Switch SmallSetVector to use DenseSet when it overflows its inline space.

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

4 files changed, 12 insertions, 7 deletions

diff --git a/include/clang/Lex/HeaderSearchOptions.h b/include/clang/Lex/HeaderSearchOptions.h
index 53909e6a32..815b68c60e 100644
--- a/include/clang/Lex/HeaderSearchOptions.h
+++ b/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 @@ public:
 
   /// \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;
diff --git a/lib/CodeGen/CGObjCMac.cpp b/lib/CodeGen/CGObjCMac.cpp
index 70fefec574..b290ae3723 100644
--- a/lib/CodeGen/CGObjCMac.cpp
+++ b/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 @@ protected:
   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();
 }
diff --git a/lib/Frontend/CompilerInstance.cpp b/lib/Frontend/CompilerInstance.cpp
index f3e883959d..b2b7b7c67b 100644
--- a/lib/Frontend/CompilerInstance.cpp
+++ b/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());
 
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 03d400b9ca..3f2e303b5c 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/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;
     }