/// different types represented in this object.
///
class DSNode {
- /// Links - Contains one entry for every _distinct_ pointer field in the
- /// memory block. These are demand allocated and indexed by the MergeMap
- /// vector.
- ///
- std::vector<DSNodeHandle> Links;
-
- /// MergeMap - Maps from every byte in the object to a signed byte number.
- /// This map is neccesary due to the merging that is possible as part of the
- /// unification algorithm. To merge two distinct bytes of the object together
- /// into a single logical byte, the indexes for the two bytes are set to the
- /// same value. This fully general merging is capable of representing all
- /// manners of array merging if neccesary.
- ///
- /// This map is also used to map outgoing pointers to various byte offsets in
- /// this data structure node. If this value is >= 0, then it indicates that
- /// the numbered entry in the Links vector contains the outgoing edge for this
- /// byte offset. In this way, the Links vector can be demand allocated and
- /// byte elements of the node may be merged without needing a Link allocated
- /// for it.
- ///
- /// Initially, each each element of the MergeMap is assigned a unique negative
- /// number, which are then merged as the unification occurs.
- ///
- std::vector<signed char> MergeMap;
-
/// Referrers - Keep track of all of the node handles that point to this
/// DSNode. These pointers may need to be updated to point to a different
/// node if this node gets merged with it.
///
std::vector<DSNodeHandle*> Referrers;
- /// TypeEntries - As part of the merging process of this algorithm, nodes of
- /// different types can be represented by this single DSNode. This vector is
- /// kept sorted.
+ /// Links - Contains one entry for every sizeof(void*) bytes in this memory
+ /// object. Note that if the node is not a multiple of size(void*) bytes
+ /// large, that there is an extra entry for the "remainder" of the node as
+ /// well. For this reason, nodes of 1 byte in size do have one link.
///
- std::vector<DSTypeRec> TypeEntries;
+ std::vector<DSNodeHandle> Links;
/// Globals - The list of global values that are merged into this node.
///
std::vector<GlobalValue*> Globals;
+ /// Type - Keep track of the current outer most type of this object, in
+ /// addition to whether or not it has been indexed like an array or not. If
+ /// the isArray bit is set, the node cannot grow.
+ ///
+ DSTypeRec Ty;
+
+ /// Size - The current size of the node. This should be equal to the size of
+ /// the current type record.
+ ///
+ unsigned Size;
+
void operator=(const DSNode &); // DO NOT IMPLEMENT
public:
enum NodeTy {
Incomplete = 1 << 4, // This node may not be complete
Modified = 1 << 5, // This node is modified in this context
Read = 1 << 6, // This node is read in this context
+#if 1
+ DEAD = 1 << 7, // This node is dead and should not be pointed to
+#endif
};
/// NodeType - A union of the above bits. "Shadow" nodes do not add any flags
/// getSize - Return the maximum number of bytes occupied by this object...
///
- unsigned getSize() const { return MergeMap.size(); }
+ unsigned getSize() const { return Size; }
- // getTypeEntries - Return the possible types and their offsets in this object
- const std::vector<DSTypeRec> &getTypeEntries() const { return TypeEntries; }
+ // getType - Return the node type of this object...
+ const DSTypeRec &getType() const { return Ty; }
/// getReferrers - Return a list of the pointers to this node...
///
const std::vector<DSNodeHandle*> &getReferrers() const { return Referrers; }
+ /// hasNoReferrers - Return true if nothing is pointing to this node at all.
+ ///
+ bool hasNoReferrers() const { return Referrers.empty(); }
+
/// isModified - Return true if this node may be modified in this context
///
bool isModified() const { return (NodeType & Modified) != 0; }
bool isRead() const { return (NodeType & Read) != 0; }
- /// hasLink - Return true if this memory object has a link at the specified
- /// location.
+ /// hasLink - Return true if this memory object has a link in slot #LinkNo
///
- bool hasLink(unsigned i) const {
- assert(i < getSize() && "Field Link index is out of range!");
- return MergeMap[i] >= 0;
+ bool hasLink(unsigned Offset) const {
+ assert((Offset & ((1 << DS::PointerShift)-1)) == 0 &&
+ "Pointer offset not aligned correctly!");
+ unsigned Index = Offset >> DS::PointerShift;
+ assert(Index < Links.size() && "Link index is out of range!");
+ return Links[Index].getNode();
}
-
- DSNodeHandle *getLink(unsigned i) {
- if (hasLink(i))
- return &Links[MergeMap[i]];
- return 0;
+ DSNodeHandle &getLink(unsigned Offset) {
+ assert((Offset & ((1 << DS::PointerShift)-1)) == 0 &&
+ "Pointer offset not aligned correctly!");
+ unsigned Index = Offset >> DS::PointerShift;
+ assert(Index < Links.size() && "Link index is out of range!");
+ return Links[Index];
}
- const DSNodeHandle *getLink(unsigned i) const {
- if (hasLink(i))
- return &Links[MergeMap[i]];
- return 0;
+ const DSNodeHandle &getLink(unsigned Offset) const {
+ assert((Offset & ((1 << DS::PointerShift)-1)) == 0 &&
+ "Pointer offset not aligned correctly!");
+ unsigned Index = Offset >> DS::PointerShift;
+ assert(Index < Links.size() && "Link index is out of range!");
+ return Links[Index];
}
- /// getMergeMapLabel - Return the merge map entry specified, to allow printing
- /// out of DSNodes nicely for DOT graphs.
+ /// mergeTypeInfo - This method merges the specified type into the current
+ /// node at the specified offset. This may update the current node's type
+ /// record if this gives more information to the node, it may do nothing to
+ /// the node if this information is already known, or it may merge the node
+ /// completely (and return true) if the information is incompatible with what
+ /// is already known.
///
- int getMergeMapLabel(unsigned i) const {
- assert(i < MergeMap.size() && "MergeMap index out of range!");
- return MergeMap[i];
- }
-
- /// getTypeRec - This method returns the specified type record if it exists.
- /// If it does not yet exist, the method checks to see whether or not the
- /// request would result in an untrackable state. If adding it would cause
- /// untrackable state, we foldNodeCompletely the node and return the void
- /// record, otherwise we add an new TypeEntry and return it.
+ /// This method returns true if the node is completely folded, otherwise
+ /// false.
///
- DSTypeRec &getTypeRec(const Type *Ty, unsigned Offset);
+ bool mergeTypeInfo(const Type *Ty, unsigned Offset);
/// foldNodeCompletely - If we determine that this node has some funny
/// behavior happening to it that we cannot represent, we fold it down to a
/// single, completely pessimistic, node. This node is represented as a
- /// single byte with a single TypeEntry of "void".
+ /// single byte with a single TypeEntry of "void" with isArray = true.
///
void foldNodeCompletely();
/// NodeHandle, replacing what was there. It is uncommon to use this method,
/// instead one of the higher level methods should be used, below.
///
- void setLink(unsigned i, const DSNodeHandle &NH);
+ void setLink(unsigned Offset, const DSNodeHandle &NH) {
+ assert((Offset & ((1 << DS::PointerShift)-1)) == 0 &&
+ "Pointer offset not aligned correctly!");
+ unsigned Index = Offset >> DS::PointerShift;
+ assert(Index < Links.size() && "Link index is out of range!");
+ Links[Index] = NH;
+ }
/// addEdgeTo - Add an edge from the current node to the specified node. This
/// can cause merging of nodes in the graph.
///
void mergeWith(const DSNodeHandle &NH, unsigned Offset);
- /// mergeIndexes - If we discover that two indexes are equivalent and must be
- /// merged, this function is used to do the dirty work.
- ///
- void mergeIndexes(unsigned idx1, unsigned idx2) {
- assert(idx1 < getSize() && idx2 < getSize() && "Indexes out of range!");
- signed char MV1 = MergeMap[idx1];
- signed char MV2 = MergeMap[idx2];
- if (MV1 != MV2)
- mergeMappedValues(MV1, MV2);
- }
-
-
/// addGlobal - Add an entry for a global value to the Globals list. This
/// also marks the node with the 'G' flag if it does not already have it.
///
/// remapLinks - Change all of the Links in the current node according to the
/// specified mapping.
- void remapLinks(std::map<const DSNode*, DSNode*> &OldNodeMap);
+ void remapLinks(std::map<const DSNode*, DSNodeHandle> &OldNodeMap);
private:
friend class DSNodeHandle;
// addReferrer - Keep the referrer set up to date...
void addReferrer(DSNodeHandle *H) { Referrers.push_back(H); }
void removeReferrer(DSNodeHandle *H);
-
- /// rewriteMergeMap - Loop over the mergemap, replacing any references to the
- /// index From to be references to the index To.
- ///
- void rewriteMergeMap(signed char From, signed char To) {
- assert(From != To && "Cannot change something into itself!");
- for (unsigned i = 0, e = MergeMap.size(); i != e; ++i)
- if (MergeMap[i] == From)
- MergeMap[i] = To;
- }
-
- /// mergeMappedValues - This is the higher level form of rewriteMergeMap. It
- /// is fully capable of merging links together if neccesary as well as simply
- /// rewriting the map entries.
- ///
- void mergeMappedValues(signed char V1, signed char V2);
-
- /// growNode - Attempt to grow the node to the specified size. This may do
- /// one of three things:
- /// 1. Grow the node, return false
- /// 2. Refuse to grow the node, but maintain a trackable situation, return
- /// false.
- /// 3. Be unable to track if node was that size, so collapse the node and
- /// return true.
- ///
- bool growNode(unsigned RequestedSize);
};
//===----------------------------------------------------------------------===//
// Define inline DSNodeHandle functions that depend on the definition of DSNode
//
-
inline void DSNodeHandle::setNode(DSNode *n) {
if (N) N->removeReferrer(this);
N = n;
if (N) N->addReferrer(this);
+ assert(!N || ((N->NodeType & DSNode::DEAD) == 0));
}
inline bool DSNodeHandle::hasLink(unsigned Num) const {
/// getLink - Treat this current node pointer as a pointer to a structure of
/// some sort. This method will return the pointer a mem[this+Num]
///
-inline const DSNodeHandle *DSNodeHandle::getLink(unsigned Num) const {
+inline const DSNodeHandle &DSNodeHandle::getLink(unsigned Off) const {
assert(N && "DSNodeHandle does not point to a node yet!");
- return N->getLink(Num+Offset);
+ return N->getLink(Offset+Off);
}
-inline DSNodeHandle *DSNodeHandle::getLink(unsigned Num) {
+inline DSNodeHandle &DSNodeHandle::getLink(unsigned Off) {
assert(N && "DSNodeHandle does not point to a node yet!");
- return N->getLink(Num+Offset);
+ return N->getLink(Off+Offset);
}
-inline void DSNodeHandle::setLink(unsigned Num, const DSNodeHandle &NH) {
+inline void DSNodeHandle::setLink(unsigned Off, const DSNodeHandle &NH) {
assert(N && "DSNodeHandle does not point to a node yet!");
- N->setLink(Num+Offset, NH);
+ N->setLink(Off+Offset, NH);
}
/// addEdgeTo - Add an edge from the current node to the specified node. This
/// can cause merging of nodes in the graph.
///
-inline void DSNodeHandle::addEdgeTo(unsigned LinkNo, const DSNodeHandle &Node) {
+inline void DSNodeHandle::addEdgeTo(unsigned Off, const DSNodeHandle &Node) {
assert(N && "DSNodeHandle does not point to a node yet!");
- N->addEdgeTo(LinkNo+Offset, Node);
+ N->addEdgeTo(Off+Offset, Node);
}
/// mergeWith - Merge the logical node pointed to by 'this' with the node
inline void DSNodeHandle::mergeWith(const DSNodeHandle &Node) {
if (N != 0)
N->mergeWith(Node, Offset);
- else { // No node to merge with, so just point to Node
+ else // No node to merge with, so just point to Node
*this = Node;
- }
}
#endif
projects / oota-llvm.git / blobdiff