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Diffstat (limited to 'llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp')
-rw-r--r--llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp1938
1 files changed, 0 insertions, 1938 deletions
diff --git a/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp b/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp
deleted file mode 100644
index e287f6625115..000000000000
--- a/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.cpp
+++ /dev/null
@@ -1,1938 +0,0 @@
-//===-- X86DisassemblerDecoder.cpp - Disassembler decoder -----------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-//
-// This file is part of the X86 Disassembler.
-// It contains the implementation of the instruction decoder.
-// Documentation for the disassembler can be found in X86Disassembler.h.
-//
-//===----------------------------------------------------------------------===//
-
-#include "X86DisassemblerDecoder.h"
-#include "llvm/ADT/StringRef.h"
-
-#include <cstdarg> /* for va_*() */
-#include <cstdio> /* for vsnprintf() */
-#include <cstdlib> /* for exit() */
-#include <cstring> /* for memset() */
-
-using namespace llvm::X86Disassembler;
-
-/// Specifies whether a ModR/M byte is needed and (if so) which
-/// instruction each possible value of the ModR/M byte corresponds to. Once
-/// this information is known, we have narrowed down to a single instruction.
-struct ModRMDecision {
- uint8_t modrm_type;
- uint16_t instructionIDs;
-};
-
-/// Specifies which set of ModR/M->instruction tables to look at
-/// given a particular opcode.
-struct OpcodeDecision {
- ModRMDecision modRMDecisions[256];
-};
-
-/// Specifies which opcode->instruction tables to look at given
-/// a particular context (set of attributes). Since there are many possible
-/// contexts, the decoder first uses CONTEXTS_SYM to determine which context
-/// applies given a specific set of attributes. Hence there are only IC_max
-/// entries in this table, rather than 2^(ATTR_max).
-struct ContextDecision {
- OpcodeDecision opcodeDecisions[IC_max];
-};
-
-#include "X86GenDisassemblerTables.inc"
-
-#ifndef NDEBUG
-#define debug(s) do { Debug(__FILE__, __LINE__, s); } while (0)
-#else
-#define debug(s) do { } while (0)
-#endif
-
-/*
- * contextForAttrs - Client for the instruction context table. Takes a set of
- * attributes and returns the appropriate decode context.
- *
- * @param attrMask - Attributes, from the enumeration attributeBits.
- * @return - The InstructionContext to use when looking up an
- * an instruction with these attributes.
- */
-static InstructionContext contextForAttrs(uint16_t attrMask) {
- return static_cast<InstructionContext>(CONTEXTS_SYM[attrMask]);
-}
-
-/*
- * modRMRequired - Reads the appropriate instruction table to determine whether
- * the ModR/M byte is required to decode a particular instruction.
- *
- * @param type - The opcode type (i.e., how many bytes it has).
- * @param insnContext - The context for the instruction, as returned by
- * contextForAttrs.
- * @param opcode - The last byte of the instruction's opcode, not counting
- * ModR/M extensions and escapes.
- * @return - true if the ModR/M byte is required, false otherwise.
- */
-static int modRMRequired(OpcodeType type,
- InstructionContext insnContext,
- uint16_t opcode) {
- const struct ContextDecision* decision = nullptr;
-
- switch (type) {
- case ONEBYTE:
- decision = &ONEBYTE_SYM;
- break;
- case TWOBYTE:
- decision = &TWOBYTE_SYM;
- break;
- case THREEBYTE_38:
- decision = &THREEBYTE38_SYM;
- break;
- case THREEBYTE_3A:
- decision = &THREEBYTE3A_SYM;
- break;
- case XOP8_MAP:
- decision = &XOP8_MAP_SYM;
- break;
- case XOP9_MAP:
- decision = &XOP9_MAP_SYM;
- break;
- case XOPA_MAP:
- decision = &XOPA_MAP_SYM;
- break;
- case THREEDNOW_MAP:
- decision = &THREEDNOW_MAP_SYM;
- break;
- }
-
- return decision->opcodeDecisions[insnContext].modRMDecisions[opcode].
- modrm_type != MODRM_ONEENTRY;
-}
-
-/*
- * decode - Reads the appropriate instruction table to obtain the unique ID of
- * an instruction.
- *
- * @param type - See modRMRequired().
- * @param insnContext - See modRMRequired().
- * @param opcode - See modRMRequired().
- * @param modRM - The ModR/M byte if required, or any value if not.
- * @return - The UID of the instruction, or 0 on failure.
- */
-static InstrUID decode(OpcodeType type,
- InstructionContext insnContext,
- uint8_t opcode,
- uint8_t modRM) {
- const struct ModRMDecision* dec = nullptr;
-
- switch (type) {
- case ONEBYTE:
- dec = &ONEBYTE_SYM.opcodeDecisions[insnContext].modRMDecisions[opcode];
- break;
- case TWOBYTE:
- dec = &TWOBYTE_SYM.opcodeDecisions[insnContext].modRMDecisions[opcode];
- break;
- case THREEBYTE_38:
- dec = &THREEBYTE38_SYM.opcodeDecisions[insnContext].modRMDecisions[opcode];
- break;
- case THREEBYTE_3A:
- dec = &THREEBYTE3A_SYM.opcodeDecisions[insnContext].modRMDecisions[opcode];
- break;
- case XOP8_MAP:
- dec = &XOP8_MAP_SYM.opcodeDecisions[insnContext].modRMDecisions[opcode];
- break;
- case XOP9_MAP:
- dec = &XOP9_MAP_SYM.opcodeDecisions[insnContext].modRMDecisions[opcode];
- break;
- case XOPA_MAP:
- dec = &XOPA_MAP_SYM.opcodeDecisions[insnContext].modRMDecisions[opcode];
- break;
- case THREEDNOW_MAP:
- dec = &THREEDNOW_MAP_SYM.opcodeDecisions[insnContext].modRMDecisions[opcode];
- break;
- }
-
- switch (dec->modrm_type) {
- default:
- debug("Corrupt table! Unknown modrm_type");
- return 0;
- case MODRM_ONEENTRY:
- return modRMTable[dec->instructionIDs];
- case MODRM_SPLITRM:
- if (modFromModRM(modRM) == 0x3)
- return modRMTable[dec->instructionIDs+1];
- return modRMTable[dec->instructionIDs];
- case MODRM_SPLITREG:
- if (modFromModRM(modRM) == 0x3)
- return modRMTable[dec->instructionIDs+((modRM & 0x38) >> 3)+8];
- return modRMTable[dec->instructionIDs+((modRM & 0x38) >> 3)];
- case MODRM_SPLITMISC:
- if (modFromModRM(modRM) == 0x3)
- return modRMTable[dec->instructionIDs+(modRM & 0x3f)+8];
- return modRMTable[dec->instructionIDs+((modRM & 0x38) >> 3)];
- case MODRM_FULL:
- return modRMTable[dec->instructionIDs+modRM];
- }
-}
-
-/*
- * specifierForUID - Given a UID, returns the name and operand specification for
- * that instruction.
- *
- * @param uid - The unique ID for the instruction. This should be returned by
- * decode(); specifierForUID will not check bounds.
- * @return - A pointer to the specification for that instruction.
- */
-static const struct InstructionSpecifier *specifierForUID(InstrUID uid) {
- return &INSTRUCTIONS_SYM[uid];
-}
-
-/*
- * consumeByte - Uses the reader function provided by the user to consume one
- * byte from the instruction's memory and advance the cursor.
- *
- * @param insn - The instruction with the reader function to use. The cursor
- * for this instruction is advanced.
- * @param byte - A pointer to a pre-allocated memory buffer to be populated
- * with the data read.
- * @return - 0 if the read was successful; nonzero otherwise.
- */
-static int consumeByte(struct InternalInstruction* insn, uint8_t* byte) {
- int ret = insn->reader(insn->readerArg, byte, insn->readerCursor);
-
- if (!ret)
- ++(insn->readerCursor);
-
- return ret;
-}
-
-/*
- * lookAtByte - Like consumeByte, but does not advance the cursor.
- *
- * @param insn - See consumeByte().
- * @param byte - See consumeByte().
- * @return - See consumeByte().
- */
-static int lookAtByte(struct InternalInstruction* insn, uint8_t* byte) {
- return insn->reader(insn->readerArg, byte, insn->readerCursor);
-}
-
-static void unconsumeByte(struct InternalInstruction* insn) {
- insn->readerCursor--;
-}
-
-#define CONSUME_FUNC(name, type) \
- static int name(struct InternalInstruction* insn, type* ptr) { \
- type combined = 0; \
- unsigned offset; \
- for (offset = 0; offset < sizeof(type); ++offset) { \
- uint8_t byte; \
- int ret = insn->reader(insn->readerArg, \
- &byte, \
- insn->readerCursor + offset); \
- if (ret) \
- return ret; \
- combined = combined | ((uint64_t)byte << (offset * 8)); \
- } \
- *ptr = combined; \
- insn->readerCursor += sizeof(type); \
- return 0; \
- }
-
-/*
- * consume* - Use the reader function provided by the user to consume data
- * values of various sizes from the instruction's memory and advance the
- * cursor appropriately. These readers perform endian conversion.
- *
- * @param insn - See consumeByte().
- * @param ptr - A pointer to a pre-allocated memory of appropriate size to
- * be populated with the data read.
- * @return - See consumeByte().
- */
-CONSUME_FUNC(consumeInt8, int8_t)
-CONSUME_FUNC(consumeInt16, int16_t)
-CONSUME_FUNC(consumeInt32, int32_t)
-CONSUME_FUNC(consumeUInt16, uint16_t)
-CONSUME_FUNC(consumeUInt32, uint32_t)
-CONSUME_FUNC(consumeUInt64, uint64_t)
-
-/*
- * dbgprintf - Uses the logging function provided by the user to log a single
- * message, typically without a carriage-return.
- *
- * @param insn - The instruction containing the logging function.
- * @param format - See printf().
- * @param ... - See printf().
- */
-static void dbgprintf(struct InternalInstruction* insn,
- const char* format,
- ...) {
- char buffer[256];
- va_list ap;
-
- if (!insn->dlog)
- return;
-
- va_start(ap, format);
- (void)vsnprintf(buffer, sizeof(buffer), format, ap);
- va_end(ap);
-
- insn->dlog(insn->dlogArg, buffer);
-}
-
-static bool isREX(struct InternalInstruction *insn, uint8_t prefix) {
- if (insn->mode == MODE_64BIT)
- return prefix >= 0x40 && prefix <= 0x4f;
- return false;
-}
-
-/*
- * setPrefixPresent - Marks that a particular prefix is present as mandatory
- *
- * @param insn - The instruction to be marked as having the prefix.
- * @param prefix - The prefix that is present.
- */
-static void setPrefixPresent(struct InternalInstruction *insn, uint8_t prefix) {
- uint8_t nextByte;
- switch (prefix) {
- case 0xf0:
- insn->hasLockPrefix = true;
- break;
- case 0xf2:
- case 0xf3:
- if (lookAtByte(insn, &nextByte))
- break;
- // TODO:
- // 1. There could be several 0x66
- // 2. if (nextByte == 0x66) and nextNextByte != 0x0f then
- // it's not mandatory prefix
- // 3. if (nextByte >= 0x40 && nextByte <= 0x4f) it's REX and we need
- // 0x0f exactly after it to be mandatory prefix
- if (isREX(insn, nextByte) || nextByte == 0x0f || nextByte == 0x66)
- // The last of 0xf2 /0xf3 is mandatory prefix
- insn->mandatoryPrefix = prefix;
- insn->repeatPrefix = prefix;
- break;
- case 0x66:
- if (lookAtByte(insn, &nextByte))
- break;
- // 0x66 can't overwrite existing mandatory prefix and should be ignored
- if (!insn->mandatoryPrefix && (nextByte == 0x0f || isREX(insn, nextByte)))
- insn->mandatoryPrefix = prefix;
- break;
- }
-}
-
-/*
- * readPrefixes - Consumes all of an instruction's prefix bytes, and marks the
- * instruction as having them. Also sets the instruction's default operand,
- * address, and other relevant data sizes to report operands correctly.
- *
- * @param insn - The instruction whose prefixes are to be read.
- * @return - 0 if the instruction could be read until the end of the prefix
- * bytes, and no prefixes conflicted; nonzero otherwise.
- */
-static int readPrefixes(struct InternalInstruction* insn) {
- bool isPrefix = true;
- uint8_t byte = 0;
- uint8_t nextByte;
-
- dbgprintf(insn, "readPrefixes()");
-
- while (isPrefix) {
- /* If we fail reading prefixes, just stop here and let the opcode reader deal with it */
- if (consumeByte(insn, &byte))
- break;
-
- /*
- * If the byte is a LOCK/REP/REPNE prefix and not a part of the opcode, then
- * break and let it be disassembled as a normal "instruction".
- */
- if (insn->readerCursor - 1 == insn->startLocation && byte == 0xf0) // LOCK
- break;
-
- if ((byte == 0xf2 || byte == 0xf3) && !lookAtByte(insn, &nextByte)) {
- /*
- * If the byte is 0xf2 or 0xf3, and any of the following conditions are
- * met:
- * - it is followed by a LOCK (0xf0) prefix
- * - it is followed by an xchg instruction
- * then it should be disassembled as a xacquire/xrelease not repne/rep.
- */
- if (((nextByte == 0xf0) ||
- ((nextByte & 0xfe) == 0x86 || (nextByte & 0xf8) == 0x90))) {
- insn->xAcquireRelease = true;
- if (!(byte == 0xf3 && nextByte == 0x90)) // PAUSE instruction support
- break;
- }
- /*
- * Also if the byte is 0xf3, and the following condition is met:
- * - it is followed by a "mov mem, reg" (opcode 0x88/0x89) or
- * "mov mem, imm" (opcode 0xc6/0xc7) instructions.
- * then it should be disassembled as an xrelease not rep.
- */
- if (byte == 0xf3 && (nextByte == 0x88 || nextByte == 0x89 ||
- nextByte == 0xc6 || nextByte == 0xc7)) {
- insn->xAcquireRelease = true;
- break;
- }
- if (isREX(insn, nextByte)) {
- uint8_t nnextByte;
- // Go to REX prefix after the current one
- if (consumeByte(insn, &nnextByte))
- return -1;
- // We should be able to read next byte after REX prefix
- if (lookAtByte(insn, &nnextByte))
- return -1;
- unconsumeByte(insn);
- }
- }
-
- switch (byte) {
- case 0xf0: /* LOCK */
- case 0xf2: /* REPNE/REPNZ */
- case 0xf3: /* REP or REPE/REPZ */
- setPrefixPresent(insn, byte);
- break;
- case 0x2e: /* CS segment override -OR- Branch not taken */
- case 0x36: /* SS segment override -OR- Branch taken */
- case 0x3e: /* DS segment override */
- case 0x26: /* ES segment override */
- case 0x64: /* FS segment override */
- case 0x65: /* GS segment override */
- switch (byte) {
- case 0x2e:
- insn->segmentOverride = SEG_OVERRIDE_CS;
- break;
- case 0x36:
- insn->segmentOverride = SEG_OVERRIDE_SS;
- break;
- case 0x3e:
- insn->segmentOverride = SEG_OVERRIDE_DS;
- break;
- case 0x26:
- insn->segmentOverride = SEG_OVERRIDE_ES;
- break;
- case 0x64:
- insn->segmentOverride = SEG_OVERRIDE_FS;
- break;
- case 0x65:
- insn->segmentOverride = SEG_OVERRIDE_GS;
- break;
- default:
- debug("Unhandled override");
- return -1;
- }
- setPrefixPresent(insn, byte);
- break;
- case 0x66: /* Operand-size override */
- insn->hasOpSize = true;
- setPrefixPresent(insn, byte);
- break;
- case 0x67: /* Address-size override */
- insn->hasAdSize = true;
- setPrefixPresent(insn, byte);
- break;
- default: /* Not a prefix byte */
- isPrefix = false;
- break;
- }
-
- if (isPrefix)
- dbgprintf(insn, "Found prefix 0x%hhx", byte);
- }
-
- insn->vectorExtensionType = TYPE_NO_VEX_XOP;
-
- if (byte == 0x62) {
- uint8_t byte1, byte2;
-
- if (consumeByte(insn, &byte1)) {
- dbgprintf(insn, "Couldn't read second byte of EVEX prefix");
- return -1;
- }
-
- if (lookAtByte(insn, &byte2)) {
- dbgprintf(insn, "Couldn't read third byte of EVEX prefix");
- return -1;
- }
-
- if ((insn->mode == MODE_64BIT || (byte1 & 0xc0) == 0xc0) &&
- ((~byte1 & 0xc) == 0xc) && ((byte2 & 0x4) == 0x4)) {
- insn->vectorExtensionType = TYPE_EVEX;
- } else {
- unconsumeByte(insn); /* unconsume byte1 */
- unconsumeByte(insn); /* unconsume byte */
- }
-
- if (insn->vectorExtensionType == TYPE_EVEX) {
- insn->vectorExtensionPrefix[0] = byte;
- insn->vectorExtensionPrefix[1] = byte1;
- if (consumeByte(insn, &insn->vectorExtensionPrefix[2])) {
- dbgprintf(insn, "Couldn't read third byte of EVEX prefix");
- return -1;
- }
- if (consumeByte(insn, &insn->vectorExtensionPrefix[3])) {
- dbgprintf(insn, "Couldn't read fourth byte of EVEX prefix");
- return -1;
- }
-
- /* We simulate the REX prefix for simplicity's sake */
- if (insn->mode == MODE_64BIT) {
- insn->rexPrefix = 0x40
- | (wFromEVEX3of4(insn->vectorExtensionPrefix[2]) << 3)
- | (rFromEVEX2of4(insn->vectorExtensionPrefix[1]) << 2)
- | (xFromEVEX2of4(insn->vectorExtensionPrefix[1]) << 1)
- | (bFromEVEX2of4(insn->vectorExtensionPrefix[1]) << 0);
- }
-
- dbgprintf(insn, "Found EVEX prefix 0x%hhx 0x%hhx 0x%hhx 0x%hhx",
- insn->vectorExtensionPrefix[0], insn->vectorExtensionPrefix[1],
- insn->vectorExtensionPrefix[2], insn->vectorExtensionPrefix[3]);
- }
- } else if (byte == 0xc4) {
- uint8_t byte1;
-
- if (lookAtByte(insn, &byte1)) {
- dbgprintf(insn, "Couldn't read second byte of VEX");
- return -1;
- }
-
- if (insn->mode == MODE_64BIT || (byte1 & 0xc0) == 0xc0)
- insn->vectorExtensionType = TYPE_VEX_3B;
- else
- unconsumeByte(insn);
-
- if (insn->vectorExtensionType == TYPE_VEX_3B) {
- insn->vectorExtensionPrefix[0] = byte;
- consumeByte(insn, &insn->vectorExtensionPrefix[1]);
- consumeByte(insn, &insn->vectorExtensionPrefix[2]);
-
- /* We simulate the REX prefix for simplicity's sake */
-
- if (insn->mode == MODE_64BIT)
- insn->rexPrefix = 0x40
- | (wFromVEX3of3(insn->vectorExtensionPrefix[2]) << 3)
- | (rFromVEX2of3(insn->vectorExtensionPrefix[1]) << 2)
- | (xFromVEX2of3(insn->vectorExtensionPrefix[1]) << 1)
- | (bFromVEX2of3(insn->vectorExtensionPrefix[1]) << 0);
-
- dbgprintf(insn, "Found VEX prefix 0x%hhx 0x%hhx 0x%hhx",
- insn->vectorExtensionPrefix[0], insn->vectorExtensionPrefix[1],
- insn->vectorExtensionPrefix[2]);
- }
- } else if (byte == 0xc5) {
- uint8_t byte1;
-
- if (lookAtByte(insn, &byte1)) {
- dbgprintf(insn, "Couldn't read second byte of VEX");
- return -1;
- }
-
- if (insn->mode == MODE_64BIT || (byte1 & 0xc0) == 0xc0)
- insn->vectorExtensionType = TYPE_VEX_2B;
- else
- unconsumeByte(insn);
-
- if (insn->vectorExtensionType == TYPE_VEX_2B) {
- insn->vectorExtensionPrefix[0] = byte;
- consumeByte(insn, &insn->vectorExtensionPrefix[1]);
-
- if (insn->mode == MODE_64BIT)
- insn->rexPrefix = 0x40
- | (rFromVEX2of2(insn->vectorExtensionPrefix[1]) << 2);
-
- switch (ppFromVEX2of2(insn->vectorExtensionPrefix[1])) {
- default:
- break;
- case VEX_PREFIX_66:
- insn->hasOpSize = true;
- break;
- }
-
- dbgprintf(insn, "Found VEX prefix 0x%hhx 0x%hhx",
- insn->vectorExtensionPrefix[0],
- insn->vectorExtensionPrefix[1]);
- }
- } else if (byte == 0x8f) {
- uint8_t byte1;
-
- if (lookAtByte(insn, &byte1)) {
- dbgprintf(insn, "Couldn't read second byte of XOP");
- return -1;
- }
-
- if ((byte1 & 0x38) != 0x0) /* 0 in these 3 bits is a POP instruction. */
- insn->vectorExtensionType = TYPE_XOP;
- else
- unconsumeByte(insn);
-
- if (insn->vectorExtensionType == TYPE_XOP) {
- insn->vectorExtensionPrefix[0] = byte;
- consumeByte(insn, &insn->vectorExtensionPrefix[1]);
- consumeByte(insn, &insn->vectorExtensionPrefix[2]);
-
- /* We simulate the REX prefix for simplicity's sake */
-
- if (insn->mode == MODE_64BIT)
- insn->rexPrefix = 0x40
- | (wFromXOP3of3(insn->vectorExtensionPrefix[2]) << 3)
- | (rFromXOP2of3(insn->vectorExtensionPrefix[1]) << 2)
- | (xFromXOP2of3(insn->vectorExtensionPrefix[1]) << 1)
- | (bFromXOP2of3(insn->vectorExtensionPrefix[1]) << 0);
-
- switch (ppFromXOP3of3(insn->vectorExtensionPrefix[2])) {
- default:
- break;
- case VEX_PREFIX_66:
- insn->hasOpSize = true;
- break;
- }
-
- dbgprintf(insn, "Found XOP prefix 0x%hhx 0x%hhx 0x%hhx",
- insn->vectorExtensionPrefix[0], insn->vectorExtensionPrefix[1],
- insn->vectorExtensionPrefix[2]);
- }
- } else if (isREX(insn, byte)) {
- if (lookAtByte(insn, &nextByte))
- return -1;
- insn->rexPrefix = byte;
- dbgprintf(insn, "Found REX prefix 0x%hhx", byte);
- } else
- unconsumeByte(insn);
-
- if (insn->mode == MODE_16BIT) {
- insn->registerSize = (insn->hasOpSize ? 4 : 2);
- insn->addressSize = (insn->hasAdSize ? 4 : 2);
- insn->displacementSize = (insn->hasAdSize ? 4 : 2);
- insn->immediateSize = (insn->hasOpSize ? 4 : 2);
- } else if (insn->mode == MODE_32BIT) {
- insn->registerSize = (insn->hasOpSize ? 2 : 4);
- insn->addressSize = (insn->hasAdSize ? 2 : 4);
- insn->displacementSize = (insn->hasAdSize ? 2 : 4);
- insn->immediateSize = (insn->hasOpSize ? 2 : 4);
- } else if (insn->mode == MODE_64BIT) {
- if (insn->rexPrefix && wFromREX(insn->rexPrefix)) {
- insn->registerSize = 8;
- insn->addressSize = (insn->hasAdSize ? 4 : 8);
- insn->displacementSize = 4;
- insn->immediateSize = 4;
- } else {
- insn->registerSize = (insn->hasOpSize ? 2 : 4);
- insn->addressSize = (insn->hasAdSize ? 4 : 8);
- insn->displacementSize = (insn->hasOpSize ? 2 : 4);
- insn->immediateSize = (insn->hasOpSize ? 2 : 4);
- }
- }
-
- return 0;
-}
-
-static int readModRM(struct InternalInstruction* insn);
-
-/*
- * readOpcode - Reads the opcode (excepting the ModR/M byte in the case of
- * extended or escape opcodes).
- *
- * @param insn - The instruction whose opcode is to be read.
- * @return - 0 if the opcode could be read successfully; nonzero otherwise.
- */
-static int readOpcode(struct InternalInstruction* insn) {
- /* Determine the length of the primary opcode */
-
- uint8_t current;
-
- dbgprintf(insn, "readOpcode()");
-
- insn->opcodeType = ONEBYTE;
-
- if (insn->vectorExtensionType == TYPE_EVEX) {
- switch (mmFromEVEX2of4(insn->vectorExtensionPrefix[1])) {
- default:
- dbgprintf(insn, "Unhandled mm field for instruction (0x%hhx)",
- mmFromEVEX2of4(insn->vectorExtensionPrefix[1]));
- return -1;
- case VEX_LOB_0F:
- insn->opcodeType = TWOBYTE;
- return consumeByte(insn, &insn->opcode);
- case VEX_LOB_0F38:
- insn->opcodeType = THREEBYTE_38;
- return consumeByte(insn, &insn->opcode);
- case VEX_LOB_0F3A:
- insn->opcodeType = THREEBYTE_3A;
- return consumeByte(insn, &insn->opcode);
- }
- } else if (insn->vectorExtensionType == TYPE_VEX_3B) {
- switch (mmmmmFromVEX2of3(insn->vectorExtensionPrefix[1])) {
- default:
- dbgprintf(insn, "Unhandled m-mmmm field for instruction (0x%hhx)",
- mmmmmFromVEX2of3(insn->vectorExtensionPrefix[1]));
- return -1;
- case VEX_LOB_0F:
- insn->opcodeType = TWOBYTE;
- return consumeByte(insn, &insn->opcode);
- case VEX_LOB_0F38:
- insn->opcodeType = THREEBYTE_38;
- return consumeByte(insn, &insn->opcode);
- case VEX_LOB_0F3A:
- insn->opcodeType = THREEBYTE_3A;
- return consumeByte(insn, &insn->opcode);
- }
- } else if (insn->vectorExtensionType == TYPE_VEX_2B) {
- insn->opcodeType = TWOBYTE;
- return consumeByte(insn, &insn->opcode);
- } else if (insn->vectorExtensionType == TYPE_XOP) {
- switch (mmmmmFromXOP2of3(insn->vectorExtensionPrefix[1])) {
- default:
- dbgprintf(insn, "Unhandled m-mmmm field for instruction (0x%hhx)",
- mmmmmFromVEX2of3(insn->vectorExtensionPrefix[1]));
- return -1;
- case XOP_MAP_SELECT_8:
- insn->opcodeType = XOP8_MAP;
- return consumeByte(insn, &insn->opcode);
- case XOP_MAP_SELECT_9:
- insn->opcodeType = XOP9_MAP;
- return consumeByte(insn, &insn->opcode);
- case XOP_MAP_SELECT_A:
- insn->opcodeType = XOPA_MAP;
- return consumeByte(insn, &insn->opcode);
- }
- }
-
- if (consumeByte(insn, &current))
- return -1;
-
- if (current == 0x0f) {
- dbgprintf(insn, "Found a two-byte escape prefix (0x%hhx)", current);
-
- if (consumeByte(insn, &current))
- return -1;
-
- if (current == 0x38) {
- dbgprintf(insn, "Found a three-byte escape prefix (0x%hhx)", current);
-
- if (consumeByte(insn, &current))
- return -1;
-
- insn->opcodeType = THREEBYTE_38;
- } else if (current == 0x3a) {
- dbgprintf(insn, "Found a three-byte escape prefix (0x%hhx)", current);
-
- if (consumeByte(insn, &current))
- return -1;
-
- insn->opcodeType = THREEBYTE_3A;
- } else if (current == 0x0f) {
- dbgprintf(insn, "Found a 3dnow escape prefix (0x%hhx)", current);
-
- // Consume operands before the opcode to comply with the 3DNow encoding
- if (readModRM(insn))
- return -1;
-
- if (consumeByte(insn, &current))
- return -1;
-
- insn->opcodeType = THREEDNOW_MAP;
- } else {
- dbgprintf(insn, "Didn't find a three-byte escape prefix");
-
- insn->opcodeType = TWOBYTE;
- }
- } else if (insn->mandatoryPrefix)
- // The opcode with mandatory prefix must start with opcode escape.
- // If not it's legacy repeat prefix
- insn->mandatoryPrefix = 0;
-
- /*
- * At this point we have consumed the full opcode.
- * Anything we consume from here on must be unconsumed.
- */
-
- insn->opcode = current;
-
- return 0;
-}
-
-/*
- * 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,
- uint16_t attrMask) {
- bool hasModRMExtension;
-
- InstructionContext 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;
-}
-
-/*
- * is16BitEquivalent - Determines whether two instruction names refer to
- * equivalent instructions but one is 16-bit whereas the other is not.
- *
- * @param orig - The instruction that is not 16-bit
- * @param equiv - The instruction that is 16-bit
- */
-static bool is16BitEquivalent(const char *orig, const char *equiv) {
- off_t i;
-
- for (i = 0;; i++) {
- if (orig[i] == '\0' && equiv[i] == '\0')
- return true;
- if (orig[i] == '\0' || equiv[i] == '\0')
- return false;
- if (orig[i] != equiv[i]) {
- if ((orig[i] == 'Q' || orig[i] == 'L') && equiv[i] == 'W')
- continue;
- if ((orig[i] == '6' || orig[i] == '3') && equiv[i] == '1')
- continue;
- if ((orig[i] == '4' || orig[i] == '2') && equiv[i] == '6')
- continue;
- return false;
- }
- }
-}
-
-/*
- * 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
- * context for the instruction before doing so.
- *
- * @param insn - The instruction whose ID is to be determined.
- * @return - 0 if the ModR/M could be read when needed or was not needed;
- * nonzero otherwise.
- */
-static int getID(struct InternalInstruction* insn, const void *miiArg) {
- uint16_t attrMask;
- uint16_t instructionID;
-
- dbgprintf(insn, "getID()");
-
- attrMask = ATTR_NONE;
-
- if (insn->mode == MODE_64BIT)
- attrMask |= ATTR_64BIT;
-
- if (insn->vectorExtensionType != TYPE_NO_VEX_XOP) {
- attrMask |= (insn->vectorExtensionType == TYPE_EVEX) ? ATTR_EVEX : ATTR_VEX;
-
- if (insn->vectorExtensionType == TYPE_EVEX) {
- switch (ppFromEVEX3of4(insn->vectorExtensionPrefix[2])) {
- case VEX_PREFIX_66:
- attrMask |= ATTR_OPSIZE;
- break;
- case VEX_PREFIX_F3:
- attrMask |= ATTR_XS;
- break;
- case VEX_PREFIX_F2:
- attrMask |= ATTR_XD;
- break;
- }
-
- if (zFromEVEX4of4(insn->vectorExtensionPrefix[3]))
- attrMask |= ATTR_EVEXKZ;
- if (bFromEVEX4of4(insn->vectorExtensionPrefix[3]))
- attrMask |= ATTR_EVEXB;
- if (aaaFromEVEX4of4(insn->vectorExtensionPrefix[3]))
- attrMask |= ATTR_EVEXK;
- if (lFromEVEX4of4(insn->vectorExtensionPrefix[3]))
- attrMask |= ATTR_VEXL;
- if (l2FromEVEX4of4(insn->vectorExtensionPrefix[3]))
- attrMask |= ATTR_EVEXL2;
- } else if (insn->vectorExtensionType == TYPE_VEX_3B) {
- switch (ppFromVEX3of3(insn->vectorExtensionPrefix[2])) {
- case VEX_PREFIX_66:
- attrMask |= ATTR_OPSIZE;
- break;
- case VEX_PREFIX_F3:
- attrMask |= ATTR_XS;
- break;
- case VEX_PREFIX_F2:
- attrMask |= ATTR_XD;
- break;
- }
-
- if (lFromVEX3of3(insn->vectorExtensionPrefix[2]))
- attrMask |= ATTR_VEXL;
- } else if (insn->vectorExtensionType == TYPE_VEX_2B) {
- switch (ppFromVEX2of2(insn->vectorExtensionPrefix[1])) {
- case VEX_PREFIX_66:
- attrMask |= ATTR_OPSIZE;
- break;
- case VEX_PREFIX_F3:
- attrMask |= ATTR_XS;
- break;
- case VEX_PREFIX_F2:
- attrMask |= ATTR_XD;
- break;
- }
-
- if (lFromVEX2of2(insn->vectorExtensionPrefix[1]))
- attrMask |= ATTR_VEXL;
- } else if (insn->vectorExtensionType == TYPE_XOP) {
- switch (ppFromXOP3of3(insn->vectorExtensionPrefix[2])) {
- case VEX_PREFIX_66:
- attrMask |= ATTR_OPSIZE;
- break;
- case VEX_PREFIX_F3:
- attrMask |= ATTR_XS;
- break;
- case VEX_PREFIX_F2:
- attrMask |= ATTR_XD;
- break;
- }
-
- if (lFromXOP3of3(insn->vectorExtensionPrefix[2]))
- attrMask |= ATTR_VEXL;
- } else {
- return -1;
- }
- } else if (!insn->mandatoryPrefix) {
- // If we don't have mandatory prefix we should use legacy prefixes here
- if (insn->hasOpSize && (insn->mode != MODE_16BIT))
- attrMask |= ATTR_OPSIZE;
- if (insn->hasAdSize)
- attrMask |= ATTR_ADSIZE;
- if (insn->opcodeType == ONEBYTE) {
- if (insn->repeatPrefix == 0xf3 && (insn->opcode == 0x90))
- // Special support for PAUSE
- attrMask |= ATTR_XS;
- } else {
- if (insn->repeatPrefix == 0xf2)
- attrMask |= ATTR_XD;
- else if (insn->repeatPrefix == 0xf3)
- attrMask |= ATTR_XS;
- }
- } else {
- switch (insn->mandatoryPrefix) {
- case 0xf2:
- attrMask |= ATTR_XD;
- break;
- case 0xf3:
- attrMask |= ATTR_XS;
- break;
- case 0x66:
- if (insn->mode != MODE_16BIT)
- attrMask |= ATTR_OPSIZE;
- break;
- case 0x67:
- attrMask |= ATTR_ADSIZE;
- break;
- }
-
- }
-
- if (insn->rexPrefix & 0x08) {
- attrMask |= ATTR_REXW;
- attrMask &= ~ATTR_ADSIZE;
- }
-
- /*
- * 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->opcodeType == ONEBYTE &&
- insn->opcode == 0xE3)
- attrMask ^= ATTR_ADSIZE;
-
- // If we're in 16-bit mode and this is one of the relative jumps and opsize
- // prefix isn't present, we need to force the opsize attribute since the
- // prefix is inverted relative to 32-bit mode.
- if (insn->mode == MODE_16BIT && !insn->hasOpSize &&
- insn->opcodeType == ONEBYTE &&
- (insn->opcode == 0xE8 || insn->opcode == 0xE9))
- attrMask |= ATTR_OPSIZE;
-
- if (insn->mode == MODE_16BIT && !insn->hasOpSize &&
- insn->opcodeType == TWOBYTE &&
- insn->opcode >= 0x80 && insn->opcode <= 0x8F)
- attrMask |= ATTR_OPSIZE;
-
- 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) {
- /*
- * 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 ((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;
- }
-
- auto SpecName = GetInstrName(instructionIDWithREXW, miiArg);
- // If not a 64-bit instruction. Switch the opcode.
- if (!is64Bit(SpecName.data())) {
- insn->instructionID = instructionIDWithREXW;
- insn->spec = specifierForUID(instructionIDWithREXW);
- return 0;
- }
- }
- }
-
- /*
- * Absolute moves, umonitor, and movdir64b 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)) ||
- (insn->opcodeType == TWOBYTE && (insn->opcode == 0xAE)) ||
- (insn->opcodeType == THREEBYTE_38 && insn->opcode == 0xF8)) {
- /* Make sure we observed the prefixes in any position. */
- if (insn->hasAdSize)
- attrMask |= ATTR_ADSIZE;
- if (insn->hasOpSize)
- attrMask |= ATTR_OPSIZE;
-
- /* In 16-bit, invert the attributes. */
- if (insn->mode == MODE_16BIT) {
- attrMask ^= ATTR_ADSIZE;
-
- /* The OpSize attribute is only valid with the absolute moves. */
- if (insn->opcodeType == ONEBYTE && ((insn->opcode & 0xFC) == 0xA0))
- attrMask ^= ATTR_OPSIZE;
- }
-
- if (getIDWithAttrMask(&instructionID, insn, attrMask))
- return -1;
-
- insn->instructionID = instructionID;
- insn->spec = specifierForUID(instructionID);
- return 0;
- }
-
- if ((insn->mode == MODE_16BIT || insn->hasOpSize) &&
- !(attrMask & ATTR_OPSIZE)) {
- /*
- * The instruction tables make no distinction between instructions that
- * allow OpSize anywhere (i.e., 16-bit operations) and that need it in a
- * particular spot (i.e., many MMX operations). In general we're
- * conservative, but in the specific case where OpSize is present but not
- * in the right place we check if there's a 16-bit operation.
- */
-
- const struct InstructionSpecifier *spec;
- uint16_t instructionIDWithOpsize;
- llvm::StringRef specName, specWithOpSizeName;
-
- spec = specifierForUID(instructionID);
-
- if (getIDWithAttrMask(&instructionIDWithOpsize,
- insn,
- attrMask | ATTR_OPSIZE)) {
- /*
- * ModRM required with OpSize but not present; give up and return version
- * without OpSize set
- */
-
- insn->instructionID = instructionID;
- insn->spec = spec;
- return 0;
- }
-
- specName = GetInstrName(instructionID, miiArg);
- specWithOpSizeName = GetInstrName(instructionIDWithOpsize, miiArg);
-
- if (is16BitEquivalent(specName.data(), specWithOpSizeName.data()) &&
- (insn->mode == MODE_16BIT) ^ insn->hasOpSize) {
- insn->instructionID = instructionIDWithOpsize;
- insn->spec = specifierForUID(instructionIDWithOpsize);
- } else {
- insn->instructionID = instructionID;
- insn->spec = spec;
- }
- return 0;
- }
-
- if (insn->opcodeType == ONEBYTE && insn->opcode == 0x90 &&
- insn->rexPrefix & 0x01) {
- /*
- * NOOP shouldn't decode as NOOP if REX.b is set. Instead
- * it should decode as XCHG %r8, %eax.
- */
-
- const struct InstructionSpecifier *spec;
- uint16_t instructionIDWithNewOpcode;
- const struct InstructionSpecifier *specWithNewOpcode;
-
- spec = specifierForUID(instructionID);
-
- /* Borrow opcode from one of the other XCHGar opcodes */
- insn->opcode = 0x91;
-
- if (getIDWithAttrMask(&instructionIDWithNewOpcode,
- insn,
- attrMask)) {
- insn->opcode = 0x90;
-
- insn->instructionID = instructionID;
- insn->spec = spec;
- return 0;
- }
-
- specWithNewOpcode = specifierForUID(instructionIDWithNewOpcode);
-
- /* Change back */
- insn->opcode = 0x90;
-
- insn->instructionID = instructionIDWithNewOpcode;
- insn->spec = specWithNewOpcode;
-
- return 0;
- }
-
- insn->instructionID = instructionID;
- insn->spec = specifierForUID(insn->instructionID);
-
- return 0;
-}
-
-/*
- * readSIB - Consumes the SIB byte to determine addressing information for an
- * instruction.
- *
- * @param insn - The instruction whose SIB byte is to be read.
- * @return - 0 if the SIB byte was successfully read; nonzero otherwise.
- */
-static int readSIB(struct InternalInstruction* insn) {
- SIBBase sibBaseBase = SIB_BASE_NONE;
- uint8_t index, base;
-
- dbgprintf(insn, "readSIB()");
-
- if (insn->consumedSIB)
- return 0;
-
- insn->consumedSIB = true;
-
- switch (insn->addressSize) {
- case 2:
- dbgprintf(insn, "SIB-based addressing doesn't work in 16-bit mode");
- return -1;
- case 4:
- insn->sibIndexBase = SIB_INDEX_EAX;
- sibBaseBase = SIB_BASE_EAX;
- break;
- case 8:
- insn->sibIndexBase = SIB_INDEX_RAX;
- sibBaseBase = SIB_BASE_RAX;
- break;
- }
-
- if (consumeByte(insn, &insn->sib))
- return -1;
-
- index = indexFromSIB(insn->sib) | (xFromREX(insn->rexPrefix) << 3);
-
- if (index == 0x4) {
- insn->sibIndex = SIB_INDEX_NONE;
- } else {
- insn->sibIndex = (SIBIndex)(insn->sibIndexBase + index);
- }
-
- insn->sibScale = 1 << scaleFromSIB(insn->sib);
-
- base = baseFromSIB(insn->sib) | (bFromREX(insn->rexPrefix) << 3);
-
- switch (base) {
- case 0x5:
- case 0xd:
- switch (modFromModRM(insn->modRM)) {
- case 0x0:
- insn->eaDisplacement = EA_DISP_32;
- insn->sibBase = SIB_BASE_NONE;
- break;
- case 0x1:
- insn->eaDisplacement = EA_DISP_8;
- insn->sibBase = (SIBBase)(sibBaseBase + base);
- break;
- case 0x2:
- insn->eaDisplacement = EA_DISP_32;
- insn->sibBase = (SIBBase)(sibBaseBase + base);
- break;
- case 0x3:
- debug("Cannot have Mod = 0b11 and a SIB byte");
- return -1;
- }
- break;
- default:
- insn->sibBase = (SIBBase)(sibBaseBase + base);
- break;
- }
-
- return 0;
-}
-
-/*
- * readDisplacement - Consumes the displacement of an instruction.
- *
- * @param insn - The instruction whose displacement is to be read.
- * @return - 0 if the displacement byte was successfully read; nonzero
- * otherwise.
- */
-static int readDisplacement(struct InternalInstruction* insn) {
- int8_t d8;
- int16_t d16;
- int32_t d32;
-
- dbgprintf(insn, "readDisplacement()");
-
- if (insn->consumedDisplacement)
- return 0;
-
- insn->consumedDisplacement = true;
- insn->displacementOffset = insn->readerCursor - insn->startLocation;
-
- switch (insn->eaDisplacement) {
- case EA_DISP_NONE:
- insn->consumedDisplacement = false;
- break;
- case EA_DISP_8:
- if (consumeInt8(insn, &d8))
- return -1;
- insn->displacement = d8;
- break;
- case EA_DISP_16:
- if (consumeInt16(insn, &d16))
- return -1;
- insn->displacement = d16;
- break;
- case EA_DISP_32:
- if (consumeInt32(insn, &d32))
- return -1;
- insn->displacement = d32;
- break;
- }
-
- insn->consumedDisplacement = true;
- return 0;
-}
-
-/*
- * readModRM - Consumes all addressing information (ModR/M byte, SIB byte, and
- * displacement) for an instruction and interprets it.
- *
- * @param insn - The instruction whose addressing information is to be read.
- * @return - 0 if the information was successfully read; nonzero otherwise.
- */
-static int readModRM(struct InternalInstruction* insn) {
- uint8_t mod, rm, reg, evexrm;
-
- dbgprintf(insn, "readModRM()");
-
- if (insn->consumedModRM)
- return 0;
-
- if (consumeByte(insn, &insn->modRM))
- return -1;
- insn->consumedModRM = true;
-
- mod = modFromModRM(insn->modRM);
- rm = rmFromModRM(insn->modRM);
- reg = regFromModRM(insn->modRM);
-
- /*
- * This goes by insn->registerSize to pick the correct register, which messes
- * up if we're using (say) XMM or 8-bit register operands. That gets fixed in
- * fixupReg().
- */
- switch (insn->registerSize) {
- case 2:
- insn->regBase = MODRM_REG_AX;
- insn->eaRegBase = EA_REG_AX;
- break;
- case 4:
- insn->regBase = MODRM_REG_EAX;
- insn->eaRegBase = EA_REG_EAX;
- break;
- case 8:
- insn->regBase = MODRM_REG_RAX;
- insn->eaRegBase = EA_REG_RAX;
- break;
- }
-
- reg |= rFromREX(insn->rexPrefix) << 3;
- rm |= bFromREX(insn->rexPrefix) << 3;
-
- evexrm = 0;
- if (insn->vectorExtensionType == TYPE_EVEX && insn->mode == MODE_64BIT) {
- reg |= r2FromEVEX2of4(insn->vectorExtensionPrefix[1]) << 4;
- evexrm = xFromEVEX2of4(insn->vectorExtensionPrefix[1]) << 4;
- }
-
- insn->reg = (Reg)(insn->regBase + reg);
-
- switch (insn->addressSize) {
- case 2: {
- EABase eaBaseBase = EA_BASE_BX_SI;
-
- switch (mod) {
- case 0x0:
- if (rm == 0x6) {
- insn->eaBase = EA_BASE_NONE;
- insn->eaDisplacement = EA_DISP_16;
- if (readDisplacement(insn))
- return -1;
- } else {
- insn->eaBase = (EABase)(eaBaseBase + rm);
- insn->eaDisplacement = EA_DISP_NONE;
- }
- break;
- case 0x1:
- insn->eaBase = (EABase)(eaBaseBase + rm);
- insn->eaDisplacement = EA_DISP_8;
- insn->displacementSize = 1;
- if (readDisplacement(insn))
- return -1;
- break;
- case 0x2:
- insn->eaBase = (EABase)(eaBaseBase + rm);
- insn->eaDisplacement = EA_DISP_16;
- if (readDisplacement(insn))
- return -1;
- break;
- case 0x3:
- insn->eaBase = (EABase)(insn->eaRegBase + rm);
- if (readDisplacement(insn))
- return -1;
- break;
- }
- break;
- }
- case 4:
- case 8: {
- EABase eaBaseBase = (insn->addressSize == 4 ? EA_BASE_EAX : EA_BASE_RAX);
-
- switch (mod) {
- case 0x0:
- insn->eaDisplacement = EA_DISP_NONE; /* readSIB may override this */
- // 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: // RIP-relative
- insn->eaBase = EA_BASE_NONE;
- insn->eaDisplacement = EA_DISP_32;
- if (readDisplacement(insn))
- return -1;
- break;
- default:
- insn->eaBase = (EABase)(eaBaseBase + rm);
- break;
- }
- break;
- case 0x1:
- insn->displacementSize = 1;
- LLVM_FALLTHROUGH;
- case 0x2:
- insn->eaDisplacement = (mod == 0x1 ? EA_DISP_8 : EA_DISP_32);
- switch (rm & 7) {
- case 0x4: // SIB byte is present
- insn->eaBase = EA_BASE_sib;
- if (readSIB(insn) || readDisplacement(insn))
- return -1;
- break;
- default:
- insn->eaBase = (EABase)(eaBaseBase + rm);
- if (readDisplacement(insn))
- return -1;
- break;
- }
- break;
- case 0x3:
- insn->eaDisplacement = EA_DISP_NONE;
- insn->eaBase = (EABase)(insn->eaRegBase + rm + evexrm);
- break;
- }
- break;
- }
- } /* switch (insn->addressSize) */
-
- return 0;
-}
-
-#define GENERIC_FIXUP_FUNC(name, base, prefix, mask) \
- static uint16_t name(struct InternalInstruction *insn, \
- OperandType type, \
- uint8_t index, \
- uint8_t *valid) { \
- *valid = 1; \
- switch (type) { \
- default: \
- debug("Unhandled register type"); \
- *valid = 0; \
- return 0; \
- case TYPE_Rv: \
- return base + index; \
- case TYPE_R8: \
- index &= mask; \
- if (index > 0xf) \
- *valid = 0; \
- if (insn->rexPrefix && \
- index >= 4 && index <= 7) { \
- return prefix##_SPL + (index - 4); \
- } else { \
- return prefix##_AL + index; \
- } \
- case TYPE_R16: \
- index &= mask; \
- if (index > 0xf) \
- *valid = 0; \
- return prefix##_AX + index; \
- case TYPE_R32: \
- index &= mask; \
- if (index > 0xf) \
- *valid = 0; \
- return prefix##_EAX + index; \
- case TYPE_R64: \
- index &= mask; \
- if (index > 0xf) \
- *valid = 0; \
- return prefix##_RAX + index; \
- case TYPE_ZMM: \
- return prefix##_ZMM0 + index; \
- case TYPE_YMM: \
- return prefix##_YMM0 + index; \
- case TYPE_XMM: \
- return prefix##_XMM0 + index; \
- case TYPE_VK: \
- index &= 0xf; \
- if (index > 7) \
- *valid = 0; \
- return prefix##_K0 + index; \
- case TYPE_VK_PAIR: \
- if (index > 7) \
- *valid = 0; \
- return prefix##_K0_K1 + (index / 2); \
- case TYPE_MM64: \
- return prefix##_MM0 + (index & 0x7); \
- case TYPE_SEGMENTREG: \
- if ((index & 7) > 5) \
- *valid = 0; \
- return prefix##_ES + (index & 7); \
- case TYPE_DEBUGREG: \
- return prefix##_DR0 + index; \
- case TYPE_CONTROLREG: \
- return prefix##_CR0 + index; \
- case TYPE_BNDR: \
- if (index > 3) \
- *valid = 0; \
- return prefix##_BND0 + index; \
- case TYPE_MVSIBX: \
- return prefix##_XMM0 + index; \
- case TYPE_MVSIBY: \
- return prefix##_YMM0 + index; \
- case TYPE_MVSIBZ: \
- return prefix##_ZMM0 + index; \
- } \
- }
-
-/*
- * fixup*Value - Consults an operand type to determine the meaning of the
- * reg or R/M field. If the operand is an XMM operand, for example, an
- * operand would be XMM0 instead of AX, which readModRM() would otherwise
- * misinterpret it as.
- *
- * @param insn - The instruction containing the operand.
- * @param type - The operand type.
- * @param index - The existing value of the field as reported by readModRM().
- * @param valid - The address of a uint8_t. The target is set to 1 if the
- * field is valid for the register class; 0 if not.
- * @return - The proper value.
- */
-GENERIC_FIXUP_FUNC(fixupRegValue, insn->regBase, MODRM_REG, 0x1f)
-GENERIC_FIXUP_FUNC(fixupRMValue, insn->eaRegBase, EA_REG, 0xf)
-
-/*
- * fixupReg - Consults an operand specifier to determine which of the
- * fixup*Value functions to use in correcting readModRM()'ss interpretation.
- *
- * @param insn - See fixup*Value().
- * @param op - The operand specifier.
- * @return - 0 if fixup was successful; -1 if the register returned was
- * invalid for its class.
- */
-static int fixupReg(struct InternalInstruction *insn,
- const struct OperandSpecifier *op) {
- uint8_t valid;
-
- dbgprintf(insn, "fixupReg()");
-
- switch ((OperandEncoding)op->encoding) {
- default:
- debug("Expected a REG or R/M encoding in fixupReg");
- return -1;
- case ENCODING_VVVV:
- insn->vvvv = (Reg)fixupRegValue(insn,
- (OperandType)op->type,
- insn->vvvv,
- &valid);
- if (!valid)
- return -1;
- break;
- case ENCODING_REG:
- insn->reg = (Reg)fixupRegValue(insn,
- (OperandType)op->type,
- insn->reg - insn->regBase,
- &valid);
- if (!valid)
- return -1;
- break;
- CASE_ENCODING_RM:
- if (insn->eaBase >= insn->eaRegBase) {
- insn->eaBase = (EABase)fixupRMValue(insn,
- (OperandType)op->type,
- insn->eaBase - insn->eaRegBase,
- &valid);
- if (!valid)
- return -1;
- }
- break;
- }
-
- return 0;
-}
-
-/*
- * readOpcodeRegister - Reads an operand from the opcode field of an
- * instruction and interprets it appropriately given the operand width.
- * Handles AddRegFrm instructions.
- *
- * @param insn - the instruction whose opcode field is to be read.
- * @param size - The width (in bytes) of the register being specified.
- * 1 means AL and friends, 2 means AX, 4 means EAX, and 8 means
- * RAX.
- * @return - 0 on success; nonzero otherwise.
- */
-static int readOpcodeRegister(struct InternalInstruction* insn, uint8_t size) {
- dbgprintf(insn, "readOpcodeRegister()");
-
- if (size == 0)
- size = insn->registerSize;
-
- switch (size) {
- case 1:
- insn->opcodeRegister = (Reg)(MODRM_REG_AL + ((bFromREX(insn->rexPrefix) << 3)
- | (insn->opcode & 7)));
- if (insn->rexPrefix &&
- insn->opcodeRegister >= MODRM_REG_AL + 0x4 &&
- insn->opcodeRegister < MODRM_REG_AL + 0x8) {
- insn->opcodeRegister = (Reg)(MODRM_REG_SPL
- + (insn->opcodeRegister - MODRM_REG_AL - 4));
- }
-
- break;
- case 2:
- insn->opcodeRegister = (Reg)(MODRM_REG_AX
- + ((bFromREX(insn->rexPrefix) << 3)
- | (insn->opcode & 7)));
- break;
- case 4:
- insn->opcodeRegister = (Reg)(MODRM_REG_EAX
- + ((bFromREX(insn->rexPrefix) << 3)
- | (insn->opcode & 7)));
- break;
- case 8:
- insn->opcodeRegister = (Reg)(MODRM_REG_RAX
- + ((bFromREX(insn->rexPrefix) << 3)
- | (insn->opcode & 7)));
- break;
- }
-
- return 0;
-}
-
-/*
- * readImmediate - Consumes an immediate operand from an instruction, given the
- * desired operand size.
- *
- * @param insn - The instruction whose operand is to be read.
- * @param size - The width (in bytes) of the operand.
- * @return - 0 if the immediate was successfully consumed; nonzero
- * otherwise.
- */
-static int readImmediate(struct InternalInstruction* insn, uint8_t size) {
- uint8_t imm8;
- uint16_t imm16;
- uint32_t imm32;
- uint64_t imm64;
-
- dbgprintf(insn, "readImmediate()");
-
- if (insn->numImmediatesConsumed == 2) {
- debug("Already consumed two immediates");
- return -1;
- }
-
- if (size == 0)
- size = insn->immediateSize;
- else
- insn->immediateSize = size;
- insn->immediateOffset = insn->readerCursor - insn->startLocation;
-
- switch (size) {
- case 1:
- if (consumeByte(insn, &imm8))
- return -1;
- insn->immediates[insn->numImmediatesConsumed] = imm8;
- break;
- case 2:
- if (consumeUInt16(insn, &imm16))
- return -1;
- insn->immediates[insn->numImmediatesConsumed] = imm16;
- break;
- case 4:
- if (consumeUInt32(insn, &imm32))
- return -1;
- insn->immediates[insn->numImmediatesConsumed] = imm32;
- break;
- case 8:
- if (consumeUInt64(insn, &imm64))
- return -1;
- insn->immediates[insn->numImmediatesConsumed] = imm64;
- break;
- }
-
- insn->numImmediatesConsumed++;
-
- return 0;
-}
-
-/*
- * readVVVV - Consumes vvvv from an instruction if it has a VEX prefix.
- *
- * @param insn - The instruction whose operand is to be read.
- * @return - 0 if the vvvv was successfully consumed; nonzero
- * otherwise.
- */
-static int readVVVV(struct InternalInstruction* insn) {
- dbgprintf(insn, "readVVVV()");
-
- int vvvv;
- if (insn->vectorExtensionType == TYPE_EVEX)
- vvvv = (v2FromEVEX4of4(insn->vectorExtensionPrefix[3]) << 4 |
- vvvvFromEVEX3of4(insn->vectorExtensionPrefix[2]));
- else if (insn->vectorExtensionType == TYPE_VEX_3B)
- vvvv = vvvvFromVEX3of3(insn->vectorExtensionPrefix[2]);
- else if (insn->vectorExtensionType == TYPE_VEX_2B)
- vvvv = vvvvFromVEX2of2(insn->vectorExtensionPrefix[1]);
- else if (insn->vectorExtensionType == TYPE_XOP)
- vvvv = vvvvFromXOP3of3(insn->vectorExtensionPrefix[2]);
- else
- return -1;
-
- if (insn->mode != MODE_64BIT)
- vvvv &= 0xf; // Can only clear bit 4. Bit 3 must be cleared later.
-
- insn->vvvv = static_cast<Reg>(vvvv);
- return 0;
-}
-
-/*
- * readMaskRegister - Reads an mask register from the opcode field of an
- * instruction.
- *
- * @param insn - The instruction whose opcode field is to be read.
- * @return - 0 on success; nonzero otherwise.
- */
-static int readMaskRegister(struct InternalInstruction* insn) {
- dbgprintf(insn, "readMaskRegister()");
-
- if (insn->vectorExtensionType != TYPE_EVEX)
- return -1;
-
- insn->writemask =
- static_cast<Reg>(aaaFromEVEX4of4(insn->vectorExtensionPrefix[3]));
- 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 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 (const auto &Op : x86OperandSets[insn->spec->operands]) {
- switch (Op.encoding) {
- case ENCODING_NONE:
- case ENCODING_SI:
- case ENCODING_DI:
- break;
- CASE_ENCODING_VSIB:
- // VSIB can use the V2 bit so check only the other bits.
- if (needVVVV)
- needVVVV = hasVVVV & ((insn->vvvv & 0xf) != 0);
- if (readModRM(insn))
- return -1;
-
- // Reject if SIB wasn't used.
- if (insn->eaBase != EA_BASE_sib && insn->eaBase != EA_BASE_sib64)
- return -1;
-
- // If sibIndex was set to SIB_INDEX_NONE, index offset is 4.
- if (insn->sibIndex == SIB_INDEX_NONE)
- insn->sibIndex = (SIBIndex)(insn->sibIndexBase + 4);
-
- // If EVEX.v2 is set this is one of the 16-31 registers.
- if (insn->vectorExtensionType == TYPE_EVEX && insn->mode == MODE_64BIT &&
- v2FromEVEX4of4(insn->vectorExtensionPrefix[3]))
- insn->sibIndex = (SIBIndex)(insn->sibIndex + 16);
-
- // Adjust the index register to the correct size.
- switch ((OperandType)Op.type) {
- default:
- debug("Unhandled VSIB index type");
- return -1;
- case TYPE_MVSIBX:
- insn->sibIndex = (SIBIndex)(SIB_INDEX_XMM0 +
- (insn->sibIndex - insn->sibIndexBase));
- break;
- case TYPE_MVSIBY:
- insn->sibIndex = (SIBIndex)(SIB_INDEX_YMM0 +
- (insn->sibIndex - insn->sibIndexBase));
- break;
- case TYPE_MVSIBZ:
- insn->sibIndex = (SIBIndex)(SIB_INDEX_ZMM0 +
- (insn->sibIndex - insn->sibIndexBase));
- break;
- }
-
- // Apply the AVX512 compressed displacement scaling factor.
- if (Op.encoding != ENCODING_REG && insn->eaDisplacement == EA_DISP_8)
- insn->displacement *= 1 << (Op.encoding - ENCODING_VSIB);
- break;
- case ENCODING_REG:
- CASE_ENCODING_RM:
- if (readModRM(insn))
- return -1;
- if (fixupReg(insn, &Op))
- return -1;
- // Apply the AVX512 compressed displacement scaling factor.
- if (Op.encoding != ENCODING_REG && insn->eaDisplacement == EA_DISP_8)
- insn->displacement *= 1 << (Op.encoding - ENCODING_RM);
- break;
- 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 (Op.type == TYPE_XMM || Op.type == TYPE_YMM)
- 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_IRC:
- insn->RC = (l2FromEVEX4of4(insn->vectorExtensionPrefix[3]) << 1) |
- lFromEVEX4of4(insn->vectorExtensionPrefix[3]);
- 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_CC:
- insn->immediates[1] = insn->opcode & 0xf;
- break;
- case ENCODING_FP:
- break;
- case ENCODING_VVVV:
- needVVVV = 0; /* Mark that we have found a VVVV operand. */
- if (!hasVVVV)
- return -1;
- if (insn->mode != MODE_64BIT)
- insn->vvvv = static_cast<Reg>(insn->vvvv & 0x7);
- if (fixupReg(insn, &Op))
- return -1;
- break;
- case ENCODING_WRITEMASK:
- if (readMaskRegister(insn))
- 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;
-}
-
-/*
- * decodeInstruction - Reads and interprets a full instruction provided by the
- * user.
- *
- * @param insn - A pointer to the instruction to be populated. Must be
- * pre-allocated.
- * @param reader - The function to be used to read the instruction's bytes.
- * @param readerArg - A generic argument to be passed to the reader to store
- * any internal state.
- * @param logger - If non-NULL, the function to be used to write log messages
- * and warnings.
- * @param loggerArg - A generic argument to be passed to the logger to store
- * any internal state.
- * @param startLoc - The address (in the reader's address space) of the first
- * byte in the instruction.
- * @param mode - The mode (real mode, IA-32e, or IA-32e in 64-bit mode) to
- * decode the instruction in.
- * @return - 0 if the instruction's memory could be read; nonzero if
- * not.
- */
-int llvm::X86Disassembler::decodeInstruction(
- struct InternalInstruction *insn, byteReader_t reader,
- const void *readerArg, dlog_t logger, void *loggerArg, const void *miiArg,
- uint64_t startLoc, DisassemblerMode mode) {
- memset(insn, 0, sizeof(struct InternalInstruction));
-
- insn->reader = reader;
- insn->readerArg = readerArg;
- insn->dlog = logger;
- insn->dlogArg = loggerArg;
- insn->startLocation = startLoc;
- insn->readerCursor = startLoc;
- insn->mode = mode;
- insn->numImmediatesConsumed = 0;
-
- if (readPrefixes(insn) ||
- readOpcode(insn) ||
- getID(insn, miiArg) ||
- insn->instructionID == 0 ||
- readOperands(insn))
- return -1;
-
- insn->operands = x86OperandSets[insn->spec->operands];
-
- insn->length = insn->readerCursor - insn->startLocation;
-
- dbgprintf(insn, "Read from 0x%llx to 0x%llx: length %zu",
- startLoc, insn->readerCursor, insn->length);
-
- if (insn->length > 15)
- dbgprintf(insn, "Instruction exceeds 15-byte limit");
-
- return 0;
-}
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-07 19:28:29 +0000