constify some methods and add a new Constant::getAggregateElement

helper method for the common operation of extracting an element
out of a constant aggregate.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148931 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2012-01-25 06:16:32 +00:00
parent 4ca829e895
commit 3d5ed2250e
3 changed files with 56 additions and 16 deletions

View File

@ -97,6 +97,13 @@ public:
/// constant exprs and other cases we can't handle, we return an empty vector.
void getVectorElements(SmallVectorImpl<Constant*> &Elts) const;
/// getAggregateElement - For aggregates (struct/array/vector) return the
/// constant that corresponds to the specified element if possible, or null if
/// not. This can return null if the element index is a ConstantExpr, or if
/// 'this' is a constant expr.
Constant *getAggregateElement(unsigned Elt) const;
Constant *getAggregateElement(Constant *Elt) 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
/// constant. Any constants on our Use list must also be destroy'd. The

View File

@ -316,19 +316,19 @@ public:
/// getSequentialElement - If this CAZ has array or vector type, return a zero
/// with the right element type.
Constant *getSequentialElement();
Constant *getSequentialElement() const;
/// getStructElement - If this CAZ has struct type, return a zero with the
/// right element type for the specified element.
Constant *getStructElement(unsigned Elt);
Constant *getStructElement(unsigned Elt) const;
/// getElementValue - Return a zero of the right value for the specified GEP
/// index.
Constant *getElementValue(Constant *C);
Constant *getElementValue(Constant *C) const;
/// getElementValue - Return a zero of the right value for the specified GEP
/// index.
Constant *getElementValue(unsigned Idx);
Constant *getElementValue(unsigned Idx) const;
/// Methods for support type inquiry through isa, cast, and dyn_cast:
///
@ -1157,19 +1157,19 @@ public:
/// getSequentialElement - If this Undef has array or vector type, return a
/// undef with the right element type.
UndefValue *getSequentialElement();
UndefValue *getSequentialElement() const;
/// getStructElement - If this undef has struct type, return a undef with the
/// right element type for the specified element.
UndefValue *getStructElement(unsigned Elt);
UndefValue *getStructElement(unsigned Elt) const;
/// getElementValue - Return an undef of the right value for the specified GEP
/// index.
UndefValue *getElementValue(Constant *C);
UndefValue *getElementValue(Constant *C) const;
/// getElementValue - Return an undef of the right value for the specified GEP
/// index.
UndefValue *getElementValue(unsigned Idx);
UndefValue *getElementValue(unsigned Idx) const;
virtual void destroyConstant();

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@ -150,6 +150,39 @@ Constant *Constant::getAllOnesValue(Type *Ty) {
getAllOnesValue(VTy->getElementType()));
}
/// getAggregateElement - For aggregates (struct/array/vector) return the
/// constant that corresponds to the specified element if possible, or null if
/// not. This can return null if the element index is a ConstantExpr, or if
/// 'this' is a constant expr.
Constant *Constant::getAggregateElement(unsigned Elt) const {
if (const ConstantStruct *CS = dyn_cast<ConstantStruct>(this))
return Elt < CS->getNumOperands() ? CS->getOperand(Elt) : 0;
if (const ConstantArray *CA = dyn_cast<ConstantArray>(this))
return Elt < CA->getNumOperands() ? CA->getOperand(Elt) : 0;
if (const ConstantVector *CV = dyn_cast<ConstantVector>(this))
return Elt < CV->getNumOperands() ? CV->getOperand(Elt) : 0;
if (const ConstantAggregateZero *CAZ =dyn_cast<ConstantAggregateZero>(this))
return CAZ->getElementValue(Elt);
if (const UndefValue *UV = dyn_cast<UndefValue>(this))
return UV->getElementValue(Elt);
if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(this))
return CDS->getElementAsConstant(Elt);
return 0;
}
Constant *Constant::getAggregateElement(Constant *Elt) const {
assert(isa<IntegerType>(Elt->getType()) && "Index must be an integer");
if (ConstantInt *CI = dyn_cast<ConstantInt>(Elt))
return getAggregateElement(CI->getZExtValue());
return 0;
}
void Constant::destroyConstantImpl() {
// When a Constant is destroyed, there may be lingering
// references to the constant by other constants in the constant pool. These
@ -594,21 +627,21 @@ bool ConstantFP::isExactlyValue(const APFloat &V) const {
/// getSequentialElement - If this CAZ has array or vector type, return a zero
/// with the right element type.
Constant *ConstantAggregateZero::getSequentialElement() {
Constant *ConstantAggregateZero::getSequentialElement() const {
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) {
Constant *ConstantAggregateZero::getStructElement(unsigned Elt) const {
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) {
Constant *ConstantAggregateZero::getElementValue(Constant *C) const {
if (isa<SequentialType>(getType()))
return getSequentialElement();
return getStructElement(cast<ConstantInt>(C)->getZExtValue());
@ -616,7 +649,7 @@ Constant *ConstantAggregateZero::getElementValue(Constant *C) {
/// getElementValue - Return a zero of the right value for the specified GEP
/// index.
Constant *ConstantAggregateZero::getElementValue(unsigned Idx) {
Constant *ConstantAggregateZero::getElementValue(unsigned Idx) const {
if (isa<SequentialType>(getType()))
return getSequentialElement();
return getStructElement(Idx);
@ -629,19 +662,19 @@ Constant *ConstantAggregateZero::getElementValue(unsigned Idx) {
/// getSequentialElement - If this undef has array or vector type, return an
/// undef with the right element type.
UndefValue *UndefValue::getSequentialElement() {
UndefValue *UndefValue::getSequentialElement() const {
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) {
UndefValue *UndefValue::getStructElement(unsigned Elt) const {
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) {
UndefValue *UndefValue::getElementValue(Constant *C) const {
if (isa<SequentialType>(getType()))
return getSequentialElement();
return getStructElement(cast<ConstantInt>(C)->getZExtValue());
@ -649,7 +682,7 @@ UndefValue *UndefValue::getElementValue(Constant *C) {
/// getElementValue - Return an undef of the right value for the specified GEP
/// index.
UndefValue *UndefValue::getElementValue(unsigned Idx) {
UndefValue *UndefValue::getElementValue(unsigned Idx) const {
if (isa<SequentialType>(getType()))
return getSequentialElement();
return getStructElement(Idx);