- 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.

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@ -292,6 +292,7 @@ public:
virtual bool isNullValue() const { return false; }
virtual void destroyConstant();
virtual void replaceUsesOfWithOnConstant(Value *From, Value *To);
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const ConstantArray *) { return true; }
@ -330,6 +331,7 @@ public:
virtual bool isNullValue() const { return false; }
virtual void destroyConstant();
virtual void replaceUsesOfWithOnConstant(Value *From, Value *To);
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const ConstantStruct *) { return true; }
@ -423,6 +425,7 @@ public:
}
virtual void destroyConstant();
virtual void replaceUsesOfWithOnConstant(Value *From, Value *To);
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const ConstantPointerRef *) { return true; }
@ -489,6 +492,7 @@ public:
virtual bool isConstantExpr() const { return true; }
virtual void destroyConstant();
virtual void replaceUsesOfWithOnConstant(Value *From, Value *To);
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const ConstantExpr *) { return true; }

View File

@ -326,6 +326,112 @@ bool ConstantFP::isValueValidForType(const Type *Ty, double Val) {
}
};
//===----------------------------------------------------------------------===//
// replaceUsesOfWithOnConstant implementations
void ConstantArray::replaceUsesOfWithOnConstant(Value *From, Value *To) {
assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
std::vector<Constant*> Values;
Values.reserve(getValues().size()); // Build replacement array...
for (unsigned i = 0, e = getValues().size(); i != e; ++i) {
Constant *Val = cast<Constant>(getValues()[i]);
if (Val == From) Val = cast<Constant>(To);
Values.push_back(Val);
}
ConstantArray *Replacement = ConstantArray::get(getType(), Values);
assert(Replacement != this && "I didn't contain From!");
// Everyone using this now uses the replacement...
replaceAllUsesWith(Replacement);
// Delete the old constant!
destroyConstant();
}
void ConstantStruct::replaceUsesOfWithOnConstant(Value *From, Value *To) {
assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
std::vector<Constant*> Values;
Values.reserve(getValues().size());
for (unsigned i = 0, e = getValues().size(); i != e; ++i) {
Constant *Val = cast<Constant>(getValues()[i]);
if (Val == From) Val = cast<Constant>(To);
Values.push_back(Val);
}
ConstantStruct *Replacement = ConstantStruct::get(getType(), Values);
assert(Replacement != this && "I didn't contain From!");
// Everyone using this now uses the replacement...
replaceAllUsesWith(Replacement);
// Delete the old constant!
destroyConstant();
}
void ConstantPointerRef::replaceUsesOfWithOnConstant(Value *From, Value *To) {
if (isa<GlobalValue>(To)) {
assert(From == getOperand(0) && "Doesn't contain from!");
ConstantPointerRef *Replacement =
ConstantPointerRef::get(cast<GlobalValue>(To));
// Everyone using this now uses the replacement...
replaceAllUsesWith(Replacement);
// Delete the old constant!
destroyConstant();
} else {
// Just replace ourselves with the To value specified.
replaceAllUsesWith(To);
// Delete the old constant!
destroyConstant();
}
}
void ConstantExpr::replaceUsesOfWithOnConstant(Value *From, Value *To) {
assert(isa<Constant>(To) && "Cannot make Constant refer to non-constant!");
ConstantExpr *Replacement = 0;
if (getOpcode() == Instruction::GetElementPtr) {
std::vector<Constant*> Indices;
Constant *Pointer = cast<Constant>(getOperand(0));
Indices.reserve(getNumOperands()-1);
if (Pointer == From) Pointer = cast<Constant>(To);
for (unsigned i = 1, e = getNumOperands(); i != e; ++i) {
Constant *Val = cast<Constant>(getOperand(i));
if (Val == From) Val = cast<Constant>(To);
Indices.push_back(Val);
}
Replacement = ConstantExpr::getGetElementPtr(Pointer, Indices);
} else if (getOpcode() == Instruction::Cast) {
assert(getOperand(0) == From && "Cast only has one use!");
Replacement = ConstantExpr::getCast(cast<Constant>(To), getType());
} else if (getNumOperands() == 2) {
Constant *C1 = cast<Constant>(getOperand(0));
Constant *C2 = cast<Constant>(getOperand(1));
if (C1 == From) C1 = cast<Constant>(To);
if (C2 == From) C2 = cast<Constant>(To);
Replacement = ConstantExpr::get(getOpcode(), C1, C2);
} else {
assert(0 && "Unknown ConstantExpr type!");
return;
}
assert(Replacement != this && "I didn't contain From!");
// Everyone using this now uses the replacement...
replaceAllUsesWith(Replacement);
// Delete the old constant!
destroyConstant();
}
//===----------------------------------------------------------------------===//
// Factory Function Implementation