From aa6f105629e264b8de47b532028f99f75a33aa70 Mon Sep 17 00:00:00 2001
From: Owen Anderson <resistor@mac.com>
Date: Mon, 20 Dec 2010 21:30:54 +0000
Subject: [PATCH] Convert one of LVI's primary maps to a DenseMap, now that we
 know are more assured of iterator stability.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122273 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Analysis/LazyValueInfo.cpp | 56 ++++++++++++++++++++++++----------
 1 file changed, 40 insertions(+), 16 deletions(-)

diff --git a/lib/Analysis/LazyValueInfo.cpp b/lib/Analysis/LazyValueInfo.cpp
index 121828fdf3d..9854beaea5c 100644
--- a/lib/Analysis/LazyValueInfo.cpp
+++ b/lib/Analysis/LazyValueInfo.cpp
@@ -287,6 +287,21 @@ raw_ostream &operator<<(raw_ostream &OS, const LVILatticeVal &Val) {
 //===----------------------------------------------------------------------===//
 
 namespace {
+  /// LVIValueHandle - A callback value handle update the cache when
+  /// values are erased.
+  class LazyValueInfoCache;
+  struct LVIValueHandle : public CallbackVH {
+    LazyValueInfoCache *Parent;
+      
+    LVIValueHandle(Value *V, LazyValueInfoCache *P)
+      : CallbackVH(V), Parent(P) { }
+      
+    void deleted();
+    void allUsesReplacedWith(Value *V) {
+      deleted();
+    }
+  };
+  
   /// LazyValueInfoCache - This is the cache kept by LazyValueInfo which
   /// maintains information about queries across the clients' queries.
   class LazyValueInfoCache {
@@ -297,19 +312,7 @@ namespace {
     typedef std::map<AssertingVH<BasicBlock>, LVILatticeVal> ValueCacheEntryTy;
 
   private:
-    /// LVIValueHandle - A callback value handle update the cache when
-    /// values are erased.
-    struct LVIValueHandle : public CallbackVH {
-      LazyValueInfoCache *Parent;
-      
-      LVIValueHandle(Value *V, LazyValueInfoCache *P)
-        : CallbackVH(V), Parent(P) { }
-      
-      void deleted();
-      void allUsesReplacedWith(Value *V) {
-        deleted();
-      }
-    };
+    friend struct LVIValueHandle;
     
     /// OverDefinedCacheUpdater - A helper object that ensures that the
     /// OverDefinedCache is updated whenever solveBlockValue returns.
@@ -332,7 +335,7 @@ namespace {
 
     /// ValueCache - This is all of the cached information for all values,
     /// mapped from Value* to key information.
-    std::map<LVIValueHandle, ValueCacheEntryTy> ValueCache;
+    DenseMap<LVIValueHandle, ValueCacheEntryTy> ValueCache;
     
     /// OverDefinedCache - This tracks, on a per-block basis, the set of 
     /// values that are over-defined at the end of that block.  This is required
@@ -389,7 +392,28 @@ namespace {
   };
 } // end anonymous namespace
 
-void LazyValueInfoCache::LVIValueHandle::deleted() {
+namespace llvm {
+  template<>
+  struct DenseMapInfo<LVIValueHandle> {
+    typedef DenseMapInfo<Value*> PointerInfo;
+    static inline LVIValueHandle getEmptyKey() {
+      return LVIValueHandle(PointerInfo::getEmptyKey(),
+                            static_cast<LazyValueInfoCache*>(0));
+    }
+    static inline LVIValueHandle getTombstoneKey() {
+      return LVIValueHandle(PointerInfo::getTombstoneKey(),
+                            static_cast<LazyValueInfoCache*>(0));
+    }
+    static unsigned getHashValue(const LVIValueHandle &Val) {
+      return PointerInfo::getHashValue(Val);
+    }
+    static bool isEqual(const LVIValueHandle &LHS, const LVIValueHandle &RHS) {
+      return LHS == RHS;
+    }
+  };
+}
+
+void LVIValueHandle::deleted() {
   for (std::set<std::pair<AssertingVH<BasicBlock>, Value*> >::iterator
        I = Parent->OverDefinedCache.begin(),
        E = Parent->OverDefinedCache.end();
@@ -414,7 +438,7 @@ void LazyValueInfoCache::eraseBlock(BasicBlock *BB) {
       OverDefinedCache.erase(tmp);
   }
 
-  for (std::map<LVIValueHandle, ValueCacheEntryTy>::iterator
+  for (DenseMap<LVIValueHandle, ValueCacheEntryTy>::iterator
        I = ValueCache.begin(), E = ValueCache.end(); I != E; ++I)
     I->second.erase(BB);
 }
-- 
2.34.1