hoist GlobalValue::removeDeadConstantUsers up to being a method on Constant.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125828 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 62 insertions, 58 deletions

diff --git a/include/llvm/Constant.h b/include/llvm/Constant.h
index defe474fb5..38045fc0c1 100644
--- a/include/llvm/Constant.h
+++ b/include/llvm/Constant.h
@@ -141,16 +141,22 @@ public:
     assert(0 && "Constants that do not have operands cannot be using 'From'!");
   }
   
-  static Constant* getNullValue(const Type* Ty);
+  static Constant *getNullValue(const Type* Ty);
   
   /// @returns the value for an integer constant of the given type that has all
   /// its bits set to true.
   /// @brief Get the all ones value
-  static Constant* getAllOnesValue(const Type* Ty);
+  static Constant *getAllOnesValue(const Type* Ty);
 
   /// getIntegerValue - Return the value for an integer or pointer constant,
   /// or a vector thereof, with the given scalar value.
-  static Constant* getIntegerValue(const Type* Ty, const APInt &V);
+  static Constant *getIntegerValue(const Type* Ty, const APInt &V);
+  
+  /// removeDeadConstantUsers - If there are any dead constant users dangling
+  /// off of this constant, remove them.  This method is useful for clients
+  /// that want to check to see if a global is unused, but don't want to deal
+  /// with potentially dead constants hanging off of the globals.
+  void removeDeadConstantUsers() const;
 };
 
 } // End llvm namespace
diff --git a/include/llvm/GlobalValue.h b/include/llvm/GlobalValue.h
index ccadc1c603..b184b8e449 100644
--- a/include/llvm/GlobalValue.h
+++ b/include/llvm/GlobalValue.h
@@ -282,12 +282,6 @@ public:
   inline Module *getParent() { return Parent; }
   inline const Module *getParent() const { return Parent; }
 
-  /// removeDeadConstantUsers - If there are any dead constant users dangling
-  /// off of this global value, remove them.  This method is useful for clients
-  /// that want to check to see if a global is unused, but don't want to deal
-  /// with potentially dead constants hanging off of the globals.
-  void removeDeadConstantUsers() const;
-
   // Methods for support type inquiry through isa, cast, and dyn_cast:
   static inline bool classof(const GlobalValue *) { return true; }
   static inline bool classof(const Value *V) {
diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index a2ac768d22..246fde1569 100644
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -262,6 +262,59 @@ void Constant::getVectorElements(SmallVectorImpl<Constant*> &Elts) const {
 }
 
 
+/// removeDeadUsersOfConstant - If the specified constantexpr is dead, remove
+/// it.  This involves recursively eliminating any dead users of the
+/// constantexpr.
+static bool removeDeadUsersOfConstant(const Constant *C) {
+  if (isa<GlobalValue>(C)) return false; // Cannot remove this
+  
+  while (!C->use_empty()) {
+    const Constant *User = dyn_cast<Constant>(C->use_back());
+    if (!User) return false; // Non-constant usage;
+    if (!removeDeadUsersOfConstant(User))
+      return false; // Constant wasn't dead
+  }
+  
+  const_cast<Constant*>(C)->destroyConstant();
+  return true;
+}
+
+
+/// removeDeadConstantUsers - If there are any dead constant users dangling
+/// off of this constant, remove them.  This method is useful for clients
+/// that want to check to see if a global is unused, but don't want to deal
+/// with potentially dead constants hanging off of the globals.
+void Constant::removeDeadConstantUsers() const {
+  Value::const_use_iterator I = use_begin(), E = use_end();
+  Value::const_use_iterator LastNonDeadUser = E;
+  while (I != E) {
+    const Constant *User = dyn_cast<Constant>(*I);
+    if (User == 0) {
+      LastNonDeadUser = I;
+      ++I;
+      continue;
+    }
+    
+    if (!removeDeadUsersOfConstant(User)) {
+      // If the constant wasn't dead, remember that this was the last live use
+      // and move on to the next constant.
+      LastNonDeadUser = I;
+      ++I;
+      continue;
+    }
+    
+    // If the constant was dead, then the iterator is invalidated.
+    if (LastNonDeadUser == E) {
+      I = use_begin();
+      if (I == E) break;
+    } else {
+      I = LastNonDeadUser;
+      ++I;
+    }
+  }
+}
+
+
 
 //===----------------------------------------------------------------------===//
 //                                ConstantInt
diff --git a/lib/VMCore/Globals.cpp b/lib/VMCore/Globals.cpp
index 96716eeb34..60000ad1b5 100644
--- a/lib/VMCore/Globals.cpp
+++ b/lib/VMCore/Globals.cpp
@@ -26,23 +26,6 @@ using namespace llvm;
 //                            GlobalValue Class
 //===----------------------------------------------------------------------===//
 
-/// removeDeadUsersOfConstant - If the specified constantexpr is dead, remove
-/// it.  This involves recursively eliminating any dead users of the
-/// constantexpr.
-static bool removeDeadUsersOfConstant(const Constant *C) {
-  if (isa<GlobalValue>(C)) return false; // Cannot remove this
-
-  while (!C->use_empty()) {
-    const Constant *User = dyn_cast<Constant>(C->use_back());
-    if (!User) return false; // Non-constant usage;
-    if (!removeDeadUsersOfConstant(User))
-      return false; // Constant wasn't dead
-  }
-
-  const_cast<Constant*>(C)->destroyConstant();
-  return true;
-}
-
 bool GlobalValue::isMaterializable() const {
   return getParent() && getParent()->isMaterializable(this);
 }
@@ -56,38 +39,6 @@ void GlobalValue::Dematerialize() {
   getParent()->Dematerialize(this);
 }
 
-/// removeDeadConstantUsers - If there are any dead constant users dangling
-/// off of this global value, remove them.  This method is useful for clients
-/// that want to check to see if a global is unused, but don't want to deal
-/// with potentially dead constants hanging off of the globals.
-void GlobalValue::removeDeadConstantUsers() const {
-  Value::const_use_iterator I = use_begin(), E = use_end();
-  Value::const_use_iterator LastNonDeadUser = E;
-  while (I != E) {
-    if (const Constant *User = dyn_cast<Constant>(*I)) {
-      if (!removeDeadUsersOfConstant(User)) {
-        // If the constant wasn't dead, remember that this was the last live use
-        // and move on to the next constant.
-        LastNonDeadUser = I;
-        ++I;
-      } else {
-        // If the constant was dead, then the iterator is invalidated.
-        if (LastNonDeadUser == E) {
-          I = use_begin();
-          if (I == E) break;
-        } else {
-          I = LastNonDeadUser;
-          ++I;
-        }
-      }
-    } else {
-      LastNonDeadUser = I;
-      ++I;
-    }
-  }
-}
-
-
 /// Override destroyConstant to make sure it doesn't get called on
 /// GlobalValue's because they shouldn't be treated like other constants.
 void GlobalValue::destroyConstant() {