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Diffstat (limited to 'llvm/utils/TableGen/RISCDisassemblerEmitter.cpp')
| -rw-r--r-- | llvm/utils/TableGen/RISCDisassemblerEmitter.cpp | 1743 |
1 files changed, 1743 insertions, 0 deletions
diff --git a/llvm/utils/TableGen/RISCDisassemblerEmitter.cpp b/llvm/utils/TableGen/RISCDisassemblerEmitter.cpp new file mode 100644 index 00000000000..35ad22a9dc6 --- /dev/null +++ b/llvm/utils/TableGen/RISCDisassemblerEmitter.cpp @@ -0,0 +1,1743 @@ +//===- RISCDisassemblerEmitter.cpp - Disassembler Generator ---------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// FIXME: document +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "risc-disassembler-emitter" + +#include "RISCDisassemblerEmitter.h" +#include "CodeGenTarget.h" +#include "Record.h" +#include "llvm/ADT/StringExtras.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/raw_ostream.h" + +#include <iomanip> +#include <vector> +#include <cstdio> +#include <map> +#include <string> +#include <sstream> + +using namespace llvm; + +//////////////////////////////////// +// Utility classes / structures // +//////////////////////////////////// + +// LLVM coding style +#define INDENT_LEVEL 2 + +/// Indenter - A little helper class to keep track of the indentation depth, +/// while the instance object is being passed around. +class Indenter { +public: + Indenter() : depth(0) {} + + void push() { + depth += INDENT_LEVEL; + } + + void pop() { + if (depth >= INDENT_LEVEL) + depth -= INDENT_LEVEL; + } + + // Conversion operator. + operator int () { + return depth; + } +private: + uint8_t depth; +}; + +///////////////////////// +// Utility functions // +///////////////////////// + +static uint8_t byteFromBitsInit(BitsInit &init) { + int width = init.getNumBits(); + + assert(width <= 8 && "Field is too large for uint8_t!"); + + int index; + uint8_t mask = 0x01; + + uint8_t ret = 0; + + for (index = 0; index < width; index++) { + if (static_cast<BitInit*>(init.getBit(index))->getValue()) + ret |= mask; + + mask <<= 1; + } + + return ret; +} + +static uint8_t getByteField(const Record &def, const char *str) { + BitsInit *bits = def.getValueAsBitsInit(str); + return byteFromBitsInit(*bits); +} + +static BitsInit &getBitsField(const Record &def, const char *str) { + BitsInit *bits = def.getValueAsBitsInit(str); + return *bits; +} + +/// sameStringExceptEndingChar - Return true if the two strings differ only in +/// the ending char. ("VST4q8a", "VST4q8b", 'a', 'b') as input returns true. +static +bool sameStringExceptEndingChar(const std::string &LHS, const std::string &RHS, + char lhc, char rhc) { + + if (LHS.length() > 1 && RHS.length() > 1 && LHS.length() == RHS.length()) { + unsigned length = LHS.length(); + return LHS.substr(0, length - 1) == RHS.substr(0, length - 1) + && LHS[length - 1] == lhc && RHS[length - 1] == rhc; + } + + return false; +} + +/// thumbInstruction - Determine whether we have a Thumb instruction. +/// See also ARMInstrFormats.td. +static bool thumbInstruction(uint8_t Form) { + return Form == 23; +} + +// The set (BIT_TRUE, BIT_FALSE, BIT_UNSET) represents a ternary logic system +// for a bit value. +// +// BIT_UNFILTERED is used as the init value for a filter position. It is used +// only for filter processings. +typedef enum { + BIT_TRUE, // '1' + BIT_FALSE, // '0' + BIT_UNSET, // '?' + BIT_UNFILTERED // unfiltered +} bit_value_t; + +static bit_value_t bitFromBits(BitsInit &bits, unsigned index) { + if (BitInit *bit = dynamic_cast<BitInit*>(bits.getBit(index))) + return bit->getValue() ? BIT_TRUE : BIT_FALSE; + + // The bit is uninitialized. + return BIT_UNSET; +} + +static void dumpBits(raw_ostream &o, BitsInit &bits) { + unsigned index; + + for (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: + assert(0 && "unexpected return value from bitFromBits"); + } + } +} + +///////////// +// Enums // +///////////// + +#define ARM_FORMATS \ + ENTRY(ARM_FORMAT_PSEUDO, 0) \ + ENTRY(ARM_FORMAT_MULFRM, 1) \ + ENTRY(ARM_FORMAT_BRFRM, 2) \ + ENTRY(ARM_FORMAT_BRMISCFRM, 3) \ + ENTRY(ARM_FORMAT_DPFRM, 4) \ + ENTRY(ARM_FORMAT_DPSOREGFRM, 5) \ + ENTRY(ARM_FORMAT_LDFRM, 6) \ + ENTRY(ARM_FORMAT_STFRM, 7) \ + ENTRY(ARM_FORMAT_LDMISCFRM, 8) \ + ENTRY(ARM_FORMAT_STMISCFRM, 9) \ + ENTRY(ARM_FORMAT_LDSTMULFRM, 10) \ + ENTRY(ARM_FORMAT_ARITHMISCFRM, 11) \ + ENTRY(ARM_FORMAT_EXTFRM, 12) \ + ENTRY(ARM_FORMAT_VFPUNARYFRM, 13) \ + ENTRY(ARM_FORMAT_VFPBINARYFRM, 14) \ + ENTRY(ARM_FORMAT_VFPCONV1FRM, 15) \ + ENTRY(ARM_FORMAT_VFPCONV2FRM, 16) \ + ENTRY(ARM_FORMAT_VFPCONV3FRM, 17) \ + ENTRY(ARM_FORMAT_VFPCONV4FRM, 18) \ + ENTRY(ARM_FORMAT_VFPCONV5FRM, 19) \ + ENTRY(ARM_FORMAT_VFPLDSTFRM, 20) \ + ENTRY(ARM_FORMAT_VFPLDSTMULFRM, 21) \ + ENTRY(ARM_FORMAT_VFPMISCFRM, 22) \ + ENTRY(ARM_FORMAT_THUMBFRM, 23) \ + ENTRY(ARM_FORMAT_NEONFRM, 24) \ + ENTRY(ARM_FORMAT_NEONGETLNFRM, 25) \ + ENTRY(ARM_FORMAT_NEONSETLNFRM, 26) \ + ENTRY(ARM_FORMAT_NEONDUPFRM, 27) \ + ENTRY(ARM_FORMAT_LDSTEXFRM, 28) \ + ENTRY(ARM_FORMAT_MISCFRM, 29) \ + ENTRY(ARM_FORMAT_THUMBMISCFRM, 30) + +// ARM instruction format specifies the encoding used by the instruction. +#define ENTRY(n, v) n = v, +typedef enum { + ARM_FORMATS + ARM_FORMAT_NA +} ARMFormat; +#undef ENTRY + +// Converts enum to const char*. +static const char *stringForARMFormat(ARMFormat form) { +#define ENTRY(n, v) case n: return #n; + switch(form) { + ARM_FORMATS + case ARM_FORMAT_NA: + default: + return ""; + } +#undef ENTRY +} + +#define NS_FORMATS \ + ENTRY(NS_FORMAT_NONE, 0) \ + ENTRY(NS_FORMAT_VLDSTLane, 1) \ + ENTRY(NS_FORMAT_VLDSTLaneDbl, 2) \ + ENTRY(NS_FORMAT_VLDSTRQ, 3) \ + ENTRY(NS_FORMAT_NVdImm, 4) \ + ENTRY(NS_FORMAT_NVdVmImm, 5) \ + ENTRY(NS_FORMAT_NVdVmImmVCVT, 6) \ + ENTRY(NS_FORMAT_NVdVmImmVDupLane, 7) \ + ENTRY(NS_FORMAT_NVdVmImmVSHLL, 8) \ + ENTRY(NS_FORMAT_NVectorShuffle, 9) \ + ENTRY(NS_FORMAT_NVectorShift, 10) \ + ENTRY(NS_FORMAT_NVectorShift2, 11) \ + ENTRY(NS_FORMAT_NVdVnVmImm, 12) \ + ENTRY(NS_FORMAT_NVdVnVmImmVectorShift, 13) \ + ENTRY(NS_FORMAT_NVdVnVmImmVectorExtract, 14) \ + ENTRY(NS_FORMAT_NVdVnVmImmMulScalar, 15) \ + ENTRY(NS_FORMAT_VTBL, 16) + +// NEON instruction sub-format further classify the NEONFrm instruction. +#define ENTRY(n, v) n = v, +typedef enum { + NS_FORMATS + NS_FORMAT_NA +} NSFormat; +#undef ENTRY + +// Converts enum to const char*. +static const char *stringForNSFormat(NSFormat form) { +#define ENTRY(n, v) case n: return #n; + switch(form) { + NS_FORMATS + case NS_FORMAT_NA: + default: + return ""; + } +#undef ENTRY +} + +// Enums for the available target names. +typedef enum { + TARGET_ARM = 0, + TARGET_THUMB +} TARGET_NAME_t; + +class AbstractFilterChooser { +public: + static TARGET_NAME_t TargetName; + static void setTargetName(TARGET_NAME_t tn) { TargetName = tn; } + virtual ~AbstractFilterChooser() {} + virtual void emitTop(raw_ostream &o, Indenter &i) = 0; + virtual void emitBot(raw_ostream &o, Indenter &i) = 0; +}; + +// Define the symbol here. +TARGET_NAME_t AbstractFilterChooser::TargetName; + +template <unsigned tBitWidth> +class FilterChooser : public AbstractFilterChooser { +protected: + // Representation of the instruction to work on. + typedef bit_value_t insn_t[tBitWidth]; + + class Filter { + protected: + FilterChooser *Owner; // pointer without ownership + unsigned StartBit; // the starting bit position + unsigned NumBits; // number of bits to filter + bool Mixed; // a mixed region contains both set and unset bits + + // Map of well-known segment value to the set of uid's with that value. + std::map<uint64_t, std::vector<unsigned> > FilteredInstructions; + + // Set of uid's with non-constant segment values. + std::vector<unsigned> VariableInstructions; + + // Map of well-known segment value to its delegate. + std::map<unsigned, 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() { + assert(NumFiltered == 1); + return LastOpcFiltered; + } + FilterChooser &getVariableFC() { + assert(NumFiltered == 1); + assert(FilterChooserMap.size() == 1); + return FilterChooserMap.find(-1)->second; + } + + 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(FilterChooser &owner, unsigned startBit, unsigned numBits, + bool mixed) : + Owner(&owner), + StartBit(startBit), + NumBits(numBits), + Mixed(mixed) + { + assert(StartBit + NumBits - 1 < tBitWidth); + + NumFiltered = 0; + LastOpcFiltered = 0; + NumVariable = 0; + + for (unsigned i = 0, e = Owner->Opcodes.size(); i != e; ++i) { + insn_t Insn; + + // Populates the insn given the uid. + Owner->insnWithID(Insn, Owner->Opcodes[i]); + + uint64_t Field; + // Scans the segment for possibly well-specified encoding bits. + bool ok = Owner->fieldFromInsn(Field, Insn, StartBit, NumBits); + + if (ok) { + // The encoding bits are well-known. Lets add the uid of the + // instruction into the bucket keyed off the constant field value. + LastOpcFiltered = Owner->Opcodes[i]; + FilteredInstructions[Field].push_back(LastOpcFiltered); + ++NumFiltered; + } else { + // Some of the encoding bit(s) are unspecfied. This contributes to + // one additional member of "Variable" instructions. + VariableInstructions.push_back(Owner->Opcodes[i]); + ++NumVariable; + } + } + + assert((FilteredInstructions.size() + VariableInstructions.size() > 0) + && "Filter returns no instruction categories"); + } + + // Divides the decoding task into sub tasks and delegates them to the + // inferior FilterChooser's. + // + // A special case arises when there's only one entry in the filtered + // instructions. In order to unambiguously decode the singleton, we need to + // match the remaining undecoded encoding bits against the singleton. + void recurse() { + std::map<uint64_t, std::vector<unsigned> >::const_iterator mapIterator; + + bit_value_t BitValueArray[tBitWidth]; + // Starts by inheriting our parent filter chooser's filter bit values. + memcpy(BitValueArray, Owner->FilterBitValues, sizeof(BitValueArray)); + + unsigned bitIndex; + + if (VariableInstructions.size()) { + // Conservatively marks each segment position as BIT_UNSET. + for (bitIndex = 0; bitIndex < NumBits; bitIndex++) + BitValueArray[StartBit + bitIndex] = BIT_UNSET; + + // Delegates to an inferior filter chooser for futher processing on this + // group of instructions whose segment values are variable. + FilterChooserMap.insert(std::pair<unsigned, FilterChooser>( + (unsigned)-1, + FilterChooser(Owner->AllInstructions, + VariableInstructions, + BitValueArray, + *Owner) + )); + } + + // No need to recurse for a singleton filtered instruction. + // See also Filter::emit(). + if (getNumFiltered() == 1) { + //Owner->SingletonExists(LastOpcFiltered); + assert(FilterChooserMap.size() == 1); + return; + } + + // Otherwise, create sub choosers. + for (mapIterator = FilteredInstructions.begin(); + mapIterator != FilteredInstructions.end(); + mapIterator++) { + + // Marks all the segment positions with either BIT_TRUE or BIT_FALSE. + for (bitIndex = 0; bitIndex < NumBits; bitIndex++) { + if (mapIterator->first & (1 << bitIndex)) + BitValueArray[StartBit + bitIndex] = BIT_TRUE; + else + BitValueArray[StartBit + bitIndex] = BIT_FALSE; + } + + // Delegates to an inferior filter chooser for futher processing on this + // category of instructions. + FilterChooserMap.insert(std::pair<unsigned, FilterChooser>( + mapIterator->first, + FilterChooser(Owner->AllInstructions, + mapIterator->second, + BitValueArray, + *Owner) + )); + } + } + + // Emit code to decode instructions given a segment or segments of bits. + void emit(raw_ostream &o, Indenter &i) { + o.indent(i) << "// Check Inst{"; + + if (NumBits > 1) + o << (StartBit + NumBits - 1) << '-'; + + o << StartBit << "} ...\n"; + + o.indent(i) << "switch (fieldFromInstruction(insn, " + << StartBit << ", " << NumBits << ")) {\n"; + + typename std::map<unsigned, FilterChooser>::iterator filterIterator; + + bool DefaultCase = false; + for (filterIterator = FilterChooserMap.begin(); + filterIterator != FilterChooserMap.end(); + filterIterator++) { + + // Field value -1 implies a non-empty set of variable instructions. + // See also recurse(). + if (filterIterator->first == (unsigned)-1) { + DefaultCase = true; + + o.indent(i) << "default:\n"; + o.indent(i) << " 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(i) << "}\n"; + + } else { + o.indent(i) << "case " << filterIterator->first << ":\n"; + } + + // 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) i.push(); + { + bool finished = filterIterator->second.emit(o, i); + // For top level default case, there's no need for a break statement. + if (Owner->isTopLevel() && DefaultCase) + break; + if (!finished) + o.indent(i) << "break;\n"; + } + if (!DefaultCase) i.pop(); + } + + // 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(i) << "}\n"; + } + } + + // Returns the number of fanout produced by the filter. More fanout implies + // the filter distinguishes more categories of instructions. + unsigned usefulness() const { + if (VariableInstructions.size()) + return FilteredInstructions.size(); + else + return FilteredInstructions.size() + 1; + } + }; // End of inner class Filter + + friend class Filter; + + // Vector of codegen instructions to choose our filter. + const std::vector<const CodeGenInstruction*> &AllInstructions; + + // Vector of uid's for this filter chooser to work on. + const std::vector<unsigned> Opcodes; + + // Vector of candidate filters. + std::vector<Filter> Filters; + + // Array of bit values passed down from our parent. + // Set to all BIT_UNFILTERED's for Parent == NULL. + bit_value_t FilterBitValues[tBitWidth]; + + // Links to the FilterChooser above us in the decoding tree. + FilterChooser *Parent; + + // Index of the best filter from Filters. + int BestIndex; + +public: + FilterChooser(const FilterChooser &FC) : + AbstractFilterChooser(), + AllInstructions(FC.AllInstructions), + Opcodes(FC.Opcodes), + Filters(FC.Filters), + Parent(FC.Parent), + BestIndex(FC.BestIndex) + { + memcpy(FilterBitValues, FC.FilterBitValues, sizeof(FilterBitValues)); + } + + FilterChooser(const std::vector<const CodeGenInstruction*> &Insts, + const std::vector<unsigned> &IDs) : + AllInstructions(Insts), + Opcodes(IDs), + Filters(), + Parent(NULL), + BestIndex(-1) + { + for (unsigned i = 0; i < tBitWidth; ++i) + FilterBitValues[i] = BIT_UNFILTERED; + + doFilter(); + } + + FilterChooser(const std::vector<const CodeGenInstruction*> &Insts, + const std::vector<unsigned> &IDs, + bit_value_t (&ParentFilterBitValues)[tBitWidth], + FilterChooser &parent) : + AllInstructions(Insts), + Opcodes(IDs), + Filters(), + Parent(&parent), + BestIndex(-1) + { + for (unsigned i = 0; i < tBitWidth; ++i) + FilterBitValues[i] = ParentFilterBitValues[i]; + + doFilter(); + } + + // The top level filter chooser has NULL as its parent. + bool isTopLevel() { return Parent == NULL; } + + // This provides an opportunity for target specific code emission. + void emitTopHook(raw_ostream &o, Indenter &i) { + if (TargetName == TARGET_ARM) { + // Emit code that references the ARMFormat data type. + o << "static const ARMFormat ARMFormats[] = {\n"; + for (unsigned i = 0, e = AllInstructions.size(); i != e; ++i) { + const Record &Def = *(AllInstructions[i]->TheDef); + const std::string &Name = Def.getName(); + if (Def.isSubClassOf("InstARM") || Def.isSubClassOf("InstThumb")) + o.indent(2) << + stringForARMFormat((ARMFormat)getByteField(Def, "Form")); + else + o << " ARM_FORMAT_NA"; + + o << ",\t// Inst #" << i << " = " << Name << '\n'; + } + o << " ARM_FORMAT_NA\t// Unreachable.\n"; + o << "};\n\n"; + + // And emit code that references the NSFormat data type. + // This is meaningful only for NEONFrm instructions. + o << "static const NSFormat NSFormats[] = {\n"; + for (unsigned i = 0, e = AllInstructions.size(); i != e; ++i) { + const Record &Def = *(AllInstructions[i]->TheDef); + const std::string &Name = Def.getName(); + if (Def.isSubClassOf("NeonI") || Def.isSubClassOf("NeonXI")) + o.indent(2) << + stringForNSFormat((NSFormat)getByteField(Def, "NSForm")); + else + o << " NS_FORMAT_NA"; + + o << ",\t// Inst #" << i << " = " << Name << '\n'; + } + o << " NS_FORMAT_NA\t// Unreachable.\n"; + o << "};\n\n"; + } + } + + // Emit the top level typedef and decodeInstruction() function. + void emitTop(raw_ostream &o, Indenter &i) { + + // Run the target specific emit hook. + emitTopHook(o, i); + + switch(tBitWidth) { + case 8: + o.indent(i) << "typedef uint8_t field_t;\n"; + break; + case 16: + o.indent(i) << "typedef uint16_t field_t;\n"; + break; + case 32: + o.indent(i) << "typedef uint32_t field_t;\n"; + break; + case 64: + o.indent(i) << "typedef uint64_t field_t;\n"; + break; + default: + assert(0 && "Unexpected instruction size!"); + } + + o << '\n'; + + o.indent(i) << "static field_t " << + "fieldFromInstruction(field_t insn, unsigned startBit, unsigned numBits)\n"; + + o.indent(i) << "{\n"; + i.push(); + { + o.indent(i) << "assert(startBit + numBits <= " << tBitWidth + << " && \"Instruction field out of bounds!\");\n"; + o << '\n'; + o.indent(i) << "field_t fieldMask;\n"; + o << '\n'; + o.indent(i) << "if (numBits == " << tBitWidth << ")\n"; + + i.push(); + { + o.indent(i) << "fieldMask = (field_t)-1;\n"; + } + i.pop(); + + o.indent(i) << "else\n"; + + i.push(); + { + o.indent(i) << "fieldMask = ((1 << numBits) - 1) << startBit;\n"; + } + i.pop(); + + o << '\n'; + o.indent(i) << "return (insn & fieldMask) >> startBit;\n"; + } + i.pop(); + o.indent(i) << "}\n"; + + o << '\n'; + + o.indent(i) << "static uint16_t decodeInstruction(field_t insn) {\n"; + + i.push(); + { + // Emits code to decode the instructions. + emit(o, i); + + o << '\n'; + o.indent(i) << "return 0;\n"; + } + i.pop(); + + o.indent(i) << "}\n"; + + o << '\n'; + + } + + // This provides an opportunity for target specific code emission after + // emitTop(). + void emitBot(raw_ostream &o, Indenter &i) { + if (TargetName == TARGET_THUMB) { + // Emit code that decodes the Thumb ISA. + o.indent(i) + << "static uint16_t decodeThumbInstruction(field_t insn) {\n"; + + i.push(); + { + // Emits code to decode the instructions. + emit(o, i); + + o << '\n'; + o.indent(i) << "return 0;\n"; + } + i.pop(); + + o.indent(i) << "}\n"; + } + } + +protected: + // Populates the insn given the uid. + void insnWithID(insn_t &Insn, unsigned Opcode) const { + assert(Opcode > 10); + BitsInit &Bits = getBitsField(*AllInstructions[Opcode]->TheDef, "Inst"); + + for (unsigned i = 0; i < tBitWidth; ++i) + Insn[i] = bitFromBits(Bits, i); + } + + // Returns the record name. + const std::string &nameWithID(unsigned Opcode) const { + return AllInstructions[Opcode]->TheDef->getName(); + } + + // Populates the field of the insn given the start position and the number of + // consecutive bits to scan for. + // + // Returns false if and on the first uninitialized bit value encountered. + // Returns true, otherwise. + const bool 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 | (1 << i); + } + + return true; + } + + void dumpFilterArray(raw_ostream &o, bit_value_t (&filter)[tBitWidth]) { + unsigned bitIndex; + + for (bitIndex = tBitWidth; 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 dumpStack(raw_ostream &o, const char *prefix) { + FilterChooser *current = this; + + while (current) { + o << prefix; + + dumpFilterArray(o, current->FilterBitValues); + + o << '\n'; + + current = current->Parent; + } + } + + Filter &bestFilter() { + assert(BestIndex != -1 && "BestIndex not set"); + return Filters[BestIndex]; + } + + // States of our finite state machines. + typedef enum { + ATTR_NONE, + ATTR_FILTERED, + ATTR_ALL_SET, + ATTR_ALL_UNSET, + ATTR_MIXED + } bitAttr_t; + + // Called from Filter::recurse() when singleton exists. For debug purpose. + void SingletonExists(unsigned Opc) { + + 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'; + } + } + + bool ValueSet(bit_value_t V) { + return (V == BIT_TRUE || V == BIT_FALSE); + } + bool ValueNotSet(bit_value_t V) { + return (V == BIT_UNSET); + } + int Value(bit_value_t V) { + return ValueNotSet(V) ? -1 : (V == BIT_FALSE ? 0 : 1); + } + bool PositionFiltered(unsigned i) { + return ValueSet(FilterBitValues[i]); + } + + // Calculates the island(s) needed to decode the instruction. + unsigned getIslands(std::vector<unsigned> &StartBits, + std::vector<unsigned> &EndBits, + std::vector<uint64_t> &FieldVals, insn_t &Insn) + { + unsigned Num, BitNo; + Num = BitNo = 0; + + uint64_t FieldVal = 0; + + // 0: Init + // 1: Water + // 2: Island + int State = 0; + int Val = -1; + + for (unsigned i = 0; i < tBitWidth; ++i) { + Val = Value(Insn[i]); + bool Filtered = PositionFiltered(i); + switch (State) { + default: + assert(0 && "Unreachable code!"); + break; + case 0: + case 1: + if (Filtered || Val == -1) + State = 1; // Still in Water + else { + State = 2; // Into the Island + BitNo = 0; + StartBits.push_back(i); + FieldVal = Val; + } + break; + case 2: + if (Filtered || Val == -1) { + State = 1; // Into the Water + EndBits.push_back(i - 1); + FieldVals.push_back(FieldVal); + ++Num; + } else { + State = 2; // Still in Island + ++BitNo; + FieldVal = FieldVal | Val << BitNo; + } + break; + } + } + // If we are still in Island after the loop, do some housekeeping. + if (State == 2) { + EndBits.push_back(tBitWidth - 1); + FieldVals.push_back(FieldVal); + ++Num; + } + + /* + printf("StartBits.size()=%u,EndBits.size()=%u,FieldVals.size()=%u,Num=%u\n", + (unsigned)StartBits.size(), (unsigned)EndBits.size(), + (unsigned)FieldVals.size(), Num); + */ + + assert(StartBits.size() == Num && EndBits.size() == Num && + FieldVals.size() == Num); + + return Num; + } + + bool LdStCopEncoding1(unsigned Opc) { + const std::string &Name = nameWithID(Opc); + if (Name == "LDC_OFFSET" || Name == "LDC_OPTION" || + Name == "LDC_POST" || Name == "LDC_PRE" || + Name == "LDCL_OFFSET" || Name == "LDCL_OPTION" || + Name == "LDCL_POST" || Name == "LDCL_PRE" || + Name == "STC_OFFSET" || Name == "STC_OPTION" || + Name == "STC_POST" || Name == "STC_PRE" || + Name == "STCL_OFFSET" || Name == "STCL_OPTION" || + Name == "STCL_POST" || Name == "STCL_PRE") + return true; + else + return false; + } + + // Emits code to decode the singleton. Return true if we have matched all the + // well-known bits. + bool emitSingletonDecoder(raw_ostream &o, Indenter &i, unsigned Opc) { + + std::vector<unsigned> StartBits; + std::vector<unsigned> EndBits; + std::vector<uint64_t> FieldVals; + insn_t Insn; + insnWithID(Insn, Opc); + + if (TargetName == TARGET_ARM && LdStCopEncoding1(Opc)) { + o.indent(i); + // A8.6.51 & A8.6.188 + // If coproc = 0b101?, i.e, slice(insn, 11, 8) = 10 or 11, escape. + o << "if (fieldFromInstruction(insn, 9, 3) == 5) break; // fallthrough\n"; + } + + // Look for islands of undecoded bits of the singleton. + getIslands(StartBits, EndBits, FieldVals, Insn); + + 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(i) << "return " << Opc << "; // " << nameWithID(Opc) << '\n'; + return true; + } + + // Otherwise, there are more decodings to be done! + + // Emit code to match the island(s) for the singleton. + o.indent(i) << "// Check "; + + for (I = Size; I != 0; --I) { + o << "Inst{" << EndBits[I-1] << '-' << StartBits[I-1] << "} "; + if (I > 1) + o << "&& "; + else + o << "for singleton decoding...\n"; + } + + o.indent(i) << "if ("; + + for (I = Size; I != 0; --I) { + NumBits = EndBits[I-1] - StartBits[I-1] + 1; + o << "fieldFromInstruction(insn, " << StartBits[I-1] << ", " << NumBits + << ") == " << FieldVals[I-1]; + if (I > 1) + o << " && "; + else + o << ")\n"; + } + + o.indent(i) << " return " << Opc << "; // " << nameWithID(Opc) << '\n'; + + return false; + } + + // Emits code to decode the singleton, and then to decode the rest. + void emitSingletonDecoder(raw_ostream &o, Indenter &i, Filter & Best) { + + unsigned Opc = Best.getSingletonOpc(); + + emitSingletonDecoder(o, i, Opc); + + // Emit code for the rest. + o.indent(i) << "else\n"; + i.push(); + { + Best.getVariableFC().emit(o, i); + } + i.pop(); + } + + // Assign a single filter and run with it. + void runSingleFilter(FilterChooser &owner, unsigned startBit, unsigned numBit, + bool mixed) { + Filters.clear(); + Filter F(*this, startBit, numBit, true); + Filters.push_back(F); + BestIndex = 0; // Sole Filter instance to choose from. + bestFilter().recurse(); + } + + bool filterProcessor(bool AllowMixed, bool Greedy = true) { + Filters.clear(); + BestIndex = -1; + unsigned numInstructions = Opcodes.size(); + + assert(numInstructions && "Filter created with no instructions"); + + // No further filtering is necessary. + if (numInstructions == 1) + return true; + + // Heuristics. See also doFilter()'s "Heuristics" comment when num of + // instructions is 3. + 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]); + + // 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); + return true; + } + } + } + + unsigned bitIndex, insnIndex; + + // We maintain tBitWidth copies of the bitAttrs automaton. + // The automaton consumes the corresponding bit from each + // instruction. + // + // Input symbols: 0, 1, and _ (unset). + // States: NONE, FILTERED, ALL_SET, ALL_UNSET, and MIXED. + // Initial state: NONE. + // + // (NONE) ------- [01] -> (ALL_SET) + // (NONE) ------- _ ----> (ALL_UNSET) + // (ALL_SET) ---- [01] -> (ALL_SET) + // (ALL_SET) ---- _ ----> (MIXED) + // (ALL_UNSET) -- [01] -> (MIXED) + // (ALL_UNSET) -- _ ----> (ALL_UNSET) + // (MIXED) ------ . ----> (MIXED) + // (FILTERED)---- . ----> (FILTERED) + + bitAttr_t bitAttrs[tBitWidth]; + + // FILTERED bit positions provide no entropy and are not worthy of pursuing. + // Filter::recurse() set either BIT_TRUE or BIT_FALSE for each position. + for (bitIndex = 0; bitIndex < tBitWidth; ++bitIndex) + if (FilterBitValues[bitIndex] == BIT_TRUE || + FilterBitValues[bitIndex] == BIT_FALSE) + bitAttrs[bitIndex] = ATTR_FILTERED; + else + bitAttrs[bitIndex] = ATTR_NONE; + + for (insnIndex = 0; insnIndex < numInstructions; ++insnIndex) { + insn_t insn; + + insnWithID(insn, Opcodes[insnIndex]); + + for (bitIndex = 0; bitIndex < tBitWidth; ++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; + } + } + } + + // The regionAttr automaton consumes the bitAttrs automatons' state, + // lowest-to-highest. + // + // Input symbols: F(iltered), (all_)S(et), (all_)U(nset), M(ixed) + // States: NONE, ALL_SET, MIXED + // Initial state: NONE + // + // (NONE) ----- F --> (NONE) + // (NONE) ----- S --> (ALL_SET) ; and set region start + // (NONE) ----- U --> (NONE) + // (NONE) ----- M --> (MIXED) ; and set region start + // (ALL_SET) -- F --> (NONE) ; and report an ALL_SET region + // (ALL_SET) -- S --> (ALL_SET) + // (ALL_SET) -- U --> (NONE) ; and report an ALL_SET region + // (ALL_SET) -- M --> (MIXED) ; and report an ALL_SET region + // (MIXED) ---- F --> (NONE) ; and report a MIXED region + // (MIXED) ---- S --> (ALL_SET) ; and report a MIXED region + // (MIXED) ---- U --> (NONE) ; and report a MIXED region + // (MIXED) ---- M --> (MIXED) + + bitAttr_t regionAttr = ATTR_NONE; + unsigned startBit = 0; + + for (bitIndex = 0; bitIndex < tBitWidth; bitIndex++) { + bitAttr_t bitAttr = bitAttrs[bitIndex]; + + assert(bitAttr != ATTR_NONE && "Bit without attributes"); + +#define SET_START \ + startBit = bitIndex; + +#define REPORT_REGION \ + if (regionAttr == ATTR_MIXED && AllowMixed) \ + Filters.push_back(Filter(*this, startBit, bitIndex - startBit, true)); \ + else if (regionAttr == ATTR_ALL_SET && !AllowMixed) \ + Filters.push_back(Filter(*this, startBit, bitIndex - startBit, false)); + + switch (regionAttr) { + case ATTR_NONE: + switch (bitAttr) { + case ATTR_FILTERED: + break; + case ATTR_ALL_SET: + SET_START + regionAttr = ATTR_ALL_SET; + break; + case ATTR_ALL_UNSET: + break; + case ATTR_MIXED: + SET_START + regionAttr = ATTR_MIXED; + break; + default: + assert(0 && "Unexpected bitAttr!"); + } + break; + case ATTR_ALL_SET: + switch (bitAttr) { + case ATTR_FILTERED: + REPORT_REGION + regionAttr = ATTR_NONE; + break; + case ATTR_ALL_SET: + break; + case ATTR_ALL_UNSET: + REPORT_REGION + regionAttr = ATTR_NONE; + break; + case ATTR_MIXED: + REPORT_REGION + SET_START + regionAttr = ATTR_MIXED; + break; + default: + assert(0 && "Unexpected bitAttr!"); + } + break; + case ATTR_MIXED: + switch (bitAttr) { + case ATTR_FILTERED: + REPORT_REGION + SET_START + regionAttr = ATTR_NONE; + break; + case ATTR_ALL_SET: + REPORT_REGION + SET_START + regionAttr = ATTR_ALL_SET; + break; + case ATTR_ALL_UNSET: + REPORT_REGION + regionAttr = ATTR_NONE; + break; + case ATTR_MIXED: + break; + default: + assert(0 && "Unexpected bitAttr!"); + } + break; + case ATTR_ALL_UNSET: + assert(0 && "regionAttr state machine has no ATTR_UNSET state"); + case ATTR_FILTERED: + assert(0 && "regionAttr state machine has no ATTR_FILTERED state"); + } + } + + // At the end, if we're still in ALL_SET or MIXED states, report a region + + switch (regionAttr) { + case ATTR_NONE: + break; + case ATTR_FILTERED: + break; + case ATTR_ALL_SET: + REPORT_REGION + break; + case ATTR_ALL_UNSET: + break; + case ATTR_MIXED: + REPORT_REGION + break; + } + +#undef SET_START +#undef REPORT_REGION + + // We have finished with the filter processings. Now it's time to choose + // the best performing filter. + + 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; + } // end of filterProcessor(bool) + + // Decides on the best configuration of filter(s) to use in order to decode + // the instructions. A conflict of instructions may occur, in which case we + // dump the conflict set to the standard error. + void doFilter() { + unsigned Num = Opcodes.size(); + assert(Num && "FilterChooser created with no instructions"); + + // Heuristics: Use Inst{31-28} as the top level filter for ARM ISA. + if (TargetName == TARGET_ARM && Parent == NULL) { + runSingleFilter(*this, 28, 4, false); + return; + } + + if (filterProcessor(false)) + return; + + if (filterProcessor(true)) + return; + + // Heuristics to cope with conflict set {t2CMPrs, t2SUBSrr, t2SUBSrs} where + // no single instruction for the maximum ATTR_MIXED region Inst{14-4} has a + // well-known encoding pattern. In such case, we backtrack and scan for the + // the very first consecutive ATTR_ALL_SET region and assign a filter to it. + if (Num == 3 && filterProcessor(true, false)) + return; + + // If we come to here, the instruction decoding has failed. + // Print out the instructions in the conflict set... + + BestIndex = -1; + + DEBUG({ + errs() << "Conflict:\n"; + + dumpStack(errs(), "\t\t"); + + for (unsigned i = 0; i < Num; i++) { + const std::string &Name = nameWithID(Opcodes[i]); + + errs() << '\t' << Name << " "; + dumpBits(errs(), + getBitsField(*AllInstructions[Opcodes[i]]->TheDef, "Inst")); + errs() << '\n'; + } + }); + } + + // 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, Indenter &i) { + 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, i, Opcodes[0]); + + } else if (BestIndex == -1) { + if (TargetName == TARGET_ARM && Opcodes.size() == 2) { + // Resolve the known conflict sets: + // + // 1. source registers are identical => VMOVDneon; otherwise => VORRd + // 2. source registers are identical => VMOVQ; otherwise => VORRq + // 3. LDR, LDRcp => return LDR for now. + // FIXME: How can we distinguish between LDR and LDRcp? Do we need to? + // 4. VLD[234]LN*a/VST[234]LN*a vs. VLD[234]LN*b/VST[234]LN*b conflicts + // are resolved returning the 'a' versions of the instructions. Note + // that the difference between a/b is that the former is for double- + // spaced even registers while the latter is for double-spaced odd + // registers. This is for codegen instruction selection purpose. + // For disassembly, it does not matter. + const std::string &name1 = nameWithID(Opcodes[0]); + const std::string &name2 = nameWithID(Opcodes[1]); + if ((name1 == "VMOVDneon" && name2 == "VORRd") || + (name1 == "VMOVQ" && name2 == "VORRq")) { + // Inserting the opening curly brace for this case block. + i.pop(); + o.indent(i) << "{\n"; + i.push(); + + o.indent(i) << "field_t N = fieldFromInstruction(insn, 7, 1), " + << "M = fieldFromInstruction(insn, 5, 1);\n"; + o.indent(i) << "field_t Vn = fieldFromInstruction(insn, 16, 4), " + << "Vm = fieldFromInstruction(insn, 0, 4);\n"; + o.indent(i) << "return (N == M && Vn == Vm) ? " + << Opcodes[0] << " /* " << name1 << " */ : " + << Opcodes[1] << " /* " << name2 << " */ ;\n"; + + // Inserting the closing curly brace for this case block. + i.pop(); + o.indent(i) << "}\n"; + i.push(); + + return true; + } + if (name1 == "LDR" && name2 == "LDRcp") { + o.indent(i) << "return " << Opcodes[0] + << "; // Returning LDR for {LDR, LDRcp}\n"; + return true; + } + if (sameStringExceptEndingChar(name1, name2, 'a', 'b')) { + o.indent(i) << "return " << Opcodes[0] << "; // Returning " << name1 + << " for {" << name1 << ", " << name2 << "}\n"; + return true; + } + + // Otherwise, it does not belong to the known conflict sets. + } + // We don't know how to decode these instructions! Dump the conflict set! + o.indent(i) << "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'; + } + return true; + } else { + // Choose the best filter to do the decodings! + Filter &Best = bestFilter(); + if (Best.getNumFiltered() == 1) + emitSingletonDecoder(o, i, Best); + else + bestFilter().emit(o, i); + return false; + } + } +}; + +/////////////// +// Backend // +/////////////// + +class RISCDisassemblerEmitter::RISCDEBackend { +public: + RISCDEBackend(RISCDisassemblerEmitter &frontend) : + NumberedInstructions(), + Opcodes(), + Frontend(frontend), + Target(), + AFC(NULL) + { + populateInstructions(); + + if (Target.getName() == "ARM") { + TargetName = TARGET_ARM; + } else { + errs() << "Target name " << Target.getName() << " not recognized\n"; + assert(0 && "Unknown target"); + } + } + + ~RISCDEBackend() { + if (AFC) { + delete AFC; + AFC = NULL; + } + } + + void getInstructionsByEnumValue(std::vector<const CodeGenInstruction*> + &NumberedInstructions) { + // Dig down to the proper namespace. Code shamelessly stolen from + // InstrEnumEmitter.cpp + std::string Namespace; + CodeGenTarget::inst_iterator II, E; + + for (II = Target.inst_begin(), E = Target.inst_end(); II != E; ++II) + if (II->second.Namespace != "TargetInstrInfo") { + Namespace = II->second.Namespace; + break; + } + + assert(!Namespace.empty() && "No instructions defined."); + + Target.getInstructionsByEnumValue(NumberedInstructions); + } + + bool populateInstruction(const CodeGenInstruction &CGI, TARGET_NAME_t TN) { + const Record &Def = *CGI.TheDef; + const std::string &Name = Def.getName(); + uint8_t Form = getByteField(Def, "Form"); + BitsInit &Bits = getBitsField(Def, "Inst"); + + if (TN == TARGET_ARM) { + // FIXME: what about Int_MemBarrierV6 and Int_SyncBarrierV6? + if ((Name != "Int_MemBarrierV7" && Name != "Int_SyncBarrierV7") && + Form == ARM_FORMAT_PSEUDO) + return false; + if (thumbInstruction(Form)) + return false; + if (Name.find("CMPz") != std::string::npos /* || + Name.find("CMNz") != std::string::npos */) + return false; + + // Ignore pseudo instructions. + if (Name == "BXr9" || Name == "BMOVPCRX" || Name == "BMOVPCRXr9") + return false; + + // VLDRQ/VSTRQ can be hanlded with the more generic VLDMD/VSTMD. + if (Name == "VLDRQ" || Name == "VSTRQ") + return false; + + // + // The following special cases are for conflict resolutions. + // + + // RSCSri and RSCSrs set the 's' bit, but are not predicated. We are + // better off using the generic RSCri and RSCrs instructions. + if (Name == "RSCSri" || Name == "RSCSrs") return false; + + // MOVCCr, MOVCCs, MOVCCi, FCYPScc, FCYPDcc, FNEGScc, and FNEGDcc are used + // in the compiler to implement conditional moves. We can ignore them in + // favor of their more generic versions of instructions. + // See also SDNode *ARMDAGToDAGISel::Select(SDValue Op). + if (Name == "MOVCCr" || Name == "MOVCCs" || Name == "MOVCCi" || + Name == "FCPYScc" || Name == "FCPYDcc" || + Name == "FNEGScc" || Name == "FNEGDcc") + return false; + + // Ditto for VMOVDcc, VMOVScc, VNEGDcc, and VNEGScc. + if (Name == "VMOVDcc" || Name == "VMOVScc" || Name == "VNEGDcc" || + Name == "VNEGScc") + return false; + + // Ignore the *_sfp instructions when decoding. They are used by the + // compiler to implement scalar floating point operations using vector + // operations in order to work around some performance issues. + if (Name.find("_sfp") != std::string::npos) return false; + + // LLVM added LDM/STM_UPD which conflicts with LDM/STM. + // Ditto for VLDMS_UPD, VLDMD_UPD, VSTMS_UPD, VSTMD_UPD. + if (Name == "LDM_UPD" || Name == "STM_UPD" || Name == "VLDMS_UPD" || + Name == "VLDMD_UPD" || Name == "VSTMS_UPD" || Name == "VSTMD_UPD") + return false; + + // LDM_RET is a special case of LDM (Load Multiple) where the registers + // loaded include the PC, causing a branch to a loaded address. Ignore + // the LDM_RET instruction when decoding. + if (Name == "LDM_RET") return false; + + // Bcc is in a more generic form than B. Ignore B when decoding. + if (Name == "B") return false; + + // Ignore the non-Darwin BL instructions and the TPsoft (TLS) instruction. + if (Name == "BL" || Name == "BL_pred" || Name == "BLX" || Name == "BX" || + Name == "TPsoft") + return false; + + // Ignore VDUPf[d|q] instructions known to conflict with VDUP32[d-q] for + // decoding. The instruction duplicates an element from an ARM core + // register into every element of the destination vector. There is no + // distinction between data types. + if (Name == "VDUPfd" || Name == "VDUPfq") return false; + + // A8-598: VEXT + // Vector Extract extracts elements from the bottom end of the second + // operand vector and the top end of the first, concatenates them and + // places the result in the destination vector. The elements of the + // vectors are treated as being 8-bit bitfields. There is no distinction + // between data types. The size of the operation can be specified in + // assembler as vext.size. If the value is 16, 32, or 64, the syntax is + // a pseudo-instruction for a VEXT instruction specifying the equivalent + // number of bytes. + // + // Variants VEXTd16, VEXTd32, VEXTd8, and VEXTdf are reduced to VEXTd8; + // variants VEXTq16, VEXTq32, VEXTq8, and VEXTqf are reduced to VEXTq8. + if (Name == "VEXTd16" || Name == "VEXTd32" || Name == "VEXTdf" || + Name == "VEXTq16" || Name == "VEXTq32" || Name == "VEXTqf") + return false; + + // Vector Reverse is similar to Vector Extract. There is no distinction + // between data types, other than size. + // + // VREV64df is equivalent to VREV64d32. + // VREV64qf is equivalent to VREV64q32. + if (Name == "VREV64df" || Name == "VREV64qf") return false; + + // VDUPLNfd is equivalent to VDUPLN32d; VDUPfdf is specialized VDUPLN32d. + // VDUPLNfq is equivalent to VDUPLN32q; VDUPfqf is specialized VDUPLN32q. + // VLD1df is equivalent to VLD1d32. + // VLD1qf is equivalent to VLD1q32. + // VLD2d64 is equivalent to VLD1q64. + // VST1df is equivalent to VST1d32. + // VST1qf is equivalent to VST1q32. + // VST2d64 is equivalent to VST1q64. + if (Name == "VDUPLNfd" || Name == "VDUPfdf" || + Name == "VDUPLNfq" || Name == "VDUPfqf" || + Name == "VLD1df" || Name == "VLD1qf" || Name == "VLD2d64" || + Name == "VST1df" || Name == "VST1qf" || Name == "VST2d64") + return false; + } else if (TN == TARGET_THUMB) { + if (!thumbInstruction(Form)) + return false; + + // Ignore pseudo instructions. + if (Name == "tInt_eh_sjlj_setjmp" || Name == "t2Int_eh_sjlj_setjmp" || + Name == "t2MOVi32imm" || Name == "tBX" || Name == "tBXr9") + return false; + + // LLVM added tLDM_UPD which conflicts with tLDM. + if (Name == "tLDM_UPD") + return false; + + // On Darwin R9 is call-clobbered. Ignore the non-Darwin counterparts. + if (Name == "tBL" || Name == "tBLXi" || Name == "tBLXr") + return false; + + // Ignore the TPsoft (TLS) instructions, which conflict with tBLr9. + if (Name == "tTPsoft" || Name == "t2TPsoft") + return false; + + // Ignore tLEApcrel and tLEApcrelJT, prefer tADDrPCi. + if (Name == "tLEApcrel" || Name == "tLEApcrelJT") + return false; + + // Ignore t2LEApcrel, prefer the generic t2ADD* for disassembly printing. + if (Name == "t2LEApcrel") + return false; + + // Ignore tADDrSP, tADDspr, and tPICADD, prefer the generic tADDhirr. + // Ignore t2SUBrSPs, prefer the t2SUB[S]r[r|s]. + // Ignore t2ADDrSPs, prefer the t2ADD[S]r[r|s]. + if (Name == "tADDrSP" || Name == "tADDspr" || Name == "tPICADD" || + Name == "t2SUBrSPs" || Name == "t2ADDrSPs") + return false; + + // Ignore t2LDRDpci, prefer the generic t2LDRDi8, t2LDRD_PRE, t2LDRD_POST. + if (Name == "t2LDRDpci") + return false; + + // Ignore t2TBB, t2TBH and prefer the generic t2TBBgen, t2TBHgen. + if (Name == "t2TBB" || Name == "t2TBH") + return false; + + // Resolve conflicts: + // + // tBfar conflicts with tBLr9 + // tCMNz conflicts with tCMN (with assembly format strings being equal) + // tPOP_RET/t2LDM_RET conflict with tPOP/t2LDM (ditto) + // tMOVCCi conflicts with tMOVi8 + // tMOVCCr conflicts with tMOVgpr2gpr + // tBR_JTr conflicts with tBRIND + // tSpill conflicts with tSTRspi + // tLDRcp conflicts with tLDRspi + // tRestore conflicts with tLDRspi + // t2LEApcrelJT conflicts with t2LEApcrel + // t2ADDrSPi/t2SUBrSPi have more generic couterparts + if (Name == "tBfar" || + /* Name == "tCMNz" || */ Name == "tCMPzi8" || Name == "tCMPzr" || + Name == "tCMPzhir" || /* Name == "t2CMNzrr" || Name == "t2CMNzrs" || + Name == "t2CMNzri" || */ Name == "t2CMPzrr" || Name == "t2CMPzrs" || + Name == "t2CMPzri" || Name == "tPOP_RET" || Name == "t2LDM_RET" || + Name == "tMOVCCi" || Name == "tMOVCCr" || Name == "tBR_JTr" || + Name == "tSpill" || Name == "tLDRcp" || Name == "tRestore" || + Name == "t2LEApcrelJT" || Name == "t2ADDrSPi" || Name == "t2SUBrSPi") + return false; + } + + // Dumps the instruction encoding format. + switch (TargetName) { + case TARGET_ARM: + case TARGET_THUMB: + DEBUG(errs() << Name << " " << stringForARMFormat((ARMFormat)Form)); + break; + } + + DEBUG({ + errs() << " "; + + // Dumps the instruction encoding bits. + dumpBits(errs(), Bits); + + errs() << '\n'; + + // Dumps the list of operand info. + for (unsigned i = 0, e = CGI.OperandList.size(); i != e; ++i) { + CodeGenInstruction::OperandInfo Info = CGI.OperandList[i]; + const std::string &OperandName = Info.Name; + const Record &OperandDef = *Info.Rec; + + errs() << "\t" << OperandName << " (" << OperandDef.getName() << ")\n"; + } + }); + + return true; + } + + void populateInstructions() { + getInstructionsByEnumValue(NumberedInstructions); + + uint16_t numUIDs = NumberedInstructions.size(); + uint16_t uid; + + const char *instClass = NULL; + + switch (TargetName) { + case TARGET_ARM: + instClass = "InstARM"; + break; + default: + assert(0 && "Unreachable code!"); + } + + for (uid = 0; uid < numUIDs; uid++) { + // filter out intrinsics + if (!NumberedInstructions[uid]->TheDef->isSubClassOf(instClass)) + continue; + + if (populateInstruction(*NumberedInstructions[uid], TargetName)) + Opcodes.push_back(uid); + } + + // Special handling for the ARM chip, which supports two modes of execution. + // This branch handles the Thumb opcodes. + if (TargetName == TARGET_ARM) { + for (uid = 0; uid < numUIDs; uid++) { + // filter out intrinsics + if (!NumberedInstructions[uid]->TheDef->isSubClassOf("InstARM") + && !NumberedInstructions[uid]->TheDef->isSubClassOf("InstThumb")) + continue; + + if (populateInstruction(*NumberedInstructions[uid], TARGET_THUMB)) + Opcodes2.push_back(uid); + } + } + } + + // Emits disassembler code for instruction decoding. This delegates to the + // FilterChooser instance to do the heavy lifting. + void emit(raw_ostream &o) { + Indenter i; + std::string s; + raw_string_ostream ro(s); + + switch (TargetName) { + case TARGET_ARM: + Frontend.EmitSourceFileHeader("ARM Disassembler", ro); + break; + default: + assert(0 && "Unreachable code!"); + } + + ro.flush(); + o << s; + + o.indent(i) << "#include <inttypes.h>\n"; + o.indent(i) << "#include <assert.h>\n"; + o << '\n'; + o << "namespace llvm {\n\n"; + + AbstractFilterChooser::setTargetName(TargetName); + + switch (TargetName) { + case TARGET_ARM: { + // Emit common utility and ARM ISA decoder. + AFC = new FilterChooser<32>(NumberedInstructions, Opcodes); + AFC->emitTop(o, i); + delete AFC; + + // Emit Thumb ISA decoder as well. + AbstractFilterChooser::setTargetName(TARGET_THUMB); + AFC = new FilterChooser<32>(NumberedInstructions, Opcodes2); + AFC->emitBot(o, i); + break; + } + default: + assert(0 && "Unreachable code!"); + } + + o << "\n} // End llvm namespace \n"; + } + +protected: + std::vector<const CodeGenInstruction*> NumberedInstructions; + std::vector<unsigned> Opcodes; + // Special case for the ARM chip, which supports ARM and Thumb ISAs. + // Opcodes2 will be populated with the Thumb opcodes. + std::vector<unsigned> Opcodes2; + RISCDisassemblerEmitter &Frontend; + CodeGenTarget Target; + AbstractFilterChooser *AFC; + + TARGET_NAME_t TargetName; +}; + +///////////////////////// +// Backend interface // +///////////////////////// + +void RISCDisassemblerEmitter::initBackend() +{ + Backend = new RISCDEBackend(*this); +} + +void RISCDisassemblerEmitter::run(raw_ostream &o) +{ + Backend->emit(o); +} + +void RISCDisassemblerEmitter::shutdownBackend() +{ + delete Backend; + Backend = NULL; +} |
