FixedLenDecoderEmitter.cpp [plain text]
#define DEBUG_TYPE "decoder-emitter"
#include "CodeGenTarget.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/MC/MCFixedLenDisassembler.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Support/LEB128.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/TableGen/Error.h"
#include "llvm/TableGen/Record.h"
#include "llvm/TableGen/TableGenBackend.h"
#include <map>
#include <string>
#include <vector>
using namespace llvm;
namespace {
struct EncodingField {
unsigned Base, Width, Offset;
EncodingField(unsigned B, unsigned W, unsigned O)
: Base(B), Width(W), Offset(O) { }
};
struct OperandInfo {
std::vector<EncodingField> Fields;
std::string Decoder;
OperandInfo(std::string D)
: Decoder(D) { }
void addField(unsigned Base, unsigned Width, unsigned Offset) {
Fields.push_back(EncodingField(Base, Width, Offset));
}
unsigned numFields() const { return Fields.size(); }
typedef std::vector<EncodingField>::const_iterator const_iterator;
const_iterator begin() const { return Fields.begin(); }
const_iterator end() const { return Fields.end(); }
};
typedef std::vector<uint8_t> DecoderTable;
typedef uint32_t DecoderFixup;
typedef std::vector<DecoderFixup> FixupList;
typedef std::vector<FixupList> FixupScopeList;
typedef SetVector<std::string> PredicateSet;
typedef SetVector<std::string> DecoderSet;
struct DecoderTableInfo {
DecoderTable Table;
FixupScopeList FixupStack;
PredicateSet Predicates;
DecoderSet Decoders;
};
}
namespace {
class FixedLenDecoderEmitter {
const std::vector<const CodeGenInstruction*> *NumberedInstructions;
public:
FixedLenDecoderEmitter(RecordKeeper &R,
std::string PredicateNamespace,
std::string GPrefix = "if (",
std::string GPostfix = " == MCDisassembler::Fail)"
" return MCDisassembler::Fail;",
std::string ROK = "MCDisassembler::Success",
std::string RFail = "MCDisassembler::Fail",
std::string L = "") :
Target(R),
PredicateNamespace(PredicateNamespace),
GuardPrefix(GPrefix), GuardPostfix(GPostfix),
ReturnOK(ROK), ReturnFail(RFail), Locals(L) {}
void emitTable(formatted_raw_ostream &o, DecoderTable &Table,
unsigned Indentation, unsigned BitWidth,
StringRef Namespace) const;
void emitPredicateFunction(formatted_raw_ostream &OS,
PredicateSet &Predicates,
unsigned Indentation) const;
void emitDecoderFunction(formatted_raw_ostream &OS,
DecoderSet &Decoders,
unsigned Indentation) const;
void run(raw_ostream &o);
private:
CodeGenTarget Target;
public:
std::string PredicateNamespace;
std::string GuardPrefix, GuardPostfix;
std::string ReturnOK, ReturnFail;
std::string Locals;
};
}
typedef enum {
BIT_TRUE, BIT_FALSE, BIT_UNSET, BIT_UNFILTERED } bit_value_t;
static bool ValueSet(bit_value_t V) {
return (V == BIT_TRUE || V == BIT_FALSE);
}
static bool ValueNotSet(bit_value_t V) {
return (V == BIT_UNSET);
}
static int Value(bit_value_t V) {
return ValueNotSet(V) ? -1 : (V == BIT_FALSE ? 0 : 1);
}
static bit_value_t bitFromBits(const BitsInit &bits, unsigned index) {
if (BitInit *bit = dyn_cast<BitInit>(bits.getBit(index)))
return bit->getValue() ? BIT_TRUE : BIT_FALSE;
return BIT_UNSET;
}
static void dumpBits(raw_ostream &o, const BitsInit &bits) {
for (unsigned index = bits.getNumBits(); index > 0; --index) {
switch (bitFromBits(bits, index - 1)) {
case BIT_TRUE:
o << "1";
break;
case BIT_FALSE:
o << "0";
break;
case BIT_UNSET:
o << "_";
break;
default:
llvm_unreachable("unexpected return value from bitFromBits");
}
}
}
static BitsInit &getBitsField(const Record &def, const char *str) {
BitsInit *bits = def.getValueAsBitsInit(str);
return *bits;
}
namespace {
class FilterChooser;
}
typedef std::vector<bit_value_t> insn_t;
namespace {
class Filter {
protected:
const FilterChooser *Owner; unsigned StartBit; unsigned NumBits; bool Mixed;
std::map<uint64_t, std::vector<unsigned> > FilteredInstructions;
std::vector<unsigned> VariableInstructions;
std::map<unsigned, const FilterChooser*> FilterChooserMap;
unsigned NumFiltered;
unsigned LastOpcFiltered;
public:
unsigned getNumFiltered() const { return NumFiltered; }
unsigned getSingletonOpc() const {
assert(NumFiltered == 1);
return LastOpcFiltered;
}
const FilterChooser &getVariableFC() const {
assert(NumFiltered == 1);
assert(FilterChooserMap.size() == 1);
return *(FilterChooserMap.find((unsigned)-1)->second);
}
Filter(const Filter &f);
Filter(FilterChooser &owner, unsigned startBit, unsigned numBits, bool mixed);
~Filter();
void recurse();
void emitTableEntry(DecoderTableInfo &TableInfo) const;
unsigned usefulness() const;
}; }
typedef enum {
ATTR_NONE,
ATTR_FILTERED,
ATTR_ALL_SET,
ATTR_ALL_UNSET,
ATTR_MIXED
} bitAttr_t;
namespace {
class FilterChooser {
protected:
friend class Filter;
const std::vector<const CodeGenInstruction*> &AllInstructions;
const std::vector<unsigned> &Opcodes;
const std::map<unsigned, std::vector<OperandInfo> > &Operands;
std::vector<Filter> Filters;
std::vector<bit_value_t> FilterBitValues;
const FilterChooser *Parent;
int BestIndex;
unsigned BitWidth;
const FixedLenDecoderEmitter *Emitter;
public:
FilterChooser(const FilterChooser &FC)
: AllInstructions(FC.AllInstructions), Opcodes(FC.Opcodes),
Operands(FC.Operands), Filters(FC.Filters),
FilterBitValues(FC.FilterBitValues), Parent(FC.Parent),
BestIndex(FC.BestIndex), BitWidth(FC.BitWidth),
Emitter(FC.Emitter) { }
FilterChooser(const std::vector<const CodeGenInstruction*> &Insts,
const std::vector<unsigned> &IDs,
const std::map<unsigned, std::vector<OperandInfo> > &Ops,
unsigned BW,
const FixedLenDecoderEmitter *E)
: AllInstructions(Insts), Opcodes(IDs), Operands(Ops), Filters(),
Parent(NULL), BestIndex(-1), BitWidth(BW), Emitter(E) {
for (unsigned i = 0; i < BitWidth; ++i)
FilterBitValues.push_back(BIT_UNFILTERED);
doFilter();
}
FilterChooser(const std::vector<const CodeGenInstruction*> &Insts,
const std::vector<unsigned> &IDs,
const std::map<unsigned, std::vector<OperandInfo> > &Ops,
const std::vector<bit_value_t> &ParentFilterBitValues,
const FilterChooser &parent)
: AllInstructions(Insts), Opcodes(IDs), Operands(Ops),
Filters(), FilterBitValues(ParentFilterBitValues),
Parent(&parent), BestIndex(-1), BitWidth(parent.BitWidth),
Emitter(parent.Emitter) {
doFilter();
}
unsigned getBitWidth() const { return BitWidth; }
protected:
void insnWithID(insn_t &Insn, unsigned Opcode) const {
BitsInit &Bits = getBitsField(*AllInstructions[Opcode]->TheDef, "Inst");
BitsInit *SFBits =
AllInstructions[Opcode]->TheDef->getValueAsBitsInit("SoftFail");
for (unsigned i = 0; i < BitWidth; ++i) {
if (SFBits && bitFromBits(*SFBits, i) == BIT_TRUE)
Insn.push_back(BIT_UNSET);
else
Insn.push_back(bitFromBits(Bits, i));
}
}
const std::string &nameWithID(unsigned Opcode) const {
return AllInstructions[Opcode]->TheDef->getName();
}
bool fieldFromInsn(uint64_t &Field, insn_t &Insn, unsigned StartBit,
unsigned NumBits) const;
void dumpFilterArray(raw_ostream &o,
const std::vector<bit_value_t> & filter) const;
void dumpStack(raw_ostream &o, const char *prefix) const;
Filter &bestFilter() {
assert(BestIndex != -1 && "BestIndex not set");
return Filters[BestIndex];
}
void SingletonExists(unsigned Opc) const;
bool PositionFiltered(unsigned i) const {
return ValueSet(FilterBitValues[i]);
}
unsigned getIslands(std::vector<unsigned> &StartBits,
std::vector<unsigned> &EndBits,
std::vector<uint64_t> &FieldVals,
const insn_t &Insn) const;
bool emitPredicateMatch(raw_ostream &o, unsigned &Indentation,
unsigned Opc) const;
bool doesOpcodeNeedPredicate(unsigned Opc) const;
unsigned getPredicateIndex(DecoderTableInfo &TableInfo, StringRef P) const;
void emitPredicateTableEntry(DecoderTableInfo &TableInfo,
unsigned Opc) const;
void emitSoftFailTableEntry(DecoderTableInfo &TableInfo,
unsigned Opc) const;
void emitSingletonTableEntry(DecoderTableInfo &TableInfo,
unsigned Opc) const;
void emitSingletonTableEntry(DecoderTableInfo &TableInfo,
const Filter &Best) const;
void emitBinaryParser(raw_ostream &o, unsigned &Indentation,
const OperandInfo &OpInfo) const;
void emitDecoder(raw_ostream &OS, unsigned Indentation, unsigned Opc) const;
unsigned getDecoderIndex(DecoderSet &Decoders, unsigned Opc) const;
void runSingleFilter(unsigned startBit, unsigned numBit, bool mixed);
void reportRegion(bitAttr_t RA, unsigned StartBit, unsigned BitIndex,
bool AllowMixed);
bool filterProcessor(bool AllowMixed, bool Greedy = true);
void doFilter();
public:
void emitTableEntries(DecoderTableInfo &TableInfo) const;
};
}
Filter::Filter(const Filter &f)
: Owner(f.Owner), StartBit(f.StartBit), NumBits(f.NumBits), Mixed(f.Mixed),
FilteredInstructions(f.FilteredInstructions),
VariableInstructions(f.VariableInstructions),
FilterChooserMap(f.FilterChooserMap), NumFiltered(f.NumFiltered),
LastOpcFiltered(f.LastOpcFiltered) {
}
Filter::Filter(FilterChooser &owner, unsigned startBit, unsigned numBits,
bool mixed)
: Owner(&owner), StartBit(startBit), NumBits(numBits), Mixed(mixed) {
assert(StartBit + NumBits - 1 < Owner->BitWidth);
NumFiltered = 0;
LastOpcFiltered = 0;
for (unsigned i = 0, e = Owner->Opcodes.size(); i != e; ++i) {
insn_t Insn;
Owner->insnWithID(Insn, Owner->Opcodes[i]);
uint64_t Field;
bool ok = Owner->fieldFromInsn(Field, Insn, StartBit, NumBits);
if (ok) {
LastOpcFiltered = Owner->Opcodes[i];
FilteredInstructions[Field].push_back(LastOpcFiltered);
++NumFiltered;
} else {
VariableInstructions.push_back(Owner->Opcodes[i]);
}
}
assert((FilteredInstructions.size() + VariableInstructions.size() > 0)
&& "Filter returns no instruction categories");
}
Filter::~Filter() {
std::map<unsigned, const FilterChooser*>::iterator filterIterator;
for (filterIterator = FilterChooserMap.begin();
filterIterator != FilterChooserMap.end();
filterIterator++) {
delete filterIterator->second;
}
}
void Filter::recurse() {
std::map<uint64_t, std::vector<unsigned> >::const_iterator mapIterator;
std::vector<bit_value_t> BitValueArray(Owner->FilterBitValues);
if (VariableInstructions.size()) {
for (unsigned bitIndex = 0; bitIndex < NumBits; ++bitIndex)
BitValueArray[StartBit + bitIndex] = BIT_UNSET;
FilterChooserMap.insert(std::pair<unsigned, const FilterChooser*>(
(unsigned)-1,
new FilterChooser(Owner->AllInstructions,
VariableInstructions,
Owner->Operands,
BitValueArray,
*Owner)
));
}
if (getNumFiltered() == 1) {
assert(FilterChooserMap.size() == 1);
return;
}
for (mapIterator = FilteredInstructions.begin();
mapIterator != FilteredInstructions.end();
mapIterator++) {
for (unsigned bitIndex = 0; bitIndex < NumBits; ++bitIndex) {
if (mapIterator->first & (1ULL << bitIndex))
BitValueArray[StartBit + bitIndex] = BIT_TRUE;
else
BitValueArray[StartBit + bitIndex] = BIT_FALSE;
}
FilterChooserMap.insert(std::pair<unsigned, const FilterChooser*>(
mapIterator->first,
new FilterChooser(Owner->AllInstructions,
mapIterator->second,
Owner->Operands,
BitValueArray,
*Owner)
));
}
}
static void resolveTableFixups(DecoderTable &Table, const FixupList &Fixups,
uint32_t DestIdx) {
for (FixupList::const_reverse_iterator I = Fixups.rbegin(),
E = Fixups.rend();
I != E; ++I) {
uint32_t FixupIdx = *I;
uint32_t Delta = DestIdx - FixupIdx - 2;
assert(Delta < 65536U && "disassembler decoding table too large!");
Table[FixupIdx] = (uint8_t)Delta;
Table[FixupIdx + 1] = (uint8_t)(Delta >> 8);
}
}
void Filter::emitTableEntry(DecoderTableInfo &TableInfo) const {
TableInfo.Table.push_back(MCD::OPC_ExtractField);
TableInfo.Table.push_back(StartBit);
TableInfo.Table.push_back(NumBits);
TableInfo.FixupStack.push_back(FixupList());
std::map<unsigned, const FilterChooser*>::const_iterator filterIterator;
DecoderTable &Table = TableInfo.Table;
size_t PrevFilter = 0;
bool HasFallthrough = false;
for (filterIterator = FilterChooserMap.begin();
filterIterator != FilterChooserMap.end();
filterIterator++) {
if (filterIterator->first == (unsigned)-1) {
HasFallthrough = true;
assert(PrevFilter != 0 && "empty filter set!");
FixupList &CurScope = TableInfo.FixupStack.back();
resolveTableFixups(Table, CurScope, Table.size());
CurScope.clear();
PrevFilter = 0; } else {
Table.push_back(MCD::OPC_FilterValue);
uint8_t Buffer[8];
unsigned Len = encodeULEB128(filterIterator->first, Buffer);
Table.insert(Table.end(), Buffer, Buffer + Len);
PrevFilter = Table.size();
Table.push_back(0);
Table.push_back(0);
}
filterIterator->second->emitTableEntries(TableInfo);
if (PrevFilter) {
uint32_t NumToSkip = Table.size() - PrevFilter - 2;
assert(NumToSkip < 65536U && "disassembler decoding table too large!");
Table[PrevFilter] = (uint8_t)NumToSkip;
Table[PrevFilter + 1] = (uint8_t)(NumToSkip >> 8);
}
}
assert(TableInfo.FixupStack.size() > 1 && "fixup stack underflow!");
FixupScopeList::iterator Source = TableInfo.FixupStack.end() - 1;
FixupScopeList::iterator Dest = Source - 1;
Dest->insert(Dest->end(), Source->begin(), Source->end());
TableInfo.FixupStack.pop_back();
if (!HasFallthrough)
TableInfo.FixupStack.back().push_back(PrevFilter);
}
unsigned Filter::usefulness() const {
if (VariableInstructions.size())
return FilteredInstructions.size();
else
return FilteredInstructions.size() + 1;
}
void FixedLenDecoderEmitter::emitTable(formatted_raw_ostream &OS,
DecoderTable &Table,
unsigned Indentation,
unsigned BitWidth,
StringRef Namespace) const {
OS.indent(Indentation) << "static const uint8_t DecoderTable" << Namespace
<< BitWidth << "[] = {\n";
Indentation += 2;
DecoderTable::const_iterator I = Table.begin();
DecoderTable::const_iterator E = Table.end();
while (I != E) {
assert (I < E && "incomplete decode table entry!");
uint64_t Pos = I - Table.begin();
OS << "/* " << Pos << " */";
OS.PadToColumn(12);
switch (*I) {
default:
PrintFatalError("invalid decode table opcode");
case MCD::OPC_ExtractField: {
++I;
unsigned Start = *I++;
unsigned Len = *I++;
OS.indent(Indentation) << "MCD::OPC_ExtractField, " << Start << ", "
<< Len << ", // Inst{";
if (Len > 1)
OS << (Start + Len - 1) << "-";
OS << Start << "} ...\n";
break;
}
case MCD::OPC_FilterValue: {
++I;
OS.indent(Indentation) << "MCD::OPC_FilterValue, ";
while (*I >= 128)
OS << utostr(*I++) << ", ";
OS << utostr(*I++) << ", ";
uint8_t Byte = *I++;
uint32_t NumToSkip = Byte;
OS << utostr(Byte) << ", ";
Byte = *I++;
OS << utostr(Byte) << ", ";
NumToSkip |= Byte << 8;
OS << "// Skip to: " << ((I - Table.begin()) + NumToSkip) << "\n";
break;
}
case MCD::OPC_CheckField: {
++I;
unsigned Start = *I++;
unsigned Len = *I++;
OS.indent(Indentation) << "MCD::OPC_CheckField, " << Start << ", "
<< Len << ", "; for (; *I >= 128; ++I)
OS << utostr(*I) << ", ";
OS << utostr(*I++) << ", ";
uint8_t Byte = *I++;
uint32_t NumToSkip = Byte;
OS << utostr(Byte) << ", ";
Byte = *I++;
OS << utostr(Byte) << ", ";
NumToSkip |= Byte << 8;
OS << "// Skip to: " << ((I - Table.begin()) + NumToSkip) << "\n";
break;
}
case MCD::OPC_CheckPredicate: {
++I;
OS.indent(Indentation) << "MCD::OPC_CheckPredicate, ";
for (; *I >= 128; ++I)
OS << utostr(*I) << ", ";
OS << utostr(*I++) << ", ";
uint8_t Byte = *I++;
uint32_t NumToSkip = Byte;
OS << utostr(Byte) << ", ";
Byte = *I++;
OS << utostr(Byte) << ", ";
NumToSkip |= Byte << 8;
OS << "// Skip to: " << ((I - Table.begin()) + NumToSkip) << "\n";
break;
}
case MCD::OPC_Decode: {
++I;
uint8_t Buffer[8], *p = Buffer;
while ((*p++ = *I++) >= 128)
assert((p - Buffer) <= (ptrdiff_t)sizeof(Buffer)
&& "ULEB128 value too large!");
unsigned Opc = decodeULEB128(Buffer);
OS.indent(Indentation) << "MCD::OPC_Decode, ";
for (p = Buffer; *p >= 128; ++p)
OS << utostr(*p) << ", ";
OS << utostr(*p) << ", ";
for (; *I >= 128; ++I)
OS << utostr(*I) << ", ";
OS << utostr(*I++) << ", ";
OS << "// Opcode: "
<< NumberedInstructions->at(Opc)->TheDef->getName() << "\n";
break;
}
case MCD::OPC_SoftFail: {
++I;
OS.indent(Indentation) << "MCD::OPC_SoftFail";
uint64_t Value = 0;
unsigned Shift = 0;
do {
OS << ", " << utostr(*I);
Value += (*I & 0x7f) << Shift;
Shift += 7;
} while (*I++ >= 128);
if (Value > 127)
OS << " /* 0x" << utohexstr(Value) << " */";
Value = 0;
Shift = 0;
do {
OS << ", " << utostr(*I);
Value += (*I & 0x7f) << Shift;
Shift += 7;
} while (*I++ >= 128);
if (Value > 127)
OS << " /* 0x" << utohexstr(Value) << " */";
OS << ",\n";
break;
}
case MCD::OPC_Fail: {
++I;
OS.indent(Indentation) << "MCD::OPC_Fail,\n";
break;
}
}
}
OS.indent(Indentation) << "0\n";
Indentation -= 2;
OS.indent(Indentation) << "};\n\n";
}
void FixedLenDecoderEmitter::
emitPredicateFunction(formatted_raw_ostream &OS, PredicateSet &Predicates,
unsigned Indentation) const {
OS.indent(Indentation) << "static bool checkDecoderPredicate(unsigned Idx, "
<< "uint64_t Bits) {\n";
Indentation += 2;
if (!Predicates.empty()) {
OS.indent(Indentation) << "switch (Idx) {\n";
OS.indent(Indentation) << "default: llvm_unreachable(\"Invalid index!\");\n";
unsigned Index = 0;
for (PredicateSet::const_iterator I = Predicates.begin(), E = Predicates.end();
I != E; ++I, ++Index) {
OS.indent(Indentation) << "case " << Index << ":\n";
OS.indent(Indentation+2) << "return (" << *I << ");\n";
}
OS.indent(Indentation) << "}\n";
} else {
OS.indent(Indentation) << "llvm_unreachable(\"Invalid index!\");\n";
}
Indentation -= 2;
OS.indent(Indentation) << "}\n\n";
}
void FixedLenDecoderEmitter::
emitDecoderFunction(formatted_raw_ostream &OS, DecoderSet &Decoders,
unsigned Indentation) const {
OS.indent(Indentation) << "template<typename InsnType>\n";
OS.indent(Indentation) << "static DecodeStatus decodeToMCInst(DecodeStatus S,"
<< " unsigned Idx, InsnType insn, MCInst &MI,\n";
OS.indent(Indentation) << " uint64_t "
<< "Address, const void *Decoder) {\n";
Indentation += 2;
OS.indent(Indentation) << "InsnType tmp;\n";
OS.indent(Indentation) << "switch (Idx) {\n";
OS.indent(Indentation) << "default: llvm_unreachable(\"Invalid index!\");\n";
unsigned Index = 0;
for (DecoderSet::const_iterator I = Decoders.begin(), E = Decoders.end();
I != E; ++I, ++Index) {
OS.indent(Indentation) << "case " << Index << ":\n";
OS << *I;
OS.indent(Indentation+2) << "return S;\n";
}
OS.indent(Indentation) << "}\n";
Indentation -= 2;
OS.indent(Indentation) << "}\n\n";
}
bool FilterChooser::fieldFromInsn(uint64_t &Field, insn_t &Insn,
unsigned StartBit, unsigned NumBits) const {
Field = 0;
for (unsigned i = 0; i < NumBits; ++i) {
if (Insn[StartBit + i] == BIT_UNSET)
return false;
if (Insn[StartBit + i] == BIT_TRUE)
Field = Field | (1ULL << i);
}
return true;
}
void FilterChooser::dumpFilterArray(raw_ostream &o,
const std::vector<bit_value_t> &filter) const {
for (unsigned bitIndex = BitWidth; bitIndex > 0; bitIndex--) {
switch (filter[bitIndex - 1]) {
case BIT_UNFILTERED:
o << ".";
break;
case BIT_UNSET:
o << "_";
break;
case BIT_TRUE:
o << "1";
break;
case BIT_FALSE:
o << "0";
break;
}
}
}
void FilterChooser::dumpStack(raw_ostream &o, const char *prefix) const {
const FilterChooser *current = this;
while (current) {
o << prefix;
dumpFilterArray(o, current->FilterBitValues);
o << '\n';
current = current->Parent;
}
}
void FilterChooser::SingletonExists(unsigned Opc) const {
insn_t Insn0;
insnWithID(Insn0, Opc);
errs() << "Singleton exists: " << nameWithID(Opc)
<< " with its decoding dominating ";
for (unsigned i = 0; i < Opcodes.size(); ++i) {
if (Opcodes[i] == Opc) continue;
errs() << nameWithID(Opcodes[i]) << ' ';
}
errs() << '\n';
dumpStack(errs(), "\t\t");
for (unsigned i = 0; i < Opcodes.size(); ++i) {
const std::string &Name = nameWithID(Opcodes[i]);
errs() << '\t' << Name << " ";
dumpBits(errs(),
getBitsField(*AllInstructions[Opcodes[i]]->TheDef, "Inst"));
errs() << '\n';
}
}
unsigned FilterChooser::getIslands(std::vector<unsigned> &StartBits,
std::vector<unsigned> &EndBits,
std::vector<uint64_t> &FieldVals,
const insn_t &Insn) const {
unsigned Num, BitNo;
Num = BitNo = 0;
uint64_t FieldVal = 0;
int State = 0;
int Val = -1;
for (unsigned i = 0; i < BitWidth; ++i) {
Val = Value(Insn[i]);
bool Filtered = PositionFiltered(i);
switch (State) {
default: llvm_unreachable("Unreachable code!");
case 0:
case 1:
if (Filtered || Val == -1)
State = 1; else {
State = 2; BitNo = 0;
StartBits.push_back(i);
FieldVal = Val;
}
break;
case 2:
if (Filtered || Val == -1) {
State = 1; EndBits.push_back(i - 1);
FieldVals.push_back(FieldVal);
++Num;
} else {
State = 2; ++BitNo;
FieldVal = FieldVal | Val << BitNo;
}
break;
}
}
if (State == 2) {
EndBits.push_back(BitWidth - 1);
FieldVals.push_back(FieldVal);
++Num;
}
assert(StartBits.size() == Num && EndBits.size() == Num &&
FieldVals.size() == Num);
return Num;
}
void FilterChooser::emitBinaryParser(raw_ostream &o, unsigned &Indentation,
const OperandInfo &OpInfo) const {
const std::string &Decoder = OpInfo.Decoder;
if (OpInfo.numFields() == 1) {
OperandInfo::const_iterator OI = OpInfo.begin();
o.indent(Indentation) << "tmp = fieldFromInstruction"
<< "(insn, " << OI->Base << ", " << OI->Width
<< ");\n";
} else {
o.indent(Indentation) << "tmp = 0;\n";
for (OperandInfo::const_iterator OI = OpInfo.begin(), OE = OpInfo.end();
OI != OE; ++OI) {
o.indent(Indentation) << "tmp |= (fieldFromInstruction"
<< "(insn, " << OI->Base << ", " << OI->Width
<< ") << " << OI->Offset << ");\n";
}
}
if (Decoder != "")
o.indent(Indentation) << Emitter->GuardPrefix << Decoder
<< "(MI, tmp, Address, Decoder)"
<< Emitter->GuardPostfix << "\n";
else
o.indent(Indentation) << "MI.addOperand(MCOperand::CreateImm(tmp));\n";
}
void FilterChooser::emitDecoder(raw_ostream &OS, unsigned Indentation,
unsigned Opc) const {
std::map<unsigned, std::vector<OperandInfo> >::const_iterator OpIter =
Operands.find(Opc);
const std::vector<OperandInfo>& InsnOperands = OpIter->second;
for (std::vector<OperandInfo>::const_iterator
I = InsnOperands.begin(), E = InsnOperands.end(); I != E; ++I) {
if (I->numFields() == 0 && I->Decoder.size()) {
OS.indent(Indentation) << Emitter->GuardPrefix << I->Decoder
<< "(MI, insn, Address, Decoder)"
<< Emitter->GuardPostfix << "\n";
break;
}
emitBinaryParser(OS, Indentation, *I);
}
}
unsigned FilterChooser::getDecoderIndex(DecoderSet &Decoders,
unsigned Opc) const {
SmallString<256> Decoder;
raw_svector_ostream S(Decoder);
unsigned I = 4;
emitDecoder(S, I, Opc);
S.flush();
Decoders.insert(Decoder.str());
DecoderSet::const_iterator P = std::find(Decoders.begin(),
Decoders.end(),
Decoder.str());
return (unsigned)(P - Decoders.begin());
}
static void emitSinglePredicateMatch(raw_ostream &o, StringRef str,
const std::string &PredicateNamespace) {
if (str[0] == '!')
o << "!(Bits & " << PredicateNamespace << "::"
<< str.slice(1,str.size()) << ")";
else
o << "(Bits & " << PredicateNamespace << "::" << str << ")";
}
bool FilterChooser::emitPredicateMatch(raw_ostream &o, unsigned &Indentation,
unsigned Opc) const {
ListInit *Predicates =
AllInstructions[Opc]->TheDef->getValueAsListInit("Predicates");
for (unsigned i = 0; i < Predicates->getSize(); ++i) {
Record *Pred = Predicates->getElementAsRecord(i);
if (!Pred->getValue("AssemblerMatcherPredicate"))
continue;
std::string P = Pred->getValueAsString("AssemblerCondString");
if (!P.length())
continue;
if (i != 0)
o << " && ";
StringRef SR(P);
std::pair<StringRef, StringRef> pairs = SR.split(',');
while (pairs.second.size()) {
emitSinglePredicateMatch(o, pairs.first, Emitter->PredicateNamespace);
o << " && ";
pairs = pairs.second.split(',');
}
emitSinglePredicateMatch(o, pairs.first, Emitter->PredicateNamespace);
}
return Predicates->getSize() > 0;
}
bool FilterChooser::doesOpcodeNeedPredicate(unsigned Opc) const {
ListInit *Predicates =
AllInstructions[Opc]->TheDef->getValueAsListInit("Predicates");
for (unsigned i = 0; i < Predicates->getSize(); ++i) {
Record *Pred = Predicates->getElementAsRecord(i);
if (!Pred->getValue("AssemblerMatcherPredicate"))
continue;
std::string P = Pred->getValueAsString("AssemblerCondString");
if (!P.length())
continue;
return true;
}
return false;
}
unsigned FilterChooser::getPredicateIndex(DecoderTableInfo &TableInfo,
StringRef Predicate) const {
TableInfo.Predicates.insert(Predicate.str());
PredicateSet::const_iterator P = std::find(TableInfo.Predicates.begin(),
TableInfo.Predicates.end(),
Predicate.str());
return (unsigned)(P - TableInfo.Predicates.begin());
}
void FilterChooser::emitPredicateTableEntry(DecoderTableInfo &TableInfo,
unsigned Opc) const {
if (!doesOpcodeNeedPredicate(Opc))
return;
SmallString<256> Predicate;
raw_svector_ostream PS(Predicate);
unsigned I = 0;
emitPredicateMatch(PS, I, Opc);
unsigned PIdx = getPredicateIndex(TableInfo, PS.str());
SmallString<16> PBytes;
raw_svector_ostream S(PBytes);
encodeULEB128(PIdx, S);
S.flush();
TableInfo.Table.push_back(MCD::OPC_CheckPredicate);
for (unsigned i = 0, e = PBytes.size(); i != e; ++i)
TableInfo.Table.push_back(PBytes[i]);
TableInfo.FixupStack.back().push_back(TableInfo.Table.size());
TableInfo.Table.push_back(0);
TableInfo.Table.push_back(0);
}
void FilterChooser::emitSoftFailTableEntry(DecoderTableInfo &TableInfo,
unsigned Opc) const {
BitsInit *SFBits =
AllInstructions[Opc]->TheDef->getValueAsBitsInit("SoftFail");
if (!SFBits) return;
BitsInit *InstBits = AllInstructions[Opc]->TheDef->getValueAsBitsInit("Inst");
APInt PositiveMask(BitWidth, 0ULL);
APInt NegativeMask(BitWidth, 0ULL);
for (unsigned i = 0; i < BitWidth; ++i) {
bit_value_t B = bitFromBits(*SFBits, i);
bit_value_t IB = bitFromBits(*InstBits, i);
if (B != BIT_TRUE) continue;
switch (IB) {
case BIT_FALSE:
PositiveMask.setBit(i);
break;
case BIT_TRUE:
NegativeMask.setBit(i);
break;
default:
StringRef Name = AllInstructions[Opc]->TheDef->getName();
errs() << "SoftFail Conflict: bit SoftFail{" << i << "} in " << Name
<< " is set but Inst{" << i << "} is unset!\n"
<< " - You can only mark a bit as SoftFail if it is fully defined"
<< " (1/0 - not '?') in Inst\n";
return;
}
}
bool NeedPositiveMask = PositiveMask.getBoolValue();
bool NeedNegativeMask = NegativeMask.getBoolValue();
if (!NeedPositiveMask && !NeedNegativeMask)
return;
TableInfo.Table.push_back(MCD::OPC_SoftFail);
SmallString<16> MaskBytes;
raw_svector_ostream S(MaskBytes);
if (NeedPositiveMask) {
encodeULEB128(PositiveMask.getZExtValue(), S);
S.flush();
for (unsigned i = 0, e = MaskBytes.size(); i != e; ++i)
TableInfo.Table.push_back(MaskBytes[i]);
} else
TableInfo.Table.push_back(0);
if (NeedNegativeMask) {
MaskBytes.clear();
S.resync();
encodeULEB128(NegativeMask.getZExtValue(), S);
S.flush();
for (unsigned i = 0, e = MaskBytes.size(); i != e; ++i)
TableInfo.Table.push_back(MaskBytes[i]);
} else
TableInfo.Table.push_back(0);
}
void FilterChooser::emitSingletonTableEntry(DecoderTableInfo &TableInfo,
unsigned Opc) const {
std::vector<unsigned> StartBits;
std::vector<unsigned> EndBits;
std::vector<uint64_t> FieldVals;
insn_t Insn;
insnWithID(Insn, Opc);
getIslands(StartBits, EndBits, FieldVals, Insn);
unsigned Size = StartBits.size();
emitPredicateTableEntry(TableInfo, Opc);
for (unsigned I = Size; I != 0; --I) {
unsigned NumBits = EndBits[I-1] - StartBits[I-1] + 1;
TableInfo.Table.push_back(MCD::OPC_CheckField);
TableInfo.Table.push_back(StartBits[I-1]);
TableInfo.Table.push_back(NumBits);
uint8_t Buffer[8], *p;
encodeULEB128(FieldVals[I-1], Buffer);
for (p = Buffer; *p >= 128 ; ++p)
TableInfo.Table.push_back(*p);
TableInfo.Table.push_back(*p);
TableInfo.FixupStack.back().push_back(TableInfo.Table.size());
TableInfo.Table.push_back(0);
TableInfo.Table.push_back(0);
}
emitSoftFailTableEntry(TableInfo, Opc);
TableInfo.Table.push_back(MCD::OPC_Decode);
uint8_t Buffer[8], *p;
encodeULEB128(Opc, Buffer);
for (p = Buffer; *p >= 128 ; ++p)
TableInfo.Table.push_back(*p);
TableInfo.Table.push_back(*p);
unsigned DIdx = getDecoderIndex(TableInfo.Decoders, Opc);
SmallString<16> Bytes;
raw_svector_ostream S(Bytes);
encodeULEB128(DIdx, S);
S.flush();
for (unsigned i = 0, e = Bytes.size(); i != e; ++i)
TableInfo.Table.push_back(Bytes[i]);
}
void FilterChooser::emitSingletonTableEntry(DecoderTableInfo &TableInfo,
const Filter &Best) const {
unsigned Opc = Best.getSingletonOpc();
TableInfo.FixupStack.push_back(FixupList());
emitSingletonTableEntry(TableInfo, Opc);
resolveTableFixups(TableInfo.Table, TableInfo.FixupStack.back(),
TableInfo.Table.size());
TableInfo.FixupStack.pop_back();
Best.getVariableFC().emitTableEntries(TableInfo);
}
void FilterChooser::runSingleFilter(unsigned startBit, unsigned numBit,
bool mixed) {
Filters.clear();
Filter F(*this, startBit, numBit, true);
Filters.push_back(F);
BestIndex = 0; bestFilter().recurse();
}
void FilterChooser::reportRegion(bitAttr_t RA, unsigned StartBit,
unsigned BitIndex, bool AllowMixed) {
if (RA == ATTR_MIXED && AllowMixed)
Filters.push_back(Filter(*this, StartBit, BitIndex - StartBit, true));
else if (RA == ATTR_ALL_SET && !AllowMixed)
Filters.push_back(Filter(*this, StartBit, BitIndex - StartBit, false));
}
bool FilterChooser::filterProcessor(bool AllowMixed, bool Greedy) {
Filters.clear();
BestIndex = -1;
unsigned numInstructions = Opcodes.size();
assert(numInstructions && "Filter created with no instructions");
if (numInstructions == 1)
return true;
if (AllowMixed && !Greedy) {
assert(numInstructions == 3);
for (unsigned i = 0; i < Opcodes.size(); ++i) {
std::vector<unsigned> StartBits;
std::vector<unsigned> EndBits;
std::vector<uint64_t> FieldVals;
insn_t Insn;
insnWithID(Insn, Opcodes[i]);
if (getIslands(StartBits, EndBits, FieldVals, Insn) > 0) {
runSingleFilter(StartBits[0], EndBits[0] - StartBits[0] + 1, true);
return true;
}
}
}
unsigned BitIndex;
std::vector<bitAttr_t> bitAttrs;
for (BitIndex = 0; BitIndex < BitWidth; ++BitIndex)
if (FilterBitValues[BitIndex] == BIT_TRUE ||
FilterBitValues[BitIndex] == BIT_FALSE)
bitAttrs.push_back(ATTR_FILTERED);
else
bitAttrs.push_back(ATTR_NONE);
for (unsigned InsnIndex = 0; InsnIndex < numInstructions; ++InsnIndex) {
insn_t insn;
insnWithID(insn, Opcodes[InsnIndex]);
for (BitIndex = 0; BitIndex < BitWidth; ++BitIndex) {
switch (bitAttrs[BitIndex]) {
case ATTR_NONE:
if (insn[BitIndex] == BIT_UNSET)
bitAttrs[BitIndex] = ATTR_ALL_UNSET;
else
bitAttrs[BitIndex] = ATTR_ALL_SET;
break;
case ATTR_ALL_SET:
if (insn[BitIndex] == BIT_UNSET)
bitAttrs[BitIndex] = ATTR_MIXED;
break;
case ATTR_ALL_UNSET:
if (insn[BitIndex] != BIT_UNSET)
bitAttrs[BitIndex] = ATTR_MIXED;
break;
case ATTR_MIXED:
case ATTR_FILTERED:
break;
}
}
}
bitAttr_t RA = ATTR_NONE;
unsigned StartBit = 0;
for (BitIndex = 0; BitIndex < BitWidth; ++BitIndex) {
bitAttr_t bitAttr = bitAttrs[BitIndex];
assert(bitAttr != ATTR_NONE && "Bit without attributes");
switch (RA) {
case ATTR_NONE:
switch (bitAttr) {
case ATTR_FILTERED:
break;
case ATTR_ALL_SET:
StartBit = BitIndex;
RA = ATTR_ALL_SET;
break;
case ATTR_ALL_UNSET:
break;
case ATTR_MIXED:
StartBit = BitIndex;
RA = ATTR_MIXED;
break;
default:
llvm_unreachable("Unexpected bitAttr!");
}
break;
case ATTR_ALL_SET:
switch (bitAttr) {
case ATTR_FILTERED:
reportRegion(RA, StartBit, BitIndex, AllowMixed);
RA = ATTR_NONE;
break;
case ATTR_ALL_SET:
break;
case ATTR_ALL_UNSET:
reportRegion(RA, StartBit, BitIndex, AllowMixed);
RA = ATTR_NONE;
break;
case ATTR_MIXED:
reportRegion(RA, StartBit, BitIndex, AllowMixed);
StartBit = BitIndex;
RA = ATTR_MIXED;
break;
default:
llvm_unreachable("Unexpected bitAttr!");
}
break;
case ATTR_MIXED:
switch (bitAttr) {
case ATTR_FILTERED:
reportRegion(RA, StartBit, BitIndex, AllowMixed);
StartBit = BitIndex;
RA = ATTR_NONE;
break;
case ATTR_ALL_SET:
reportRegion(RA, StartBit, BitIndex, AllowMixed);
StartBit = BitIndex;
RA = ATTR_ALL_SET;
break;
case ATTR_ALL_UNSET:
reportRegion(RA, StartBit, BitIndex, AllowMixed);
RA = ATTR_NONE;
break;
case ATTR_MIXED:
break;
default:
llvm_unreachable("Unexpected bitAttr!");
}
break;
case ATTR_ALL_UNSET:
llvm_unreachable("regionAttr state machine has no ATTR_UNSET state");
case ATTR_FILTERED:
llvm_unreachable("regionAttr state machine has no ATTR_FILTERED state");
}
}
switch (RA) {
case ATTR_NONE:
break;
case ATTR_FILTERED:
break;
case ATTR_ALL_SET:
reportRegion(RA, StartBit, BitIndex, AllowMixed);
break;
case ATTR_ALL_UNSET:
break;
case ATTR_MIXED:
reportRegion(RA, StartBit, BitIndex, AllowMixed);
break;
}
BestIndex = 0;
bool AllUseless = true;
unsigned BestScore = 0;
for (unsigned i = 0, e = Filters.size(); i != e; ++i) {
unsigned Usefulness = Filters[i].usefulness();
if (Usefulness)
AllUseless = false;
if (Usefulness > BestScore) {
BestIndex = i;
BestScore = Usefulness;
}
}
if (!AllUseless)
bestFilter().recurse();
return !AllUseless;
}
void FilterChooser::doFilter() {
unsigned Num = Opcodes.size();
assert(Num && "FilterChooser created with no instructions");
if (filterProcessor(false))
return;
if (filterProcessor(true))
return;
if (Num == 3 && filterProcessor(true, false))
return;
BestIndex = -1;
}
void FilterChooser::emitTableEntries(DecoderTableInfo &TableInfo) const {
if (Opcodes.size() == 1) {
emitSingletonTableEntry(TableInfo, Opcodes[0]);
return;
}
if (BestIndex != -1) {
const Filter &Best = Filters[BestIndex];
if (Best.getNumFiltered() == 1)
emitSingletonTableEntry(TableInfo, Best);
else
Best.emitTableEntry(TableInfo);
return;
}
errs() << "Decoding Conflict:\n";
dumpStack(errs(), "\t\t");
for (unsigned i = 0; i < Opcodes.size(); ++i) {
const std::string &Name = nameWithID(Opcodes[i]);
errs() << '\t' << Name << " ";
dumpBits(errs(),
getBitsField(*AllInstructions[Opcodes[i]]->TheDef, "Inst"));
errs() << '\n';
}
}
static bool populateInstruction(CodeGenTarget &Target,
const CodeGenInstruction &CGI, unsigned Opc,
std::map<unsigned, std::vector<OperandInfo> > &Operands){
const Record &Def = *CGI.TheDef;
if (Def.getValueAsBit("isAsmParserOnly") ||
Def.getValueAsBit("isCodeGenOnly"))
return false;
BitsInit &Bits = getBitsField(Def, "Inst");
if (Bits.allInComplete()) return false;
std::vector<OperandInfo> InsnOperands;
std::string InstDecoder = Def.getValueAsString("DecoderMethod");
if (InstDecoder != "") {
InsnOperands.push_back(OperandInfo(InstDecoder));
Operands[Opc] = InsnOperands;
return true;
}
std::vector<std::pair<Init*, std::string> > InOutOperands;
DagInit *Out = Def.getValueAsDag("OutOperandList");
DagInit *In = Def.getValueAsDag("InOperandList");
for (unsigned i = 0; i < Out->getNumArgs(); ++i)
InOutOperands.push_back(std::make_pair(Out->getArg(i), Out->getArgName(i)));
for (unsigned i = 0; i < In->getNumArgs(); ++i)
InOutOperands.push_back(std::make_pair(In->getArg(i), In->getArgName(i)));
std::map<std::string, std::string> TiedNames;
for (unsigned i = 0; i < CGI.Operands.size(); ++i) {
int tiedTo = CGI.Operands[i].getTiedRegister();
if (tiedTo != -1) {
std::pair<unsigned, unsigned> SO =
CGI.Operands.getSubOperandNumber(tiedTo);
TiedNames[InOutOperands[i].second] = InOutOperands[SO.first].second;
TiedNames[InOutOperands[SO.first].second] = InOutOperands[i].second;
}
}
std::map<std::string, std::vector<OperandInfo> > NumberedInsnOperands;
std::set<std::string> NumberedInsnOperandsNoTie;
if (Target.getInstructionSet()->
getValueAsBit("decodePositionallyEncodedOperands")) {
const std::vector<RecordVal> &Vals = Def.getValues();
unsigned NumberedOp = 0;
for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
if (Vals[i].getPrefix() || Vals[i].getValue()->isComplete())
continue;
unsigned bi = 0;
for (; bi < Bits.getNumBits(); ++bi) {
VarInit *Var = 0;
VarBitInit *BI = dyn_cast<VarBitInit>(Bits.getBit(bi));
if (BI)
Var = dyn_cast<VarInit>(BI->getBitVar());
else
Var = dyn_cast<VarInit>(Bits.getBit(bi));
if (Var && Var->getName() == Vals[i].getName())
break;
}
if (bi == Bits.getNumBits())
continue;
unsigned OpIdx;
if (CGI.Operands.hasOperandNamed(Vals[i].getName(), OpIdx))
continue;
unsigned bitStart = bi++, bitWidth = 1;
for (; bi < Bits.getNumBits(); ++bi) {
VarInit *Var = 0;
VarBitInit *BI = dyn_cast<VarBitInit>(Bits.getBit(bi));
if (BI)
Var = dyn_cast<VarInit>(BI->getBitVar());
else
Var = dyn_cast<VarInit>(Bits.getBit(bi));
if (!Var)
break;
if (Var->getName() != Vals[i].getName())
break;
++bitWidth;
}
unsigned NumberOps = CGI.Operands.size();
while (NumberedOp < NumberOps &&
CGI.Operands.isFlatOperandNotEmitted(NumberedOp))
++NumberedOp;
OpIdx = NumberedOp++;
std::pair<unsigned, unsigned> SO =
CGI.Operands.getSubOperandNumber(OpIdx);
const std::string &Name = CGI.Operands[SO.first].Name;
DEBUG(dbgs() << "Numbered operand mapping for " << Def.getName() << ": " <<
Name << "(" << SO.first << ", " << SO.second << ") => " <<
Vals[i].getName() << "\n");
std::string Decoder = "";
Record *TypeRecord = CGI.Operands[SO.first].Rec;
RecordVal *DecoderString = TypeRecord->getValue("DecoderMethod");
StringInit *String = DecoderString ?
dyn_cast<StringInit>(DecoderString->getValue()) : 0;
if (String && String->getValue() != "")
Decoder = String->getValue();
if (Decoder == "" &&
CGI.Operands[SO.first].MIOperandInfo &&
CGI.Operands[SO.first].MIOperandInfo->getNumArgs()) {
Init *Arg = CGI.Operands[SO.first].MIOperandInfo->
getArg(SO.second);
if (TypedInit *TI = cast<TypedInit>(Arg)) {
RecordRecTy *Type = cast<RecordRecTy>(TI->getType());
TypeRecord = Type->getRecord();
}
}
bool isReg = false;
if (TypeRecord->isSubClassOf("RegisterOperand"))
TypeRecord = TypeRecord->getValueAsDef("RegClass");
if (TypeRecord->isSubClassOf("RegisterClass")) {
Decoder = "Decode" + TypeRecord->getName() + "RegisterClass";
isReg = true;
} else if (TypeRecord->isSubClassOf("PointerLikeRegClass")) {
Decoder = "DecodePointerLikeRegClass" +
utostr(TypeRecord->getValueAsInt("RegClassKind"));
isReg = true;
}
DecoderString = TypeRecord->getValue("DecoderMethod");
String = DecoderString ?
dyn_cast<StringInit>(DecoderString->getValue()) : 0;
if (!isReg && String && String->getValue() != "")
Decoder = String->getValue();
OperandInfo OpInfo(Decoder);
OpInfo.addField(bitStart, bitWidth, 0);
NumberedInsnOperands[Name].push_back(OpInfo);
if (CGI.Operands[SO.first].MIOperandInfo &&
CGI.Operands[SO.first].MIOperandInfo->getNumArgs() > 1 &&
String && String->getValue() != "")
NumberedInsnOperandsNoTie.insert(Name);
}
}
for (std::vector<std::pair<Init*, std::string> >::const_iterator
NI = InOutOperands.begin(), NE = InOutOperands.end(); NI != NE; ++NI) {
if (!NumberedInsnOperands[NI->second].empty()) {
InsnOperands.insert(InsnOperands.end(),
NumberedInsnOperands[NI->second].begin(),
NumberedInsnOperands[NI->second].end());
continue;
} else if (!NumberedInsnOperands[TiedNames[NI->second]].empty()) {
if (!NumberedInsnOperandsNoTie.count(TiedNames[NI->second])) {
unsigned i = CGI.Operands.getOperandNamed(TiedNames[NI->second]);
int tiedTo = CGI.Operands[i].getTiedRegister();
if (tiedTo == -1) {
i = CGI.Operands.getOperandNamed(NI->second);
tiedTo = CGI.Operands[i].getTiedRegister();
}
if (tiedTo != -1) {
std::pair<unsigned, unsigned> SO =
CGI.Operands.getSubOperandNumber(tiedTo);
InsnOperands.push_back(NumberedInsnOperands[TiedNames[NI->second]]
[SO.second]);
}
}
continue;
}
std::string Decoder = "";
TypedInit *TI = cast<TypedInit>(NI->first);
RecordRecTy *Type = cast<RecordRecTy>(TI->getType());
Record *TypeRecord = Type->getRecord();
bool isReg = false;
if (TypeRecord->isSubClassOf("RegisterOperand"))
TypeRecord = TypeRecord->getValueAsDef("RegClass");
if (TypeRecord->isSubClassOf("RegisterClass")) {
Decoder = "Decode" + TypeRecord->getName() + "RegisterClass";
isReg = true;
} else if (TypeRecord->isSubClassOf("PointerLikeRegClass")) {
Decoder = "DecodePointerLikeRegClass" +
utostr(TypeRecord->getValueAsInt("RegClassKind"));
isReg = true;
}
RecordVal *DecoderString = TypeRecord->getValue("DecoderMethod");
StringInit *String = DecoderString ?
dyn_cast<StringInit>(DecoderString->getValue()) : 0;
if (!isReg && String && String->getValue() != "")
Decoder = String->getValue();
OperandInfo OpInfo(Decoder);
unsigned Base = ~0U;
unsigned Width = 0;
unsigned Offset = 0;
for (unsigned bi = 0; bi < Bits.getNumBits(); ++bi) {
VarInit *Var = 0;
VarBitInit *BI = dyn_cast<VarBitInit>(Bits.getBit(bi));
if (BI)
Var = dyn_cast<VarInit>(BI->getBitVar());
else
Var = dyn_cast<VarInit>(Bits.getBit(bi));
if (!Var) {
if (Base != ~0U) {
OpInfo.addField(Base, Width, Offset);
Base = ~0U;
Width = 0;
Offset = 0;
}
continue;
}
if (Var->getName() != NI->second &&
Var->getName() != TiedNames[NI->second]) {
if (Base != ~0U) {
OpInfo.addField(Base, Width, Offset);
Base = ~0U;
Width = 0;
Offset = 0;
}
continue;
}
if (Base == ~0U) {
Base = bi;
Width = 1;
Offset = BI ? BI->getBitNum() : 0;
} else if (BI && BI->getBitNum() != Offset + Width) {
OpInfo.addField(Base, Width, Offset);
Base = bi;
Width = 1;
Offset = BI->getBitNum();
} else {
++Width;
}
}
if (Base != ~0U)
OpInfo.addField(Base, Width, Offset);
if (OpInfo.numFields() > 0)
InsnOperands.push_back(OpInfo);
}
Operands[Opc] = InsnOperands;
#if 0
DEBUG({
dumpBits(errs(), Bits);
errs() << '\n';
for (unsigned i = 0, e = CGI.Operands.size(); i != e; ++i) {
const CGIOperandList::OperandInfo &Info = CGI.Operands[i];
const std::string &OperandName = Info.Name;
const Record &OperandDef = *Info.Rec;
errs() << "\t" << OperandName << " (" << OperandDef.getName() << ")\n";
}
});
#endif
return true;
}
static void emitFieldFromInstruction(formatted_raw_ostream &OS) {
OS << "// Helper function for extracting fields from encoded instructions.\n"
<< "template<typename InsnType>\n"
<< "static InsnType fieldFromInstruction(InsnType insn, unsigned startBit,\n"
<< " unsigned numBits) {\n"
<< " assert(startBit + numBits <= (sizeof(InsnType)*8) &&\n"
<< " \"Instruction field out of bounds!\");\n"
<< " InsnType fieldMask;\n"
<< " if (numBits == sizeof(InsnType)*8)\n"
<< " fieldMask = (InsnType)(-1LL);\n"
<< " else\n"
<< " fieldMask = (((InsnType)1 << numBits) - 1) << startBit;\n"
<< " return (insn & fieldMask) >> startBit;\n"
<< "}\n\n";
}
static void emitDecodeInstruction(formatted_raw_ostream &OS) {
OS << "template<typename InsnType>\n"
<< "static DecodeStatus decodeInstruction(const uint8_t DecodeTable[], MCInst &MI,\n"
<< " InsnType insn, uint64_t Address,\n"
<< " const void *DisAsm,\n"
<< " const MCSubtargetInfo &STI) {\n"
<< " uint64_t Bits = STI.getFeatureBits();\n"
<< "\n"
<< " const uint8_t *Ptr = DecodeTable;\n"
<< " uint32_t CurFieldValue = 0;\n"
<< " DecodeStatus S = MCDisassembler::Success;\n"
<< " for (;;) {\n"
<< " ptrdiff_t Loc = Ptr - DecodeTable;\n"
<< " switch (*Ptr) {\n"
<< " default:\n"
<< " errs() << Loc << \": Unexpected decode table opcode!\\n\";\n"
<< " return MCDisassembler::Fail;\n"
<< " case MCD::OPC_ExtractField: {\n"
<< " unsigned Start = *++Ptr;\n"
<< " unsigned Len = *++Ptr;\n"
<< " ++Ptr;\n"
<< " CurFieldValue = fieldFromInstruction(insn, Start, Len);\n"
<< " DEBUG(dbgs() << Loc << \": OPC_ExtractField(\" << Start << \", \"\n"
<< " << Len << \"): \" << CurFieldValue << \"\\n\");\n"
<< " break;\n"
<< " }\n"
<< " case MCD::OPC_FilterValue: {\n"
<< " // Decode the field value.\n"
<< " unsigned Len;\n"
<< " InsnType Val = decodeULEB128(++Ptr, &Len);\n"
<< " Ptr += Len;\n"
<< " // NumToSkip is a plain 16-bit integer.\n"
<< " unsigned NumToSkip = *Ptr++;\n"
<< " NumToSkip |= (*Ptr++) << 8;\n"
<< "\n"
<< " // Perform the filter operation.\n"
<< " if (Val != CurFieldValue)\n"
<< " Ptr += NumToSkip;\n"
<< " DEBUG(dbgs() << Loc << \": OPC_FilterValue(\" << Val << \", \" << NumToSkip\n"
<< " << \"): \" << ((Val != CurFieldValue) ? \"FAIL:\" : \"PASS:\")\n"
<< " << \" continuing at \" << (Ptr - DecodeTable) << \"\\n\");\n"
<< "\n"
<< " break;\n"
<< " }\n"
<< " case MCD::OPC_CheckField: {\n"
<< " unsigned Start = *++Ptr;\n"
<< " unsigned Len = *++Ptr;\n"
<< " InsnType FieldValue = fieldFromInstruction(insn, Start, Len);\n"
<< " // Decode the field value.\n"
<< " uint32_t ExpectedValue = decodeULEB128(++Ptr, &Len);\n"
<< " Ptr += Len;\n"
<< " // NumToSkip is a plain 16-bit integer.\n"
<< " unsigned NumToSkip = *Ptr++;\n"
<< " NumToSkip |= (*Ptr++) << 8;\n"
<< "\n"
<< " // If the actual and expected values don't match, skip.\n"
<< " if (ExpectedValue != FieldValue)\n"
<< " Ptr += NumToSkip;\n"
<< " DEBUG(dbgs() << Loc << \": OPC_CheckField(\" << Start << \", \"\n"
<< " << Len << \", \" << ExpectedValue << \", \" << NumToSkip\n"
<< " << \"): FieldValue = \" << FieldValue << \", ExpectedValue = \"\n"
<< " << ExpectedValue << \": \"\n"
<< " << ((ExpectedValue == FieldValue) ? \"PASS\\n\" : \"FAIL\\n\"));\n"
<< " break;\n"
<< " }\n"
<< " case MCD::OPC_CheckPredicate: {\n"
<< " unsigned Len;\n"
<< " // Decode the Predicate Index value.\n"
<< " unsigned PIdx = decodeULEB128(++Ptr, &Len);\n"
<< " Ptr += Len;\n"
<< " // NumToSkip is a plain 16-bit integer.\n"
<< " unsigned NumToSkip = *Ptr++;\n"
<< " NumToSkip |= (*Ptr++) << 8;\n"
<< " // Check the predicate.\n"
<< " bool Pred;\n"
<< " if (!(Pred = checkDecoderPredicate(PIdx, Bits)))\n"
<< " Ptr += NumToSkip;\n"
<< " (void)Pred;\n"
<< " DEBUG(dbgs() << Loc << \": OPC_CheckPredicate(\" << PIdx << \"): \"\n"
<< " << (Pred ? \"PASS\\n\" : \"FAIL\\n\"));\n"
<< "\n"
<< " break;\n"
<< " }\n"
<< " case MCD::OPC_Decode: {\n"
<< " unsigned Len;\n"
<< " // Decode the Opcode value.\n"
<< " unsigned Opc = decodeULEB128(++Ptr, &Len);\n"
<< " Ptr += Len;\n"
<< " unsigned DecodeIdx = decodeULEB128(Ptr, &Len);\n"
<< " Ptr += Len;\n"
<< " DEBUG(dbgs() << Loc << \": OPC_Decode: opcode \" << Opc\n"
<< " << \", using decoder \" << DecodeIdx << \"\\n\" );\n"
<< " DEBUG(dbgs() << \"----- DECODE SUCCESSFUL -----\\n\");\n"
<< "\n"
<< " MI.setOpcode(Opc);\n"
<< " return decodeToMCInst(S, DecodeIdx, insn, MI, Address, DisAsm);\n"
<< " }\n"
<< " case MCD::OPC_SoftFail: {\n"
<< " // Decode the mask values.\n"
<< " unsigned Len;\n"
<< " InsnType PositiveMask = decodeULEB128(++Ptr, &Len);\n"
<< " Ptr += Len;\n"
<< " InsnType NegativeMask = decodeULEB128(Ptr, &Len);\n"
<< " Ptr += Len;\n"
<< " bool Fail = (insn & PositiveMask) || (~insn & NegativeMask);\n"
<< " if (Fail)\n"
<< " S = MCDisassembler::SoftFail;\n"
<< " DEBUG(dbgs() << Loc << \": OPC_SoftFail: \" << (Fail ? \"FAIL\\n\":\"PASS\\n\"));\n"
<< " break;\n"
<< " }\n"
<< " case MCD::OPC_Fail: {\n"
<< " DEBUG(dbgs() << Loc << \": OPC_Fail\\n\");\n"
<< " return MCDisassembler::Fail;\n"
<< " }\n"
<< " }\n"
<< " }\n"
<< " llvm_unreachable(\"bogosity detected in disassembler state machine!\");\n"
<< "}\n\n";
}
void FixedLenDecoderEmitter::run(raw_ostream &o) {
formatted_raw_ostream OS(o);
OS << "#include \"llvm/MC/MCInst.h\"\n";
OS << "#include \"llvm/Support/Debug.h\"\n";
OS << "#include \"llvm/Support/DataTypes.h\"\n";
OS << "#include \"llvm/Support/LEB128.h\"\n";
OS << "#include \"llvm/Support/raw_ostream.h\"\n";
OS << "#include <assert.h>\n";
OS << '\n';
OS << "namespace llvm {\n\n";
emitFieldFromInstruction(OS);
Target.reverseBitsForLittleEndianEncoding();
NumberedInstructions = &Target.getInstructionsByEnumValue();
std::map<std::pair<std::string, unsigned>,
std::vector<unsigned> > OpcMap;
std::map<unsigned, std::vector<OperandInfo> > Operands;
for (unsigned i = 0; i < NumberedInstructions->size(); ++i) {
const CodeGenInstruction *Inst = NumberedInstructions->at(i);
const Record *Def = Inst->TheDef;
unsigned Size = Def->getValueAsInt("Size");
if (Def->getValueAsString("Namespace") == "TargetOpcode" ||
Def->getValueAsBit("isPseudo") ||
Def->getValueAsBit("isAsmParserOnly") ||
Def->getValueAsBit("isCodeGenOnly"))
continue;
std::string DecoderNamespace = Def->getValueAsString("DecoderNamespace");
if (Size) {
if (populateInstruction(Target, *Inst, i, Operands)) {
OpcMap[std::make_pair(DecoderNamespace, Size)].push_back(i);
}
}
}
DecoderTableInfo TableInfo;
for (std::map<std::pair<std::string, unsigned>,
std::vector<unsigned> >::const_iterator
I = OpcMap.begin(), E = OpcMap.end(); I != E; ++I) {
FilterChooser FC(*NumberedInstructions, I->second, Operands,
8*I->first.second, this);
TableInfo.Table.clear();
TableInfo.FixupStack.clear();
TableInfo.Table.reserve(16384);
TableInfo.FixupStack.push_back(FixupList());
FC.emitTableEntries(TableInfo);
assert(TableInfo.FixupStack.size() == 1 && "fixup stack phasing error!");
resolveTableFixups(TableInfo.Table, TableInfo.FixupStack.back(),
TableInfo.Table.size());
TableInfo.FixupStack.clear();
TableInfo.Table.push_back(MCD::OPC_Fail);
emitTable(OS, TableInfo.Table, 0, FC.getBitWidth(), I->first.first);
OS.flush();
}
emitPredicateFunction(OS, TableInfo.Predicates, 0);
emitDecoderFunction(OS, TableInfo.Decoders, 0);
emitDecodeInstruction(OS);
OS << "\n} // End llvm namespace\n";
}
namespace llvm {
void EmitFixedLenDecoder(RecordKeeper &RK, raw_ostream &OS,
std::string PredicateNamespace,
std::string GPrefix,
std::string GPostfix,
std::string ROK,
std::string RFail,
std::string L) {
FixedLenDecoderEmitter(RK, PredicateNamespace, GPrefix, GPostfix,
ROK, RFail, L).run(OS);
}
}