llvm-6502/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp
Hal Finkel aa6047d23d PPC: Use HWEncoding and TRI->getEncodingValue
As pointed out by Jakob, we don't need to maintain a separate
register-numbering table. Instead we should let TableGen generate the table for
us from the information (already present) in PPCRegisterInfo.td.
TRI->getEncodingValue is now used to access register-encoding values.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178067 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-26 20:08:20 +00:00

240 lines
9.6 KiB
C++

//===-- PPCMCCodeEmitter.cpp - Convert PPC 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 PPCMCCodeEmitter class.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "mccodeemitter"
#include "MCTargetDesc/PPCMCTargetDesc.h"
#include "MCTargetDesc/PPCFixupKinds.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/MCSubtargetInfo.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
STATISTIC(MCNumEmitted, "Number of MC instructions emitted");
namespace {
class PPCMCCodeEmitter : public MCCodeEmitter {
PPCMCCodeEmitter(const PPCMCCodeEmitter &) LLVM_DELETED_FUNCTION;
void operator=(const PPCMCCodeEmitter &) LLVM_DELETED_FUNCTION;
const MCSubtargetInfo &STI;
const MCContext &CTX;
Triple TT;
public:
PPCMCCodeEmitter(const MCInstrInfo &mcii, const MCSubtargetInfo &sti,
MCContext &ctx)
: STI(sti), CTX(ctx), TT(STI.getTargetTriple()) {
}
~PPCMCCodeEmitter() {}
unsigned getDirectBrEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned getCondBrEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned getHA16Encoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned getLO16Encoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned getMemRIEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned getMemRIXEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned getTLSRegEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned get_crbitm_encoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) 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,
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;
void EncodeInstruction(const MCInst &MI, raw_ostream &OS,
SmallVectorImpl<MCFixup> &Fixups) const {
uint64_t Bits = getBinaryCodeForInstr(MI, Fixups);
// BL8_NOP etc. all have a size of 8 because of the following 'nop'.
unsigned Size = 4; // FIXME: Have Desc.getSize() return the correct value!
unsigned Opcode = MI.getOpcode();
if (Opcode == PPC::BL8_NOP || Opcode == PPC::BLA8_NOP ||
Opcode == PPC::BL8_NOP_TLSGD || Opcode == PPC::BL8_NOP_TLSLD)
Size = 8;
// Output the constant in big endian byte order.
int ShiftValue = (Size * 8) - 8;
for (unsigned i = 0; i != Size; ++i) {
OS << (char)(Bits >> ShiftValue);
Bits <<= 8;
}
++MCNumEmitted; // Keep track of the # of mi's emitted.
}
};
} // end anonymous namespace
MCCodeEmitter *llvm::createPPCMCCodeEmitter(const MCInstrInfo &MCII,
const MCRegisterInfo &MRI,
const MCSubtargetInfo &STI,
MCContext &Ctx) {
return new PPCMCCodeEmitter(MCII, STI, Ctx);
}
unsigned PPCMCCodeEmitter::
getDirectBrEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const {
const MCOperand &MO = MI.getOperand(OpNo);
if (MO.isReg() || MO.isImm()) return getMachineOpValue(MI, MO, Fixups);
// Add a fixup for the branch target.
Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
(MCFixupKind)PPC::fixup_ppc_br24));
// For special TLS calls, add another fixup for the symbol. Apparently
// BL8_NOP, BL8_NOP_TLSGD, and BL8_NOP_TLSLD are sufficiently
// similar that TblGen will not generate a separate case for the latter
// two, so this is the only way to get the extra fixup generated.
unsigned Opcode = MI.getOpcode();
if (Opcode == PPC::BL8_NOP_TLSGD || Opcode == PPC::BL8_NOP_TLSLD) {
const MCOperand &MO2 = MI.getOperand(OpNo+1);
Fixups.push_back(MCFixup::Create(0, MO2.getExpr(),
(MCFixupKind)PPC::fixup_ppc_nofixup));
}
return 0;
}
unsigned PPCMCCodeEmitter::getCondBrEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const {
const MCOperand &MO = MI.getOperand(OpNo);
if (MO.isReg() || MO.isImm()) return getMachineOpValue(MI, MO, Fixups);
// Add a fixup for the branch target.
Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
(MCFixupKind)PPC::fixup_ppc_brcond14));
return 0;
}
unsigned PPCMCCodeEmitter::getHA16Encoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const {
const MCOperand &MO = MI.getOperand(OpNo);
if (MO.isReg() || MO.isImm()) return getMachineOpValue(MI, MO, Fixups);
// Add a fixup for the branch target.
Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
(MCFixupKind)PPC::fixup_ppc_ha16));
return 0;
}
unsigned PPCMCCodeEmitter::getLO16Encoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const {
const MCOperand &MO = MI.getOperand(OpNo);
if (MO.isReg() || MO.isImm()) return getMachineOpValue(MI, MO, Fixups);
// Add a fixup for the branch target.
Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
(MCFixupKind)PPC::fixup_ppc_lo16));
return 0;
}
unsigned PPCMCCodeEmitter::getMemRIEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const {
// Encode (imm, reg) as a memri, which has the low 16-bits as the
// displacement and the next 5 bits as the register #.
assert(MI.getOperand(OpNo+1).isReg());
unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups) << 16;
const MCOperand &MO = MI.getOperand(OpNo);
if (MO.isImm())
return (getMachineOpValue(MI, MO, Fixups) & 0xFFFF) | RegBits;
// Add a fixup for the displacement field.
Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
(MCFixupKind)PPC::fixup_ppc_lo16));
return RegBits;
}
unsigned PPCMCCodeEmitter::getMemRIXEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const {
// Encode (imm, reg) as a memrix, which has the low 14-bits as the
// displacement and the next 5 bits as the register #.
assert(MI.getOperand(OpNo+1).isReg());
unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups) << 14;
const MCOperand &MO = MI.getOperand(OpNo);
if (MO.isImm())
return (getMachineOpValue(MI, MO, Fixups) & 0x3FFF) | RegBits;
// Add a fixup for the displacement field.
Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
(MCFixupKind)PPC::fixup_ppc_lo16_ds));
return RegBits;
}
unsigned PPCMCCodeEmitter::getTLSRegEncoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const {
const MCOperand &MO = MI.getOperand(OpNo);
if (MO.isReg()) return getMachineOpValue(MI, MO, Fixups);
// Add a fixup for the TLS register, which simply provides a relocation
// hint to the linker that this statement is part of a relocation sequence.
// Return the thread-pointer register's encoding.
Fixups.push_back(MCFixup::Create(0, MO.getExpr(),
(MCFixupKind)PPC::fixup_ppc_tlsreg));
return CTX.getRegisterInfo().getEncodingValue(PPC::X13);
}
unsigned PPCMCCodeEmitter::
get_crbitm_encoding(const MCInst &MI, unsigned OpNo,
SmallVectorImpl<MCFixup> &Fixups) const {
const MCOperand &MO = MI.getOperand(OpNo);
assert((MI.getOpcode() == PPC::MTCRF ||
MI.getOpcode() == PPC::MFOCRF ||
MI.getOpcode() == PPC::MTCRF8) &&
(MO.getReg() >= PPC::CR0 && MO.getReg() <= PPC::CR7));
return 0x80 >> CTX.getRegisterInfo().getEncodingValue(MO.getReg());
}
unsigned PPCMCCodeEmitter::
getMachineOpValue(const MCInst &MI, const MCOperand &MO,
SmallVectorImpl<MCFixup> &Fixups) const {
if (MO.isReg()) {
// MTCRF/MFOCRF should go through get_crbitm_encoding for the CR operand.
// The GPR operand should come through here though.
assert((MI.getOpcode() != PPC::MTCRF && MI.getOpcode() != PPC::MFOCRF) ||
MO.getReg() < PPC::CR0 || MO.getReg() > PPC::CR7);
return CTX.getRegisterInfo().getEncodingValue(MO.getReg());
}
assert(MO.isImm() &&
"Relocation required in an instruction that we cannot encode!");
return MO.getImm();
}
#include "PPCGenMCCodeEmitter.inc"