llvm-6502/lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.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

227 lines
9.0 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 getS16ImmEncoding(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::getS16ImmEncoding(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(2, MO.getExpr(),
(MCFixupKind)PPC::fixup_ppc_half16));
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(2, MO.getExpr(),
(MCFixupKind)PPC::fixup_ppc_half16));
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) >> 2) & 0x3FFF) | RegBits;
// Add a fixup for the displacement field.
Fixups.push_back(MCFixup::Create(2, MO.getExpr(),
(MCFixupKind)PPC::fixup_ppc_half16ds));
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"