Today the front-ends (llvm-gcc and clang) generate multiple llvm.dbg.compile_units...

[oota-llvm.git] / lib / Analysis / ConstantFolding.cpp

diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index d3d0eb61ec15c0146ff6cc544d65fff6ebdcc20a..ea559c1010eac0927d1adb28a8e54889622c3bdd 100644 (file)
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -87,7 +87,7 @@ static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV,
 
 
 /// SymbolicallyEvaluateBinop - One of Op0/Op1 is a constant expression.
-/// Attempt to symbolically evaluate the result of  a binary operator merging
+/// Attempt to symbolically evaluate the result of a binary operator merging
 /// these together.  If target data info is available, it is provided as TD, 
 /// otherwise TD is null.
 static Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0,
@@ -113,7 +113,6 @@ static Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0,
       }
   }
     
-  // TODO: Fold icmp setne/seteq as well.
   return 0;
 }
 
@@ -281,7 +280,7 @@ static Constant *FoldBitCast(Constant *C, const Type *DestTy,
 Constant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) {
   if (PHINode *PN = dyn_cast<PHINode>(I)) {
     if (PN->getNumIncomingValues() == 0)
-      return Constant::getNullValue(PN->getType());
+      return UndefValue::get(PN->getType());
 
     Constant *Result = dyn_cast<Constant>(PN->getIncomingValue(0));
     if (Result == 0) return 0;
@@ -368,10 +367,12 @@ Constant *llvm::ConstantFoldInstOperands(unsigned Opcode, const Type *DestTy,
       if (TD && CE->getOpcode() == Instruction::IntToPtr) {
         Constant *Input = CE->getOperand(0);
         unsigned InWidth = Input->getType()->getPrimitiveSizeInBits();
-        Constant *Mask = 
-          ConstantInt::get(APInt::getLowBitsSet(InWidth,
-                                                TD->getPointerSizeInBits()));
-        Input = ConstantExpr::getAnd(Input, Mask);
+        if (TD->getPointerSizeInBits() < InWidth) {
+          Constant *Mask = 
+            ConstantInt::get(APInt::getLowBitsSet(InWidth,
+                                                  TD->getPointerSizeInBits()));
+          Input = ConstantExpr::getAnd(Input, Mask);
+        }
         // Do a zext or trunc to get to the dest size.
         return ConstantExpr::getIntegerCast(Input, DestTy, false);
       }