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factor the snazzy string matcher code that Daniel hates 

out of AsmMatcherEmitter.cpp into its own class.

llvm-svn: 113137
This commit is contained in:
Chris Lattner 2010-09-06 02:01:51 +00:00
parent fb43da66b5
commit ca5a3554b5
3 changed files with 198 additions and 134 deletions
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144
llvm/utils/TableGen/AsmMatcherEmitter.cpp
View File

@ -76,6 +76,7 @@
#include "AsmMatcherEmitter.h"
#include "CodeGenTarget.h"
#include "Record.h"
#include "StringMatcher.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/STLExtras.h"
@ -1397,133 +1398,6 @@ static void EmitIsSubclass(CodeGenTarget &Target,
OS << "}\n\n";
}
typedef std::pair<std::string, std::string> StringPair;
/// FindFirstNonCommonLetter - Find the first character in the keys of the
/// string pairs that is not shared across the whole set of strings. All
/// strings are assumed to have the same length.
static unsigned
FindFirstNonCommonLetter(const std::vector<const StringPair*> &Matches) {
assert(!Matches.empty());
for (unsigned i = 0, e = Matches[0]->first.size(); i != e; ++i) {
// Check to see if letter i is the same across the set.
char Letter = Matches[0]->first[i];
for (unsigned str = 0, e = Matches.size(); str != e; ++str)
if (Matches[str]->first[i] != Letter)
return i;
}
return Matches[0]->first.size();
}
/// EmitStringMatcherForChar - Given a set of strings that are known to be the
/// same length and whose characters leading up to CharNo are the same, emit
/// code to verify that CharNo and later are the same.
///
/// \return - True if control can leave the emitted code fragment.
static bool EmitStringMatcherForChar(const std::string &StrVariableName,
const std::vector<const StringPair*> &Matches,
unsigned CharNo, unsigned IndentCount,
raw_ostream &OS) {
assert(!Matches.empty() && "Must have at least one string to match!");
std::string Indent(IndentCount*2+4, ' ');
// If we have verified that the entire string matches, we're done: output the
// matching code.
if (CharNo == Matches[0]->first.size()) {
assert(Matches.size() == 1 && "Had duplicate keys to match on");
// FIXME: If Matches[0].first has embeded \n, this will be bad.
OS << Indent << Matches[0]->second << "\t // \"" << Matches[0]->first
<< "\"\n";
return false;
}
// Bucket the matches by the character we are comparing.
std::map<char, std::vector<const StringPair*> > MatchesByLetter;
for (unsigned i = 0, e = Matches.size(); i != e; ++i)
MatchesByLetter[Matches[i]->first[CharNo]].push_back(Matches[i]);
// If we have exactly one bucket to match, see how many characters are common
// across the whole set and match all of them at once.
if (MatchesByLetter.size() == 1) {
unsigned FirstNonCommonLetter = FindFirstNonCommonLetter(Matches);
unsigned NumChars = FirstNonCommonLetter-CharNo;
// Emit code to break out if the prefix doesn't match.
if (NumChars == 1) {
// Do the comparison with if (Str[1] != 'f')
// FIXME: Need to escape general characters.
OS << Indent << "if (" << StrVariableName << "[" << CharNo << "] != '"
<< Matches[0]->first[CharNo] << "')\n";
OS << Indent << " break;\n";
} else {
// Do the comparison with if (Str.substr(1,3) != "foo").
// FIXME: Need to escape general strings.
OS << Indent << "if (" << StrVariableName << ".substr(" << CharNo << ","
<< NumChars << ") != \"";
OS << Matches[0]->first.substr(CharNo, NumChars) << "\")\n";
OS << Indent << " break;\n";
}
return EmitStringMatcherForChar(StrVariableName, Matches,
FirstNonCommonLetter, IndentCount, OS);
}
// Otherwise, we have multiple possible things, emit a switch on the
// character.
OS << Indent << "switch (" << StrVariableName << "[" << CharNo << "]) {\n";
OS << Indent << "default: break;\n";
for (std::map<char, std::vector<const StringPair*> >::iterator LI =
MatchesByLetter.begin(), E = MatchesByLetter.end(); LI != E; ++LI) {
// TODO: escape hard stuff (like \n) if we ever care about it.
OS << Indent << "case '" << LI->first << "':\t // "
<< LI->second.size() << " strings to match.\n";
if (EmitStringMatcherForChar(StrVariableName, LI->second, CharNo+1,
IndentCount+1, OS))
OS << Indent << " break;\n";
}
OS << Indent << "}\n";
return true;
}
/// EmitStringMatcher - Given a list of strings and code to execute when they
/// match, output a simple switch tree to classify the input string.
///
/// If a match is found, the code in Vals[i].second is executed; control must
/// not exit this code fragment. If nothing matches, execution falls through.
///
/// \param StrVariableName - The name of the variable to test.
static void EmitStringMatcher(const std::string &StrVariableName,
const std::vector<StringPair> &Matches,
raw_ostream &OS) {
// First level categorization: group strings by length.
std::map<unsigned, std::vector<const StringPair*> > MatchesByLength;
for (unsigned i = 0, e = Matches.size(); i != e; ++i)
MatchesByLength[Matches[i].first.size()].push_back(&Matches[i]);
// Output a switch statement on length and categorize the elements within each
// bin.
OS << " switch (" << StrVariableName << ".size()) {\n";
OS << " default: break;\n";
for (std::map<unsigned, std::vector<const StringPair*> >::iterator LI =
MatchesByLength.begin(), E = MatchesByLength.end(); LI != E; ++LI) {
OS << " case " << LI->first << ":\t // " << LI->second.size()
<< " strings to match.\n";
if (EmitStringMatcherForChar(StrVariableName, LI->second, 0, 0, OS))
OS << " break;\n";
}
OS << " }\n";
}
/// EmitMatchTokenString - Emit the function to match a token string to the
@ -1532,18 +1406,19 @@ static void EmitMatchTokenString(CodeGenTarget &Target,
std::vector<ClassInfo*> &Infos,
raw_ostream &OS) {
// Construct the match list.
std::vector<StringPair> Matches;
std::vector<StringMatcher::StringPair> Matches;
for (std::vector<ClassInfo*>::iterator it = Infos.begin(),
ie = Infos.end(); it != ie; ++it) {
ClassInfo &CI = **it;
if (CI.Kind == ClassInfo::Token)
Matches.push_back(StringPair(CI.ValueName, "return " + CI.Name + ";"));
Matches.push_back(StringMatcher::StringPair(CI.ValueName,
"return " + CI.Name + ";"));
}
OS << "static MatchClassKind MatchTokenString(StringRef Name) {\n";
EmitStringMatcher("Name", Matches, OS);
StringMatcher("Name", Matches, OS).Emit();
OS << " return InvalidMatchClass;\n";
OS << "}\n\n";
@ -1554,19 +1429,20 @@ static void EmitMatchTokenString(CodeGenTarget &Target,
static void EmitMatchRegisterName(CodeGenTarget &Target, Record *AsmParser,
raw_ostream &OS) {
// Construct the match list.
std::vector<StringPair> Matches;
std::vector<StringMatcher::StringPair> Matches;
for (unsigned i = 0, e = Target.getRegisters().size(); i != e; ++i) {
const CodeGenRegister &Reg = Target.getRegisters()[i];
if (Reg.TheDef->getValueAsString("AsmName").empty())
continue;
Matches.push_back(StringPair(Reg.TheDef->getValueAsString("AsmName"),
"return " + utostr(i + 1) + ";"));
Matches.push_back(StringMatcher::StringPair(
Reg.TheDef->getValueAsString("AsmName"),
"return " + utostr(i + 1) + ";"));
}
OS << "static unsigned MatchRegisterName(StringRef Name) {\n";
EmitStringMatcher("Name", Matches, OS);
StringMatcher("Name", Matches, OS).Emit();
OS << " return 0;\n";
OS << "}\n\n";

134
llvm/utils/TableGen/StringMatcher.cpp Normal file
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@ -0,0 +1,134 @@
//===- StringMatcher.cpp - Generate a matcher for input strings -----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the StringMatcher class.
//
//===----------------------------------------------------------------------===//
#include "StringMatcher.h"
#include "llvm/Support/raw_ostream.h"
#include <map>
using namespace llvm;
/// FindFirstNonCommonLetter - Find the first character in the keys of the
/// string pairs that is not shared across the whole set of strings. All
/// strings are assumed to have the same length.
static unsigned
FindFirstNonCommonLetter(const std::vector<const
StringMatcher::StringPair*> &Matches) {
assert(!Matches.empty());
for (unsigned i = 0, e = Matches[0]->first.size(); i != e; ++i) {
// Check to see if letter i is the same across the set.
char Letter = Matches[0]->first[i];
for (unsigned str = 0, e = Matches.size(); str != e; ++str)
if (Matches[str]->first[i] != Letter)
return i;
}
return Matches[0]->first.size();
}
/// EmitStringMatcherForChar - Given a set of strings that are known to be the
/// same length and whose characters leading up to CharNo are the same, emit
/// code to verify that CharNo and later are the same.
///
/// \return - True if control can leave the emitted code fragment.
bool StringMatcher::
EmitStringMatcherForChar(const std::vector<const StringPair*> &Matches,
unsigned CharNo, unsigned IndentCount) const {
assert(!Matches.empty() && "Must have at least one string to match!");
std::string Indent(IndentCount*2+4, ' ');
// If we have verified that the entire string matches, we're done: output the
// matching code.
if (CharNo == Matches[0]->first.size()) {
assert(Matches.size() == 1 && "Had duplicate keys to match on");
// FIXME: If Matches[0].first has embeded \n, this will be bad.
OS << Indent << Matches[0]->second << "\t // \"" << Matches[0]->first
<< "\"\n";
return false;
}
// Bucket the matches by the character we are comparing.
std::map<char, std::vector<const StringPair*> > MatchesByLetter;
for (unsigned i = 0, e = Matches.size(); i != e; ++i)
MatchesByLetter[Matches[i]->first[CharNo]].push_back(Matches[i]);
// If we have exactly one bucket to match, see how many characters are common
// across the whole set and match all of them at once.
if (MatchesByLetter.size() == 1) {
unsigned FirstNonCommonLetter = FindFirstNonCommonLetter(Matches);
unsigned NumChars = FirstNonCommonLetter-CharNo;
// Emit code to break out if the prefix doesn't match.
if (NumChars == 1) {
// Do the comparison with if (Str[1] != 'f')
// FIXME: Need to escape general characters.
OS << Indent << "if (" << StrVariableName << "[" << CharNo << "] != '"
<< Matches[0]->first[CharNo] << "')\n";
OS << Indent << " break;\n";
} else {
// Do the comparison with if (Str.substr(1,3) != "foo").
// FIXME: Need to escape general strings.
OS << Indent << "if (" << StrVariableName << ".substr(" << CharNo << ","
<< NumChars << ") != \"";
OS << Matches[0]->first.substr(CharNo, NumChars) << "\")\n";
OS << Indent << " break;\n";
}
return EmitStringMatcherForChar(Matches, FirstNonCommonLetter, IndentCount);
}
// Otherwise, we have multiple possible things, emit a switch on the
// character.
OS << Indent << "switch (" << StrVariableName << "[" << CharNo << "]) {\n";
OS << Indent << "default: break;\n";
for (std::map<char, std::vector<const StringPair*> >::iterator LI =
MatchesByLetter.begin(), E = MatchesByLetter.end(); LI != E; ++LI) {
// TODO: escape hard stuff (like \n) if we ever care about it.
OS << Indent << "case '" << LI->first << "':\t // "
<< LI->second.size() << " strings to match.\n";
if (EmitStringMatcherForChar(LI->second, CharNo+1, IndentCount+1))
OS << Indent << " break;\n";
}
OS << Indent << "}\n";
return true;
}
/// Emit - Top level entry point.
///
void StringMatcher::Emit() const {
// First level categorization: group strings by length.
std::map<unsigned, std::vector<const StringPair*> > MatchesByLength;
for (unsigned i = 0, e = Matches.size(); i != e; ++i)
MatchesByLength[Matches[i].first.size()].push_back(&Matches[i]);
// Output a switch statement on length and categorize the elements within each
// bin.
OS << " switch (" << StrVariableName << ".size()) {\n";
OS << " default: break;\n";
for (std::map<unsigned, std::vector<const StringPair*> >::iterator LI =
MatchesByLength.begin(), E = MatchesByLength.end(); LI != E; ++LI) {
OS << " case " << LI->first << ":\t // " << LI->second.size()
<< " strings to match.\n";
if (EmitStringMatcherForChar(LI->second, 0, 0))
OS << " break;\n";
}
OS << " }\n";
}

54
llvm/utils/TableGen/StringMatcher.h Normal file
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@ -0,0 +1,54 @@
//===- StringMatcher.h - Generate a matcher for input strings ---*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the StringMatcher class.
//
//===----------------------------------------------------------------------===//
#ifndef STRINGMATCHER_H
#define STRINGMATCHER_H
#include <vector>
#include <string>
#include <utility>
#include "llvm/ADT/StringRef.h"
namespace llvm {
class raw_ostream;
/// StringMatcher - Given a list of strings and code to execute when they match,
/// output a simple switch tree to classify the input string.
///
/// If a match is found, the code in Vals[i].second is executed; control must
/// not exit this code fragment. If nothing matches, execution falls through.
///
class StringMatcher {
public:
typedef std::pair<std::string, std::string> StringPair;
private:
StringRef StrVariableName;
const std::vector<StringPair> &Matches;
raw_ostream &OS;
public:
StringMatcher(StringRef strVariableName,
const std::vector<StringPair> &matches, raw_ostream &os)
: StrVariableName(strVariableName), Matches(matches), OS(os) {}
void Emit() const;
private:
bool EmitStringMatcherForChar(const std::vector<const StringPair*> &Matches,
unsigned CharNo, unsigned IndentCount) const;
};
} // end llvm namespace.
#endif