From d33bb62823b37dab31f996cfbe7a5b8563d85e9b Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Wed, 18 Nov 2015 06:52:18 +0000
Subject: [PATCH] Default SetVector to use a DenseSet.

We use to have an odd difference among MapVector and SetVector. The map
used a DenseMop, but the set used a SmallSet, which in turn uses a
std::set.

I have changed SetVector to use a DenseSet. If you were depending on the
old behaviour you can pass an explicit set type or use SmallSetVector.
The common cases for needing to do it are:

* Optimizing for small sets.
* Sets for types not supported by DenseSet.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253439 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/ADT/SetVector.h              |  3 ++-
 lib/Analysis/AliasAnalysisEvaluator.cpp   | 10 ++++------
 utils/TableGen/AsmMatcherEmitter.cpp      |  6 +++---
 utils/TableGen/FixedLenDecoderEmitter.cpp |  4 ++--
 4 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/include/llvm/ADT/SetVector.h b/include/llvm/ADT/SetVector.h
index ad0a0dfac63..3ab202d8d71 100644
--- a/include/llvm/ADT/SetVector.h
+++ b/include/llvm/ADT/SetVector.h
@@ -20,6 +20,7 @@
 #ifndef LLVM_ADT_SETVECTOR_H
 #define LLVM_ADT_SETVECTOR_H
 
+#include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/SmallSet.h"
 #include <algorithm>
 #include <cassert>
@@ -33,7 +34,7 @@ namespace llvm {
 /// property of a deterministic iteration order. The order of iteration is the
 /// order of insertion.
 template <typename T, typename Vector = std::vector<T>,
-                      typename Set = SmallSet<T, 16> >
+          typename Set = DenseSet<T>>
 class SetVector {
 public:
   typedef T value_type;
diff --git a/lib/Analysis/AliasAnalysisEvaluator.cpp b/lib/Analysis/AliasAnalysisEvaluator.cpp
index b1dca1d9375..c2a95cc31ea 100644
--- a/lib/Analysis/AliasAnalysisEvaluator.cpp
+++ b/lib/Analysis/AliasAnalysisEvaluator.cpp
@@ -145,7 +145,7 @@ bool AAEval::runOnFunction(Function &F) {
   AliasAnalysis &AA = getAnalysis<AAResultsWrapperPass>().getAAResults();
 
   SetVector<Value *> Pointers;
-  SetVector<CallSite> CallSites;
+  SmallSetVector<CallSite, 16> CallSites;
   SetVector<Value *> Loads;
   SetVector<Value *> Stores;
 
@@ -284,8 +284,7 @@ bool AAEval::runOnFunction(Function &F) {
   }
 
   // Mod/ref alias analysis: compare all pairs of calls and values
-  for (SetVector<CallSite>::iterator C = CallSites.begin(),
-         Ce = CallSites.end(); C != Ce; ++C) {
+  for (auto C = CallSites.begin(), Ce = CallSites.end(); C != Ce; ++C) {
     Instruction *I = C->getInstruction();
 
     for (SetVector<Value *>::iterator V = Pointers.begin(), Ve = Pointers.end();
@@ -316,9 +315,8 @@ bool AAEval::runOnFunction(Function &F) {
   }
 
   // Mod/ref alias analysis: compare all pairs of calls
-  for (SetVector<CallSite>::iterator C = CallSites.begin(),
-         Ce = CallSites.end(); C != Ce; ++C) {
-    for (SetVector<CallSite>::iterator D = CallSites.begin(); D != Ce; ++D) {
+  for (auto C = CallSites.begin(), Ce = CallSites.end(); C != Ce; ++C) {
+    for (auto D = CallSites.begin(); D != Ce; ++D) {
       if (D == C)
         continue;
       switch (AA.getModRefInfo(*C, *D)) {
diff --git a/utils/TableGen/AsmMatcherEmitter.cpp b/utils/TableGen/AsmMatcherEmitter.cpp
index f1b9ab39387..e55bbd37610 100644
--- a/utils/TableGen/AsmMatcherEmitter.cpp
+++ b/utils/TableGen/AsmMatcherEmitter.cpp
@@ -1722,7 +1722,7 @@ void MatchableInfo::buildAliasResultOperands() {
 }
 
 static unsigned getConverterOperandID(const std::string &Name,
-                                      SetVector<std::string> &Table,
+                                      SmallSetVector<std::string, 16> &Table,
                                       bool &IsNew) {
   IsNew = Table.insert(Name);
 
@@ -1738,8 +1738,8 @@ static unsigned getConverterOperandID(const std::string &Name,
 static void emitConvertFuncs(CodeGenTarget &Target, StringRef ClassName,
                              std::vector<std::unique_ptr<MatchableInfo>> &Infos,
                              raw_ostream &OS) {
-  SetVector<std::string> OperandConversionKinds;
-  SetVector<std::string> InstructionConversionKinds;
+  SmallSetVector<std::string, 16> OperandConversionKinds;
+  SmallSetVector<std::string, 16> InstructionConversionKinds;
   std::vector<std::vector<uint8_t> > ConversionTable;
   size_t MaxRowLength = 2; // minimum is custom converter plus terminator.
 
diff --git a/utils/TableGen/FixedLenDecoderEmitter.cpp b/utils/TableGen/FixedLenDecoderEmitter.cpp
index df61511c8dd..8ca4a1bf540 100644
--- a/utils/TableGen/FixedLenDecoderEmitter.cpp
+++ b/utils/TableGen/FixedLenDecoderEmitter.cpp
@@ -65,8 +65,8 @@ typedef std::vector<uint8_t> DecoderTable;
 typedef uint32_t DecoderFixup;
 typedef std::vector<DecoderFixup> FixupList;
 typedef std::vector<FixupList> FixupScopeList;
-typedef SetVector<std::string> PredicateSet;
-typedef SetVector<std::string> DecoderSet;
+typedef SmallSetVector<std::string, 16> PredicateSet;
+typedef SmallSetVector<std::string, 16> DecoderSet;
 struct DecoderTableInfo {
   DecoderTable Table;
   FixupScopeList FixupStack;