//===- X86DisassemblerTables.cpp - Disassembler tables ----------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is part of the X86 Disassembler Emitter.
// It contains the implementation of the disassembler tables.
// Documentation for the disassembler emitter in general can be found in
// X86DisasemblerEmitter.h.
//
//===----------------------------------------------------------------------===//
#include "X86DisassemblerShared.h"
#include "X86DisassemblerTables.h"
#include "llvm/TableGen/TableGenBackend.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Format.h"
using namespace llvm;
using namespace X86Disassembler;
/// inheritsFrom - Indicates whether all instructions in one class also belong
/// to another class.
///
/// @param child - The class that may be the subset
/// @param parent - The class that may be the superset
/// @return - True if child is a subset of parent, false otherwise.
static inline bool inheritsFrom(InstructionContext child,
InstructionContext parent,
bool VEX_LIG = false) {
if (child == parent)
return true;
switch (parent) {
case IC:
return(inheritsFrom(child, IC_64BIT) ||
inheritsFrom(child, IC_OPSIZE) ||
inheritsFrom(child, IC_XD) ||
inheritsFrom(child, IC_XS));
case IC_64BIT:
return(inheritsFrom(child, IC_64BIT_REXW) ||
inheritsFrom(child, IC_64BIT_OPSIZE) ||
inheritsFrom(child, IC_64BIT_XD) ||
inheritsFrom(child, IC_64BIT_XS));
case IC_OPSIZE:
return inheritsFrom(child, IC_64BIT_OPSIZE);
case IC_XD:
return inheritsFrom(child, IC_64BIT_XD);
case IC_XS:
return inheritsFrom(child, IC_64BIT_XS);
case IC_XD_OPSIZE:
return inheritsFrom(child, IC_64BIT_XD_OPSIZE);
case IC_XS_OPSIZE:
return inheritsFrom(child, IC_64BIT_XS_OPSIZE);
case IC_64BIT_REXW:
return(inheritsFrom(child, IC_64BIT_REXW_XS) ||
inheritsFrom(child, IC_64BIT_REXW_XD) ||
inheritsFrom(child, IC_64BIT_REXW_OPSIZE));
case IC_64BIT_OPSIZE:
return(inheritsFrom(child, IC_64BIT_REXW_OPSIZE));
case IC_64BIT_XD:
return(inheritsFrom(child, IC_64BIT_REXW_XD));
case IC_64BIT_XS:
return(inheritsFrom(child, IC_64BIT_REXW_XS));
case IC_64BIT_XD_OPSIZE:
case IC_64BIT_XS_OPSIZE:
return false;
case IC_64BIT_REXW_XD:
case IC_64BIT_REXW_XS:
case IC_64BIT_REXW_OPSIZE:
return false;
case IC_VEX:
return inheritsFrom(child, IC_VEX_W) ||
(VEX_LIG && inheritsFrom(child, IC_VEX_L));
case IC_VEX_XS:
return inheritsFrom(child, IC_VEX_W_XS) ||
(VEX_LIG && inheritsFrom(child, IC_VEX_L_XS));
case IC_VEX_XD:
return inheritsFrom(child, IC_VEX_W_XD) ||
(VEX_LIG && inheritsFrom(child, IC_VEX_L_XD));
case IC_VEX_OPSIZE:
return inheritsFrom(child, IC_VEX_W_OPSIZE) ||
(VEX_LIG && inheritsFrom(child, IC_VEX_L_OPSIZE));
case IC_VEX_W:
case IC_VEX_W_XS:
case IC_VEX_W_XD:
case IC_VEX_W_OPSIZE:
return false;
case IC_VEX_L:
case IC_VEX_L_XS:
case IC_VEX_L_XD:
case IC_VEX_L_OPSIZE:
return false;
default:
llvm_unreachable("Unknown instruction class");
return false;
}
}
/// outranks - Indicates whether, if an instruction has two different applicable
/// classes, which class should be preferred when performing decode. This
/// imposes a total ordering (ties are resolved toward "lower")
///
/// @param upper - The class that may be preferable
/// @param lower - The class that may be less preferable
/// @return - True if upper is to be preferred, false otherwise.
static inline bool outranks(InstructionContext upper,
InstructionContext lower) {
assert(upper < IC_max);
assert(lower < IC_max);
#define ENUM_ENTRY(n, r, d) r,
static int ranks[IC_max] = {
INSTRUCTION_CONTEXTS
};
#undef ENUM_ENTRY
return (ranks[upper] > ranks[lower]);
}
/// stringForContext - Returns a string containing the name of a particular
/// InstructionContext, usually for diagnostic purposes.
///
/// @param insnContext - The instruction class to transform to a string.
/// @return - A statically-allocated string constant that contains the
/// name of the instruction class.
static inline const char* stringForContext(InstructionContext insnContext) {
switch (insnContext) {
default:
llvm_unreachable("Unhandled instruction class");
#define ENUM_ENTRY(n, r, d) case n: return #n; break;
INSTRUCTION_CONTEXTS
#undef ENUM_ENTRY
}
return 0;
}
/// stringForOperandType - Like stringForContext, but for OperandTypes.
static inline const char* stringForOperandType(OperandType type) {
switch (type) {
default:
llvm_unreachable("Unhandled type");
#define ENUM_ENTRY(i, d) case i: return #i;
TYPES
#undef ENUM_ENTRY
}
}
/// stringForOperandEncoding - like stringForContext, but for
/// OperandEncodings.
static inline const char* stringForOperandEncoding(OperandEncoding encoding) {
switch (encoding) {
default:
llvm_unreachable("Unhandled encoding");
#define ENUM_ENTRY(i, d) case i: return #i;
ENCODINGS
#undef ENUM_ENTRY
}
}
void DisassemblerTables::emitOneID(raw_ostream &o,
uint32_t &i,
InstrUID id,
bool addComma) const {
if (id)
o.indent(i * 2) << format("0x%hx", id);
else
o.indent(i * 2) << 0;
if (addComma)
o << ", ";
else
o << " ";
o << "/* ";
o << InstructionSpecifiers[id].name;
o << "*/";
o << "\n";
}
/// emitEmptyTable - Emits the modRMEmptyTable, which is used as a ID table by
/// all ModR/M decisions for instructions that are invalid for all possible
/// ModR/M byte values.
///
/// @param o - The output stream on which to emit the table.
/// @param i - The indentation level for that output stream.
static void emitEmptyTable(raw_ostream &o, uint32_t &i)
{
o.indent(i * 2) << "static const InstrUID modRMEmptyTable[1] = { 0 };\n";
o << "\n";
}
/// getDecisionType - Determines whether a ModRM decision with 255 entries can
/// be compacted by eliminating redundant information.
///
/// @param decision - The decision to be compacted.
/// @return - The compactest available representation for the decision.
static ModRMDecisionType getDecisionType(ModRMDecision &decision)
{
bool satisfiesOneEntry = true;
bool satisfiesSplitRM = true;
uint16_t index;
for (index = 0; index < 256; ++index) {
if (decision.instructionIDs[index] != decision.instructionIDs[0])
satisfiesOneEntry = false;
if (((index & 0xc0) == 0xc0) &&
(decision.instructionIDs[index] != decision.instructionIDs[0xc0]))
satisfiesSplitRM = false;
if (((index & 0xc0) != 0xc0) &&
(decision.instructionIDs[index] != decision.instructionIDs[0x00]))
satisfiesSplitRM = false;
}
if (satisfiesOneEntry)
return MODRM_ONEENTRY;
if (satisfiesSplitRM)
return MODRM_SPLITRM;
return MODRM_FULL;
}
/// stringForDecisionType - Returns a statically-allocated string corresponding
/// to a particular decision type.
///
/// @param dt - The decision type.
/// @return - A pointer to the statically-allocated string (e.g.,
/// "MODRM_ONEENTRY" for MODRM_ONEENTRY).
static const char* stringForDecisionType(ModRMDecisionType dt)
{
#define ENUM_ENTRY(n) case n: return #n;
switch (dt) {
default:
llvm_unreachable("Unknown decision type");
MODRMTYPES
};
#undef ENUM_ENTRY
}
/// stringForModifierType - Returns a statically-allocated string corresponding
/// to an opcode modifier type.
///
/// @param mt - The modifier type.
/// @return - A pointer to the statically-allocated string (e.g.,
/// "MODIFIER_NONE" for MODIFIER_NONE).
static const char* stringForModifierType(ModifierType mt)
{
#define ENUM_ENTRY(n) case n: return #n;
switch(mt) {
default:
llvm_unreachable("Unknown modifier type");
MODIFIER_TYPES
};
#undef ENUM_ENTRY
}
DisassemblerTables::DisassemblerTables() {
unsigned i;
for (i = 0; i < array_lengthof(Tables); i++) {
Tables[i] = new ContextDecision;
memset(Tables[i], 0, sizeof(ContextDecision));
}
HasConflicts = false;
}
DisassemblerTables::~DisassemblerTables() {
unsigned i;
for (i = 0; i < array_lengthof(Tables); i++)
delete Tables[i];
}
void DisassemblerTables::emitModRMDecision(raw_ostream &o1,
raw_ostream &o2,
uint32_t &i1,
uint32_t &i2,
ModRMDecision &decision)
const {
static uint64_t sTableNumber = 0;
uint64_t thisTableNumber = sTableNumber;
ModRMDecisionType dt = getDecisionType(decision);
uint16_t index;
if (dt == MODRM_ONEENTRY && decision.instructionIDs[0] == 0)
{
o2.indent(i2) << "{ /* ModRMDecision */" << "\n";
i2++;
o2.indent(i2) << stringForDecisionType(dt) << "," << "\n";
o2.indent(i2) << "modRMEmptyTable";
i2--;
o2.indent(i2) << "}";
return;
}
o1.indent(i1) << "static const InstrUID modRMTable" << thisTableNumber;
switch (dt) {
default:
llvm_unreachable("Unknown decision type");
case MODRM_ONEENTRY:
o1 << "[1]";
break;
case MODRM_SPLITRM:
o1 << "[2]";
break;
case MODRM_FULL:
o1 << "[256]";
break;
}
o1 << " = {" << "\n";
i1++;
switch (dt) {
default:
llvm_unreachable("Unknown decision type");
case MODRM_ONEENTRY:
emitOneID(o1, i1, decision.instructionIDs[0], false);
break;
case MODRM_SPLITRM:
emitOneID(o1, i1, decision.instructionIDs[0x00], true); // mod = 0b00
emitOneID(o1, i1, decision.instructionIDs[0xc0], false); // mod = 0b11
break;
case MODRM_FULL:
for (index = 0; index < 256; ++index)
emitOneID(o1, i1, decision.instructionIDs[index], index < 255);
break;
}
i1--;
o1.indent(i1) << "};" << "\n";
o1 << "\n";
o2.indent(i2) << "{ /* struct ModRMDecision */" << "\n";
i2++;
o2.indent(i2) << stringForDecisionType(dt) << "," << "\n";
o2.indent(i2) << "modRMTable" << sTableNumber << "\n";
i2--;
o2.indent(i2) << "}";
++sTableNumber;
}
void DisassemblerTables::emitOpcodeDecision(
raw_ostream &o1,
raw_ostream &o2,
uint32_t &i1,
uint32_t &i2,
OpcodeDecision &decision) const {
uint16_t index;
o2.indent(i2) << "{ /* struct OpcodeDecision */" << "\n";
i2++;
o2.indent(i2) << "{" << "\n";
i2++;
for (index = 0; index < 256; ++index) {
o2.indent(i2);
o2 << "/* 0x" << format("%02hhx", index) << " */" << "\n";
emitModRMDecision(o1, o2, i1, i2, decision.modRMDecisions[index]);
if (index < 255)
o2 << ",";
o2 << "\n";
}
i2--;
o2.indent(i2) << "}" << "\n";
i2--;
o2.indent(i2) << "}" << "\n";
}
void DisassemblerTables::emitContextDecision(
raw_ostream &o1,
raw_ostream &o2,
uint32_t &i1,
uint32_t &i2,
ContextDecision &decision,
const char* name) const {
o2.indent(i2) << "static const struct ContextDecision " << name << " = {\n";
i2++;
o2.indent(i2) << "{ /* opcodeDecisions */" << "\n";
i2++;
unsigned index;
for (index = 0; index < IC_max; ++index) {
o2.indent(i2) << "/* ";
o2 << stringForContext((InstructionContext)index);
o2 << " */";
o2 << "\n";
emitOpcodeDecision(o1, o2, i1, i2, decision.opcodeDecisions[index]);
if (index + 1 < IC_max)
o2 << ", ";
}
i2--;
o2.indent(i2) << "}" << "\n";
i2--;
o2.indent(i2) << "};" << "\n";
}
void DisassemblerTables::emitInstructionInfo(raw_ostream &o, uint32_t &i)
const {
o.indent(i * 2) << "static const struct InstructionSpecifier ";
o << INSTRUCTIONS_STR "[" << InstructionSpecifiers.size() << "] = {\n";
i++;
uint16_t numInstructions = InstructionSpecifiers.size();
uint16_t index, operandIndex;
for (index = 0; index < numInstructions; ++index) {
o.indent(i * 2) << "{ /* " << index << " */" << "\n";
i++;
o.indent(i * 2) <<
stringForModifierType(InstructionSpecifiers[index].modifierType);
o << "," << "\n";
o.indent(i * 2) << "0x";
o << format("%02hhx", (uint16_t)InstructionSpecifiers[index].modifierBase);
o << "," << "\n";
o.indent(i * 2) << "{" << "\n";
i++;
for (operandIndex = 0; operandIndex < X86_MAX_OPERANDS; ++operandIndex) {
o.indent(i * 2) << "{ ";
o << stringForOperandEncoding(InstructionSpecifiers[index]
.operands[operandIndex]
.encoding);
o << ", ";
o << stringForOperandType(InstructionSpecifiers[index]
.operands[operandIndex]
.type);
o << " }";
if (operandIndex < X86_MAX_OPERANDS - 1)
o << ",";
o << "\n";
}
i--;
o.indent(i * 2) << "}," << "\n";
o.indent(i * 2) << "\"" << InstructionSpecifiers[index].name << "\"";
o << "\n";
i--;
o.indent(i * 2) << "}";
if (index + 1 < numInstructions)
o << ",";
o << "\n";
}
i--;
o.indent(i * 2) << "};" << "\n";
}
void DisassemblerTables::emitContextTable(raw_ostream &o, uint32_t &i) const {
uint16_t index;
o.indent(i * 2) << "static const InstructionContext " CONTEXTS_STR
"[256] = {\n";
i++;
for (index = 0; index < 256; ++index) {
o.indent(i * 2);
if ((index & ATTR_VEXL) && (index & ATTR_OPSIZE))
o << "IC_VEX_L_OPSIZE";
else if ((index & ATTR_VEXL) && (index & ATTR_XD))
o << "IC_VEX_L_XD";
else if ((index & ATTR_VEXL) && (index & ATTR_XS))
o << "IC_VEX_L_XS";
else if ((index & ATTR_VEX) && (index & ATTR_REXW) && (index & ATTR_OPSIZE))
o << "IC_VEX_W_OPSIZE";
else if ((index & ATTR_VEX) && (index & ATTR_REXW) && (index & ATTR_XD))
o << "IC_VEX_W_XD";
else if ((index & ATTR_VEX) && (index & ATTR_REXW) && (index & ATTR_XS))
o << "IC_VEX_W_XS";
else if (index & ATTR_VEXL)
o << "IC_VEX_L";
else if ((index & ATTR_VEX) && (index & ATTR_REXW))
o << "IC_VEX_W";
else if ((index & ATTR_VEX) && (index & ATTR_OPSIZE))
o << "IC_VEX_OPSIZE";
else if ((index & ATTR_VEX) && (index & ATTR_XD))
o << "IC_VEX_XD";
else if ((index & ATTR_VEX) && (index & ATTR_XS))
o << "IC_VEX_XS";
else if (index & ATTR_VEX)
o << "IC_VEX";
else if ((index & ATTR_64BIT) && (index & ATTR_REXW) && (index & ATTR_XS))
o << "IC_64BIT_REXW_XS";
else if ((index & ATTR_64BIT) && (index & ATTR_REXW) && (index & ATTR_XD))
o << "IC_64BIT_REXW_XD";
else if ((index & ATTR_64BIT) && (index & ATTR_REXW) &&
(index & ATTR_OPSIZE))
o << "IC_64BIT_REXW_OPSIZE";
else if ((index & ATTR_64BIT) && (index & ATTR_XD) && (index & ATTR_OPSIZE))
o << "IC_64BIT_XD_OPSIZE";
else if ((index & ATTR_64BIT) && (index & ATTR_XS) && (index & ATTR_OPSIZE))
o << "IC_64BIT_XS_OPSIZE";
else if ((index & ATTR_64BIT) && (index & ATTR_XS))
o << "IC_64BIT_XS";
else if ((index & ATTR_64BIT) && (index & ATTR_XD))
o << "IC_64BIT_XD";
else if ((index & ATTR_64BIT) && (index & ATTR_OPSIZE))
o << "IC_64BIT_OPSIZE";
else if ((index & ATTR_64BIT) && (index & ATTR_REXW))
o << "IC_64BIT_REXW";
else if ((index & ATTR_64BIT))
o << "IC_64BIT";
else if ((index & ATTR_XS) && (index & ATTR_OPSIZE))
o << "IC_XS_OPSIZE";
else if ((index & ATTR_XD) && (index & ATTR_OPSIZE))
o << "IC_XD_OPSIZE";
else if (index & ATTR_XS)
o << "IC_XS";
else if (index & ATTR_XD)
o << "IC_XD";
else if (index & ATTR_OPSIZE)
o << "IC_OPSIZE";
else
o << "IC";
if (index < 255)
o << ",";
else
o << " ";
o << " /* " << index << " */";
o << "\n";
}
i--;
o.indent(i * 2) << "};" << "\n";
}
void DisassemblerTables::emitContextDecisions(raw_ostream &o1,
raw_ostream &o2,
uint32_t &i1,
uint32_t &i2)
const {
emitContextDecision(o1, o2, i1, i2, *Tables[0], ONEBYTE_STR);
emitContextDecision(o1, o2, i1, i2, *Tables[1], TWOBYTE_STR);
emitContextDecision(o1, o2, i1, i2, *Tables[2], THREEBYTE38_STR);
emitContextDecision(o1, o2, i1, i2, *Tables[3], THREEBYTE3A_STR);
emitContextDecision(o1, o2, i1, i2, *Tables[4], THREEBYTEA6_STR);
emitContextDecision(o1, o2, i1, i2, *Tables[5], THREEBYTEA7_STR);
}
void DisassemblerTables::emit(raw_ostream &o) const {
uint32_t i1 = 0;
uint32_t i2 = 0;
std::string s1;
std::string s2;
raw_string_ostream o1(s1);
raw_string_ostream o2(s2);
emitInstructionInfo(o, i2);
o << "\n";
emitContextTable(o, i2);
o << "\n";
emitEmptyTable(o1, i1);
emitContextDecisions(o1, o2, i1, i2);
o << o1.str();
o << "\n";
o << o2.str();
o << "\n";
o << "\n";
}
void DisassemblerTables::setTableFields(ModRMDecision &decision,
const ModRMFilter &filter,
InstrUID uid,
uint8_t opcode) {
unsigned index;
for (index = 0; index < 256; ++index) {
if (filter.accepts(index)) {
if (decision.instructionIDs[index] == uid)
continue;
if (decision.instructionIDs[index] != 0) {
InstructionSpecifier &newInfo =
InstructionSpecifiers[uid];
InstructionSpecifier &previousInfo =
InstructionSpecifiers[decision.instructionIDs[index]];
if(newInfo.filtered)
continue; // filtered instructions get lowest priority
if(previousInfo.name == "NOOP" && (newInfo.name == "XCHG16ar" ||
newInfo.name == "XCHG32ar" ||
newInfo.name == "XCHG32ar64" ||
newInfo.name == "XCHG64ar"))
continue; // special case for XCHG*ar and NOOP
if (outranks(previousInfo.insnContext, newInfo.insnContext))
continue;
if (previousInfo.insnContext == newInfo.insnContext &&
!previousInfo.filtered) {
errs() << "Error: Primary decode conflict: ";
errs() << newInfo.name << " would overwrite " << previousInfo.name;
errs() << "\n";
errs() << "ModRM " << index << "\n";
errs() << "Opcode " << (uint16_t)opcode << "\n";
errs() << "Context " << stringForContext(newInfo.insnContext) << "\n";
HasConflicts = true;
}
}
decision.instructionIDs[index] = uid;
}
}
}
void DisassemblerTables::setTableFields(OpcodeType type,
InstructionContext insnContext,
uint8_t opcode,
const ModRMFilter &filter,
InstrUID uid,
bool is32bit,
bool ignoresVEX_L) {
unsigned index;
ContextDecision &decision = *Tables[type];
for (index = 0; index < IC_max; ++index) {
if (is32bit && inheritsFrom((InstructionContext)index, IC_64BIT))
continue;
if (inheritsFrom((InstructionContext)index,
InstructionSpecifiers[uid].insnContext, ignoresVEX_L))
setTableFields(decision.opcodeDecisions[index].modRMDecisions[opcode],
filter,
uid,
opcode);
}
}