Add some accessor methods to CAZ and UndefValue that help simplify clients.

Make some CDS methods public.

llvm-svn: 148785

include/llvm/Constants.h

@@ -310,10 +310,22 @@ protected:
     return User::operator new(s, 0);
   }
 public:
-  static ConstantAggregateZero* get(Type *Ty);
+  static ConstantAggregateZero *get(Type *Ty);
   
   virtual void destroyConstant();
 
+  /// getSequentialElement - If this CAZ has array or vector type, return a zero
+  /// with the right element type.
+  Constant *getSequentialElement();
+
+  /// getStructElement - If this CAZ has struct type, return a zero with the
+  /// right element type for the specified element.
+  Constant *getStructElement(unsigned Elt);
+
+  /// getElementValue - Return a zero of the right value for the specified GEP
+  /// index.
+  Constant *getElementValue(Constant *C);
+  
   /// Methods for support type inquiry through isa, cast, and dyn_cast:
   ///
   static bool classof(const ConstantAggregateZero *) { return true; }
@@ -568,8 +580,12 @@ protected:
   }
 public:
   
-  virtual void destroyConstant();
-
+  /// isElementTypeCompatible - Return true if a ConstantDataSequential can be
+  /// formed with a vector or array of the specified element type.
+  /// ConstantDataArray only works with normal float and int types that are
+  /// stored densely in memory, not with things like i42 or x86_f80.
+  static bool isElementTypeCompatible(const Type *Ty);
+  
   /// getElementAsInteger - If this is a sequential container of integers (of
   /// any size), return the specified element in the low bits of a uint64_t.
   uint64_t getElementAsInteger(unsigned i) const;
@@ -601,7 +617,13 @@ public:
   /// getElementType - Return the element type of the array/vector.
   Type *getElementType() const;
 
+  /// getElementByteSize - Return the size (in bytes) of each element in the
+  /// array/vector.  The size of the elements is known to be a multiple of one
+  /// byte.
+  uint64_t getElementByteSize() const;
 
+  virtual void destroyConstant();
+  
   /// Methods for support type inquiry through isa, cast, and dyn_cast:
   ///
   static bool classof(const ConstantDataSequential *) { return true; }
@@ -610,7 +632,6 @@ public:
            V->getValueID() == ConstantDataVectorVal;
   }
 private:
-  uint64_t getElementByteSize() const;
   const char *getElementPointer(unsigned Elt) const;
 };
 
@@ -1074,6 +1095,18 @@ public:
   ///
   static UndefValue *get(Type *T);
 
+  /// getSequentialElement - If this Undef has array or vector type, return a
+  /// undef with the right element type.
+  UndefValue *getSequentialElement();
+  
+  /// getStructElement - If this undef has struct type, return a undef with the
+  /// right element type for the specified element.
+  UndefValue *getStructElement(unsigned Elt);
+  
+  /// getElementValue - Return an undef of the right value for the specified GEP
+  /// index.
+  UndefValue *getElementValue(Constant *C);
+  
   virtual void destroyConstant();
 
   /// Methods for support type inquiry through isa, cast, and dyn_cast:

lib/VMCore/Constants.cpp

@@ -598,6 +598,57 @@ bool ConstantFP::isExactlyValue(const APFloat &V) const {
   return Val.bitwiseIsEqual(V);
 }
 
+//===----------------------------------------------------------------------===//
+//                   ConstantAggregateZero Implementation
+//===----------------------------------------------------------------------===//
+
+/// getSequentialElement - If this CAZ has array or vector type, return a zero
+/// with the right element type.
+Constant *ConstantAggregateZero::getSequentialElement() {
+  return Constant::getNullValue(
+                            cast<SequentialType>(getType())->getElementType());
+}
+
+/// getStructElement - If this CAZ has struct type, return a zero with the
+/// right element type for the specified element.
+Constant *ConstantAggregateZero::getStructElement(unsigned Elt) {
+  return Constant::getNullValue(
+                              cast<StructType>(getType())->getElementType(Elt));
+}
+
+/// getElementValue - Return a zero of the right value for the specified GEP
+/// index if we can, otherwise return null (e.g. if C is a ConstantExpr).
+Constant *ConstantAggregateZero::getElementValue(Constant *C) {
+  if (isa<SequentialType>(getType()))
+    return getSequentialElement();
+  return getStructElement(cast<ConstantInt>(C)->getZExtValue());
+}
+
+//===----------------------------------------------------------------------===//
+//                         UndefValue Implementation
+//===----------------------------------------------------------------------===//
+
+/// getSequentialElement - If this undef has array or vector type, return an
+/// undef with the right element type.
+UndefValue *UndefValue::getSequentialElement() {
+  return UndefValue::get(cast<SequentialType>(getType())->getElementType());
+}
+
+/// getStructElement - If this undef has struct type, return a zero with the
+/// right element type for the specified element.
+UndefValue *UndefValue::getStructElement(unsigned Elt) {
+  return UndefValue::get(cast<StructType>(getType())->getElementType(Elt));
+}
+
+/// getElementValue - Return an undef of the right value for the specified GEP
+/// index if we can, otherwise return null (e.g. if C is a ConstantExpr).
+UndefValue *UndefValue::getElementValue(Constant *C) {
+  if (isa<SequentialType>(getType()))
+    return getSequentialElement();
+  return getStructElement(cast<ConstantInt>(C)->getZExtValue());
+}
+
+
 //===----------------------------------------------------------------------===//
 //                            ConstantXXX Classes
 //===----------------------------------------------------------------------===//
@@ -990,6 +1041,7 @@ bool ConstantFP::isValueValidForType(Type *Ty, const APFloat& Val) {
   }
 }
 
+
 //===----------------------------------------------------------------------===//
 //                      Factory Function Implementation
 
@@ -1004,7 +1056,7 @@ ConstantAggregateZero *ConstantAggregateZero::get(Type *Ty) {
   return Entry;
 }
 
-/// destroyConstant - Remove the constant from the constant table...
+/// destroyConstant - Remove the constant from the constant table.
 ///
 void ConstantAggregateZero::destroyConstant() {
   getContext().pImpl->CAZConstants.erase(getType());
@@ -1924,9 +1976,11 @@ Type *ConstantDataSequential::getElementType() const {
   return getType()->getElementType();
 }
 
-/// isElementTypeConstantDataCompatible - Return true if this type is valid for
-/// a ConstantDataSequential.  This is i8/i16/i32/i64/float/double.
-static bool isElementTypeConstantDataCompatible(const Type *Ty) {
+/// isElementTypeCompatible - Return true if a ConstantDataSequential can be
+/// formed with a vector or array of the specified element type.
+/// ConstantDataArray only works with normal float and int types that are
+/// stored densely in memory, not with things like i42 or x86_f80.
+bool ConstantDataSequential::isElementTypeCompatible(const Type *Ty) {
   if (Ty->isFloatTy() || Ty->isDoubleTy()) return true;
   if (const IntegerType *IT = dyn_cast<IntegerType>(Ty)) {
     switch (IT->getBitWidth()) {
@@ -1960,13 +2014,13 @@ static bool isAllZeros(StringRef Arr) {
       return false;
   return true;
 }
+
 /// getImpl - This is the underlying implementation of all of the
 /// ConstantDataSequential::get methods.  They all thunk down to here, providing
 /// the correct element type.  We take the bytes in as an StringRef because
 /// we *want* an underlying "char*" to avoid TBAA type punning violations.
 Constant *ConstantDataSequential::getImpl(StringRef Elements, Type *Ty) {
-  assert(isElementTypeConstantDataCompatible(cast<SequentialType>(Ty)->
-                                             getElementType()));
+  assert(isElementTypeCompatible(cast<SequentialType>(Ty)->getElementType()));
   // If the elements are all zero, return a CAZ, which is more dense.
   if (isAllZeros(Elements))
     return ConstantAggregateZero::get(Ty);