[OptTable] Precompute OptTable prefixes union table through tablegen

This avoid rediscovering this table when reading each options, providing a sensible 2% speedup when processing and empty file, and a measurable speedup on typical workloads, see: This is optional, the legacy, on-the-fly, approach can still be used through the GenericOptTable class, while the new one is used through PrecomputedOptTable. https://llvm-compile-time-tracker.com/compare.php?from=4da6cb3202817ee2897d6b690e4af950459caea4&to=19a492b704e8f5c1dea120b9c0d3859bd78796be&stat=instructions:u Differential Revision: https://reviews.llvm.org/D140800
alexbatashev · Jan 12, 2023 · 07bb29d · 07bb29d
1 parent bbe463d
commit 07bb29d
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Showing 38 changed files with 256 additions and 143 deletions.
diff --git a/clang/lib/Driver/DriverOptions.cpp b/clang/lib/Driver/DriverOptions.cpp
@@ -27,6 +27,14 @@ using namespace llvm::opt;
 #include "clang/Driver/Options.inc"
 #undef PREFIX
 
+static constexpr const llvm::StringLiteral PrefixTable_init[] =
+#define PREFIX_UNION(VALUES) VALUES
+#include "clang/Driver/Options.inc"
+#undef PREFIX_UNION
+    ;
+static constexpr const llvm::ArrayRef<llvm::StringLiteral>
+    PrefixTable(PrefixTable_init, std::size(PrefixTable_init) - 1);
+
 static constexpr OptTable::Info InfoTable[] = {
 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,  \
                HELPTEXT, METAVAR, VALUES)                                      \
@@ -38,12 +46,10 @@ static constexpr OptTable::Info InfoTable[] = {
 
 namespace {
 
-class DriverOptTable : public OptTable {
+class DriverOptTable : public PrecomputedOptTable {
 public:
-  DriverOptTable()
-    : OptTable(InfoTable) {}
+  DriverOptTable() : PrecomputedOptTable(InfoTable, PrefixTable) {}
 };
-
 }
 
 const llvm::opt::OptTable &clang::driver::getDriverOptTable() {

diff --git a/clang/lib/Driver/ToolChains/Gnu.cpp b/clang/lib/Driver/ToolChains/Gnu.cpp
@@ -23,6 +23,7 @@
 #include "clang/Driver/Options.h"
 #include "clang/Driver/Tool.h"
 #include "clang/Driver/ToolChain.h"
+#include "llvm/ADT/StringSet.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/Option/ArgList.h"
 #include "llvm/Support/CodeGen.h"

diff --git a/clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp b/clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp
@@ -138,9 +138,9 @@ static constexpr OptTable::Info InfoTable[] = {
 #undef OPTION
 };
 
-class WrapperOptTable : public opt::OptTable {
+class WrapperOptTable : public opt::GenericOptTable {
 public:
-  WrapperOptTable() : OptTable(InfoTable) {}
+  WrapperOptTable() : opt::GenericOptTable(InfoTable) {}
 };
 
 const OptTable &getOptTable() {

diff --git a/lld/COFF/Driver.h b/lld/COFF/Driver.h
@@ -33,7 +33,7 @@ using llvm::COFF::MachineTypes;
 using llvm::COFF::WindowsSubsystem;
 using std::optional;
 
-class COFFOptTable : public llvm::opt::OptTable {
+class COFFOptTable : public llvm::opt::GenericOptTable {
 public:
   COFFOptTable();
 };

diff --git a/lld/COFF/DriverUtils.cpp b/lld/COFF/DriverUtils.cpp
@@ -794,7 +794,7 @@ static constexpr llvm::opt::OptTable::Info infoTable[] = {
 #undef OPTION
 };
 
-COFFOptTable::COFFOptTable() : OptTable(infoTable, true) {}
+COFFOptTable::COFFOptTable() : GenericOptTable(infoTable, true) {}
 
 // Set color diagnostics according to --color-diagnostics={auto,always,never}
 // or --no-color-diagnostics flags.

diff --git a/lld/ELF/Driver.h b/lld/ELF/Driver.h
@@ -16,7 +16,7 @@
 
 namespace lld::elf {
 // Parses command line options.
-class ELFOptTable : public llvm::opt::OptTable {
+class ELFOptTable : public llvm::opt::GenericOptTable {
 public:
   ELFOptTable();
   llvm::opt::InputArgList parse(ArrayRef<const char *> argv);

diff --git a/lld/ELF/DriverUtils.cpp b/lld/ELF/DriverUtils.cpp
@@ -50,7 +50,7 @@ static constexpr opt::OptTable::Info optInfo[] = {
 #undef OPTION
 };
 
-ELFOptTable::ELFOptTable() : OptTable(optInfo) {}
+ELFOptTable::ELFOptTable() : GenericOptTable(optInfo) {}
 
 // Set color diagnostics according to --color-diagnostics={auto,always,never}
 // or --no-color-diagnostics flags.

diff --git a/lld/MachO/Driver.h b/lld/MachO/Driver.h
@@ -25,7 +25,7 @@ namespace lld::macho {
 class DylibFile;
 class InputFile;
 
-class MachOOptTable : public llvm::opt::OptTable {
+class MachOOptTable : public llvm::opt::GenericOptTable {
 public:
   MachOOptTable();
   llvm::opt::InputArgList parse(ArrayRef<const char *> argv);

diff --git a/lld/MachO/DriverUtils.cpp b/lld/MachO/DriverUtils.cpp
@@ -51,7 +51,7 @@ static constexpr OptTable::Info optInfo[] = {
 #undef OPTION
 };
 
-MachOOptTable::MachOOptTable() : OptTable(optInfo) {}
+MachOOptTable::MachOOptTable() : GenericOptTable(optInfo) {}
 
 // Set color diagnostics according to --color-diagnostics={auto,always,never}
 // or --no-color-diagnostics flags.

diff --git a/lld/MinGW/Driver.cpp b/lld/MinGW/Driver.cpp
@@ -79,9 +79,9 @@ static constexpr opt::OptTable::Info infoTable[] = {
 };
 
 namespace {
-class MinGWOptTable : public opt::OptTable {
+class MinGWOptTable : public opt::GenericOptTable {
 public:
-  MinGWOptTable() : OptTable(infoTable, false) {}
+  MinGWOptTable() : opt::GenericOptTable(infoTable, false) {}
   opt::InputArgList parse(ArrayRef<const char *> argv);
 };
 } // namespace

diff --git a/lld/wasm/Driver.cpp b/lld/wasm/Driver.cpp
@@ -120,9 +120,9 @@ static constexpr opt::OptTable::Info optInfo[] = {
 };
 
 namespace {
-class WasmOptTable : public llvm::opt::OptTable {
+class WasmOptTable : public opt::GenericOptTable {
 public:
-  WasmOptTable() : OptTable(optInfo) {}
+  WasmOptTable() : opt::GenericOptTable(optInfo) {}
   opt::InputArgList parse(ArrayRef<const char *> argv);
 };
 } // namespace

diff --git a/lldb/tools/driver/Driver.cpp b/lldb/tools/driver/Driver.cpp
@@ -78,9 +78,9 @@ static constexpr opt::OptTable::Info InfoTable[] = {
 #undef OPTION
 };
 
-class LLDBOptTable : public opt::OptTable {
+class LLDBOptTable : public opt::GenericOptTable {
 public:
-  LLDBOptTable() : OptTable(InfoTable) {}
+  LLDBOptTable() : opt::GenericOptTable(InfoTable) {}
 };
 } // namespace
 

diff --git a/lldb/tools/lldb-server/lldb-gdbserver.cpp b/lldb/tools/lldb-server/lldb-gdbserver.cpp
@@ -297,9 +297,9 @@ static constexpr opt::OptTable::Info InfoTable[] = {
 #undef OPTION
 };
 
-class LLGSOptTable : public opt::OptTable {
+class LLGSOptTable : public opt::GenericOptTable {
 public:
-  LLGSOptTable() : OptTable(InfoTable) {}
+  LLGSOptTable() : opt::GenericOptTable(InfoTable) {}
 
   void PrintHelp(llvm::StringRef Name) {
     std::string Usage =

diff --git a/lldb/tools/lldb-vscode/lldb-vscode.cpp b/lldb/tools/lldb-vscode/lldb-vscode.cpp
@@ -96,9 +96,9 @@ static constexpr llvm::opt::OptTable::Info InfoTable[] = {
 #include "Options.inc"
 #undef OPTION
 };
-class LLDBVSCodeOptTable : public llvm::opt::OptTable {
+class LLDBVSCodeOptTable : public llvm::opt::GenericOptTable {
 public:
-  LLDBVSCodeOptTable() : OptTable(InfoTable, true) {}
+  LLDBVSCodeOptTable() : llvm::opt::GenericOptTable(InfoTable, true) {}
 };
 
 typedef void (*RequestCallback)(const llvm::json::Object &command);

diff --git a/llvm/include/llvm/Option/OptTable.h b/llvm/include/llvm/Option/OptTable.h
@@ -12,7 +12,6 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringRef.h"
-#include "llvm/ADT/StringSet.h"
 #include "llvm/Option/OptSpecifier.h"
 #include "llvm/Support/StringSaver.h"
 #include <cassert>
@@ -68,14 +67,17 @@ class OptTable {
   unsigned InputOptionID = 0;
   unsigned UnknownOptionID = 0;
 
+protected:
   /// The index of the first option which can be parsed (i.e., is not a
   /// special option like 'input' or 'unknown', and is not an option group).
   unsigned FirstSearchableIndex = 0;
 
+  /// The union of the first element of all option prefixes.
+  SmallString<8> PrefixChars;
+
   /// The union of all option prefixes. If an argument does not begin with
   /// one of these, it is an input.
-  StringSet<> PrefixesUnion;
-  SmallString<8> PrefixChars;
+  virtual ArrayRef<StringLiteral> getPrefixesUnion() const = 0;
 
 private:
   const Info &getInfo(OptSpecifier Opt) const {
@@ -88,10 +90,15 @@ class OptTable {
                                           unsigned &Index) const;
 
 protected:
+  /// Initialize OptTable using Tablegen'ed OptionInfos. Child class must
+  /// manually call \c buildPrefixChars once they are fully constructed.
   OptTable(ArrayRef<Info> OptionInfos, bool IgnoreCase = false);
 
+  /// Build (or rebuild) the PrefixChars member.
+  void buildPrefixChars();
+
 public:
-  ~OptTable();
+  virtual ~OptTable();
 
   /// Return the total number of option classes.
   unsigned getNumOptions() const { return OptionInfos.size(); }
@@ -246,6 +253,32 @@ class OptTable {
                  bool ShowHidden = false, bool ShowAllAliases = false) const;
 };
 
+/// Specialization of OptTable
+class GenericOptTable : public OptTable {
+  SmallVector<StringLiteral> PrefixesUnionBuffer;
+
+protected:
+  GenericOptTable(ArrayRef<Info> OptionInfos, bool IgnoreCase = false);
+  ArrayRef<StringLiteral> getPrefixesUnion() const final {
+    return PrefixesUnionBuffer;
+  }
+};
+
+class PrecomputedOptTable : public OptTable {
+  ArrayRef<StringLiteral> PrefixesUnion;
+
+protected:
+  PrecomputedOptTable(ArrayRef<Info> OptionInfos,
+                      ArrayRef<StringLiteral> PrefixesTable,
+                      bool IgnoreCase = false)
+      : OptTable(OptionInfos, IgnoreCase), PrefixesUnion(PrefixesTable) {
+    buildPrefixChars();
+  }
+  ArrayRef<StringLiteral> getPrefixesUnion() const final {
+    return PrefixesUnion;
+  }
+};
+
 } // end namespace opt
 
 } // end namespace llvm

diff --git a/llvm/lib/ExecutionEngine/JITLink/COFFDirectiveParser.cpp b/llvm/lib/ExecutionEngine/JITLink/COFFDirectiveParser.cpp
@@ -27,6 +27,14 @@ using namespace jitlink;
 #include "COFFOptions.inc"
 #undef PREFIX
 
+static constexpr const StringLiteral PrefixTable_init[] =
+#define PREFIX_UNION(VALUES) VALUES
+#include "COFFOptions.inc"
+#undef PREFIX_UNION
+    ;
+static constexpr const ArrayRef<StringLiteral>
+    PrefixTable(PrefixTable_init, std::size(PrefixTable_init) - 1);
+
 // Create table mapping all options defined in COFFOptions.td
 static constexpr opt::OptTable::Info infoTable[] = {
 #define OPTION(X1, X2, ID, KIND, GROUP, ALIAS, X7, X8, X9, X10, X11, X12)      \
@@ -46,9 +54,9 @@ static constexpr opt::OptTable::Info infoTable[] = {
 #undef OPTION
 };
 
-class COFFOptTable : public opt::OptTable {
+class COFFOptTable : public opt::PrecomputedOptTable {
 public:
-  COFFOptTable() : OptTable(infoTable, true) {}
+  COFFOptTable() : PrecomputedOptTable(infoTable, PrefixTable, true) {}
 };
 
 static COFFOptTable optTable;