From 3b77f56194952bc3767c11e8b216906d404fcb2c Mon Sep 17 00:00:00 2001
From: Owen Anderson <resistor@mac.com>
Date: Mon, 20 Dec 2010 22:28:03 +0000
Subject: [PATCH] Revert r122114 (CallbackVH observing use-list changes)
 because it caused severe slowdowns on the Linux self-host configuration.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122279 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Support/ValueHandle.h |  6 -----
 include/llvm/Value.h               |  2 +-
 lib/VMCore/Value.cpp               | 38 ------------------------------
 3 files changed, 1 insertion(+), 45 deletions(-)

diff --git a/include/llvm/Support/ValueHandle.h b/include/llvm/Support/ValueHandle.h
index 7e5bc1b4cf4..c0cdc35e99b 100644
--- a/include/llvm/Support/ValueHandle.h
+++ b/include/llvm/Support/ValueHandle.h
@@ -105,7 +105,6 @@ private:
   // Callbacks made from Value.
   static void ValueIsDeleted(Value *V);
   static void ValueIsRAUWd(Value *Old, Value *New);
-  static void ValueAddedUse(Use &U);
 
   // Internal implementation details.
   ValueHandleBase **getPrevPtr() const { return PrevPair.getPointer(); }
@@ -390,11 +389,6 @@ public:
   /// implemented as a CallbackVH, it would use this method to call
   /// setValPtr(new_value).  AssertingVH would do nothing in this method.
   virtual void allUsesReplacedWith(Value *) {}
-  
-  /// Called when a new Use is added to the use-list of this->getValPtr(),
-  /// after the Use has been appended to the list.  Other VH kinds would ignore
-  /// this callback, but clients can use it to trigger re-analysis of Values.
-  virtual void addedUse(Use &) {}
 };
 
 // Specialize simplify_type to allow CallbackVH to participate in
diff --git a/include/llvm/Value.h b/include/llvm/Value.h
index df610aa7bd1..b530287829f 100644
--- a/include/llvm/Value.h
+++ b/include/llvm/Value.h
@@ -195,7 +195,7 @@ public:
 
   /// addUse - This method should only be used by the Use class.
   ///
-  void addUse(Use &U);
+  void addUse(Use &U) { U.addToList(&UseList); }
 
   /// An enumeration for keeping track of the concrete subclass of Value that
   /// is actually instantiated. Values of this enumeration are kept in the 
diff --git a/lib/VMCore/Value.cpp b/lib/VMCore/Value.cpp
index 3c32c566e1f..76cfb9082a5 100644
--- a/lib/VMCore/Value.cpp
+++ b/lib/VMCore/Value.cpp
@@ -281,16 +281,6 @@ void Value::takeName(Value *V) {
 }
 
 
-/// addUse - This method should only be used by the Use class.
-///
-void Value::addUse(Use &U) {
-  U.addToList(&UseList);
-  
-  // Notify all ValueHandles (if present) that this value added a Use.
-  if (HasValueHandle)
-    ValueHandleBase::ValueAddedUse(U);
-}
-
 // uncheckedReplaceAllUsesWith - This is exactly the same as replaceAllUsesWith,
 // except that it doesn't have all of the asserts.  The asserts fail because we
 // are half-way done resolving types, which causes some types to exist as two
@@ -579,34 +569,6 @@ void ValueHandleBase::ValueIsDeleted(Value *V) {
   }
 }
 
-void ValueHandleBase::ValueAddedUse(Use &U) {
-  assert(U->HasValueHandle && "Should only be called if ValueHandles present");
-
-  // Get the linked list base, which is guaranteed to exist since the
-  // HasValueHandle flag is set.
-  LLVMContextImpl *pImpl = U->getContext().pImpl;
-  ValueHandleBase *Entry = pImpl->ValueHandles[U.get()];
-
-  assert(Entry && "Value bit set but no entries exist");
-
-  // We use a local ValueHandleBase as an iterator so that
-  // ValueHandles can add and remove themselves from the list without
-  // breaking our iteration.  This is not really an AssertingVH; we
-  // just have to give ValueHandleBase some kind.
-  for (ValueHandleBase Iterator(Assert, *Entry); Entry; Entry = Iterator.Next) {
-    Iterator.RemoveFromUseList();
-    Iterator.AddToExistingUseListAfter(Entry);
-    assert(Entry->Next == &Iterator && "Loop invariant broken.");
-
-    switch (Entry->getKind()) {
-    default:
-      break;
-    case Callback:
-      static_cast<CallbackVH*>(Entry)->addedUse(U);
-      break;
-    }
-  }
-}
 
 void ValueHandleBase::ValueIsRAUWd(Value *Old, Value *New) {
   assert(Old->HasValueHandle &&"Should only be called if ValueHandles present");
-- 
2.34.1