[llvm-commits] [llvm] r67454 - in /llvm/trunk: include/llvm/GlobalVariable.h lib/Transforms/Scalar/InstructionCombining.cpp lib/Transforms/Scalar/SCCP.cpp lib/Transforms/Utils/CloneFunction.cpp

[Duncan Sands]

Author: baldrick
Date: Sat Mar 21 16:27:31 2009
New Revision: 67454

URL: http://llvm.org/viewvc/llvm-project?rev=67454&view=rev
Log:
Factorize out a concept - no functionality change.

Modified:
    llvm/trunk/include/llvm/GlobalVariable.h
    llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
    llvm/trunk/lib/Transforms/Scalar/SCCP.cpp
    llvm/trunk/lib/Transforms/Utils/CloneFunction.cpp

Modified: llvm/trunk/include/llvm/GlobalVariable.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/GlobalVariable.h?rev=67454&r1=67453&r2=67454&view=diff

==============================================================================
--- llvm/trunk/include/llvm/GlobalVariable.h (original)
+++ llvm/trunk/include/llvm/GlobalVariable.h Sat Mar 21 16:27:31 2009
@@ -78,6 +78,15 @@
   ///
   inline bool hasInitializer() const { return !isDeclaration(); }
 
+  /// hasDefinitiveInitializer - Whether the global variable has an initializer,
+  /// and this is the initializer that will be used in the final executable.
+  inline bool hasDefinitiveInitializer() const {
+    return hasInitializer() &&
+      // The initializer of a global variable with weak linkage may change at
+      // link time.
+      !mayBeOverridden();
+  }
+
   /// getInitializer - Return the initializer for this global variable.  It is
   /// illegal to call this method if the global is external, because we cannot
   /// tell what the value is initialized to!

Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=67454&r1=67453&r2=67454&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Sat Mar 21 16:27:31 2009
@@ -11227,15 +11227,14 @@
 
     // Instcombine load (constant global) into the value loaded.
     if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Op))
-      if (GV->isConstant() && !GV->isDeclaration() && !GV->mayBeOverridden())
+      if (GV->isConstant() && GV->hasDefinitiveInitializer())
         return ReplaceInstUsesWith(LI, GV->getInitializer());
 
     // Instcombine load (constantexpr_GEP global, 0, ...) into the value loaded.
     if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Op)) {
       if (CE->getOpcode() == Instruction::GetElementPtr) {
         if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0)))
-          if (GV->isConstant() && !GV->isDeclaration() &&
-              !GV->mayBeOverridden())
+          if (GV->isConstant() && GV->hasDefinitiveInitializer())
             if (Constant *V = 
                ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE))
               return ReplaceInstUsesWith(LI, V);
@@ -11259,7 +11258,7 @@
   // If this load comes from anywhere in a constant global, and if the global
   // is all undef or zero, we know what it loads.
   if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Op->getUnderlyingObject())){
-    if (GV->isConstant() && GV->hasInitializer() && !GV->mayBeOverridden()) {
+    if (GV->isConstant() && GV->hasDefinitiveInitializer()) {
       if (GV->getInitializer()->isNullValue())
         return ReplaceInstUsesWith(LI, Constant::getNullValue(LI.getType()));
       else if (isa<UndefValue>(GV->getInitializer()))

Modified: llvm/trunk/lib/Transforms/Scalar/SCCP.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SCCP.cpp?rev=67454&r1=67453&r2=67454&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SCCP.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SCCP.cpp Sat Mar 21 16:27:31 2009
@@ -1131,7 +1131,7 @@
     // Transform load (constant global) into the value loaded.
     if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Ptr)) {
       if (GV->isConstant()) {
-        if (!GV->isDeclaration() && !GV->mayBeOverridden()) {
+        if (GV->hasDefinitiveInitializer()) {
           markConstant(IV, &I, GV->getInitializer());
           return;
         }
@@ -1150,7 +1150,7 @@
     if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
       if (CE->getOpcode() == Instruction::GetElementPtr)
     if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0)))
-      if (GV->isConstant() && !GV->isDeclaration() && !GV->mayBeOverridden())
+      if (GV->isConstant() && GV->hasDefinitiveInitializer())
         if (Constant *V =
              ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE)) {
           markConstant(IV, &I, V);

Modified: llvm/trunk/lib/Transforms/Utils/CloneFunction.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/CloneFunction.cpp?rev=67454&r1=67453&r2=67454&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Utils/CloneFunction.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/CloneFunction.cpp Sat Mar 21 16:27:31 2009
@@ -335,8 +335,7 @@
     if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0]))
       if (!LI->isVolatile() && CE->getOpcode() == Instruction::GetElementPtr)
         if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0)))
-          if (GV->isConstant() && !GV->isDeclaration() &&
-              !GV->mayBeOverridden())
+          if (GV->isConstant() && GV->hasDefinitiveInitializer())
             return ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(),
                                                           CE);