[llvm-commits] [llvm] r151984 - /llvm/trunk/utils/TableGen/AsmMatcherEmitter.cpp
Benjamin Kramer
benny.kra at googlemail.com
Sat Mar 3 11:13:26 PST 2012
Author: d0k
Date: Sat Mar 3 13:13:26 2012
New Revision: 151984
URL: http://llvm.org/viewvc/llvm-project?rev=151984&view=rev
Log:
Shrink the asm matcher tables.
- Shrink the opcode field to 16 bits.
- Shrink the AsmVariantID field to 8 bits.
- Store the mnemonic string in a string table, store a 16 bit index.
- Store a pascal-style length byte in the string instead of a null terminator,
so we can avoid calling strlen on every entry we visit during mnemonic search.
Shrinks X86AsmParser.o from 434k to 201k on x86_64 and eliminates relocs from the table.
Modified:
llvm/trunk/utils/TableGen/AsmMatcherEmitter.cpp
Modified: llvm/trunk/utils/TableGen/AsmMatcherEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/AsmMatcherEmitter.cpp?rev=151984&r1=151983&r2=151984&view=diff
==============================================================================
--- llvm/trunk/utils/TableGen/AsmMatcherEmitter.cpp (original)
+++ llvm/trunk/utils/TableGen/AsmMatcherEmitter.cpp Sat Mar 3 13:13:26 2012
@@ -99,6 +99,7 @@
#include "AsmMatcherEmitter.h"
#include "CodeGenTarget.h"
#include "StringMatcher.h"
+#include "StringToOffsetTable.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/PointerUnion.h"
#include "llvm/ADT/SmallPtrSet.h"
@@ -2302,32 +2303,39 @@
// following the mnemonic.
OS << "namespace {\n";
OS << " struct MatchEntry {\n";
- OS << " unsigned Opcode;\n";
- OS << " const char *Mnemonic;\n";
+ OS << " static const char *MnemonicTable;\n";
+ OS << " uint16_t Opcode;\n";
+ OS << " uint16_t Mnemonic;\n";
OS << " " << getMinimalTypeForRange(Info.Matchables.size())
<< " ConvertFn;\n";
OS << " " << getMinimalTypeForRange(Info.Classes.size())
<< " Classes[" << MaxNumOperands << "];\n";
OS << " " << getMinimalTypeForRange(1ULL << Info.SubtargetFeatures.size())
<< " RequiredFeatures;\n";
- OS << " unsigned AsmVariantID;\n";
+ OS << " uint8_t AsmVariantID;\n\n";
+ OS << " StringRef getMnemonic() const {\n";
+ OS << " return StringRef(MnemonicTable + Mnemonic + 1,\n";
+ OS << " MnemonicTable[Mnemonic]);\n";
+ OS << " }\n";
OS << " };\n\n";
OS << " // Predicate for searching for an opcode.\n";
OS << " struct LessOpcode {\n";
OS << " bool operator()(const MatchEntry &LHS, StringRef RHS) {\n";
- OS << " return StringRef(LHS.Mnemonic) < RHS;\n";
+ OS << " return LHS.getMnemonic() < RHS;\n";
OS << " }\n";
OS << " bool operator()(StringRef LHS, const MatchEntry &RHS) {\n";
- OS << " return LHS < StringRef(RHS.Mnemonic);\n";
+ OS << " return LHS < RHS.getMnemonic();\n";
OS << " }\n";
OS << " bool operator()(const MatchEntry &LHS, const MatchEntry &RHS) {\n";
- OS << " return StringRef(LHS.Mnemonic) < StringRef(RHS.Mnemonic);\n";
+ OS << " return LHS.getMnemonic() < RHS.getMnemonic();\n";
OS << " }\n";
OS << " };\n";
OS << "} // end anonymous namespace.\n\n";
+ StringToOffsetTable StringTable;
+
OS << "static const MatchEntry MatchTable["
<< Info.Matchables.size() << "] = {\n";
@@ -2336,8 +2344,11 @@
it != ie; ++it) {
MatchableInfo &II = **it;
+ // Store a pascal-style length byte in the mnemonic.
+ std::string LenMnemonic = char(II.Mnemonic.size()) + II.Mnemonic.str();
OS << " { " << Target.getName() << "::"
- << II.getResultInst()->TheDef->getName() << ", \"" << II.Mnemonic << "\""
+ << II.getResultInst()->TheDef->getName() << ", "
+ << StringTable.GetOrAddStringOffset(LenMnemonic, false)
<< ", " << II.ConversionFnKind << ", { ";
for (unsigned i = 0, e = II.AsmOperands.size(); i != e; ++i) {
MatchableInfo::AsmOperand &Op = II.AsmOperands[i];
@@ -2361,6 +2372,10 @@
OS << "};\n\n";
+ OS << "const char *MatchEntry::MnemonicTable =\n";
+ StringTable.EmitString(OS);
+ OS << ";\n\n";
+
// A method to determine if a mnemonic is in the list.
OS << "bool " << Target.getName() << ClassName << "::\n"
<< "MnemonicIsValid(StringRef Mnemonic) {\n";
@@ -2424,7 +2439,7 @@
OS << " it != ie; ++it) {\n";
OS << " // equal_range guarantees that instruction mnemonic matches.\n";
- OS << " assert(Mnemonic == it->Mnemonic);\n";
+ OS << " assert(Mnemonic == it->getMnemonic());\n";
// Emit check that the subclasses match.
OS << " if (VariantID != it->AsmVariantID) continue;\n";
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