbolRefExpr::VK_Mips_GOT_LO16:
FixupKind = Mips::fixup_Mips_GOT_LO16;
break;
case MCSymbolRefExpr::VK_Mips_CALL_HI16:
FixupKind = Mips::fixup_Mips_CALL_HI16;
break;
case MCSymbolRefExpr::VK_Mips_CALL_LO16:
FixupKind = Mips::fixup_Mips_CALL_LO16;
break;
} // switch
Fixups.push_back(MCFixup::Create(0, Expr, MCFixupKind(FixupKind)));
return 0;
}
return 0;
}
/// getMachineOpValue - Return binary encoding of operand. If the machine
/// operand requires relocation, record the relocation and return zero.
unsigned MipsMCCodeEmitter::
getMachineOpValue(const MCInst &MI, const MCOperand &MO,
SmallVectorImpl<MCFixup> &Fixups) const {
if (MO.isReg()) {
unsigned Reg = MO.getReg();
unsigned RegNo = Ctx.getRegisterInfo()->getEncodingValue(Reg);
return RegNo;
} else if (MO.isImm()) {
return static_cast<unsigned>(MO.getImm());
} else if (MO.isFPImm()) {
return static_cast<unsigned>(APFloat(MO.getFPImm())
.bitcastToAPInt().getHiBits(32).getLimitedValue());
}
// MO must be an Expr.
assert(MO.isExpr());
return getExprOpValue(MO.getExpr(),Fixups);
}
/// getMemEncoding - Return binary encoding of memory related operand.
/// If the offset operand requires relocation, record the relocation.
unsigned
MipsMCCodeEmitter::getMemEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const {
// Base register is encoded in bits 20-16, offset is encoded in bits 15-0.
assert(MI.getOperand(OpNo).isReg());
unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo),Fixups) << 16;
unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups);
return (OffBits & 0xFFFF) | RegBits;
}
unsigned
MipsMCCodeEmitter::getSizeExtEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const {
assert(MI.getOperand(OpNo).isImm());
unsigned SizeEncoding = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups);
return SizeEncoding - 1;
}
// FIXME: should be called getMSBEncoding
//
unsigned
MipsMCCodeEmitter::getSizeInsEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const {
assert(MI.getOperand(OpNo-1).isImm());
assert(MI.getOperand(OpNo).isImm());
unsigned Position = getMachineOpValue(MI, MI.getOperand(OpNo-1), Fixups);
unsigned Size = getMachineOpValue(MI, MI.getOperand(OpNo), Fixups);
return Position + Size - 1;
}
#include "MipsGenMCCodeEmitter.inc"