uint8_t prefix,
uint64_t location)
{
- if (insn->prefixPresent[prefix] == 1 &&
- insn->prefixLocations[prefix] == location)
- return true;
- else
- return false;
+ return insn->prefixPresent[prefix] == 1 &&
+ insn->prefixLocations[prefix] == location;
}
/*
* then it should be disassembled as a xacquire/xrelease not repne/rep.
*/
if ((byte == 0xf2 || byte == 0xf3) &&
- ((nextByte == 0xf0) |
+ ((nextByte == 0xf0) ||
((nextByte & 0xfe) == 0x86 || (nextByte & 0xf8) == 0x90)))
insn->xAcquireRelease = true;
/*
if ((insn->mode == MODE_64BIT || (byte1 & 0xc0) == 0xc0) &&
((~byte1 & 0xc) == 0xc) && ((byte2 & 0x4) == 0x4)) {
insn->vectorExtensionType = TYPE_EVEX;
- }
- else {
+ } else {
unconsumeByte(insn); /* unconsume byte1 */
unconsumeByte(insn); /* unconsume byte */
insn->necessaryPrefixLocation = insn->readerCursor - 2;
insn->vectorExtensionPrefix[0], insn->vectorExtensionPrefix[1],
insn->vectorExtensionPrefix[2], insn->vectorExtensionPrefix[3]);
}
- }
- else if (byte == 0xc4) {
+ } else if (byte == 0xc4) {
uint8_t byte1;
if (lookAtByte(insn, &byte1)) {
if (insn->mode == MODE_64BIT || (byte1 & 0xc0) == 0xc0) {
insn->vectorExtensionType = TYPE_VEX_3B;
insn->necessaryPrefixLocation = insn->readerCursor - 1;
- }
- else {
+ } else {
unconsumeByte(insn);
insn->necessaryPrefixLocation = insn->readerCursor - 1;
}
insn->vectorExtensionPrefix[0], insn->vectorExtensionPrefix[1],
insn->vectorExtensionPrefix[2]);
}
- }
- else if (byte == 0xc5) {
+ } else if (byte == 0xc5) {
uint8_t byte1;
if (lookAtByte(insn, &byte1)) {
if (insn->mode == MODE_64BIT || (byte1 & 0xc0) == 0xc0) {
insn->vectorExtensionType = TYPE_VEX_2B;
- }
- else {
+ } else {
unconsumeByte(insn);
}
| (rFromVEX2of2(insn->vectorExtensionPrefix[1]) << 2);
}
- switch (ppFromVEX2of2(insn->vectorExtensionPrefix[1]))
- {
+ switch (ppFromVEX2of2(insn->vectorExtensionPrefix[1])) {
default:
break;
case VEX_PREFIX_66:
insn->vectorExtensionPrefix[0],
insn->vectorExtensionPrefix[1]);
}
- }
- else if (byte == 0x8f) {
+ } else if (byte == 0x8f) {
uint8_t byte1;
if (lookAtByte(insn, &byte1)) {
if ((byte1 & 0x38) != 0x0) { /* 0 in these 3 bits is a POP instruction. */
insn->vectorExtensionType = TYPE_XOP;
insn->necessaryPrefixLocation = insn->readerCursor - 1;
- }
- else {
+ } else {
unconsumeByte(insn);
insn->necessaryPrefixLocation = insn->readerCursor - 1;
}
| (bFromXOP2of3(insn->vectorExtensionPrefix[1]) << 0);
}
- switch (ppFromXOP3of3(insn->vectorExtensionPrefix[2]))
- {
+ switch (ppFromXOP3of3(insn->vectorExtensionPrefix[2])) {
default:
break;
case VEX_PREFIX_66:
insn->vectorExtensionPrefix[0], insn->vectorExtensionPrefix[1],
insn->vectorExtensionPrefix[2]);
}
- }
- else {
+ } else {
if (insn->mode == MODE_64BIT) {
if ((byte & 0xf0) == 0x40) {
uint8_t opcodeByte;
insn->opcodeType = ONEBYTE;
- if (insn->vectorExtensionType == TYPE_EVEX)
- {
+ if (insn->vectorExtensionType == TYPE_EVEX) {
switch (mmFromEVEX2of4(insn->vectorExtensionPrefix[1])) {
default:
dbgprintf(insn, "Unhandled mm field for instruction (0x%hhx)",
insn->opcodeType = THREEBYTE_3A;
return consumeByte(insn, &insn->opcode);
}
- }
- else if (insn->vectorExtensionType == TYPE_VEX_3B) {
+ } else if (insn->vectorExtensionType == TYPE_VEX_3B) {
switch (mmmmmFromVEX2of3(insn->vectorExtensionPrefix[1])) {
default:
dbgprintf(insn, "Unhandled m-mmmm field for instruction (0x%hhx)",
insn->opcodeType = THREEBYTE_3A;
return consumeByte(insn, &insn->opcode);
}
- }
- else if (insn->vectorExtensionType == TYPE_VEX_2B) {
+ } else if (insn->vectorExtensionType == TYPE_VEX_2B) {
insn->opcodeType = TWOBYTE;
return consumeByte(insn, &insn->opcode);
- }
- else if (insn->vectorExtensionType == TYPE_XOP) {
+ } else if (insn->vectorExtensionType == TYPE_XOP) {
switch (mmmmmFromXOP2of3(insn->vectorExtensionPrefix[1])) {
default:
dbgprintf(insn, "Unhandled m-mmmm field for instruction (0x%hhx)",
}
}
+/*
+ * is64Bit - Determines whether this instruction is a 64-bit instruction.
+ *
+ * @param name - The instruction that is not 16-bit
+ */
+static bool is64Bit(const char* name) {
+ off_t i;
+
+ for (i = 0;; ++i) {
+ if (name[i] == '\0')
+ return false;
+ if (name[i] == '6' && name[i+1] == '4')
+ return true;
+ }
+}
+
/*
* getID - Determines the ID of an instruction, consuming the ModR/M byte as
* appropriate for extended and escape opcodes. Determines the attributes and
attrMask |= ATTR_EVEXL;
if (l2FromEVEX4of4(insn->vectorExtensionPrefix[3]))
attrMask |= ATTR_EVEXL2;
- }
- else if (insn->vectorExtensionType == TYPE_VEX_3B) {
+ } else if (insn->vectorExtensionType == TYPE_VEX_3B) {
switch (ppFromVEX3of3(insn->vectorExtensionPrefix[2])) {
case VEX_PREFIX_66:
attrMask |= ATTR_OPSIZE;
if (lFromVEX3of3(insn->vectorExtensionPrefix[2]))
attrMask |= ATTR_VEXL;
- }
- else if (insn->vectorExtensionType == TYPE_VEX_2B) {
+ } else if (insn->vectorExtensionType == TYPE_VEX_2B) {
switch (ppFromVEX2of2(insn->vectorExtensionPrefix[1])) {
case VEX_PREFIX_66:
attrMask |= ATTR_OPSIZE;
if (lFromVEX2of2(insn->vectorExtensionPrefix[1]))
attrMask |= ATTR_VEXL;
- }
- else if (insn->vectorExtensionType == TYPE_XOP) {
+ } else if (insn->vectorExtensionType == TYPE_XOP) {
switch (ppFromXOP3of3(insn->vectorExtensionPrefix[2])) {
case VEX_PREFIX_66:
attrMask |= ATTR_OPSIZE;
if (lFromXOP3of3(insn->vectorExtensionPrefix[2]))
attrMask |= ATTR_VEXL;
- }
- else {
+ } else {
return -1;
}
- }
- else {
+ } else {
if (insn->mode != MODE_16BIT && isPrefixAtLocation(insn, 0x66, insn->necessaryPrefixLocation))
attrMask |= ATTR_OPSIZE;
else if (isPrefixAtLocation(insn, 0x67, insn->necessaryPrefixLocation))
if (insn->rexPrefix & 0x08)
attrMask |= ATTR_REXW;
- if (getIDWithAttrMask(&instructionID, insn, attrMask))
- return -1;
-
/*
* JCXZ/JECXZ need special handling for 16-bit mode because the meaning
* of the AdSize prefix is inverted w.r.t. 32-bit mode.
*/
- if (insn->mode == MODE_16BIT && insn->opcode == 0xE3) {
- const struct InstructionSpecifier *spec;
- spec = specifierForUID(instructionID);
+ if (insn->mode == MODE_16BIT && insn->opcodeType == ONEBYTE &&
+ insn->opcode == 0xE3)
+ attrMask ^= ATTR_ADSIZE;
+
+ /*
+ * In 64-bit mode all f64 superscripted opcodes ignore opcode size prefix
+ * CALL/JMP/JCC instructions need to ignore 0x66 and consume 4 bytes
+ */
+
+ if (insn->mode == MODE_64BIT &&
+ isPrefixAtLocation(insn, 0x66, insn->necessaryPrefixLocation)) {
+ switch (insn->opcode) {
+ case 0xE8:
+ case 0xE9:
+ // Take care of psubsb and other mmx instructions.
+ if (insn->opcodeType == ONEBYTE) {
+ attrMask ^= ATTR_OPSIZE;
+ insn->immediateSize = 4;
+ insn->displacementSize = 4;
+ }
+ break;
+ case 0x82:
+ case 0x83:
+ case 0x84:
+ case 0x85:
+ case 0x86:
+ case 0x87:
+ case 0x88:
+ case 0x89:
+ case 0x8A:
+ case 0x8B:
+ case 0x8C:
+ case 0x8D:
+ case 0x8E:
+ case 0x8F:
+ // Take care of lea and three byte ops.
+ if (insn->opcodeType == TWOBYTE) {
+ attrMask ^= ATTR_OPSIZE;
+ insn->immediateSize = 4;
+ insn->displacementSize = 4;
+ }
+ break;
+ }
+ }
+ if (getIDWithAttrMask(&instructionID, insn, attrMask))
+ return -1;
+
+ /* The following clauses compensate for limitations of the tables. */
+
+ if (insn->mode != MODE_64BIT &&
+ insn->vectorExtensionType != TYPE_NO_VEX_XOP) {
/*
- * Check for Ii8PCRel instructions. We could alternatively do a
- * string-compare on the names, but this is probably cheaper.
+ * The tables can't distinquish between cases where the W-bit is used to
+ * select register size and cases where its a required part of the opcode.
*/
- if (x86OperandSets[spec->operands][0].type == TYPE_REL8) {
- attrMask ^= ATTR_ADSIZE;
- if (getIDWithAttrMask(&instructionID, insn, attrMask))
- return -1;
+ if ((insn->vectorExtensionType == TYPE_EVEX &&
+ wFromEVEX3of4(insn->vectorExtensionPrefix[2])) ||
+ (insn->vectorExtensionType == TYPE_VEX_3B &&
+ wFromVEX3of3(insn->vectorExtensionPrefix[2])) ||
+ (insn->vectorExtensionType == TYPE_XOP &&
+ wFromXOP3of3(insn->vectorExtensionPrefix[2]))) {
+
+ uint16_t instructionIDWithREXW;
+ if (getIDWithAttrMask(&instructionIDWithREXW,
+ insn, attrMask | ATTR_REXW)) {
+ insn->instructionID = instructionID;
+ insn->spec = specifierForUID(instructionID);
+ return 0;
+ }
+
+ const char *SpecName = GetInstrName(instructionIDWithREXW, miiArg);
+ // If not a 64-bit instruction. Switch the opcode.
+ if (!is64Bit(SpecName)) {
+ insn->instructionID = instructionIDWithREXW;
+ insn->spec = specifierForUID(instructionIDWithREXW);
+ return 0;
+ }
}
}
- /* The following clauses compensate for limitations of the tables. */
+ /*
+ * Absolute moves need special handling.
+ * -For 16-bit mode because the meaning of the AdSize and OpSize prefixes are
+ * inverted w.r.t.
+ * -For 32-bit mode we need to ensure the ADSIZE prefix is observed in
+ * any position.
+ */
+ if (insn->opcodeType == ONEBYTE && ((insn->opcode & 0xFC) == 0xA0)) {
+ /* Make sure we observed the prefixes in any position. */
+ if (insn->prefixPresent[0x67])
+ attrMask |= ATTR_ADSIZE;
+ if (insn->prefixPresent[0x66])
+ attrMask |= ATTR_OPSIZE;
+
+ /* In 16-bit, invert the attributes. */
+ if (insn->mode == MODE_16BIT)
+ attrMask ^= ATTR_ADSIZE | ATTR_OPSIZE;
+
+ if (getIDWithAttrMask(&instructionID, insn, attrMask))
+ return -1;
+
+ insn->instructionID = instructionID;
+ insn->spec = specifierForUID(instructionID);
+ return 0;
+ }
if ((insn->mode == MODE_16BIT || insn->prefixPresent[0x66]) &&
!(attrMask & ATTR_OPSIZE)) {
return -1;
index = indexFromSIB(insn->sib) | (xFromREX(insn->rexPrefix) << 3);
+
+ // FIXME: The fifth bit (bit index 4) is only to be used for instructions
+ // that understand VSIB indexing. ORing the bit in here is mildy dangerous
+ // because performing math on an 'enum SIBIndex' can produce garbage.
+ // Excluding the "none" value, it should cover 6 spaces of register names:
+ // - 16 possibilities for 16-bit GPR starting at SIB_INDEX_BX_SI
+ // - 16 possibilities for 32-bit GPR starting at SIB_INDEX_EAX
+ // - 16 possibilities for 64-bit GPR starting at SIB_INDEX_RAX
+ // - 32 possibilities for each of XMM, YMM, ZMM registers
+ // When sibIndexBase gets assigned SIB_INDEX_RAX as it does in 64-bit mode,
+ // summing in a fully decoded index between 0 and 31 can end up with a value
+ // that looks like something in the low half of the XMM range.
+ // translateRMMemory() tries to reverse the damage, with only partial success,
+ // as evidenced by known bugs in "test/MC/Disassembler/X86/x86-64.txt"
if (insn->vectorExtensionType == TYPE_EVEX)
index |= v2FromEVEX4of4(insn->vectorExtensionPrefix[3]) << 4;
- switch (index) {
- case 0x4:
+ if (index == 0x4) {
insn->sibIndex = SIB_INDEX_NONE;
- break;
- default:
+ } else {
insn->sibIndex = (SIBIndex)(sibIndexBase + index);
- if (insn->sibIndex == SIB_INDEX_sib ||
- insn->sibIndex == SIB_INDEX_sib64)
- insn->sibIndex = SIB_INDEX_NONE;
- break;
}
- switch (scaleFromSIB(insn->sib)) {
- case 0:
- insn->sibScale = 1;
- break;
- case 1:
- insn->sibScale = 2;
- break;
- case 2:
- insn->sibScale = 4;
- break;
- case 3:
- insn->sibScale = 8;
- break;
- }
+ insn->sibScale = 1 << scaleFromSIB(insn->sib);
base = baseFromSIB(insn->sib) | (bFromREX(insn->rexPrefix) << 3);
switch (mod) {
case 0x0:
insn->eaDisplacement = EA_DISP_NONE; /* readSIB may override this */
- switch (rm) {
- case 0x14:
- case 0x4:
- case 0xc: /* in case REXW.b is set */
+ // In determining whether RIP-relative mode is used (rm=5),
+ // or whether a SIB byte is present (rm=4),
+ // the extension bits (REX.b and EVEX.x) are ignored.
+ switch (rm & 7) {
+ case 0x4: // SIB byte is present
insn->eaBase = (insn->addressSize == 4 ?
EA_BASE_sib : EA_BASE_sib64);
if (readSIB(insn) || readDisplacement(insn))
return -1;
break;
- case 0x5:
+ case 0x5: // RIP-relative
insn->eaBase = EA_BASE_NONE;
insn->eaDisplacement = EA_DISP_32;
if (readDisplacement(insn))
/* FALLTHROUGH */
case 0x2:
insn->eaDisplacement = (mod == 0x1 ? EA_DISP_8 : EA_DISP_32);
- switch (rm) {
- case 0x14:
- case 0x4:
- case 0xc: /* in case REXW.b is set */
+ switch (rm & 7) {
+ case 0x4: // SIB byte is present
insn->eaBase = EA_BASE_sib;
if (readSIB(insn) || readDisplacement(insn))
return -1;
case TYPE_XMM: \
return prefix##_XMM0 + index; \
case TYPE_VK1: \
+ case TYPE_VK2: \
+ case TYPE_VK4: \
case TYPE_VK8: \
case TYPE_VK16: \
- return prefix##_K0 + index; \
- case TYPE_MM64: \
- case TYPE_MM32: \
- case TYPE_MM: \
+ case TYPE_VK32: \
+ case TYPE_VK64: \
if (index > 7) \
*valid = 0; \
- return prefix##_MM0 + index; \
+ return prefix##_K0 + index; \
+ case TYPE_MM64: \
+ return prefix##_MM0 + (index & 0x7); \
case TYPE_SEGMENTREG: \
if (index > 5) \
*valid = 0; \
return prefix##_ES + index; \
case TYPE_DEBUGREG: \
- if (index > 7) \
- *valid = 0; \
return prefix##_DR0 + index; \
case TYPE_CONTROLREG: \
- if (index > 8) \
- *valid = 0; \
return prefix##_CR0 + index; \
} \
}
}
if (readImmediate(insn, 1))
return -1;
- if (Op.type == TYPE_IMM3 &&
- insn->immediates[insn->numImmediatesConsumed - 1] > 7)
- return -1;
- if (Op.type == TYPE_IMM5 &&
- insn->immediates[insn->numImmediatesConsumed - 1] > 31)
- return -1;
if (Op.type == TYPE_XMM128 ||
Op.type == TYPE_XMM256)
sawRegImm = 1;