//===--------------------------------------------------------------------===//
template <class _Ptr, class _USE_iterator> // Predecessor Iterator
-class PredIterator : public bidirectional_iterator<_Ptr, ptrdiff_t> {
- typedef bidirectional_iterator<_Ptr, ptrdiff_t> super;
+class PredIterator : public forward_iterator<_Ptr, ptrdiff_t> {
+ typedef forward_iterator<_Ptr, ptrdiff_t> super;
_Ptr *BB;
_USE_iterator It;
public:
typedef PredIterator<_Ptr,_USE_iterator> _Self;
typedef typename super::pointer pointer;
- inline void advancePastConstants() {
+ inline void advancePastNonTerminators() {
// Loop to ignore non terminator uses (for example PHI nodes)...
while (It != BB->use_end() && !isa<TerminatorInst>(*It))
++It;
}
inline PredIterator(_Ptr *bb) : BB(bb), It(bb->use_begin()) {
- advancePastConstants();
+ advancePastNonTerminators();
}
inline PredIterator(_Ptr *bb, bool) : BB(bb), It(bb->use_end()) {}
inline _Self& operator++() { // Preincrement
assert(It != BB->use_end() && "pred_iterator out of range!");
- ++It; advancePastConstants();
+ ++It; advancePastNonTerminators();
return *this;
}
inline _Self operator++(int) { // Postincrement
_Self tmp = *this; ++*this; return tmp;
}
-
- inline _Self& operator--() { --It; return *this; } // Predecrement
- inline _Self operator--(int) { // Postdecrement
- _Self tmp = *this; --*this; return tmp;
- }
};
typedef PredIterator<BasicBlock, Value::use_iterator> pred_iterator;
#ifndef LLVM_USE_H
#define LLVM_USE_H
-#include "llvm/ADT/ilist"
+#include "llvm/Support/Casting.h"
+#include "llvm/ADT/iterator"
namespace llvm {
-template<typename NodeTy> struct ilist_traits;
class Value;
class User;
Value *operator->() { return Val; }
const Value *operator->() const { return Val; }
+ Use *getNext() const { return Next; }
private:
- // NOTE!! The Next/Prev fields MUST stay at the start of this structure. The
- // end-token for the ilist is allocated as JUST the next/prev pair to reduce
- // memory usage instead of allocating an entire Use.
- struct NextPrevPtrs {
- Use *Next, *Prev;
- } UseLinks;
-
+ Use *Next, **Prev;
Value *Val;
User *U;
- friend struct ilist_traits<Use>;
-};
-template<>
-struct ilist_traits<Use> {
- static Use *getPrev(Use *N) { return N->UseLinks.Prev; }
- static Use *getNext(Use *N) { return N->UseLinks.Next; }
- static const Use *getPrev(const Use *N) { return N->UseLinks.Prev; }
- static const Use *getNext(const Use *N) { return N->UseLinks.Next; }
- static void setPrev(Use *N, Use *Prev) { N->UseLinks.Prev = Prev; }
- static void setNext(Use *N, Use *Next) { N->UseLinks.Next = Next; }
-
- /// createSentinel - this is used to create the end marker for the use list.
- /// Note that we only allocate a UseLinks structure, which is just enough to
- /// hold the next/prev pointers. This saves us 8 bytes of memory for every
- /// Value allocated.
- static Use *createSentinel() { return (Use*)new Use::NextPrevPtrs(); }
- static void destroySentinel(Use *S) { delete (Use::NextPrevPtrs*)S; }
-
- void addNodeToList(Use *NTy) {}
- void removeNodeFromList(Use *NTy) {}
- void transferNodesFromList(iplist<Use, ilist_traits> &L2,
- ilist_iterator<Use> first,
- ilist_iterator<Use> last) {}
-};
+ void addToList(Use **List) {
+ Next = *List;
+ if (Next) Next->Prev = &Next;
+ Prev = List;
+ *List = this;
+ }
+ void removeFromList() {
+ *Prev = Next;
+ if (Next) Next->Prev = Prev;
+ }
+ friend class Value;
+};
+// simplify_type - Allow clients to treat uses just like values when using
+// casting operators.
template<> struct simplify_type<Use> {
typedef Value* SimpleType;
static SimpleType getSimplifiedValue(const Use &Val) {
}
};
-struct UseListIteratorWrapper : public iplist<Use>::iterator {
- typedef iplist<Use>::iterator Super;
- UseListIteratorWrapper() {}
- UseListIteratorWrapper(const Super &RHS) : Super(RHS) {}
- UseListIteratorWrapper &operator=(const Super &RHS) {
- Super::operator=(RHS);
- return *this;
- }
- inline User *operator*() const;
- User *operator->() const { return operator*(); }
+template<typename UserTy> // UserTy == 'User' or 'const User'
+class value_use_iterator : public forward_iterator<UserTy*, ptrdiff_t> {
+ typedef forward_iterator<UserTy*, ptrdiff_t> super;
+ typedef value_use_iterator<UserTy> _Self;
+
+ Use *U;
+ value_use_iterator(Use *u) : U(u) {}
+ friend class Value;
+public:
+ typedef typename super::reference reference;
+ typedef typename super::pointer pointer;
- UseListIteratorWrapper operator--() { return Super::operator--(); }
- UseListIteratorWrapper operator++() { return Super::operator++(); }
+ value_use_iterator(const _Self &I) : U(I.U) {}
+ value_use_iterator() {}
- UseListIteratorWrapper operator--(int) { // postdecrement operators...
- UseListIteratorWrapper tmp = *this;
- --*this;
- return tmp;
+ bool operator==(const _Self &x) const {
+ return U == x.U;
}
- UseListIteratorWrapper operator++(int) { // postincrement operators...
- UseListIteratorWrapper tmp = *this;
- ++*this;
- return tmp;
+ bool operator!=(const _Self &x) const {
+ return !operator==(x);
}
-};
-
-struct UseListConstIteratorWrapper : public iplist<Use>::const_iterator {
- typedef iplist<Use>::const_iterator Super;
- UseListConstIteratorWrapper() {}
- UseListConstIteratorWrapper(const Super &RHS) : Super(RHS) {}
- // Allow conversion from non-const to const iterators
- UseListConstIteratorWrapper(const UseListIteratorWrapper &RHS) : Super(RHS) {}
- UseListConstIteratorWrapper(const iplist<Use>::iterator &RHS) : Super(RHS) {}
-
- UseListConstIteratorWrapper &operator=(const Super &RHS) {
- Super::operator=(RHS);
- return *this;
+ // Iterator traversal: forward iteration only
+ _Self &operator++() { // Preincrement
+ assert(U && "Cannot increment end iterator!");
+ U = U->getNext();
+ return *this;
+ }
+ _Self operator++(int) { // Postincrement
+ _Self tmp = *this; ++*this; return tmp;
}
- inline const User *operator*() const;
- const User *operator->() const { return operator*(); }
+ // Retrieve a reference to the current SCC
+ UserTy *operator*() const {
+ assert(U && "Cannot increment end iterator!");
+ return U->getUser();
+ }
- UseListConstIteratorWrapper operator--() { return Super::operator--(); }
- UseListConstIteratorWrapper operator++() { return Super::operator++(); }
+ UserTy *operator->() const { return operator*(); }
- UseListConstIteratorWrapper operator--(int) { // postdecrement operators...
- UseListConstIteratorWrapper tmp = *this;
- --*this;
- return tmp;
- }
- UseListConstIteratorWrapper operator++(int) { // postincrement operators...
- UseListConstIteratorWrapper tmp = *this;
- ++*this;
- return tmp;
- }
+ Use &getUse() const { return *U; }
};
} // End llvm namespace
class Value {
unsigned SubclassID; // Subclass identifier (for isa/dyn_cast)
PATypeHolder Ty;
- iplist<Use> Uses;
+ Use *UseList;
std::string Name;
void operator=(const Value &); // Do not implement
//----------------------------------------------------------------------
// Methods for handling the vector of uses of this Value.
//
- typedef UseListIteratorWrapper use_iterator;
- typedef UseListConstIteratorWrapper use_const_iterator;
- typedef iplist<Use>::size_type size_type;
-
- size_type use_size() const { return Uses.size(); }
- bool use_empty() const { return Uses.empty(); }
- use_iterator use_begin() { return Uses.begin(); }
- use_const_iterator use_begin() const { return Uses.begin(); }
- use_iterator use_end() { return Uses.end(); }
- use_const_iterator use_end() const { return Uses.end(); }
- User *use_back() { return Uses.back().getUser(); }
- const User *use_back() const { return Uses.back().getUser(); }
+ typedef value_use_iterator<User> use_iterator;
+ typedef value_use_iterator<const User> use_const_iterator;
+
+ bool use_empty() const { return UseList == 0; }
+ use_iterator use_begin() { return use_iterator(UseList); }
+ use_const_iterator use_begin() const { return use_const_iterator(UseList); }
+ use_iterator use_end() { return use_iterator(0); }
+ use_const_iterator use_end() const { return use_const_iterator(0); }
+ User *use_back() { return *use_begin(); }
+ const User *use_back() const { return *use_begin(); }
/// hasOneUse - Return true if there is exactly one user of this value. This
/// is specialized because it is a common request and does not require
/// traversing the whole use list.
///
bool hasOneUse() const {
- iplist<Use>::const_iterator I = Uses.begin(), E = Uses.end();
+ use_const_iterator I = use_begin(), E = use_end();
if (I == E) return false;
return ++I == E;
}
+ /// hasNUses - Return true if this Value has exactly N users.
+ ///
+ bool hasNUses(unsigned N) const;
+
+ /// getNumUses - This method computes the number of uses of this Value. This
+ /// is a linear time operation. Use hasOneUse or hasNUses to check for
+ /// specific values.
+ unsigned getNumUses() const;
+
/// addUse/killUse - These two methods should only be used by the Use class.
///
- void addUse(Use &U) { Uses.push_back(&U); }
- void killUse(Use &U) { Uses.remove(&U); }
+ void addUse(Use &U) { U.addToList(&UseList); }
/// getValueType - Return an ID for the concrete type of this object. This is
/// used to implement the classof checks. This should not be used for any
return OS;
}
-
-inline User *UseListIteratorWrapper::operator*() const {
- return Super::operator*().getUser();
-}
-
-inline const User *UseListConstIteratorWrapper::operator*() const {
- return Super::operator*().getUser();
-}
-
-
void Use::init(Value *v, User *user) {
Val = v;
U = user;
}
Use::~Use() {
- if (Val) Val->killUse(*this);
+ if (Val) removeFromList();
}
void Use::set(Value *V) {
- if (Val) Val->killUse(*this);
+ if (Val) removeFromList();
Val = V;
if (V) V->addUse(*this);
}
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