Switch SmallSetVector to use DenseSet when it overflows its inline sp…

…ace.

Summary:
SetVector already used DenseSet, but SmallSetVector used std::set.  This
leads to surprising performance differences.  Moreover, it means that
the set of key types accepted by SetVector and SmallSetVector are
quite different!

In order to make this change, we had to convert some callsites that used
SmallSetVector<std::string, N> to use SmallSetVector<CachedHashString, N>
instead.

Reviewers: timshen

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D25648

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@284887 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Lex/HeaderSearchOptions.h

@@ -11,6 +11,7 @@
 #define LLVM_CLANG_LEX_HEADERSEARCHOPTIONS_H
 
 #include "clang/Basic/LLVM.h"
+#include "llvm/ADT/CachedHashString.h"
 #include "llvm/ADT/IntrusiveRefCntPtr.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/StringRef.h"
@@ -144,7 +145,7 @@ class HeaderSearchOptions : public RefCountedBase<HeaderSearchOptions> {
 
   /// \brief The set of macro names that should be ignored for the purposes
   /// of computing the module hash.
-  llvm::SmallSetVector<std::string, 16> ModulesIgnoreMacros;
+  llvm::SmallSetVector<llvm::CachedHashString, 16> ModulesIgnoreMacros;
 
   /// \brief The set of user-provided virtual filesystem overlay files.
   std::vector<std::string> VFSOverlayFiles;

lib/CodeGen/CGObjCMac.cpp

@@ -11,9 +11,9 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "CGObjCRuntime.h"
 #include "CGBlocks.h"
 #include "CGCleanup.h"
+#include "CGObjCRuntime.h"
 #include "CGRecordLayout.h"
 #include "CodeGenFunction.h"
 #include "CodeGenModule.h"
@@ -25,6 +25,7 @@
 #include "clang/Basic/LangOptions.h"
 #include "clang/CodeGen/CGFunctionInfo.h"
 #include "clang/Frontend/CodeGenOptions.h"
+#include "llvm/ADT/CachedHashString.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/SmallPtrSet.h"
@@ -843,7 +844,7 @@ class CGObjCCommonMac : public CodeGen::CGObjCRuntime {
   llvm::DenseMap<Selector, llvm::GlobalVariable*> MethodVarNames;
 
   /// DefinedCategoryNames - list of category names in form Class_Category.
-  llvm::SmallSetVector<std::string, 16> DefinedCategoryNames;
+  llvm::SmallSetVector<llvm::CachedHashString, 16> DefinedCategoryNames;
 
   /// MethodVarTypes - uniqued method type signatures. We have to use
   /// a StringMap here because have no other unique reference.
@@ -3156,7 +3157,7 @@ void CGObjCMac::GenerateCategory(const ObjCCategoryImplDecl *OCD) {
                         "__OBJC,__category,regular,no_dead_strip",
                         CGM.getPointerAlign(), true);
   DefinedCategories.push_back(GV);
-  DefinedCategoryNames.insert(ExtName.str());
+  DefinedCategoryNames.insert(llvm::CachedHashString(ExtName));
   // method definition entries must be clear for next implementation.
   MethodDefinitions.clear();
 }

lib/Frontend/CompilerInstance.cpp

@@ -955,7 +955,8 @@ static bool compileModuleImpl(CompilerInstance &ImportingInstance,
       std::remove_if(PPOpts.Macros.begin(), PPOpts.Macros.end(),
                      [&HSOpts](const std::pair<std::string, bool> &def) {
         StringRef MacroDef = def.first;
-        return HSOpts.ModulesIgnoreMacros.count(MacroDef.split('=').first) > 0;
+        return HSOpts.ModulesIgnoreMacros.count(
+                   llvm::CachedHashString(MacroDef.split('=').first)) > 0;
       }),
       PPOpts.Macros.end());
 

lib/Frontend/CompilerInvocation.cpp

@@ -1432,7 +1432,8 @@ static void ParseHeaderSearchArgs(HeaderSearchOptions &Opts, ArgList &Args) {
 
   for (const Arg *A : Args.filtered(OPT_fmodules_ignore_macro)) {
     StringRef MacroDef = A->getValue();
-    Opts.ModulesIgnoreMacros.insert(MacroDef.split('=').first);
+    Opts.ModulesIgnoreMacros.insert(
+        llvm::CachedHashString(MacroDef.split('=').first));
   }
 
   // Add -I..., -F..., and -index-header-map options in order.
@@ -2519,7 +2520,8 @@ std::string CompilerInvocation::getModuleHash() const {
     if (!hsOpts.ModulesIgnoreMacros.empty()) {
       // Check whether we're ignoring this macro.
       StringRef MacroDef = I->first;
-      if (hsOpts.ModulesIgnoreMacros.count(MacroDef.split('=').first))
+      if (hsOpts.ModulesIgnoreMacros.count(
+              llvm::CachedHashString(MacroDef.split('=').first)))
         continue;
     }