/*
* getIDWithAttrMask - Determines the ID of an instruction, consuming
* the ModR/M byte as appropriate for extended and escape opcodes,
* and using a supplied attribute mask.
*
* @param instructionID - A pointer whose target is filled in with the ID of the
* instruction.
* @param insn - The instruction whose ID is to be determined.
* @param attrMask - The attribute mask to search.
* @return - 0 if the ModR/M could be read when needed or was not
* needed; nonzero otherwise.
*/
static int getIDWithAttrMask(uint16_t* instructionID,
struct InternalInstruction* insn,
uint8_t attrMask) {
BOOL hasModRMExtension;
uint8_t instructionClass;
instructionClass = contextForAttrs(attrMask);
hasModRMExtension = modRMRequired(insn->opcodeType,
instructionClass,
insn->opcode);
if (hasModRMExtension) {
if (readModRM(insn))
return -1;
*instructionID = decode(insn->opcodeType,
instructionClass,
insn->opcode,
insn->modRM);
} else {
*instructionID = decode(insn->opcodeType,
instructionClass,
insn->opcode,
0);
}
return 0;
}
/*
* readOperands - Consults the specifier for an instruction and consumes all
* operands for that instruction, interpreting them as it goes.
*
* @param insn - The instruction whose operands are to be read and interpreted.
* @return - 0 if all operands could be read; nonzero otherwise.
*/
static int readOperands(struct InternalInstruction* insn) {
int index;
int hasVVVV, needVVVV;
int sawRegImm = 0;
dbgprintf(insn, "readOperands()");
/* If non-zero vvvv specified, need to make sure one of the operands
uses it. */
hasVVVV = !readVVVV(insn);
needVVVV = hasVVVV && (insn->vvvv != 0);
for (index = 0; index < X86_MAX_OPERANDS; ++index) {
switch (insn->spec->operands[index].encoding) {
case ENCODING_NONE:
break;
case ENCODING_REG:
case ENCODING_RM:
if (readModRM(insn))
return -1;
if (fixupReg(insn, &insn->spec->operands[index]))
return -1;
break;
case ENCODING_CB:
case ENCODING_CW:
case ENCODING_CD:
case ENCODING_CP:
case ENCODING_CO:
case ENCODING_CT:
dbgprintf(insn, "We currently don't hande code-offset encodings");
return -1;
case ENCODING_IB:
if (sawRegImm) {
/* Saw a register immediate so don't read again and instead split the
previous immediate. FIXME: This is a hack. */
insn->immediates[insn->numImmediatesConsumed] =
insn->immediates[insn->numImmediatesConsumed - 1] & 0xf;
++insn->numImmediatesConsumed;
break;
}
if (readImmediate(insn, 1))
return -1;
if (insn->spec->operands[index].type == TYPE_IMM3 &&
insn->immediates[insn->numImmediatesConsumed - 1] > 7)
return -1;
if (insn->spec->operands[index].type == TYPE_XMM128 ||
insn->spec->operands[index].type == TYPE_XMM256)
sawRegImm = 1;
break;
case ENCODING_IW:
if (readImmediate(insn, 2))
return -1;
break;
case ENCODING_ID:
if (readImmediate(insn, 4))
return -1;
break;
case ENCODING_IO:
if (readImmediate(insn, 8))
return -1;
break;
case ENCODING_Iv:
if (readImmediate(insn, insn->immediateSize))
return -1;
break;
case ENCODING_Ia:
if (readImmediate(insn, insn->addressSize))
return -1;
break;
case ENCODING_RB:
if (readOpcodeRegister(insn, 1))
return -1;
break;
case ENCODING_RW:
if (readOpcodeRegister(insn, 2))
return -1;
break;
case ENCODING_RD:
if (readOpcodeRegister(insn, 4))
return -1;
break;
case ENCODING_RO:
if (readOpcodeRegister(insn, 8))
return -1;
break;
case ENCODING_Rv:
if (readOpcodeRegister(insn, 0))
return -1;
break;
case ENCODING_I:
if (readOpcodeModifier(insn))
return -1;
break;
case ENCODING_VVVV:
needVVVV = 0; /* Mark that we have found a VVVV operand. */
if (!hasVVVV)
return -1;
if (fixupReg(insn, &insn->spec->operands[index]))
return -1;
break;
case ENCODING_DUP:
break;
default:
dbgprintf(insn, "Encountered an operand with an unknown encoding.");
return -1;
}
}
/* If we didn't find ENCODING_VVVV operand, but non-zero vvvv present, fail */
if (needVVVV) return -1;
return 0;
}
/*
* readOperands - Consults the specifier for an instruction and consumes all
* operands for that instruction, interpreting them as it goes.
*
* @param insn - The instruction whose operands are to be read and interpreted.
* @return - 0 if all operands could be read; nonzero otherwise.
*/
static int readOperands(struct InternalInstruction* insn) {
int index;
dbgprintf(insn, "readOperands()");
for (index = 0; index < X86_MAX_OPERANDS; ++index) {
switch (insn->spec->operands[index].encoding) {
case ENCODING_NONE:
break;
case ENCODING_REG:
case ENCODING_RM:
if (readModRM(insn))
return -1;
if (fixupReg(insn, &insn->spec->operands[index]))
return -1;
break;
case ENCODING_CB:
case ENCODING_CW:
case ENCODING_CD:
case ENCODING_CP:
case ENCODING_CO:
case ENCODING_CT:
dbgprintf(insn, "We currently don't hande code-offset encodings");
return -1;
case ENCODING_IB:
if (readImmediate(insn, 1))
return -1;
break;
case ENCODING_IW:
if (readImmediate(insn, 2))
return -1;
break;
case ENCODING_ID:
if (readImmediate(insn, 4))
return -1;
break;
case ENCODING_IO:
if (readImmediate(insn, 8))
return -1;
break;
case ENCODING_Iv:
readImmediate(insn, insn->immediateSize);
break;
case ENCODING_Ia:
readImmediate(insn, insn->addressSize);
break;
case ENCODING_RB:
readOpcodeRegister(insn, 1);
break;
case ENCODING_RW:
readOpcodeRegister(insn, 2);
break;
case ENCODING_RD:
readOpcodeRegister(insn, 4);
break;
case ENCODING_RO:
readOpcodeRegister(insn, 8);
break;
case ENCODING_Rv:
readOpcodeRegister(insn, 0);
break;
case ENCODING_I:
readOpcodeModifier(insn);
break;
case ENCODING_DUP:
break;
default:
dbgprintf(insn, "Encountered an operand with an unknown encoding.");
return -1;
}
}
return 0;
}