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

llvm-svn: 284887

3 files changed, 10 insertions, 6 deletions

diff --git a/clang/lib/CodeGen/CGObjCMac.cpp b/clang/lib/CodeGen/CGObjCMac.cpp
index 70fefec574d..b290ae37239 100644
--- a/clang/lib/CodeGen/CGObjCMac.cpp
+++ b/clang/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/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index f3e883959da..b2b7b7c67ba 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/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/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 03d400b9cac..3f2e303b5c3 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/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;
     }