add a Constant::getAllOnesValue helper function, which works on integers

AND vectors.

llvm-svn: 37586

llvm/include/llvm/Constant.h

@@ -48,6 +48,11 @@ public:
   ///
   static Constant *getNullValue(const Type *Ty);
 
+  /// Static constructor to get a '-1' constant.  This supports integers and
+  /// vectors.
+  ///
+  static Constant *getAllOnesValue(const Type *Ty);
+  
   /// isNullValue - Return true if this is the value that would be returned by
   /// getNullValue.
   virtual bool isNullValue() const = 0;

llvm/lib/VMCore/Constants.cpp

@@ -122,6 +122,11 @@ Constant *Constant::getNullValue(const Type *Ty) {
   }
 }
 
+Constant *Constant::getAllOnesValue(const Type *Ty) {
+  if (const IntegerType* ITy = dyn_cast<IntegerType>(Ty))
+    return ConstantInt::get(APInt::getAllOnesValue(ITy->getBitWidth()));
+  return ConstantVector::getAllOnesValue(cast<VectorType>(Ty));
+}
 
 // Static constructor to create an integral constant with all bits set
 ConstantInt *ConstantInt::getAllOnesValue(const Type *Ty) {