//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
#include "llvm/User.h"
namespace llvm {
+ class APInt;
+
+ template<typename T> class SmallVectorImpl;
/// This is an important base class in LLVM. It provides the common facilities
/// of all constant values in an LLVM program. A constant is a value that is
/// Note that Constants are immutable (once created they never change)
/// and are fully shared by structural equivalence. This means that two
/// structurally equivalent constants will always have the same address.
-/// Constant's are created on demand as needed and never deleted: thus clients
+/// Constants are created on demand as needed and never deleted: thus clients
/// don't have to worry about the lifetime of the objects.
/// @brief LLVM Constant Representation
class Constant : public User {
void operator=(const Constant &); // Do not implement
Constant(const Constant &); // Do not implement
+
protected:
- Constant(const Type *Ty, ValueTy vty, Use *Ops, unsigned NumOps)
- : User(Ty, vty, Ops, NumOps) {}
+ Constant(const Type *ty, ValueTy vty, Use *Ops, unsigned NumOps)
+ : User(ty, vty, Ops, NumOps) {}
void destroyConstantImpl();
-public:
- /// Static constructor to get a '0' constant of arbitrary type...
- ///
- static Constant *getNullValue(const Type *Ty);
-
- /// Static constructor to get a '-1' constant. This supports integers and
- /// vectors.
- ///
- static Constant *getAllOnesValue(const Type *Ty);
+ void setOperand(unsigned i, Value *V) {
+ User::setOperand(i, V);
+ }
+public:
/// isNullValue - Return true if this is the value that would be returned by
/// getNullValue.
virtual bool isNullValue() const = 0;
- virtual void print(std::ostream &O) const;
- void print(std::ostream *O) const { if (O) print(*O); }
-
+ /// isNegativeZeroValue - Return true if the value is what would be returned
+ /// by getZeroValueForNegation.
+ virtual bool isNegativeZeroValue() const { return isNullValue(); }
+
/// canTrap - Return true if evaluation of this constant could trap. This is
/// true for things like constant expressions that could divide by zero.
bool canTrap() const;
- /// ContaintsRelocations - Return true if the constant value contains
- /// relocations which cannot be resolved at compile time.
- bool ContainsRelocations() const;
-
- // Specialize get/setOperand for Constant's as their operands are always
- // constants as well.
- Constant *getOperand(unsigned i) {
- return static_cast<Constant*>(User::getOperand(i));
- }
- const Constant *getOperand(unsigned i) const {
- return static_cast<const Constant*>(User::getOperand(i));
+ /// isConstantUsed - Return true if the constant has users other than constant
+ /// exprs and other dangling things.
+ bool isConstantUsed() const;
+
+ enum PossibleRelocationsTy {
+ NoRelocation = 0,
+ LocalRelocation = 1,
+ GlobalRelocations = 2
+ };
+
+ /// getRelocationInfo - This method classifies the entry according to
+ /// whether or not it may generate a relocation entry. This must be
+ /// conservative, so if it might codegen to a relocatable entry, it should say
+ /// so. The return values are:
+ ///
+ /// NoRelocation: This constant pool entry is guaranteed to never have a
+ /// relocation applied to it (because it holds a simple constant like
+ /// '4').
+ /// LocalRelocation: This entry has relocations, but the entries are
+ /// guaranteed to be resolvable by the static linker, so the dynamic
+ /// linker will never see them.
+ /// GlobalRelocations: This entry may have arbitrary relocations.
+ ///
+ /// FIXME: This really should not be in VMCore.
+ PossibleRelocationsTy getRelocationInfo() const;
+
+ // Specialize get/setOperand for Users as their operands are always
+ // constants or BasicBlocks as well.
+ User *getOperand(unsigned i) {
+ return static_cast<User*>(User::getOperand(i));
}
- void setOperand(unsigned i, Constant *C) {
- User::setOperand(i, C);
+ const User *getOperand(unsigned i) const {
+ return static_cast<const User*>(User::getOperand(i));
}
+
+ /// getVectorElements - This method, which is only valid on constant of vector
+ /// type, returns the elements of the vector in the specified smallvector.
+ /// This handles breaking down a vector undef into undef elements, etc. For
+ /// constant exprs and other cases we can't handle, we return an empty vector.
+ void getVectorElements(SmallVectorImpl<Constant*> &Elts) const;
/// destroyConstant - Called if some element of this constant is no longer
/// valid. At this point only other constants may be on the use_list for this
"implemented for all constants that have operands!");
assert(0 && "Constants that do not have operands cannot be using 'From'!");
}
+
+ 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);
- /// getStringValue - Turn an LLVM constant pointer that eventually points to a
- /// global into a string value. Return an empty string if we can't do it.
- /// Parameter Chop determines if the result is chopped at the first null
- /// terminator.
- ///
- std::string getStringValue(bool Chop = true, unsigned Offset = 0);
+ /// 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);
};
} // End llvm namespace