#include "llvm/User.h"
namespace llvm {
- template<typename T> class SmallVectorImpl;
+ class APInt;
- /// If object contains references to other objects, then relocations are
- /// usually required for emission of such object (especially in PIC mode). One
- /// usually distinguishes local and global relocations. Local relocations are
- /// made wrt objects in the same module and these objects have local (internal
- /// or private) linkage. Global relocations are made wrt externally visible
- /// objects. In most cases local relocations can be resolved via so-called
- /// 'pre-link' technique.
- namespace Reloc {
- const unsigned None = 0;
- const unsigned Local = 1 << 0; ///< Local relocations are required
- const unsigned Global = 1 << 1; ///< Global relocations are required
- const unsigned LocalOrGlobal = Local | Global;
- }
+ 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
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)
+ Constant(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, bool locked = true);
-
- /// 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;
+ bool isNullValue() const;
+
+ /// isAllOnesValue - Return true if this is the value that would be returned by
+ /// getAllOnesValue.
+ bool isAllOnesValue() const;
+
+ /// isNegativeZeroValue - Return true if the value is what would be returned
+ /// by getZeroValueForNegation.
+ bool isNegativeZeroValue() const;
/// 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;
- /// ContainsRelocations - Return true if the constant value contains
- /// relocations which cannot be resolved at compile time. Note that answer is
- /// not exclusive: there can be possibility that relocations of other kind are
- /// required as well.
- bool ContainsRelocations(unsigned Kind = Reloc::LocalOrGlobal) const;
-
- // Specialize get/setOperand for Constants 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));
- }
- void setOperand(unsigned i, Constant *C) {
- User::setOperand(i, C);
- }
+ /// 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;
/// getVectorElements - This method, which is only valid on constant of vector
/// type, returns the elements of the vector in the specified smallvector.
/// available cached constants. Implementations should call
/// destroyConstantImpl as the last thing they do, to destroy all users and
/// delete this.
- virtual void destroyConstant(bool locked = true) {
- assert(0 && "Not reached!");
- }
+ virtual void destroyConstant() { assert(0 && "Not reached!"); }
//// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const Constant *) { return true; }
"implemented for all constants that have operands!");
assert(0 && "Constants that do not have operands cannot be using 'From'!");
}
+
+ static Constant *getNullValue(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(Type* Ty);
+
+ /// getIntegerValue - Return the value for an integer or pointer constant,
+ /// or a vector thereof, with the given scalar value.
+ static Constant *getIntegerValue(Type* Ty, const APInt &V);
+
+ /// removeDeadConstantUsers - If there are any dead constant users dangling
+ /// off of this constant, remove them. This method is useful for clients
+ /// that want to check to see if a global is unused, but don't want to deal
+ /// with potentially dead constants hanging off of the globals.
+ void removeDeadConstantUsers() const;
};
} // End llvm namespace
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