/src/capstonenext/arch/PowerPC/PPCDisassembler.c

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/* Capstone Disassembly Engine, http://www.capstone-engine.org */
/* By Nguyen Anh Quynh <aquynh@gmail.com>, 2013-2022, */
/*    Rot127 <unisono@quyllur.org> 2022-2023 */
/* Automatically translated source file from LLVM. */

/* LLVM-commit: <commit> */
/* LLVM-tag: <tag> */

/* Only small edits allowed. */
/* For multiple similar edits, please create a Patch for the translator. */

/* Capstone's C++ file translator: */
/* https://github.com/capstone-engine/capstone/tree/next/suite/auto-sync */

//===------ PPCDisassembler.cpp - Disassembler for PowerPC ------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include <capstone/platform.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "../../LEB128.h"
#include "../../MCDisassembler.h"
#include "../../MCFixedLenDisassembler.h"
#include "../../MCInst.h"
#include "../../MCInstPrinter.h"
#include "../../MCInstrDesc.h"
#include "../../MCRegisterInfo.h"
#include "../../SStream.h"
#include "../../utils.h"
#include "PPCLinkage.h"
#include "PPCMapping.h"
#include "PPCMCTargetDesc.h"
#include "PPCPredicates.h"

#define CONCAT(a, b) CONCAT_(a, b)
#define CONCAT_(a, b) a##_##b

DEFINE_PPC_REGCLASSES

#define DEBUG_TYPE "ppc-disassembler"

DecodeStatus getInstruction(csh ud, const uint8_t *Bytes, size_t BytesLen,
          MCInst *MI, uint16_t *Size, uint64_t Address,
          void *Info);
// end anonymous namespace

static DecodeStatus decodeCondBrTarget(MCInst *Inst, unsigned Imm,
               uint64_t Address, const void *Decoder)
{
  MCOperand_CreateImm0(Inst, (SignExtend32((Imm), 14)));
  return MCDisassembler_Success;
}

static DecodeStatus decodeDirectBrTarget(MCInst *Inst, unsigned Imm,
           uint64_t Address, const void *Decoder)
{
  int32_t Offset = SignExtend32((Imm), 24);
  MCOperand_CreateImm0(Inst, (Offset));
  return MCDisassembler_Success;
}

// FIXME: These can be generated by TableGen from the existing register
// encoding values!

static DecodeStatus decodeRegisterClass(MCInst *Inst, uint64_t RegNo,
          const MCPhysReg *Regs)
{
  MCOperand_CreateReg0(Inst, (Regs[RegNo]));
  return MCDisassembler_Success;
}

static DecodeStatus DecodeCRRCRegisterClass(MCInst *Inst, uint64_t RegNo,
              uint64_t Address,
              const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, CRRegs);
}

static DecodeStatus DecodeCRBITRCRegisterClass(MCInst *Inst, uint64_t RegNo,
                 uint64_t Address,
                 const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, CRBITRegs);
}

static DecodeStatus DecodeF4RCRegisterClass(MCInst *Inst, uint64_t RegNo,
              uint64_t Address,
              const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, FRegs);
}

static DecodeStatus DecodeF8RCRegisterClass(MCInst *Inst, uint64_t RegNo,
              uint64_t Address,
              const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, FRegs);
}

static DecodeStatus DecodeVFRCRegisterClass(MCInst *Inst, uint64_t RegNo,
              uint64_t Address,
              const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, VFRegs);
}

static DecodeStatus DecodeVRRCRegisterClass(MCInst *Inst, uint64_t RegNo,
              uint64_t Address,
              const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, VRegs);
}

static DecodeStatus DecodeVSRCRegisterClass(MCInst *Inst, uint64_t RegNo,
              uint64_t Address,
              const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, VSRegs);
}

static DecodeStatus DecodeVSFRCRegisterClass(MCInst *Inst, uint64_t RegNo,
               uint64_t Address,
               const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, VSFRegs);
}

static DecodeStatus DecodeVSSRCRegisterClass(MCInst *Inst, uint64_t RegNo,
               uint64_t Address,
               const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, VSSRegs);
}

static DecodeStatus DecodeGPRCRegisterClass(MCInst *Inst, uint64_t RegNo,
              uint64_t Address,
              const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, RRegs);
}

static DecodeStatus DecodeGPRC_NOR0RegisterClass(MCInst *Inst, uint64_t RegNo,
             uint64_t Address,
             const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, RRegsNoR0);
}

static DecodeStatus DecodeG8RCRegisterClass(MCInst *Inst, uint64_t RegNo,
              uint64_t Address,
              const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, XRegs);
}

static DecodeStatus DecodeG8pRCRegisterClass(MCInst *Inst, uint64_t RegNo,
               uint64_t Address,
               const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, XRegs);
}

static DecodeStatus DecodeG8RC_NOX0RegisterClass(MCInst *Inst, uint64_t RegNo,
             uint64_t Address,
             const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, XRegsNoX0);
}

#define DecodePointerLikeRegClass0 DecodeGPRCRegisterClass
#define DecodePointerLikeRegClass1 DecodeGPRC_NOR0RegisterClass

static DecodeStatus DecodeSPERCRegisterClass(MCInst *Inst, uint64_t RegNo,
               uint64_t Address,
               const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, SPERegs);
}

static DecodeStatus DecodeACCRCRegisterClass(MCInst *Inst, uint64_t RegNo,
               uint64_t Address,
               const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, ACCRegs);
}

static DecodeStatus DecodeWACCRCRegisterClass(MCInst *Inst, uint64_t RegNo,
                uint64_t Address,
                const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, WACCRegs);
}

static DecodeStatus DecodeWACC_HIRCRegisterClass(MCInst *Inst, uint64_t RegNo,
             uint64_t Address,
             const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, WACC_HIRegs);
}

// TODO: Make this function static when the register class is used by a new
//       instruction.
DecodeStatus DecodeDMRROWRCRegisterClass(MCInst *Inst, uint64_t RegNo,
           uint64_t Address, const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, DMRROWRegs);
}

static DecodeStatus DecodeDMRROWpRCRegisterClass(MCInst *Inst, uint64_t RegNo,
             uint64_t Address,
             const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, DMRROWpRegs);
}

static DecodeStatus DecodeDMRRCRegisterClass(MCInst *Inst, uint64_t RegNo,
               uint64_t Address,
               const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, DMRRegs);
}

// TODO: Make this function static when the register class is used by a new
//       instruction.
DecodeStatus DecodeDMRpRCRegisterClass(MCInst *Inst, uint64_t RegNo,
               uint64_t Address, const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, DMRpRegs);
}

static DecodeStatus DecodeVSRpRCRegisterClass(MCInst *Inst, uint64_t RegNo,
                uint64_t Address,
                const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, VSRpRegs);
}

#define DecodeQSRCRegisterClass DecodeQFRCRegisterClass
#define DecodeQBRCRegisterClass DecodeQFRCRegisterClass

static DecodeStatus DecodeQFRCRegisterClass(MCInst *Inst, uint64_t RegNo,
              uint64_t Address,
              const void *Decoder)
{
  return decodeRegisterClass(Inst, RegNo, QFRegs);
}

#define DEFINE_decodeUImmOperand(N) \
  static DecodeStatus CONCAT(decodeUImmOperand, \
           N)(MCInst * Inst, uint64_t Imm, \
              int64_t Address, const void *Decoder) \
  { \
    MCOperand_CreateImm0(Inst, (Imm)); \
    return MCDisassembler_Success; \
  }
DEFINE_decodeUImmOperand(5) DEFINE_decodeUImmOperand(16)
  DEFINE_decodeUImmOperand(6) DEFINE_decodeUImmOperand(10)
    DEFINE_decodeUImmOperand(8) DEFINE_decodeUImmOperand(7)
      DEFINE_decodeUImmOperand(12)

#define DEFINE_decodeSImmOperand(N) \
  static DecodeStatus CONCAT(decodeSImmOperand, \
           N)(MCInst * Inst, uint64_t Imm, \
              int64_t Address, const void *Decoder) \
  { \
    MCOperand_CreateImm0(Inst, (SignExtend64(Imm, N))); \
    return MCDisassembler_Success; \
  }
        DEFINE_decodeSImmOperand(16)
          DEFINE_decodeSImmOperand(5)
            DEFINE_decodeSImmOperand(34)

              static DecodeStatus
  decodeImmZeroOperand(MCInst *Inst, uint64_t Imm, int64_t Address,
           const void *Decoder)
{
  if (Imm != 0)
    return MCDisassembler_Fail;
  MCOperand_CreateImm0(Inst, (Imm));
  return MCDisassembler_Success;
}

static DecodeStatus decodeVSRpEvenOperands(MCInst *Inst, uint64_t RegNo,
             uint64_t Address,
             const void *Decoder)
{
  if (RegNo & 1)
    return MCDisassembler_Fail;
  MCOperand_CreateReg0(Inst, (VSRpRegs[RegNo >> 1]));
  return MCDisassembler_Success;
}

static DecodeStatus decodeMemRIOperands(MCInst *Inst, uint64_t Imm,
          int64_t Address, const void *Decoder)
{
  // Decode the memri field (imm, reg), which has the low 16-bits as the
  // displacement and the next 5 bits as the register #.

  uint64_t Base = Imm >> 16;
  uint64_t Disp = Imm & 0xFFFF;

  switch (MCInst_getOpcode(Inst)) {
  default:
    break;
  case PPC_LBZU:
  case PPC_LHAU:
  case PPC_LHZU:
  case PPC_LWZU:
  case PPC_LFSU:
  case PPC_LFDU:
    // Add the tied output operand.
    MCOperand_CreateReg0(Inst, (RRegsNoR0[Base]));
    break;
  case PPC_STBU:
  case PPC_STHU:
  case PPC_STWU:
  case PPC_STFSU:
  case PPC_STFDU:
    MCInst_insert0(Inst, 0,
             MCOperand_CreateReg1(Inst, RRegsNoR0[Base]));
    break;
  }

  MCOperand_CreateImm0(Inst, (SignExtend64(Disp, 16)));
  MCOperand_CreateReg0(Inst, (RRegsNoR0[Base]));
  return MCDisassembler_Success;
}

static DecodeStatus decodeMemRIXOperands(MCInst *Inst, uint64_t Imm,
           int64_t Address, const void *Decoder)
{
  // Decode the memrix field (imm, reg), which has the low 14-bits as the
  // displacement and the next 5 bits as the register #.

  uint64_t Base = Imm >> 14;
  uint64_t Disp = Imm & 0x3FFF;

  if (MCInst_getOpcode(Inst) == PPC_LDU)
    // Add the tied output operand.
    MCOperand_CreateReg0(Inst, (RRegsNoR0[Base]));
  else if (MCInst_getOpcode(Inst) == PPC_STDU)
    MCInst_insert0(Inst, 0,
             MCOperand_CreateReg1(Inst, RRegsNoR0[Base]));

  MCOperand_CreateImm0(Inst, (SignExtend64(Disp << 2, 16)));
  MCOperand_CreateReg0(Inst, (RRegsNoR0[Base]));
  return MCDisassembler_Success;
}

static DecodeStatus decodeMemRIHashOperands(MCInst *Inst, uint64_t Imm,
              int64_t Address,
              const void *Decoder)
{
  // Decode the memrix field for a hash store or hash check operation.
  // The field is composed of a register and an immediate value that is 6 bits
  // and covers the range -8 to -512. The immediate is always negative and 2s
  // complement which is why we sign extend a 7 bit value.
  const uint64_t Base = Imm >> 6;
  const int64_t Disp = SignExtend64((Imm & 0x3F) + 64, 7) * 8;

  MCOperand_CreateImm0(Inst, (Disp));
  MCOperand_CreateReg0(Inst, (RRegs[Base]));
  return MCDisassembler_Success;
}

static DecodeStatus decodeMemRIX16Operands(MCInst *Inst, uint64_t Imm,
             int64_t Address, const void *Decoder)
{
  // Decode the memrix16 field (imm, reg), which has the low 12-bits as the
  // displacement with 16-byte aligned, and the next 5 bits as the register #.

  uint64_t Base = Imm >> 12;
  uint64_t Disp = Imm & 0xFFF;

  MCOperand_CreateImm0(Inst, (SignExtend64(Disp << 4, 16)));
  MCOperand_CreateReg0(Inst, (RRegsNoR0[Base]));
  return MCDisassembler_Success;
}

static DecodeStatus decodeMemRI34PCRelOperands(MCInst *Inst, uint64_t Imm,
                 int64_t Address,
                 const void *Decoder)
{
  // Decode the memri34_pcrel field (imm, reg), which has the low 34-bits as
  // the displacement, and the next 5 bits as an immediate 0.
  uint64_t Base = Imm >> 34;
  uint64_t Disp = Imm & 0x3FFFFFFFFUL;

  MCOperand_CreateImm0(Inst, (SignExtend64(Disp, 34)));
  return decodeImmZeroOperand(Inst, Base, Address, Decoder);
}

static DecodeStatus decodeMemRI34Operands(MCInst *Inst, uint64_t Imm,
            int64_t Address, const void *Decoder)
{
  // Decode the memri34 field (imm, reg), which has the low 34-bits as the
  // displacement, and the next 5 bits as the register #.
  uint64_t Base = Imm >> 34;
  uint64_t Disp = Imm & 0x3FFFFFFFFUL;

  MCOperand_CreateImm0(Inst, (SignExtend64(Disp, 34)));
  MCOperand_CreateReg0(Inst, (RRegsNoR0[Base]));
  return MCDisassembler_Success;
}

static DecodeStatus decodeSPE8Operands(MCInst *Inst, uint64_t Imm,
               int64_t Address, const void *Decoder)
{
  // Decode the spe8disp field (imm, reg), which has the low 5-bits as the
  // displacement with 8-byte aligned, and the next 5 bits as the register #.

  uint64_t Base = Imm >> 5;
  uint64_t Disp = Imm & 0x1F;

  MCOperand_CreateImm0(Inst, (Disp << 3));
  MCOperand_CreateReg0(Inst, (RRegsNoR0[Base]));
  return MCDisassembler_Success;
}

static DecodeStatus decodeSPE4Operands(MCInst *Inst, uint64_t Imm,
               int64_t Address, const void *Decoder)
{
  // Decode the spe4disp field (imm, reg), which has the low 5-bits as the
  // displacement with 4-byte aligned, and the next 5 bits as the register #.

  uint64_t Base = Imm >> 5;
  uint64_t Disp = Imm & 0x1F;

  MCOperand_CreateImm0(Inst, (Disp << 2));
  MCOperand_CreateReg0(Inst, (RRegsNoR0[Base]));
  return MCDisassembler_Success;
}

static DecodeStatus decodeSPE2Operands(MCInst *Inst, uint64_t Imm,
               int64_t Address, const void *Decoder)
{
  // Decode the spe2disp field (imm, reg), which has the low 5-bits as the
  // displacement with 2-byte aligned, and the next 5 bits as the register #.

  uint64_t Base = Imm >> 5;
  uint64_t Disp = Imm & 0x1F;

  MCOperand_CreateImm0(Inst, (Disp << 1));
  MCOperand_CreateReg0(Inst, (RRegsNoR0[Base]));
  return MCDisassembler_Success;
}

static DecodeStatus decodeCRBitMOperand(MCInst *Inst, uint64_t Imm,
          int64_t Address, const void *Decoder)
{
  // The cr bit encoding is 0x80 >> cr_reg_num.

  unsigned Zeros = CountTrailingZeros_32(Imm);
  if (Zeros >= 8)
    return MCDisassembler_Fail;

  MCOperand_CreateReg0(Inst, (CRRegs[7 - Zeros]));
  return MCDisassembler_Success;
}

#include "PPCGenDisassemblerTables.inc"

DecodeStatus getInstruction(csh ud, const uint8_t *Bytes, size_t BytesLen,
          MCInst *MI, uint16_t *Size, uint64_t Address,
          void *Info)
{
  // If this is an 8-byte prefixed instruction, handle it here.
  // Note: prefixed instructions aren't technically 8-byte entities - the
  // prefix
  //       appears in memory at an address 4 bytes prior to that of the base
  //       instruction regardless of endianness. So we read the two pieces and
  //       rebuild the 8-byte instruction.
  // TODO: In this function we call decodeInstruction several times with
  //       different decoder tables. It may be possible to only call once by
  //       looking at the top 6 bits of the instruction.
  if (PPC_getFeatureBits(MI->csh->mode, PPC_FeaturePrefixInstrs) &&
      BytesLen >= 8) {
    uint32_t Prefix = readBytes32(MI, Bytes);
    uint32_t BaseInst = readBytes32(MI, Bytes + 4);
    uint64_t Inst = BaseInst | (uint64_t)Prefix << 32;
    DecodeStatus result =
      decodeInstruction_4(DecoderTable64, MI, Inst, Address);
    if (result != MCDisassembler_Fail) {
      *Size = 8;
      return result;
    }
  }

  // Get the four bytes of the instruction.
  *Size = 4;
  if (BytesLen < 4) {
    *Size = 0;
    return MCDisassembler_Fail;
  }

  // Read the instruction in the proper endianness.
  uint64_t Inst = readBytes32(MI, Bytes);

  if (PPC_getFeatureBits(MI->csh->mode, PPC_FeatureQPX)) {
    DecodeStatus result = decodeInstruction_4(DecoderTableQPX32, MI,
                Inst, Address);
    if (result != MCDisassembler_Fail)
      return result;
  } else if (PPC_getFeatureBits(MI->csh->mode, PPC_FeatureSPE)) {
    DecodeStatus result = decodeInstruction_4(DecoderTableSPE32, MI,
                Inst, Address);
    if (result != MCDisassembler_Fail)
      return result;
  } else if (PPC_getFeatureBits(MI->csh->mode, PPC_FeaturePS)) {
    DecodeStatus result = decodeInstruction_4(DecoderTablePS32, MI,
                Inst, Address);
    if (result != MCDisassembler_Fail)
      return result;
  }

  return decodeInstruction_4(DecoderTable32, MI, Inst, Address);
}

DecodeStatus PPC_LLVM_getInstruction(csh handle, const uint8_t *Bytes,
             size_t BytesLen, MCInst *MI,
             uint16_t *Size, uint64_t Address,
             void *Info)
{
  return getInstruction(handle, Bytes, BytesLen, MI, Size, Address, Info);
}

Coverage Report

Created: 2023-09-25 06:24