- Add new Constant::replaceUsesOfWithOnConstant which has an end result

similar to User::replaceUsesOfWith but actually does the right thing for
    constants.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4102 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner
2002-10-09 23:12:25 +00:00
parent 4bbd839d10
commit c251f9e0ae
3 changed files with 133 additions and 2 deletions

View File

@@ -16,10 +16,11 @@ protected:
void destroyConstantImpl();
public:
/// setName - Specialize setName to handle symbol table majik...
// setName - Specialize setName to handle symbol table majik...
virtual void setName(const std::string &name, SymbolTable *ST = 0);
/// Static constructor to get a '0' constant of arbitrary type...
///
static Constant *getNullValue(const Type *Ty);
/// isNullValue - Return true if this is the value that would be returned by
@@ -29,6 +30,7 @@ public:
virtual void print(std::ostream &O) const;
/// isConstantExpr - Return true if this is a ConstantExpr
///
virtual bool isConstantExpr() const { return false; }
@@ -49,12 +51,31 @@ public:
virtual void destroyConstant() { assert(0 && "Not reached!"); }
/// Methods for support type inquiry through isa, cast, and dyn_cast:
//// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const Constant *) { return true; }
static inline bool classof(const Value *V) {
return V->getValueType() == Value::ConstantVal;
}
/// replaceUsesOfWithOnConstant - This method is a special form of
/// User::replaceUsesOfWith (which does not work on constants) that does work
/// on constants. Basically this method goes through the trouble of building
/// a new constant that is equivalent to the current one, with all uses of
/// From replaced with uses of To. After this construction is completed, all
/// of the users of 'this' are replaced to use the new constant, and then
/// 'this' is deleted. In general, you should not call this method, instead,
/// use Value::replaceAllUsesWith, which automatically dispatches to this
/// method as needed.
///
virtual void replaceUsesOfWithOnConstant(Value *From, Value *To) {
// Provide a default implementation for constants (like integers) that
// cannot use any other values. This cannot be called at runtime, but needs
// to be here to avoid link errors.
assert(getNumOperands() == 0 && "replaceUsesOfWithOnConstant must be "
"implemented for all constants that have operands!");
assert(0 && "Constants that do not have operands cannot be using 'From'!");
}
// WARNING: Only to be used by Bytecode & Assembly Parsers! USER CODE SHOULD
// NOT USE THIS!!
// Returns the number of uses of OldV that were replaced.