//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "decoder-emitter"
-
-#include "FixedLenDecoderEmitter.h"
#include "CodeGenTarget.h"
-#include "Record.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 <vector>
+#include "llvm/TableGen/Error.h"
+#include "llvm/TableGen/Record.h"
#include <map>
#include <string>
+#include <vector>
using namespace llvm;
+#define DEBUG_TYPE "decoder-emitter"
+
+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;
+};
+
+} // End anonymous namespace
+
+namespace {
+class FixedLenDecoderEmitter {
+ const std::vector<const CodeGenInstruction*> *NumberedInstructions;
+public:
+
+ // Defaults preserved here for documentation, even though they aren't
+ // strictly necessary given the way that this is currently being called.
+ 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) {}
+
+ // Emit the decoder state machine table.
+ 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;
+
+ // run - Output the code emitter
+ void run(raw_ostream &o);
+
+private:
+ CodeGenTarget Target;
+public:
+ std::string PredicateNamespace;
+ std::string GuardPrefix, GuardPostfix;
+ std::string ReturnOK, ReturnFail;
+ std::string Locals;
+};
+} // End anonymous namespace
+
// The set (BIT_TRUE, BIT_FALSE, BIT_UNSET) represents a ternary logic system
// for a bit value.
//
static int Value(bit_value_t V) {
return ValueNotSet(V) ? -1 : (V == BIT_FALSE ? 0 : 1);
}
-static bit_value_t bitFromBits(BitsInit &bits, unsigned index) {
- if (BitInit *bit = dynamic_cast<BitInit*>(bits.getBit(index)))
+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;
// The bit is uninitialized.
return BIT_UNSET;
}
// Prints the bit value for each position.
-static void dumpBits(raw_ostream &o, BitsInit &bits) {
- unsigned index;
-
- for (index = bits.getNumBits(); index > 0; index--) {
+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";
o << "_";
break;
default:
- assert(0 && "unexpected return value from bitFromBits");
+ llvm_unreachable("unexpected return value from bitFromBits");
}
}
}
}
// Forward declaration.
+namespace {
class FilterChooser;
+} // End anonymous namespace
// Representation of the instruction to work on.
typedef std::vector<bit_value_t> insn_t;
/// decoder could try to decode the even/odd register numbering and assign to
/// VST4q8a or VST4q8b, but for the time being, the decoder chooses the "a"
/// version and return the Opcode since the two have the same Asm format string.
+namespace {
class Filter {
protected:
- FilterChooser *Owner; // points to the FilterChooser who owns this filter
+ const FilterChooser *Owner;// points to the FilterChooser who owns this filter
unsigned StartBit; // the starting bit position
unsigned NumBits; // number of bits to filter
bool Mixed; // a mixed region contains both set and unset bits
std::vector<unsigned> VariableInstructions;
// Map of well-known segment value to its delegate.
- std::map<unsigned, FilterChooser*> FilterChooserMap;
+ std::map<unsigned, std::unique_ptr<const FilterChooser>> FilterChooserMap;
// Number of instructions which fall under FilteredInstructions category.
unsigned NumFiltered;
// Keeps track of the last opcode in the filtered bucket.
unsigned LastOpcFiltered;
- // Number of instructions which fall under VariableInstructions category.
- unsigned NumVariable;
-
public:
- unsigned getNumFiltered() { return NumFiltered; }
- unsigned getNumVariable() { return NumVariable; }
- unsigned getSingletonOpc() {
+ unsigned getNumFiltered() const { return NumFiltered; }
+ unsigned getSingletonOpc() const {
assert(NumFiltered == 1);
return LastOpcFiltered;
}
// Return the filter chooser for the group of instructions without constant
// segment values.
- FilterChooser &getVariableFC() {
+ const FilterChooser &getVariableFC() const {
assert(NumFiltered == 1);
assert(FilterChooserMap.size() == 1);
return *(FilterChooserMap.find((unsigned)-1)->second);
}
- Filter(const Filter &f);
+ Filter(Filter &&f);
Filter(FilterChooser &owner, unsigned startBit, unsigned numBits, bool mixed);
~Filter();
// match the remaining undecoded encoding bits against the singleton.
void recurse();
- // Emit code to decode instructions given a segment or segments of bits.
- void emit(raw_ostream &o, unsigned &Indentation);
+ // Emit table entries to decode instructions given a segment or segments of
+ // bits.
+ void emitTableEntry(DecoderTableInfo &TableInfo) const;
// Returns the number of fanout produced by the filter. More fanout implies
// the filter distinguishes more categories of instructions.
unsigned usefulness() const;
}; // End of class Filter
+} // End anonymous namespace
// These are states of our finite state machines used in FilterChooser's
// filterProcessor() which produces the filter candidates to use.
/// It is useful to think of a Filter as governing the switch stmts of the
/// decoding tree. And each case is delegated to an inferior FilterChooser to
/// decide what further remaining bits to look at.
+namespace {
class FilterChooser {
protected:
friend class Filter;
const std::vector<const CodeGenInstruction*> &AllInstructions;
// Vector of uid's for this filter chooser to work on.
- const std::vector<unsigned> Opcodes;
+ const std::vector<unsigned> &Opcodes;
// Lookup table for the operand decoding of instructions.
- std::map<unsigned, std::vector<OperandInfo> > &Operands;
+ const std::map<unsigned, std::vector<OperandInfo> > &Operands;
// Vector of candidate filters.
std::vector<Filter> Filters;
std::vector<bit_value_t> FilterBitValues;
// Links to the FilterChooser above us in the decoding tree.
- FilterChooser *Parent;
+ const FilterChooser *Parent;
// Index of the best filter from Filters.
int BestIndex;
// Width of instructions
unsigned BitWidth;
+ // Parent emitter
+ const FixedLenDecoderEmitter *Emitter;
+
+ FilterChooser(const FilterChooser &) = delete;
+ void operator=(const FilterChooser &) = delete;
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) { }
FilterChooser(const std::vector<const CodeGenInstruction*> &Insts,
const std::vector<unsigned> &IDs,
- std::map<unsigned, std::vector<OperandInfo> > &Ops,
- unsigned BW) :
- AllInstructions(Insts), Opcodes(IDs), Operands(Ops), Filters(),
- Parent(NULL), BestIndex(-1), BitWidth(BW) {
- for (unsigned i = 0; i < BitWidth; ++i)
- FilterBitValues.push_back(BIT_UNFILTERED);
-
+ const std::map<unsigned, std::vector<OperandInfo> > &Ops,
+ unsigned BW,
+ const FixedLenDecoderEmitter *E)
+ : AllInstructions(Insts), Opcodes(IDs), Operands(Ops), Filters(),
+ FilterBitValues(BW, BIT_UNFILTERED), Parent(nullptr), BestIndex(-1),
+ BitWidth(BW), Emitter(E) {
doFilter();
}
FilterChooser(const std::vector<const CodeGenInstruction*> &Insts,
const std::vector<unsigned> &IDs,
- std::map<unsigned, std::vector<OperandInfo> > &Ops,
- std::vector<bit_value_t> &ParentFilterBitValues,
- FilterChooser &parent) :
- AllInstructions(Insts), Opcodes(IDs), Operands(Ops),
+ 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) {
+ Parent(&parent), BestIndex(-1), BitWidth(parent.BitWidth),
+ Emitter(parent.Emitter) {
doFilter();
}
- // The top level filter chooser has NULL as its parent.
- bool isTopLevel() { return Parent == NULL; }
-
- // Emit the top level typedef and decodeInstruction() function.
- void emitTop(raw_ostream &o, unsigned Indentation, std::string Namespace);
+ unsigned getBitWidth() const { return BitWidth; }
protected:
// Populates the insn given the uid.
void insnWithID(insn_t &Insn, unsigned Opcode) const {
BitsInit &Bits = getBitsField(*AllInstructions[Opcode]->TheDef, "Inst");
- for (unsigned i = 0; i < BitWidth; ++i)
- Insn.push_back(bitFromBits(Bits, i));
+ // We may have a SoftFail bitmask, which specifies a mask where an encoding
+ // may differ from the value in "Inst" and yet still be valid, but the
+ // disassembler should return SoftFail instead of Success.
+ //
+ // This is used for marking UNPREDICTABLE instructions in the ARM world.
+ 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));
+ }
}
// Returns the record name.
// Returns false if there exists any uninitialized bit value in the range.
// Returns true, otherwise.
bool fieldFromInsn(uint64_t &Field, insn_t &Insn, unsigned StartBit,
- unsigned NumBits) const;
+ unsigned NumBits) const;
/// dumpFilterArray - dumpFilterArray prints out debugging info for the given
/// filter array as a series of chars.
- void dumpFilterArray(raw_ostream &o, std::vector<bit_value_t> & filter);
+ void dumpFilterArray(raw_ostream &o,
+ const std::vector<bit_value_t> & filter) const;
/// dumpStack - dumpStack traverses the filter chooser chain and calls
/// dumpFilterArray on each filter chooser up to the top level one.
- void dumpStack(raw_ostream &o, const char *prefix);
+ void dumpStack(raw_ostream &o, const char *prefix) const;
Filter &bestFilter() {
assert(BestIndex != -1 && "BestIndex not set");
}
// Called from Filter::recurse() when singleton exists. For debug purpose.
- void SingletonExists(unsigned Opc);
+ void SingletonExists(unsigned Opc) const;
- bool PositionFiltered(unsigned i) {
+ bool PositionFiltered(unsigned i) const {
return ValueSet(FilterBitValues[i]);
}
// Inst{20} = 1 && Inst{3-0} == 0b1111 represents two islands of yet-to-be
// decoded bits in order to verify that the instruction matches the Opcode.
unsigned getIslands(std::vector<unsigned> &StartBits,
- std::vector<unsigned> &EndBits, std::vector<uint64_t> &FieldVals,
- insn_t &Insn);
+ std::vector<unsigned> &EndBits,
+ std::vector<uint64_t> &FieldVals,
+ const insn_t &Insn) const;
+
+ // Emits code to check the Predicates member of an instruction are true.
+ // Returns true if predicate matches were emitted, false otherwise.
+ 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;
- // Emits code to decode the singleton. Return true if we have matched all the
- // well-known bits.
- bool emitSingletonDecoder(raw_ostream &o, unsigned &Indentation,unsigned Opc);
+ void emitSoftFailTableEntry(DecoderTableInfo &TableInfo,
+ unsigned Opc) const;
+
+ // Emits table entries to decode the singleton.
+ void emitSingletonTableEntry(DecoderTableInfo &TableInfo,
+ unsigned Opc) const;
// Emits code to decode the singleton, and then to decode the rest.
- void emitSingletonDecoder(raw_ostream &o, unsigned &Indentation,Filter &Best);
+ void emitSingletonTableEntry(DecoderTableInfo &TableInfo,
+ const Filter &Best) const;
+
+ void emitBinaryParser(raw_ostream &o, unsigned &Indentation,
+ const OperandInfo &OpInfo) const;
- void emitBinaryParser(raw_ostream &o , unsigned &Indentation,
- OperandInfo &OpInfo);
+ void emitDecoder(raw_ostream &OS, unsigned Indentation, unsigned Opc) const;
+ unsigned getDecoderIndex(DecoderSet &Decoders, unsigned Opc) const;
// Assign a single filter and run with it.
- void runSingleFilter(FilterChooser &owner, unsigned startBit, unsigned numBit,
- bool mixed);
+ void runSingleFilter(unsigned startBit, unsigned numBit, bool mixed);
// reportRegion is a helper function for filterProcessor to mark a region as
// eligible for use as a filter region.
void reportRegion(bitAttr_t RA, unsigned StartBit, unsigned BitIndex,
- bool AllowMixed);
+ bool AllowMixed);
// FilterProcessor scans the well-known encoding bits of the instructions and
// builds up a list of candidate filters. It chooses the best filter and
// dump the conflict set to the standard error.
void doFilter();
- // Emits code to decode our share of instructions. Returns true if the
- // emitted code causes a return, which occurs if we know how to decode
- // the instruction at this level or the instruction is not decodeable.
- bool emit(raw_ostream &o, unsigned &Indentation);
+public:
+ // emitTableEntries - Emit state machine entries to decode our share of
+ // instructions.
+ void emitTableEntries(DecoderTableInfo &TableInfo) const;
};
+} // End anonymous namespace
///////////////////////////
// //
-// Filter Implmenetation //
+// Filter Implementation //
// //
///////////////////////////
-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), NumVariable(f.NumVariable) {
+Filter::Filter(Filter &&f)
+ : Owner(f.Owner), StartBit(f.StartBit), NumBits(f.NumBits), Mixed(f.Mixed),
+ FilteredInstructions(std::move(f.FilteredInstructions)),
+ VariableInstructions(std::move(f.VariableInstructions)),
+ FilterChooserMap(std::move(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) {
+ bool mixed)
+ : Owner(&owner), StartBit(startBit), NumBits(numBits), Mixed(mixed) {
assert(StartBit + NumBits - 1 < Owner->BitWidth);
NumFiltered = 0;
LastOpcFiltered = 0;
- NumVariable = 0;
for (unsigned i = 0, e = Owner->Opcodes.size(); i != e; ++i) {
insn_t Insn;
FilteredInstructions[Field].push_back(LastOpcFiltered);
++NumFiltered;
} else {
- // Some of the encoding bit(s) are unspecfied. This contributes to
+ // Some of the encoding bit(s) are unspecified. This contributes to
// one additional member of "Variable" instructions.
VariableInstructions.push_back(Owner->Opcodes[i]);
- ++NumVariable;
}
}
}
Filter::~Filter() {
- std::map<unsigned, FilterChooser*>::iterator filterIterator;
- for (filterIterator = FilterChooserMap.begin();
- filterIterator != FilterChooserMap.end();
- filterIterator++) {
- delete filterIterator->second;
- }
}
// Divides the decoding task into sub tasks and delegates them to the
// instructions. In order to unambiguously decode the singleton, we need to
// match the remaining undecoded encoding bits against the singleton.
void Filter::recurse() {
- std::map<uint64_t, std::vector<unsigned> >::const_iterator mapIterator;
-
// Starts by inheriting our parent filter chooser's filter bit values.
std::vector<bit_value_t> BitValueArray(Owner->FilterBitValues);
- unsigned bitIndex;
-
- if (VariableInstructions.size()) {
+ if (!VariableInstructions.empty()) {
// Conservatively marks each segment position as BIT_UNSET.
- for (bitIndex = 0; bitIndex < NumBits; bitIndex++)
+ for (unsigned bitIndex = 0; bitIndex < NumBits; ++bitIndex)
BitValueArray[StartBit + bitIndex] = BIT_UNSET;
// Delegates to an inferior filter chooser for further processing on this
// group of instructions whose segment values are variable.
- FilterChooserMap.insert(std::pair<unsigned, FilterChooser*>(
- (unsigned)-1,
- new FilterChooser(Owner->AllInstructions,
- VariableInstructions,
- Owner->Operands,
- BitValueArray,
- *Owner)
- ));
+ FilterChooserMap.insert(
+ std::make_pair(-1U, llvm::make_unique<FilterChooser>(
+ Owner->AllInstructions, VariableInstructions,
+ Owner->Operands, BitValueArray, *Owner)));
}
// No need to recurse for a singleton filtered instruction.
- // See also Filter::emit().
+ // See also Filter::emit*().
if (getNumFiltered() == 1) {
//Owner->SingletonExists(LastOpcFiltered);
assert(FilterChooserMap.size() == 1);
}
// Otherwise, create sub choosers.
- for (mapIterator = FilteredInstructions.begin();
- mapIterator != FilteredInstructions.end();
- mapIterator++) {
+ for (const auto &Inst : FilteredInstructions) {
// Marks all the segment positions with either BIT_TRUE or BIT_FALSE.
- for (bitIndex = 0; bitIndex < NumBits; bitIndex++) {
- if (mapIterator->first & (1ULL << bitIndex))
+ for (unsigned bitIndex = 0; bitIndex < NumBits; ++bitIndex) {
+ if (Inst.first & (1ULL << bitIndex))
BitValueArray[StartBit + bitIndex] = BIT_TRUE;
else
BitValueArray[StartBit + bitIndex] = BIT_FALSE;
// Delegates to an inferior filter chooser for further processing on this
// category of instructions.
- FilterChooserMap.insert(std::pair<unsigned, FilterChooser*>(
- mapIterator->first,
- new FilterChooser(Owner->AllInstructions,
- mapIterator->second,
- Owner->Operands,
- BitValueArray,
- *Owner)
- ));
+ FilterChooserMap.insert(std::make_pair(
+ Inst.first, llvm::make_unique<FilterChooser>(
+ Owner->AllInstructions, Inst.second,
+ Owner->Operands, BitValueArray, *Owner)));
}
}
-// Emit code to decode instructions given a segment or segments of bits.
-void Filter::emit(raw_ostream &o, unsigned &Indentation) {
- o.indent(Indentation) << "// Check Inst{";
-
- if (NumBits > 1)
- o << (StartBit + NumBits - 1) << '-';
-
- o << StartBit << "} ...\n";
+static void resolveTableFixups(DecoderTable &Table, const FixupList &Fixups,
+ uint32_t DestIdx) {
+ // Any NumToSkip fixups in the current scope can resolve to the
+ // current location.
+ for (FixupList::const_reverse_iterator I = Fixups.rbegin(),
+ E = Fixups.rend();
+ I != E; ++I) {
+ // Calculate the distance from the byte following the fixup entry byte
+ // to the destination. The Target is calculated from after the 16-bit
+ // NumToSkip entry itself, so subtract two from the displacement here
+ // to account for that.
+ uint32_t FixupIdx = *I;
+ uint32_t Delta = DestIdx - FixupIdx - 2;
+ // Our NumToSkip entries are 16-bits. Make sure our table isn't too
+ // big.
+ assert(Delta < 65536U && "disassembler decoding table too large!");
+ Table[FixupIdx] = (uint8_t)Delta;
+ Table[FixupIdx + 1] = (uint8_t)(Delta >> 8);
+ }
+}
- o.indent(Indentation) << "switch (fieldFromInstruction" << Owner->BitWidth
- << "(insn, " << StartBit << ", "
- << NumBits << ")) {\n";
+// Emit table entries to decode instructions given a segment or segments
+// of bits.
+void Filter::emitTableEntry(DecoderTableInfo &TableInfo) const {
+ TableInfo.Table.push_back(MCD::OPC_ExtractField);
+ TableInfo.Table.push_back(StartBit);
+ TableInfo.Table.push_back(NumBits);
- std::map<unsigned, FilterChooser*>::iterator filterIterator;
+ // A new filter entry begins a new scope for fixup resolution.
+ TableInfo.FixupStack.push_back(FixupList());
- bool DefaultCase = false;
- for (filterIterator = FilterChooserMap.begin();
- filterIterator != FilterChooserMap.end();
- filterIterator++) {
+ DecoderTable &Table = TableInfo.Table;
+ size_t PrevFilter = 0;
+ bool HasFallthrough = false;
+ for (auto &Filter : FilterChooserMap) {
// Field value -1 implies a non-empty set of variable instructions.
// See also recurse().
- if (filterIterator->first == (unsigned)-1) {
- DefaultCase = true;
-
- o.indent(Indentation) << "default:\n";
- o.indent(Indentation) << " break; // fallthrough\n";
-
- // Closing curly brace for the switch statement.
- // This is unconventional because we want the default processing to be
- // performed for the fallthrough cases as well, i.e., when the "cases"
- // did not prove a decoded instruction.
- o.indent(Indentation) << "}\n";
-
- } else
- o.indent(Indentation) << "case " << filterIterator->first << ":\n";
+ if (Filter.first == (unsigned)-1) {
+ HasFallthrough = true;
+
+ // Each scope should always have at least one filter value to check
+ // for.
+ assert(PrevFilter != 0 && "empty filter set!");
+ FixupList &CurScope = TableInfo.FixupStack.back();
+ // Resolve any NumToSkip fixups in the current scope.
+ resolveTableFixups(Table, CurScope, Table.size());
+ CurScope.clear();
+ PrevFilter = 0; // Don't re-process the filter's fallthrough.
+ } else {
+ Table.push_back(MCD::OPC_FilterValue);
+ // Encode and emit the value to filter against.
+ uint8_t Buffer[8];
+ unsigned Len = encodeULEB128(Filter.first, Buffer);
+ Table.insert(Table.end(), Buffer, Buffer + Len);
+ // Reserve space for the NumToSkip entry. We'll backpatch the value
+ // later.
+ PrevFilter = Table.size();
+ Table.push_back(0);
+ Table.push_back(0);
+ }
// We arrive at a category of instructions with the same segment value.
// Now delegate to the sub filter chooser for further decodings.
// The case may fallthrough, which happens if the remaining well-known
// encoding bits do not match exactly.
- if (!DefaultCase) { ++Indentation; ++Indentation; }
-
- bool finished = filterIterator->second->emit(o, Indentation);
- // For top level default case, there's no need for a break statement.
- if (Owner->isTopLevel() && DefaultCase)
- break;
- if (!finished)
- o.indent(Indentation) << "break;\n";
-
- if (!DefaultCase) { --Indentation; --Indentation; }
+ Filter.second->emitTableEntries(TableInfo);
+
+ // Now that we've emitted the body of the handler, update the NumToSkip
+ // of the filter itself to be able to skip forward when false. Subtract
+ // two as to account for the width of the NumToSkip field itself.
+ 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);
+ }
}
- // If there is no default case, we still need to supply a closing brace.
- if (!DefaultCase) {
- // Closing curly brace for the switch statement.
- o.indent(Indentation) << "}\n";
- }
+ // Any remaining unresolved fixups bubble up to the parent fixup scope.
+ 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 there is no fallthrough, then the final filter should get fixed
+ // up according to the enclosing scope rather than the current position.
+ if (!HasFallthrough)
+ TableInfo.FixupStack.back().push_back(PrevFilter);
}
// Returns the number of fanout produced by the filter. More fanout implies
// the filter distinguishes more categories of instructions.
unsigned Filter::usefulness() const {
- if (VariableInstructions.size())
+ if (!VariableInstructions.empty())
return FilteredInstructions.size();
else
return FilteredInstructions.size() + 1;
// //
//////////////////////////////////
-// Emit the top level typedef and decodeInstruction() function.
-void FilterChooser::emitTop(raw_ostream &o, unsigned Indentation,
- std::string Namespace) {
- o.indent(Indentation) <<
- "static bool decode" << Namespace << "Instruction" << BitWidth
- << "(MCInst &MI, uint" << BitWidth << "_t insn, uint64_t Address, "
- << "const void *Decoder) {\n";
- o.indent(Indentation) << " unsigned tmp = 0;\n (void)tmp;\n";
+// Emit the decoder state machine table.
+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; ++Indentation;
- // Emits code to decode the instructions.
- emit(o, Indentation);
+ Indentation += 2;
- o << '\n';
- o.indent(Indentation) << "return false;\n";
- --Indentation; --Indentation;
+ // FIXME: We may be able to use the NumToSkip values to recover
+ // appropriate indentation levels.
+ DecoderTable::const_iterator I = Table.begin();
+ DecoderTable::const_iterator E = Table.end();
+ while (I != E) {
+ assert (I < E && "incomplete decode table entry!");
- o.indent(Indentation) << "}\n";
+ uint64_t Pos = I - Table.begin();
+ OS << "/* " << Pos << " */";
+ OS.PadToColumn(12);
- o << '\n';
+ 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, ";
+ // The filter value is ULEB128 encoded.
+ while (*I >= 128)
+ OS << utostr(*I++) << ", ";
+ OS << utostr(*I++) << ", ";
+
+ // 16-bit numtoskip value.
+ 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 << ", ";// << Val << ", " << NumToSkip << ",\n";
+ // ULEB128 encoded field value.
+ for (; *I >= 128; ++I)
+ OS << utostr(*I) << ", ";
+ OS << utostr(*I++) << ", ";
+ // 16-bit numtoskip value.
+ 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++) << ", ";
+
+ // 16-bit numtoskip value.
+ 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;
+ // Extract the ULEB128 encoded Opcode to a buffer.
+ uint8_t Buffer[8], *p = Buffer;
+ while ((*p++ = *I++) >= 128)
+ assert((p - Buffer) <= (ptrdiff_t)sizeof(Buffer)
+ && "ULEB128 value too large!");
+ // Decode the Opcode value.
+ unsigned Opc = decodeULEB128(Buffer);
+ OS.indent(Indentation) << "MCD::OPC_Decode, ";
+ for (p = Buffer; *p >= 128; ++p)
+ OS << utostr(*p) << ", ";
+ OS << utostr(*p) << ", ";
+
+ // Decoder index.
+ 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";
+ // Positive mask
+ 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) << " */";
+ // Negative mask
+ 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 {
+ // The predicate function is just a big switch statement based on the
+ // input predicate index.
+ 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 (const auto &Predicate : Predicates) {
+ OS.indent(Indentation) << "case " << Index++ << ":\n";
+ OS.indent(Indentation+2) << "return (" << Predicate << ");\n";
+ }
+ OS.indent(Indentation) << "}\n";
+ } else {
+ // No case statement to emit
+ 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 {
+ // The decoder function is just a big switch statement based on the
+ // input decoder index.
+ 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 (const auto &Decoder : Decoders) {
+ OS.indent(Indentation) << "case " << Index++ << ":\n";
+ OS << Decoder;
+ OS.indent(Indentation+2) << "return S;\n";
+ }
+ OS.indent(Indentation) << "}\n";
+ Indentation -= 2;
+ OS.indent(Indentation) << "}\n\n";
}
// Populates the field of the insn given the start position and the number of
// Returns false if and on the first uninitialized bit value encountered.
// Returns true, otherwise.
bool FilterChooser::fieldFromInsn(uint64_t &Field, insn_t &Insn,
- unsigned StartBit, unsigned NumBits) const {
+ unsigned StartBit, unsigned NumBits) const {
Field = 0;
for (unsigned i = 0; i < NumBits; ++i) {
/// dumpFilterArray - dumpFilterArray prints out debugging info for the given
/// filter array as a series of chars.
void FilterChooser::dumpFilterArray(raw_ostream &o,
- std::vector<bit_value_t> &filter) {
- unsigned bitIndex;
-
- for (bitIndex = BitWidth; bitIndex > 0; bitIndex--) {
+ const std::vector<bit_value_t> &filter) const {
+ for (unsigned bitIndex = BitWidth; bitIndex > 0; bitIndex--) {
switch (filter[bitIndex - 1]) {
case BIT_UNFILTERED:
o << ".";
/// dumpStack - dumpStack traverses the filter chooser chain and calls
/// dumpFilterArray on each filter chooser up to the top level one.
-void FilterChooser::dumpStack(raw_ostream &o, const char *prefix) {
- FilterChooser *current = this;
+void FilterChooser::dumpStack(raw_ostream &o, const char *prefix) const {
+ const FilterChooser *current = this;
while (current) {
o << prefix;
}
// Called from Filter::recurse() when singleton exists. For debug purpose.
-void FilterChooser::SingletonExists(unsigned Opc) {
+void FilterChooser::SingletonExists(unsigned Opc) const {
insn_t Insn0;
insnWithID(Insn0, Opc);
errs() << '\n';
dumpStack(errs(), "\t\t");
- for (unsigned i = 0; i < Opcodes.size(); i++) {
+ for (unsigned i = 0; i < Opcodes.size(); ++i) {
const std::string &Name = nameWithID(Opcodes[i]);
errs() << '\t' << Name << " ";
// Inst{20} = 1 && Inst{3-0} == 0b1111 represents two islands of yet-to-be
// decoded bits in order to verify that the instruction matches the Opcode.
unsigned FilterChooser::getIslands(std::vector<unsigned> &StartBits,
- std::vector<unsigned> &EndBits, std::vector<uint64_t> &FieldVals,
- insn_t &Insn) {
+ std::vector<unsigned> &EndBits,
+ std::vector<uint64_t> &FieldVals,
+ const insn_t &Insn) const {
unsigned Num, BitNo;
Num = BitNo = 0;
Val = Value(Insn[i]);
bool Filtered = PositionFiltered(i);
switch (State) {
- default:
- assert(0 && "Unreachable code!");
- break;
+ default: llvm_unreachable("Unreachable code!");
case 0:
case 1:
if (Filtered || Val == -1)
}
void FilterChooser::emitBinaryParser(raw_ostream &o, unsigned &Indentation,
- OperandInfo &OpInfo) {
- std::string &Decoder = OpInfo.Decoder;
-
- if (OpInfo.numFields() == 1) {
- OperandInfo::iterator OI = OpInfo.begin();
- o.indent(Indentation) << " tmp = fieldFromInstruction" << BitWidth
- << "(insn, " << OI->Base << ", " << OI->Width
- << ");\n";
- } else {
- o.indent(Indentation) << " tmp = 0;\n";
- for (OperandInfo::iterator OI = OpInfo.begin(), OE = OpInfo.end();
- OI != OE; ++OI) {
- o.indent(Indentation) << " tmp |= (fieldFromInstruction" << BitWidth
- << "(insn, " << OI->Base << ", " << OI->Width
- << ") << " << OI->Offset << ");\n";
- }
+ const OperandInfo &OpInfo) const {
+ const std::string &Decoder = OpInfo.Decoder;
+
+ if (OpInfo.numFields() != 1)
+ o.indent(Indentation) << "tmp = 0;\n";
+
+ for (const EncodingField &EF : OpInfo) {
+ o.indent(Indentation) << "tmp ";
+ if (OpInfo.numFields() != 1) o << '|';
+ o << "= fieldFromInstruction"
+ << "(insn, " << EF.Base << ", " << EF.Width << ')';
+ if (OpInfo.numFields() != 1 || EF.Offset != 0)
+ o << " << " << EF.Offset;
+ o << ";\n";
}
if (Decoder != "")
- o.indent(Indentation) << " if (!" << Decoder
- << "(MI, tmp, Address, Decoder)) return false;\n";
+ o.indent(Indentation) << Emitter->GuardPrefix << Decoder
+ << "(MI, tmp, Address, Decoder)"
+ << Emitter->GuardPostfix << "\n";
else
- o.indent(Indentation) << " MI.addOperand(MCOperand::CreateImm(tmp));\n";
+ o.indent(Indentation) << "MI.addOperand(MCOperand::CreateImm(tmp));\n";
}
-// Emits code to decode the singleton. Return true if we have matched all the
-// well-known bits.
-bool FilterChooser::emitSingletonDecoder(raw_ostream &o, unsigned &Indentation,
- unsigned Opc) {
- std::vector<unsigned> StartBits;
- std::vector<unsigned> EndBits;
- std::vector<uint64_t> FieldVals;
- insn_t Insn;
- insnWithID(Insn, Opc);
+void FilterChooser::emitDecoder(raw_ostream &OS, unsigned Indentation,
+ unsigned Opc) const {
+ for (const auto &Op : Operands.find(Opc)->second) {
+ // If a custom instruction decoder was specified, use that.
+ if (Op.numFields() == 0 && Op.Decoder.size()) {
+ OS.indent(Indentation) << Emitter->GuardPrefix << Op.Decoder
+ << "(MI, insn, Address, Decoder)"
+ << Emitter->GuardPostfix << "\n";
+ break;
+ }
- // Look for islands of undecoded bits of the singleton.
- getIslands(StartBits, EndBits, FieldVals, Insn);
+ emitBinaryParser(OS, Indentation, Op);
+ }
+}
- unsigned Size = StartBits.size();
- unsigned I, NumBits;
-
- // If we have matched all the well-known bits, just issue a return.
- if (Size == 0) {
- o.indent(Indentation) << "{\n";
- o.indent(Indentation) << " MI.setOpcode(" << Opc << ");\n";
- std::vector<OperandInfo>& InsnOperands = Operands[Opc];
- for (std::vector<OperandInfo>::iterator
- I = InsnOperands.begin(), E = InsnOperands.end(); I != E; ++I) {
- // If a custom instruction decoder was specified, use that.
- if (I->numFields() == 0 && I->Decoder.size()) {
- o.indent(Indentation) << " if (!" << I->Decoder
- << "(MI, insn, Address, Decoder)) return false;\n";
- break;
- }
+unsigned FilterChooser::getDecoderIndex(DecoderSet &Decoders,
+ unsigned Opc) const {
+ // Build up the predicate string.
+ SmallString<256> Decoder;
+ // FIXME: emitDecoder() function can take a buffer directly rather than
+ // a stream.
+ raw_svector_ostream S(Decoder);
+ unsigned I = 4;
+ emitDecoder(S, I, Opc);
+ S.flush();
+
+ // Using the full decoder string as the key value here is a bit
+ // heavyweight, but is effective. If the string comparisons become a
+ // performance concern, we can implement a mangling of the predicate
+ // data easilly enough with a map back to the actual string. That's
+ // overkill for now, though.
+
+ // Make sure the predicate is in the table.
+ Decoders.insert(Decoder.str());
+ // Now figure out the index for when we write out the table.
+ 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 << " && ";
- emitBinaryParser(o, Indentation, *I);
+ 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;
- o.indent(Indentation) << " return true; // " << nameWithID(Opc)
- << '\n';
- o.indent(Indentation) << "}\n";
return true;
}
+ return false;
+}
- // Otherwise, there are more decodings to be done!
+unsigned FilterChooser::getPredicateIndex(DecoderTableInfo &TableInfo,
+ StringRef Predicate) const {
+ // Using the full predicate string as the key value here is a bit
+ // heavyweight, but is effective. If the string comparisons become a
+ // performance concern, we can implement a mangling of the predicate
+ // data easilly enough with a map back to the actual string. That's
+ // overkill for now, though.
+
+ // Make sure the predicate is in the table.
+ TableInfo.Predicates.insert(Predicate.str());
+ // Now figure out the index for when we write out the table.
+ PredicateSet::const_iterator P = std::find(TableInfo.Predicates.begin(),
+ TableInfo.Predicates.end(),
+ Predicate.str());
+ return (unsigned)(P - TableInfo.Predicates.begin());
+}
- // Emit code to match the island(s) for the singleton.
- o.indent(Indentation) << "// Check ";
+void FilterChooser::emitPredicateTableEntry(DecoderTableInfo &TableInfo,
+ unsigned Opc) const {
+ if (!doesOpcodeNeedPredicate(Opc))
+ return;
- for (I = Size; I != 0; --I) {
- o << "Inst{" << EndBits[I-1] << '-' << StartBits[I-1] << "} ";
- if (I > 1)
- o << "&& ";
- else
- o << "for singleton decoding...\n";
- }
+ // Build up the predicate string.
+ SmallString<256> Predicate;
+ // FIXME: emitPredicateMatch() functions can take a buffer directly rather
+ // than a stream.
+ raw_svector_ostream PS(Predicate);
+ unsigned I = 0;
+ emitPredicateMatch(PS, I, Opc);
+
+ // Figure out the index into the predicate table for the predicate just
+ // computed.
+ 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);
+ // Predicate index
+ for (unsigned i = 0, e = PBytes.size(); i != e; ++i)
+ TableInfo.Table.push_back(PBytes[i]);
+ // Push location for NumToSkip backpatching.
+ TableInfo.FixupStack.back().push_back(TableInfo.Table.size());
+ TableInfo.Table.push_back(0);
+ TableInfo.Table.push_back(0);
+}
- o.indent(Indentation) << "if (";
+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");
- for (I = Size; I != 0; --I) {
- NumBits = EndBits[I-1] - StartBits[I-1] + 1;
- o << "fieldFromInstruction" << BitWidth << "(insn, "
- << StartBits[I-1] << ", " << NumBits
- << ") == " << FieldVals[I-1];
- if (I > 1)
- o << " && ";
- else
- o << ") {\n";
- }
- o.indent(Indentation) << " MI.setOpcode(" << Opc << ");\n";
- std::vector<OperandInfo>& InsnOperands = Operands[Opc];
- for (std::vector<OperandInfo>::iterator
- I = InsnOperands.begin(), E = InsnOperands.end(); I != E; ++I) {
- // If a custom instruction decoder was specified, use that.
- if (I->numFields() == 0 && I->Decoder.size()) {
- o.indent(Indentation) << " " << I->Decoder
- << "(MI, insn, Address, Decoder);\n";
+ 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:
+ // The bit is meant to be false, so emit a check to see if it is true.
+ PositiveMask.setBit(i);
break;
+ case BIT_TRUE:
+ // The bit is meant to be true, so emit a check to see if it is false.
+ NegativeMask.setBit(i);
+ break;
+ default:
+ // The bit is not set; this must be an error!
+ 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;
}
-
- emitBinaryParser(o, Indentation, *I);
}
- o.indent(Indentation) << " return true; // " << nameWithID(Opc)
- << '\n';
- o.indent(Indentation) << "}\n";
- return false;
+ 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);
}
-// Emits code to decode the singleton, and then to decode the rest.
-void FilterChooser::emitSingletonDecoder(raw_ostream &o, unsigned &Indentation,
- Filter &Best) {
+// Emits table entries to decode the singleton.
+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);
+
+ // Look for islands of undecoded bits of the singleton.
+ getIslands(StartBits, EndBits, FieldVals, Insn);
+
+ unsigned Size = StartBits.size();
+
+ // Emit the predicate table entry if one is needed.
+ emitPredicateTableEntry(TableInfo, Opc);
+
+ // Check any additional encoding fields needed.
+ 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);
+ // Push location for NumToSkip backpatching.
+ TableInfo.FixupStack.back().push_back(TableInfo.Table.size());
+ // The fixup is always 16-bits, so go ahead and allocate the space
+ // in the table so all our relative position calculations work OK even
+ // before we fully resolve the real value here.
+ TableInfo.Table.push_back(0);
+ TableInfo.Table.push_back(0);
+ }
+
+ // Check for soft failure of the match.
+ 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();
+
+ // Decoder index
+ for (unsigned i = 0, e = Bytes.size(); i != e; ++i)
+ TableInfo.Table.push_back(Bytes[i]);
+}
+// Emits table entries to decode the singleton, and then to decode the rest.
+void FilterChooser::emitSingletonTableEntry(DecoderTableInfo &TableInfo,
+ const Filter &Best) const {
unsigned Opc = Best.getSingletonOpc();
- emitSingletonDecoder(o, Indentation, Opc);
+ // complex singletons need predicate checks from the first singleton
+ // to refer forward to the variable filterchooser that follows.
+ TableInfo.FixupStack.push_back(FixupList());
- // Emit code for the rest.
- o.indent(Indentation) << "else\n";
+ emitSingletonTableEntry(TableInfo, Opc);
- Indentation += 2;
- Best.getVariableFC().emit(o, Indentation);
- Indentation -= 2;
+ resolveTableFixups(TableInfo.Table, TableInfo.FixupStack.back(),
+ TableInfo.Table.size());
+ TableInfo.FixupStack.pop_back();
+
+ Best.getVariableFC().emitTableEntries(TableInfo);
}
+
// Assign a single filter and run with it. Top level API client can initialize
// with a single filter to start the filtering process.
-void FilterChooser::runSingleFilter(FilterChooser &owner, unsigned startBit,
- unsigned numBit, bool mixed) {
+void FilterChooser::runSingleFilter(unsigned startBit, unsigned numBit,
+ bool mixed) {
Filters.clear();
- Filter F(*this, startBit, numBit, true);
- Filters.push_back(F);
+ Filters.push_back(Filter(*this, startBit, numBit, true));
BestIndex = 0; // Sole Filter instance to choose from.
bestFilter().recurse();
}
// reportRegion is a helper function for filterProcessor to mark a region as
// eligible for use as a filter region.
void FilterChooser::reportRegion(bitAttr_t RA, unsigned StartBit,
- unsigned BitIndex, bool AllowMixed) {
+ 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)
// Look for islands of undecoded bits of any instruction.
if (getIslands(StartBits, EndBits, FieldVals, Insn) > 0) {
// Found an instruction with island(s). Now just assign a filter.
- runSingleFilter(*this, StartBits[0], EndBits[0] - StartBits[0] + 1,
- true);
+ runSingleFilter(StartBits[0], EndBits[0] - StartBits[0] + 1, true);
return true;
}
}
}
- unsigned BitIndex, InsnIndex;
+ unsigned BitIndex;
// We maintain BIT_WIDTH copies of the bitAttrs automaton.
// The automaton consumes the corresponding bit from each
else
bitAttrs.push_back(ATTR_NONE);
- for (InsnIndex = 0; InsnIndex < numInstructions; ++InsnIndex) {
+ for (unsigned InsnIndex = 0; InsnIndex < numInstructions; ++InsnIndex) {
insn_t insn;
insnWithID(insn, Opcodes[InsnIndex]);
bitAttr_t RA = ATTR_NONE;
unsigned StartBit = 0;
- for (BitIndex = 0; BitIndex < BitWidth; BitIndex++) {
+ for (BitIndex = 0; BitIndex < BitWidth; ++BitIndex) {
bitAttr_t bitAttr = bitAttrs[BitIndex];
assert(bitAttr != ATTR_NONE && "Bit without attributes");
RA = ATTR_MIXED;
break;
default:
- assert(0 && "Unexpected bitAttr!");
+ llvm_unreachable("Unexpected bitAttr!");
}
break;
case ATTR_ALL_SET:
RA = ATTR_MIXED;
break;
default:
- assert(0 && "Unexpected bitAttr!");
+ llvm_unreachable("Unexpected bitAttr!");
}
break;
case ATTR_MIXED:
case ATTR_MIXED:
break;
default:
- assert(0 && "Unexpected bitAttr!");
+ llvm_unreachable("Unexpected bitAttr!");
}
break;
case ATTR_ALL_UNSET:
- assert(0 && "regionAttr state machine has no ATTR_UNSET state");
+ llvm_unreachable("regionAttr state machine has no ATTR_UNSET state");
case ATTR_FILTERED:
- assert(0 && "regionAttr state machine has no ATTR_FILTERED state");
+ llvm_unreachable("regionAttr state machine has no ATTR_FILTERED state");
}
}
BestIndex = -1;
}
-// Emits code to decode our share of instructions. Returns true if the
-// emitted code causes a return, which occurs if we know how to decode
-// the instruction at this level or the instruction is not decodeable.
-bool FilterChooser::emit(raw_ostream &o, unsigned &Indentation) {
- if (Opcodes.size() == 1)
+// emitTableEntries - Emit state machine entries to decode our share of
+// instructions.
+void FilterChooser::emitTableEntries(DecoderTableInfo &TableInfo) const {
+ if (Opcodes.size() == 1) {
// There is only one instruction in the set, which is great!
// Call emitSingletonDecoder() to see whether there are any remaining
// encodings bits.
- return emitSingletonDecoder(o, Indentation, Opcodes[0]);
+ emitSingletonTableEntry(TableInfo, Opcodes[0]);
+ return;
+ }
// Choose the best filter to do the decodings!
if (BestIndex != -1) {
- Filter &Best = bestFilter();
+ const Filter &Best = Filters[BestIndex];
if (Best.getNumFiltered() == 1)
- emitSingletonDecoder(o, Indentation, Best);
+ emitSingletonTableEntry(TableInfo, Best);
else
- bestFilter().emit(o, Indentation);
- return false;
+ Best.emitTableEntry(TableInfo);
+ return;
}
- // We don't know how to decode these instructions! Return 0 and dump the
- // conflict set!
- o.indent(Indentation) << "return 0;" << " // Conflict set: ";
- for (int i = 0, N = Opcodes.size(); i < N; ++i) {
- o << nameWithID(Opcodes[i]);
- if (i < (N - 1))
- o << ", ";
- else
- o << '\n';
- }
+ // We don't know how to decode these instructions! Dump the
+ // conflict set and bail.
// Print out useful conflict information for postmortem analysis.
errs() << "Decoding Conflict:\n";
dumpStack(errs(), "\t\t");
- for (unsigned i = 0; i < Opcodes.size(); i++) {
+ for (unsigned i = 0; i < Opcodes.size(); ++i) {
const std::string &Name = nameWithID(Opcodes[i]);
errs() << '\t' << Name << " ";
getBitsField(*AllInstructions[Opcodes[i]]->TheDef, "Inst"));
errs() << '\n';
}
-
- return true;
}
-static bool populateInstruction(const CodeGenInstruction &CGI,
- unsigned Opc,
- std::map<unsigned, std::vector<OperandInfo> >& Operands){
+static bool populateInstruction(CodeGenTarget &Target,
+ const CodeGenInstruction &CGI, unsigned Opc,
+ std::map<unsigned, std::vector<OperandInfo> > &Operands){
const Record &Def = *CGI.TheDef;
// If all the bit positions are not specified; do not decode this instruction.
// We are bound to fail! For proper disassembly, the well-known encoding bits
// of the instruction must be fully specified.
- //
- // This also removes pseudo instructions from considerations of disassembly,
- // which is a better design and less fragile than the name matchings.
- // Ignore "asm parser only" instructions.
- if (Def.getValueAsBit("isAsmParserOnly") ||
- Def.getValueAsBit("isCodeGenOnly"))
- return false;
BitsInit &Bits = getBitsField(Def, "Inst");
if (Bits.allInComplete()) return false;
for (unsigned i = 0; i < CGI.Operands.size(); ++i) {
int tiedTo = CGI.Operands[i].getTiedRegister();
if (tiedTo != -1) {
- TiedNames[InOutOperands[i].second] = InOutOperands[tiedTo].second;
- TiedNames[InOutOperands[tiedTo].second] = InOutOperands[i].second;
+ 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;
+
+ std::set<unsigned> NamedOpIndices;
+ if (Target.getInstructionSet()->
+ getValueAsBit("noNamedPositionallyEncodedOperands"))
+ // Collect the set of operand indices that might correspond to named
+ // operand, and skip these when assigning operands based on position.
+ for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
+ unsigned OpIdx;
+ if (!CGI.Operands.hasOperandNamed(Vals[i].getName(), OpIdx))
+ continue;
+
+ NamedOpIndices.insert(OpIdx);
+ }
+
+ for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
+ // Ignore fixed fields in the record, we're looking for values like:
+ // bits<5> RST = { ?, ?, ?, ?, ? };
+ if (Vals[i].getPrefix() || Vals[i].getValue()->isComplete())
+ continue;
+
+ // Determine if Vals[i] actually contributes to the Inst encoding.
+ unsigned bi = 0;
+ for (; bi < Bits.getNumBits(); ++bi) {
+ VarInit *Var = nullptr;
+ 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;
+
+ // Skip variables that correspond to explicitly-named operands.
+ unsigned OpIdx;
+ if (CGI.Operands.hasOperandNamed(Vals[i].getName(), OpIdx))
+ continue;
+
+ // Get the bit range for this operand:
+ unsigned bitStart = bi++, bitWidth = 1;
+ for (; bi < Bits.getNumBits(); ++bi) {
+ VarInit *Var = nullptr;
+ 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) ||
+ (!NamedOpIndices.empty() && NamedOpIndices.count(
+ CGI.Operands.getSubOperandNumber(NumberedOp).first))))
+ ++NumberedOp;
+
+ OpIdx = NumberedOp++;
+
+ // OpIdx now holds the ordered operand number of Vals[i].
+ 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()) : nullptr;
+ 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()) : nullptr;
+ if (!isReg && String && String->getValue() != "")
+ Decoder = String->getValue();
+
+ OperandInfo OpInfo(Decoder);
+ OpInfo.addField(bitStart, bitWidth, 0);
+
+ NumberedInsnOperands[Name].push_back(OpInfo);
+
+ // FIXME: For complex operands with custom decoders we can't handle tied
+ // sub-operands automatically. Skip those here and assume that this is
+ // fixed up elsewhere.
+ if (CGI.Operands[SO.first].MIOperandInfo &&
+ CGI.Operands[SO.first].MIOperandInfo->getNumArgs() > 1 &&
+ String && String->getValue() != "")
+ NumberedInsnOperandsNoTie.insert(Name);
}
}
// For each operand, see if we can figure out where it is encoded.
- for (std::vector<std::pair<Init*, std::string> >::iterator
- NI = InOutOperands.begin(), NE = InOutOperands.end(); NI != NE; ++NI) {
+ for (const auto &Op : InOutOperands) {
+ if (!NumberedInsnOperands[Op.second].empty()) {
+ InsnOperands.insert(InsnOperands.end(),
+ NumberedInsnOperands[Op.second].begin(),
+ NumberedInsnOperands[Op.second].end());
+ continue;
+ }
+ if (!NumberedInsnOperands[TiedNames[Op.second]].empty()) {
+ if (!NumberedInsnOperandsNoTie.count(TiedNames[Op.second])) {
+ // Figure out to which (sub)operand we're tied.
+ unsigned i = CGI.Operands.getOperandNamed(TiedNames[Op.second]);
+ int tiedTo = CGI.Operands[i].getTiedRegister();
+ if (tiedTo == -1) {
+ i = CGI.Operands.getOperandNamed(Op.second);
+ tiedTo = CGI.Operands[i].getTiedRegister();
+ }
+
+ if (tiedTo != -1) {
+ std::pair<unsigned, unsigned> SO =
+ CGI.Operands.getSubOperandNumber(tiedTo);
+
+ InsnOperands.push_back(NumberedInsnOperands[TiedNames[Op.second]]
+ [SO.second]);
+ }
+ }
+ continue;
+ }
+
std::string Decoder = "";
// At this point, we can locate the field, but we need to know how to
// for decoding register classes.
// FIXME: This need to be extended to handle instructions with custom
// decoder methods, and operands with (simple) MIOperandInfo's.
- TypedInit *TI = dynamic_cast<TypedInit*>(NI->first);
- RecordRecTy *Type = dynamic_cast<RecordRecTy*>(TI->getType());
+ TypedInit *TI = cast<TypedInit>(Op.first);
+ RecordRecTy *Type = cast<RecordRecTy>(TI->getType());
Record *TypeRecord = Type->getRecord();
bool isReg = false;
if (TypeRecord->isSubClassOf("RegisterOperand"))
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 ?
- dynamic_cast<StringInit*>(DecoderString->getValue()) : 0;
+ dyn_cast<StringInit>(DecoderString->getValue()) : nullptr;
if (!isReg && String && String->getValue() != "")
Decoder = String->getValue();
unsigned Offset = 0;
for (unsigned bi = 0; bi < Bits.getNumBits(); ++bi) {
- VarInit *Var = 0;
- VarBitInit *BI = dynamic_cast<VarBitInit*>(Bits.getBit(bi));
+ VarInit *Var = nullptr;
+ VarBitInit *BI = dyn_cast<VarBitInit>(Bits.getBit(bi));
if (BI)
- Var = dynamic_cast<VarInit*>(BI->getVariable());
+ Var = dyn_cast<VarInit>(BI->getBitVar());
else
- Var = dynamic_cast<VarInit*>(Bits.getBit(bi));
+ Var = dyn_cast<VarInit>(Bits.getBit(bi));
if (!Var) {
if (Base != ~0U) {
continue;
}
- if (Var->getName() != NI->second &&
- Var->getName() != TiedNames[NI->second]) {
+ if (Var->getName() != Op.second &&
+ Var->getName() != TiedNames[Op.second]) {
if (Base != ~0U) {
OpInfo.addField(Base, Width, Offset);
Base = ~0U;
return true;
}
-static void emitHelper(llvm::raw_ostream &o, unsigned BitWidth) {
- unsigned Indentation = 0;
- std::string WidthStr = "uint" + utostr(BitWidth) + "_t";
-
- o << '\n';
-
- o.indent(Indentation) << "static " << WidthStr <<
- " fieldFromInstruction" << BitWidth <<
- "(" << WidthStr <<" insn, unsigned startBit, unsigned numBits)\n";
-
- o.indent(Indentation) << "{\n";
-
- ++Indentation; ++Indentation;
- o.indent(Indentation) << "assert(startBit + numBits <= " << BitWidth
- << " && \"Instruction field out of bounds!\");\n";
- o << '\n';
- o.indent(Indentation) << WidthStr << " fieldMask;\n";
- o << '\n';
- o.indent(Indentation) << "if (numBits == " << BitWidth << ")\n";
-
- ++Indentation; ++Indentation;
- o.indent(Indentation) << "fieldMask = (" << WidthStr << ")-1;\n";
- --Indentation; --Indentation;
-
- o.indent(Indentation) << "else\n";
-
- ++Indentation; ++Indentation;
- o.indent(Indentation) << "fieldMask = ((1 << numBits) - 1) << startBit;\n";
- --Indentation; --Indentation;
-
- o << '\n';
- o.indent(Indentation) << "return (insn & fieldMask) >> startBit;\n";
- --Indentation; --Indentation;
-
- o.indent(Indentation) << "}\n";
+// emitFieldFromInstruction - Emit the templated helper function
+// fieldFromInstruction().
+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";
+}
- o << '\n';
+// emitDecodeInstruction - Emit the templated helper function
+// decodeInstruction().
+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";
}
// Emits disassembler code for instruction decoding.
-void FixedLenDecoderEmitter::run(raw_ostream &o)
-{
- o << "#include \"llvm/MC/MCInst.h\"\n";
- o << "#include \"llvm/Support/DataTypes.h\"\n";
- o << "#include <assert.h>\n";
- o << '\n';
- o << "namespace llvm {\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();
// Parameterize the decoders based on namespace and instruction width.
- NumberedInstructions = Target.getInstructionsByEnumValue();
+ 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[i];
- Record *Def = Inst->TheDef;
+ 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") ||
std::string DecoderNamespace = Def->getValueAsString("DecoderNamespace");
if (Size) {
- if (populateInstruction(*Inst, i, Operands)) {
+ if (populateInstruction(Target, *Inst, i, Operands)) {
OpcMap[std::make_pair(DecoderNamespace, Size)].push_back(i);
}
}
}
- std::set<unsigned> Sizes;
- for (std::map<std::pair<std::string, unsigned>,
- std::vector<unsigned> >::iterator
- I = OpcMap.begin(), E = OpcMap.end(); I != E; ++I) {
- // If we haven't visited this instruction width before, emit the
- // helper method to extract fields.
- if (!Sizes.count(I->first.second)) {
- emitHelper(o, 8*I->first.second);
- Sizes.insert(I->first.second);
- }
-
+ DecoderTableInfo TableInfo;
+ for (const auto &Opc : OpcMap) {
// Emit the decoder for this namespace+width combination.
- FilterChooser FC(NumberedInstructions, I->second, Operands,
- 8*I->first.second);
- FC.emitTop(o, 0, I->first.first);
+ FilterChooser FC(*NumberedInstructions, Opc.second, Operands,
+ 8*Opc.first.second, this);
+
+ // The decode table is cleared for each top level decoder function. The
+ // predicates and decoders themselves, however, are shared across all
+ // decoders to give more opportunities for uniqueing.
+ TableInfo.Table.clear();
+ TableInfo.FixupStack.clear();
+ TableInfo.Table.reserve(16384);
+ TableInfo.FixupStack.push_back(FixupList());
+ FC.emitTableEntries(TableInfo);
+ // Any NumToSkip fixups in the top level scope can resolve to the
+ // OPC_Fail at the end of the table.
+ assert(TableInfo.FixupStack.size() == 1 && "fixup stack phasing error!");
+ // Resolve any NumToSkip fixups in the current scope.
+ resolveTableFixups(TableInfo.Table, TableInfo.FixupStack.back(),
+ TableInfo.Table.size());
+ TableInfo.FixupStack.clear();
+
+ TableInfo.Table.push_back(MCD::OPC_Fail);
+
+ // Print the table to the output stream.
+ emitTable(OS, TableInfo.Table, 0, FC.getBitWidth(), Opc.first.first);
+ OS.flush();
}
- o << "\n} // End llvm namespace \n";
+ // Emit the predicate function.
+ emitPredicateFunction(OS, TableInfo.Predicates, 0);
+
+ // Emit the decoder function.
+ emitDecoderFunction(OS, TableInfo.Decoders, 0);
+
+ // Emit the main entry point for the decoder, decodeInstruction().
+ 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);
+}
+
+} // End llvm namespace
projects / oota-llvm.git / blobdiff