Switch the fixed-length disassembler to be table-driven.
Refactor the TableGen'erated fixed length disassemblmer to use a
table-driven state machine rather than a massive set of nested
switch() statements.
As a result, the ARM Disassembler (ARMDisassembler.cpp) builds much more
quickly and generates a smaller end result. For a Release+Asserts build on
a 16GB 3.4GHz i7 iMac w/ SSD:
Time to compile at -O2 (averaged w/ hot caches):
Previous: 35.5s
New: 8.9s
TEXT size:
Previous: 447,251
New: 297,661
Builds in 25% of the time previously required and generates code 66% of
the size.
Execution time of the disassembler is only slightly slower (7% disassembling
10 million ARM instructions, 19.6s vs 21.0s). The new implementation has
not yet been tuned, however, so the performance should almost certainly
be recoverable should it become a concern.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161888 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/FixedLenDecoderEmitter.cpp b/utils/TableGen/FixedLenDecoderEmitter.cpp
index 2cdde55..52a1132 100644
--- a/utils/TableGen/FixedLenDecoderEmitter.cpp
+++ b/utils/TableGen/FixedLenDecoderEmitter.cpp
@@ -17,9 +17,15 @@
#include "CodeGenTarget.h"
#include "llvm/TableGen/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 "llvm/TableGen/TableGenBackend.h"
@@ -35,9 +41,7 @@
EncodingField(unsigned B, unsigned W, unsigned O)
: Base(B), Width(W), Offset(O) { }
};
-} // End anonymous namespace
-namespace {
struct OperandInfo {
std::vector<EncodingField> Fields;
std::string Decoder;
@@ -56,10 +60,25 @@
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
@@ -77,6 +96,17 @@
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);
@@ -238,8 +268,9 @@
// 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) const;
+ // 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.
@@ -338,12 +369,7 @@
doFilter();
}
- // The top level filter chooser has NULL as its parent.
- bool isTopLevel() const { return Parent == NULL; }
-
- // Emit the top level typedef and decodeInstruction() function.
- void emitTop(raw_ostream &o, unsigned Indentation,
- const std::string &Namespace) const;
+ unsigned getBitWidth() const { return BitWidth; }
protected:
// Populates the insn given the uid.
@@ -414,21 +440,28 @@
bool emitPredicateMatch(raw_ostream &o, unsigned &Indentation,
unsigned Opc) const;
- void emitSoftFailCheck(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) const;
+ 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,
- const Filter &Best) const;
+ void emitSingletonTableEntry(DecoderTableInfo &TableInfo,
+ const Filter &Best) const;
- void emitBinaryParser(raw_ostream &o , unsigned &Indentation,
+ void emitBinaryParser(raw_ostream &o, unsigned &Indentation,
const OperandInfo &OpInfo) const;
+ void emitDecoder(raw_ostream &OS, unsigned Indentation, unsigned Opc) const;
+ unsigned getDecoderIndex(DecoderSet &Decoders, unsigned Opc) const;
+
// Assign a single filter and run with it.
void runSingleFilter(unsigned startBit, unsigned numBit, bool mixed);
@@ -447,10 +480,10 @@
// 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) const;
+public:
+ // emitTableEntries - Emit state machine entries to decode our share of
+ // instructions.
+ void emitTableEntries(DecoderTableInfo &TableInfo) const;
};
} // End anonymous namespace
@@ -544,7 +577,7 @@
}
// 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);
@@ -577,64 +610,100 @@
}
}
-// Emit code to decode instructions given a segment or segments of bits.
-void Filter::emit(raw_ostream &o, unsigned &Indentation) const {
- o.indent(Indentation) << "// Check Inst{";
+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);
+ }
+}
- if (NumBits > 1)
- o << (StartBit + NumBits - 1) << '-';
+// 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);
- o << StartBit << "} ...\n";
-
- o.indent(Indentation) << "switch (fieldFromInstruction" << Owner->BitWidth
- << "(insn, " << StartBit << ", "
- << NumBits << ")) {\n";
+ // A new filter entry begins a new scope for fixup resolution.
+ TableInfo.FixupStack.push_back(FixupList());
std::map<unsigned, const FilterChooser*>::const_iterator filterIterator;
- bool DefaultCase = false;
+ DecoderTable &Table = TableInfo.Table;
+
+ size_t PrevFilter = 0;
+ bool HasFallthrough = 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;
+ HasFallthrough = 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";
+ // 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(filterIterator->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; }
+ filterIterator->second->emitTableEntries(TableInfo);
- filterIterator->second->emit(o, Indentation);
- // For top level default case, there's no need for a break statement.
- if (Owner->isTopLevel() && DefaultCase)
- break;
-
- o.indent(Indentation) << "break;\n";
-
- if (!DefaultCase) { --Indentation; --Indentation; }
+ // 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
@@ -652,31 +721,205 @@
// //
//////////////////////////////////
-// Emit the top level typedef and decodeInstruction() function.
-void FilterChooser::emitTop(raw_ostream &o, unsigned Indentation,
- const std::string &Namespace) const {
- o.indent(Indentation) <<
- "static MCDisassembler::DecodeStatus decode" << Namespace << "Instruction"
- << BitWidth << "(MCInst &MI, uint" << BitWidth
- << "_t insn, uint64_t Address, "
- << "const void *Decoder, const MCSubtargetInfo &STI) {\n";
- o.indent(Indentation) << " unsigned tmp = 0;\n";
- o.indent(Indentation) << " (void)tmp;\n";
- o.indent(Indentation) << Emitter->Locals << "\n";
- o.indent(Indentation) << " uint64_t Bits = STI.getFeatureBits();\n";
- o.indent(Indentation) << " (void)Bits;\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 " << Emitter->ReturnFail << ";\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:
+ throw "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;
+ OS.indent(Indentation) << "switch (Idx) {\n";
+ OS.indent(Indentation) << "default: llvm_unreachable(\"Invalid index!\");\n";
+ unsigned Index = 0;
+ for (PredicateSet::const_iterator I = Predicates.begin(), E = Predicates.end();
+ I != E; ++I, ++Index) {
+ OS.indent(Indentation) << "case " << Index << ":\n";
+ OS.indent(Indentation+2) << "return (" << *I << ");\n";
+ }
+ OS.indent(Indentation) << "}\n";
+ 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, void *Decoder) {\n";
+ Indentation += 2;
+ OS.indent(Indentation) << "InsnType tmp;\n";
+ OS.indent(Indentation) << "switch (Idx) {\n";
+ OS.indent(Indentation) << "default: llvm_unreachable(\"Invalid index!\");\n";
+ unsigned Index = 0;
+ for (DecoderSet::const_iterator I = Decoders.begin(), E = Decoders.end();
+ I != E; ++I, ++Index) {
+ OS.indent(Indentation) << "case " << Index << ":\n";
+ OS << *I << "\n";
+ 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
@@ -827,14 +1070,14 @@
if (OpInfo.numFields() == 1) {
OperandInfo::const_iterator OI = OpInfo.begin();
- o.indent(Indentation) << " tmp = fieldFromInstruction" << BitWidth
- << "(insn, " << OI->Base << ", " << OI->Width
- << ");\n";
+ o.indent(Indentation) << " tmp = fieldFromInstruction"
+ << "(insn, " << OI->Base << ", " << OI->Width
+ << ");\n";
} else {
o.indent(Indentation) << " tmp = 0;\n";
for (OperandInfo::const_iterator OI = OpInfo.begin(), OE = OpInfo.end();
OI != OE; ++OI) {
- o.indent(Indentation) << " tmp |= (fieldFromInstruction" << BitWidth
+ o.indent(Indentation) << " tmp |= (fieldFromInstruction"
<< "(insn, " << OI->Base << ", " << OI->Width
<< ") << " << OI->Offset << ");\n";
}
@@ -849,6 +1092,51 @@
}
+void FilterChooser::emitDecoder(raw_ostream &OS, unsigned Indentation,
+ unsigned Opc) const {
+ std::map<unsigned, std::vector<OperandInfo> >::const_iterator OpIter =
+ Operands.find(Opc);
+ const std::vector<OperandInfo>& InsnOperands = OpIter->second;
+ for (std::vector<OperandInfo>::const_iterator
+ I = InsnOperands.begin(), E = InsnOperands.end(); I != E; ++I) {
+ // If a custom instruction decoder was specified, use that.
+ if (I->numFields() == 0 && I->Decoder.size()) {
+ OS.indent(Indentation) << " " << Emitter->GuardPrefix << I->Decoder
+ << "(MI, insn, Address, Decoder)"
+ << Emitter->GuardPostfix << "\n";
+ break;
+ }
+
+ emitBinaryParser(OS, Indentation, *I);
+ }
+}
+
+unsigned FilterChooser::getDecoderIndex(DecoderSet &Decoders,
+ unsigned Opc) const {
+ // 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 = 0;
+ 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] == '!')
@@ -887,8 +1175,74 @@
return Predicates->getSize() > 0;
}
-void FilterChooser::emitSoftFailCheck(raw_ostream &o, unsigned Indentation,
- unsigned Opc) const {
+bool FilterChooser::doesOpcodeNeedPredicate(unsigned Opc) const {
+ ListInit *Predicates =
+ AllInstructions[Opc]->TheDef->getValueAsListInit("Predicates");
+ for (unsigned i = 0; i < Predicates->getSize(); ++i) {
+ Record *Pred = Predicates->getElementAsRecord(i);
+ if (!Pred->getValue("AssemblerMatcherPredicate"))
+ continue;
+
+ std::string P = Pred->getValueAsString("AssemblerCondString");
+
+ if (!P.length())
+ continue;
+
+ return true;
+ }
+ return false;
+}
+
+unsigned FilterChooser::getPredicateIndex(DecoderTableInfo &TableInfo,
+ StringRef Predicate) const {
+ // 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());
+}
+
+void FilterChooser::emitPredicateTableEntry(DecoderTableInfo &TableInfo,
+ unsigned Opc) const {
+ if (!doesOpcodeNeedPredicate(Opc))
+ return;
+
+ // 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 (int 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);
+}
+
+void FilterChooser::emitSoftFailTableEntry(DecoderTableInfo &TableInfo,
+ unsigned Opc) const {
BitsInit *SFBits =
AllInstructions[Opc]->TheDef->getValueAsBitsInit("SoftFail");
if (!SFBits) return;
@@ -914,13 +1268,11 @@
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"
+ 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";
- o << "#error SoftFail Conflict, " << Name << "::SoftFail{" << i
- << "} set but Inst{" << i << "} undefined!\n";
+ return;
}
}
@@ -930,27 +1282,31 @@
if (!NeedPositiveMask && !NeedNegativeMask)
return;
- std::string PositiveMaskStr = PositiveMask.toString(16, /*signed=*/false);
- std::string NegativeMaskStr = NegativeMask.toString(16, /*signed=*/false);
- StringRef BitExt = "";
- if (BitWidth > 32)
- BitExt = "ULL";
+ TableInfo.Table.push_back(MCD::OPC_SoftFail);
- o.indent(Indentation) << "if (";
- if (NeedPositiveMask)
- o << "insn & 0x" << PositiveMaskStr << BitExt;
- if (NeedPositiveMask && NeedNegativeMask)
- o << " || ";
- if (NeedNegativeMask)
- o << "~insn & 0x" << NegativeMaskStr << BitExt;
- o << ")\n";
- o.indent(Indentation+2) << "S = MCDisassembler::SoftFail;\n";
+ SmallString<16> MaskBytes;
+ raw_svector_ostream S(MaskBytes);
+ if (NeedPositiveMask) {
+ encodeULEB128(PositiveMask.getZExtValue(), S);
+ S.flush();
+ for (int 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 (int 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. Return true if we have matched all the
-// well-known bits.
-bool FilterChooser::emitSingletonDecoder(raw_ostream &o, unsigned &Indentation,
- unsigned Opc) const {
+// 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;
@@ -963,105 +1319,69 @@
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) << "if (";
- if (!emitPredicateMatch(o, Indentation, Opc))
- o << "1";
- o << ") {\n";
- emitSoftFailCheck(o, Indentation+2, Opc);
- o.indent(Indentation) << " MI.setOpcode(" << Opc << ");\n";
- std::map<unsigned, std::vector<OperandInfo> >::const_iterator OpIter =
- Operands.find(Opc);
- const std::vector<OperandInfo>& InsnOperands = OpIter->second;
- for (std::vector<OperandInfo>::const_iterator
- I = InsnOperands.begin(), E = InsnOperands.end(); I != E; ++I) {
- // If a custom instruction decoder was specified, use that.
- if (I->numFields() == 0 && I->Decoder.size()) {
- o.indent(Indentation) << " " << Emitter->GuardPrefix << I->Decoder
- << "(MI, insn, Address, Decoder)"
- << Emitter->GuardPostfix << "\n";
- break;
- }
+ // Emit the predicate table entry if one is needed.
+ emitPredicateTableEntry(TableInfo, Opc);
- emitBinaryParser(o, Indentation, *I);
- }
-
- o.indent(Indentation) << " return " << Emitter->ReturnOK << "; // "
- << nameWithID(Opc) << '\n';
- o.indent(Indentation) << "}\n"; // Closing predicate block.
- return true;
- }
-
- // Otherwise, there are more decodings to be done!
-
- // Emit code to match the island(s) for the singleton.
- o.indent(Indentation) << "// 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(Indentation) << "if (";
- if (emitPredicateMatch(o, Indentation, Opc)) {
- o << " &&\n";
- o.indent(Indentation+4);
- }
-
+ // Check any additional encoding fields needed.
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";
+ 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);
}
- emitSoftFailCheck(o, Indentation+2, Opc);
- o.indent(Indentation) << " MI.setOpcode(" << Opc << ");\n";
- std::map<unsigned, std::vector<OperandInfo> >::const_iterator OpIter =
- Operands.find(Opc);
- const std::vector<OperandInfo>& InsnOperands = OpIter->second;
- for (std::vector<OperandInfo>::const_iterator
- I = InsnOperands.begin(), E = InsnOperands.end(); I != E; ++I) {
- // If a custom instruction decoder was specified, use that.
- if (I->numFields() == 0 && I->Decoder.size()) {
- o.indent(Indentation) << " " << Emitter->GuardPrefix << I->Decoder
- << "(MI, insn, Address, Decoder)"
- << Emitter->GuardPostfix << "\n";
- break;
- }
- emitBinaryParser(o, Indentation, *I);
- }
- o.indent(Indentation) << " return " << Emitter->ReturnOK << "; // "
- << nameWithID(Opc) << '\n';
- o.indent(Indentation) << "}\n";
+ // Check for soft failure of the match.
+ emitSoftFailTableEntry(TableInfo, Opc);
- return false;
+ 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 (int i = 0, e = Bytes.size(); i != e; ++i)
+ TableInfo.Table.push_back(Bytes[i]);
}
-// Emits code to decode the singleton, and then to decode the rest.
-void FilterChooser::emitSingletonDecoder(raw_ostream &o, unsigned &Indentation,
- const Filter &Best) const {
-
+// 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(unsigned startBit, unsigned numBit,
@@ -1341,36 +1661,29 @@
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) const {
- 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) {
const Filter &Best = Filters[BestIndex];
if (Best.getNumFiltered() == 1)
- emitSingletonDecoder(o, Indentation, Best);
+ emitSingletonTableEntry(TableInfo, Best);
else
- Best.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";
@@ -1385,8 +1698,6 @@
getBitsField(*AllInstructions[Opcodes[i]]->TheDef, "Inst"));
errs() << '\n';
}
-
- return true;
}
static bool populateInstruction(const CodeGenInstruction &CGI, unsigned Opc,
@@ -1549,62 +1860,168 @@
return true;
}
-static void emitHelper(llvm::raw_ostream &o, unsigned BitWidth) {
- unsigned Indentation = 0;
- std::string WidthStr = "uint" + utostr(BitWidth) + "_t";
+// 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 = ((1 << numBits) - 1) << startBit;\n"
+ << " return (insn & fieldMask) >> startBit;\n"
+ << "}\n\n";
+}
- 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";
-
- 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;\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, (void*)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";
+ 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);
// Parameterize the decoders based on namespace and instruction width.
- const std::vector<const CodeGenInstruction*> &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];
+ 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" ||
@@ -1622,24 +2039,48 @@
}
}
+ DecoderTableInfo TableInfo;
std::set<unsigned> Sizes;
for (std::map<std::pair<std::string, unsigned>,
std::vector<unsigned> >::const_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);
- }
-
// Emit the decoder for this namespace+width combination.
- FilterChooser FC(NumberedInstructions, I->second, Operands,
+ FilterChooser FC(*NumberedInstructions, I->second, Operands,
8*I->first.second, this);
- FC.emitTop(o, 0, I->first.first);
+
+ // 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(), I->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 {