[PATCH] D139274: Store OptTable::Info::Name as a StringRef

[serge via Phabricator via cfe-commits]

serge-sans-paille created this revision.
serge-sans-paille added reviewers: thakis, aaron.ballman, nikic.
Herald added a subscriber: hiraditya.
Herald added a project: All.
serge-sans-paille requested review of this revision.
Herald added subscribers: llvm-commits, cfe-commits, MaskRay.
Herald added projects: clang, LLVM.

This avoids implicit conversion to StringRef at several points, which in
turns avoid redundant calls to strlen.

It also eventually gives a consistent, humble speedup in compilation
time

https://llvm-compile-time-tracker.com/compare.php?from=5f5b942823474e98e43a27d515a87ce140396c53&to=60e13b778119fc32d50dc38ff1a564a87146e9c6&stat=instructions:u


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D139274

Files:
  clang/lib/Driver/ToolChains/Gnu.cpp
  llvm/include/llvm/Option/OptTable.h
  llvm/lib/Option/OptTable.cpp
  llvm/utils/TableGen/OptParserEmitter.cpp


Index: llvm/utils/TableGen/OptParserEmitter.cpp
===================================================================
--- llvm/utils/TableGen/OptParserEmitter.cpp
+++ llvm/utils/TableGen/OptParserEmitter.cpp
@@ -54,9 +54,9 @@
 
 static void emitNameUsingSpelling(raw_ostream &OS, const Record &R) {
   size_t PrefixLength;
-  OS << "&";
+  OS << "llvm::StringRef(";
   write_cstring(OS, StringRef(getOptionSpelling(R, PrefixLength)));
-  OS << "[" << PrefixLength << "]";
+  OS << ").substr(" << PrefixLength << ")";
 }
 
 class MarshallingInfo {
Index: llvm/lib/Option/OptTable.cpp
===================================================================
--- llvm/lib/Option/OptTable.cpp
+++ llvm/lib/Option/OptTable.cpp
@@ -87,7 +87,7 @@
 
 // Support lower_bound between info and an option name.
 static inline bool operator<(const OptTable::Info &I, const char *Name) {
-  return StrCmpOptionNameIgnoreCase(I.Name, Name) < 0;
+  return StrCmpOptionNameIgnoreCase(I.Name.data(), Name) < 0;
 }
 
 } // end namespace opt
@@ -321,7 +321,7 @@
   return BestDistance;
 }
 
-bool OptTable::addValues(const char *Option, const char *Values) {
+bool OptTable::addValues(StringRef Option, const char *Values) {
   for (size_t I = FirstSearchableIndex, E = OptionInfos.size(); I < E; I++) {
     Info &In = OptionInfos[I];
     if (optionMatches(In, Option)) {
Index: llvm/include/llvm/Option/OptTable.h
===================================================================
--- llvm/include/llvm/Option/OptTable.h
+++ llvm/include/llvm/Option/OptTable.h
@@ -44,7 +44,7 @@
     /// A null terminated array of prefix strings to apply to name while
     /// matching.
     const char *const *Prefixes;
-    const char *Name;
+    StringRef Name;
     const char *HelpText;
     const char *MetaVar;
     unsigned ID;
@@ -102,9 +102,7 @@
   const Option getOption(OptSpecifier Opt) const;
 
   /// Lookup the name of the given option.
-  const char *getOptionName(OptSpecifier id) const {
-    return getInfo(id).Name;
-  }
+  StringRef getOptionName(OptSpecifier id) const { return getInfo(id).Name; }
 
   /// Get the kind of the given option.
   unsigned getOptionKind(OptSpecifier id) const {
@@ -184,7 +182,7 @@
   ///  takes
   ///
   /// \return true in success, and false in fail.
-  bool addValues(const char *Option, const char *Values);
+  bool addValues(StringRef Option, const char *Values);
 
   /// Parse a single argument; returning the new argument and
   /// updating Index.
Index: clang/lib/Driver/ToolChains/Gnu.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Gnu.cpp
+++ clang/lib/Driver/ToolChains/Gnu.cpp
@@ -331,8 +331,8 @@
   if (HasStaticPIE && Args.hasArg(options::OPT_nopie)) {
     const Driver &D = TC.getDriver();
     const llvm::opt::OptTable &Opts = D.getOpts();
-    const char *StaticPIEName = Opts.getOptionName(options::OPT_static_pie);
-    const char *NoPIEName = Opts.getOptionName(options::OPT_nopie);
+    StringRef StaticPIEName = Opts.getOptionName(options::OPT_static_pie);
+    StringRef NoPIEName = Opts.getOptionName(options::OPT_nopie);
     D.Diag(diag::err_drv_cannot_mix_options) << StaticPIEName << NoPIEName;
   }
   return HasStaticPIE;


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