llvm-6502/include/llvm/Analysis/DataStructure/DSNode.h
Chris Lattner 3ee382c68f add a method
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20709 91177308-0d34-0410-b5e6-96231b3b80d8
2005-03-20 03:29:39 +00:00

504 lines
19 KiB
C++

//===- DSNode.h - Node definition for datastructure graphs ------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Data structure graph nodes and some implementation of DSNodeHandle.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_DSNODE_H
#define LLVM_ANALYSIS_DSNODE_H
#include "llvm/Analysis/DataStructure/DSSupport.h"
#include "llvm/ADT/hash_map"
namespace llvm {
template<typename BaseType>
class DSNodeIterator; // Data structure graph traversal iterator
class TargetData;
//===----------------------------------------------------------------------===//
/// DSNode - Data structure node class
///
/// This class represents an untyped memory object of Size bytes. It keeps
/// track of any pointers that have been stored into the object as well as the
/// different types represented in this object.
///
class DSNode {
/// NumReferrers - The number of DSNodeHandles pointing to this node... if
/// this is a forwarding node, then this is the number of node handles which
/// are still forwarding over us.
///
unsigned NumReferrers;
/// ForwardNH - This NodeHandle contain the node (and offset into the node)
/// that this node really is. When nodes get folded together, the node to be
/// eliminated has these fields filled in, otherwise ForwardNH.getNode() is
/// null.
///
DSNodeHandle ForwardNH;
/// Next, Prev - These instance variables are used to keep the node on a
/// doubly-linked ilist in the DSGraph.
///
DSNode *Next, *Prev;
friend struct ilist_traits<DSNode>;
/// Size - The current size of the node. This should be equal to the size of
/// the current type record.
///
unsigned Size;
/// ParentGraph - The graph this node is currently embedded into.
///
DSGraph *ParentGraph;
/// Ty - 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.
///
const Type *Ty; // The type itself...
/// 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<DSNodeHandle> Links;
/// Globals - The list of global values that are merged into this node.
///
std::vector<GlobalValue*> Globals;
void operator=(const DSNode &); // DO NOT IMPLEMENT
DSNode(const DSNode &); // DO NOT IMPLEMENT
public:
enum NodeTy {
ShadowNode = 0, // Nothing is known about this node...
AllocaNode = 1 << 0, // This node was allocated with alloca
HeapNode = 1 << 1, // This node was allocated with malloc
GlobalNode = 1 << 2, // This node was allocated by a global var decl
UnknownNode = 1 << 3, // This node points to unknown allocated memory
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
Array = 1 << 7, // This node is treated like an array
//#ifndef NDEBUG
DEAD = 1 << 8, // This node is dead and should not be pointed to
//#endif
Composition = AllocaNode | HeapNode | GlobalNode | UnknownNode,
};
/// NodeType - A union of the above bits. "Shadow" nodes do not add any flags
/// to the nodes in the data structure graph, so it is possible to have nodes
/// with a value of 0 for their NodeType.
///
private:
unsigned short NodeType;
public:
/// DSNode ctor - Create a node of the specified type, inserting it into the
/// specified graph.
///
DSNode(const Type *T, DSGraph *G);
/// DSNode "copy ctor" - Copy the specified node, inserting it into the
/// specified graph. If NullLinks is true, then null out all of the links,
/// but keep the same number of them. This can be used for efficiency if the
/// links are just going to be clobbered anyway.
///
DSNode(const DSNode &, DSGraph *G, bool NullLinks = false);
~DSNode() {
dropAllReferences();
assert(hasNoReferrers() && "Referrers to dead node exist!");
}
// Iterator for graph interface... Defined in DSGraphTraits.h
typedef DSNodeIterator<DSNode> iterator;
typedef DSNodeIterator<const DSNode> const_iterator;
inline iterator begin();
inline iterator end();
inline const_iterator begin() const;
inline const_iterator end() const;
//===--------------------------------------------------
// Accessors
/// getSize - Return the maximum number of bytes occupied by this object...
///
unsigned getSize() const { return Size; }
/// getType - Return the node type of this object...
///
const Type *getType() const { return Ty; }
bool isArray() const { return NodeType & Array; }
/// hasNoReferrers - Return true if nothing is pointing to this node at all.
///
bool hasNoReferrers() const { return getNumReferrers() == 0; }
/// getNumReferrers - This method returns the number of referrers to the
/// current node. Note that if this node is a forwarding node, this will
/// return the number of nodes forwarding over the node!
unsigned getNumReferrers() const { return NumReferrers; }
DSGraph *getParentGraph() const { return ParentGraph; }
void setParentGraph(DSGraph *G) { ParentGraph = G; }
/// getTargetData - Get the target data object used to construct this node.
///
const TargetData &getTargetData() const;
/// getForwardNode - This method returns the node that this node is forwarded
/// to, if any.
///
DSNode *getForwardNode() const { return ForwardNH.getNode(); }
/// isForwarding - Return true if this node is forwarding to another.
///
bool isForwarding() const { return !ForwardNH.isNull(); }
/// stopForwarding - When the last reference to this forwarding node has been
/// dropped, delete the node.
///
void stopForwarding() {
assert(isForwarding() &&
"Node isn't forwarding, cannot stopForwarding()!");
ForwardNH.setTo(0, 0);
assert(ParentGraph == 0 &&
"Forwarding nodes must have been removed from graph!");
delete this;
}
/// hasLink - Return true if this memory object has a link in slot #LinkNo
///
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();
}
/// getLink - Return the link at the specified offset.
///
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 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];
}
/// getNumLinks - Return the number of links in a node...
///
unsigned getNumLinks() const { return Links.size(); }
/// edge_* - Provide iterators for accessing outgoing edges. Some outgoing
/// edges may be null.
typedef std::vector<DSNodeHandle>::iterator edge_iterator;
typedef std::vector<DSNodeHandle>::const_iterator const_edge_iterator;
edge_iterator edge_begin() { return Links.begin(); }
edge_iterator edge_end() { return Links.end(); }
const_edge_iterator edge_begin() const { return Links.begin(); }
const_edge_iterator edge_end() const { return Links.end(); }
/// 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.
///
/// This method returns true if the node is completely folded, otherwise
/// false.
///
bool mergeTypeInfo(const Type *Ty, unsigned Offset,
bool FoldIfIncompatible = true);
/// 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" with isArray = true.
///
void foldNodeCompletely();
/// isNodeCompletelyFolded - Return true if this node has been completely
/// folded down to something that can never be expanded, effectively losing
/// all of the field sensitivity that may be present in the node.
///
bool isNodeCompletelyFolded() const;
/// setLink - Set the link at the specified offset to the specified
/// 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 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;
}
/// getPointerSize - Return the size of a pointer for the current target.
///
unsigned getPointerSize() const { return DS::PointerSize; }
/// addEdgeTo - Add an edge from the current node to the specified node. This
/// can cause merging of nodes in the graph.
///
void addEdgeTo(unsigned Offset, const DSNodeHandle &NH);
/// mergeWith - Merge this node and the specified node, moving all links to
/// and from the argument node into the current node, deleting the node
/// argument. Offset indicates what offset the specified node is to be merged
/// into the current node.
///
/// The specified node may be a null pointer (in which case, nothing happens).
///
void mergeWith(const DSNodeHandle &NH, unsigned Offset);
/// 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.
///
void addGlobal(GlobalValue *GV);
/// removeGlobal - Remove the specified global that is explicitly in the
/// globals list.
void removeGlobal(GlobalValue *GV);
void mergeGlobals(const std::vector<GlobalValue*> &RHS);
void clearGlobals() { std::vector<GlobalValue*>().swap(Globals); }
/// getGlobalsList - Return the set of global leaders that are represented by
/// this node. Note that globals that are in this equivalence class but are
/// not leaders are not returned: for that, use addFullGlobalsList().
const std::vector<GlobalValue*> &getGlobalsList() const { return Globals; }
/// addFullGlobalsList - Compute the full set of global values that are
/// represented by this node. Unlike getGlobalsList(), this requires fair
/// amount of work to compute, so don't treat this method call as free.
void addFullGlobalsList(std::vector<GlobalValue*> &List) const;
/// addFullFunctionList - Identical to addFullGlobalsList, but only return the
/// functions in the full list.
void addFullFunctionList(std::vector<Function*> &List) const;
/// globals_iterator/begin/end - Provide iteration methods over the global
/// value leaders set that is merged into this node. Like the getGlobalsList
/// method, these iterators do not return globals that are part of the
/// equivalence classes for globals in this node, but aren't leaders.
typedef std::vector<GlobalValue*>::const_iterator globals_iterator;
globals_iterator globals_begin() const { return Globals.begin(); }
globals_iterator globals_end() const { return Globals.end(); }
/// maskNodeTypes - Apply a mask to the node types bitfield.
///
void maskNodeTypes(unsigned Mask) {
NodeType &= Mask;
}
void mergeNodeFlags(unsigned RHS) {
NodeType |= RHS;
}
/// getNodeFlags - Return all of the flags set on the node. If the DEAD flag
/// is set, hide it from the caller.
///
unsigned getNodeFlags() const { return NodeType & ~DEAD; }
bool isAllocaNode() const { return NodeType & AllocaNode; }
bool isHeapNode() const { return NodeType & HeapNode; }
bool isGlobalNode() const { return NodeType & GlobalNode; }
bool isUnknownNode() const { return NodeType & UnknownNode; }
bool isModified() const { return NodeType & Modified; }
bool isRead() const { return NodeType & Read; }
bool isIncomplete() const { return NodeType & Incomplete; }
bool isComplete() const { return !isIncomplete(); }
bool isDeadNode() const { return NodeType & DEAD; }
DSNode *setAllocaNodeMarker() { NodeType |= AllocaNode; return this; }
DSNode *setHeapNodeMarker() { NodeType |= HeapNode; return this; }
DSNode *setGlobalNodeMarker() { NodeType |= GlobalNode; return this; }
DSNode *setUnknownNodeMarker() { NodeType |= UnknownNode; return this; }
DSNode *setIncompleteMarker() { NodeType |= Incomplete; return this; }
DSNode *setModifiedMarker() { NodeType |= Modified; return this; }
DSNode *setReadMarker() { NodeType |= Read; return this; }
DSNode *setArrayMarker() { NodeType |= Array; return this; }
void makeNodeDead() {
Globals.clear();
assert(hasNoReferrers() && "Dead node shouldn't have refs!");
NodeType = DEAD;
}
/// forwardNode - Mark this node as being obsolete, and all references to it
/// should be forwarded to the specified node and offset.
///
void forwardNode(DSNode *To, unsigned Offset);
void print(std::ostream &O, const DSGraph *G) const;
void dump() const;
void assertOK() const;
void dropAllReferences() {
Links.clear();
if (isForwarding())
ForwardNH.setTo(0, 0);
}
/// remapLinks - Change all of the Links in the current node according to the
/// specified mapping.
///
void remapLinks(hash_map<const DSNode*, DSNodeHandle> &OldNodeMap);
/// markReachableNodes - This method recursively traverses the specified
/// DSNodes, marking any nodes which are reachable. All reachable nodes it
/// adds to the set, which allows it to only traverse visited nodes once.
///
void markReachableNodes(hash_set<const DSNode*> &ReachableNodes) const;
private:
friend class DSNodeHandle;
// static mergeNodes - Helper for mergeWith()
static void MergeNodes(DSNodeHandle& CurNodeH, DSNodeHandle& NH);
};
//===----------------------------------------------------------------------===//
// Define the ilist_traits specialization for the DSGraph ilist.
//
template<>
struct ilist_traits<DSNode> {
static DSNode *getPrev(const DSNode *N) { return N->Prev; }
static DSNode *getNext(const DSNode *N) { return N->Next; }
static void setPrev(DSNode *N, DSNode *Prev) { N->Prev = Prev; }
static void setNext(DSNode *N, DSNode *Next) { N->Next = Next; }
static DSNode *createSentinel() { return new DSNode(0,0); }
static void destroySentinel(DSNode *N) { delete N; }
//static DSNode *createNode(const DSNode &V) { return new DSNode(V); }
void addNodeToList(DSNode *NTy) {}
void removeNodeFromList(DSNode *NTy) {}
void transferNodesFromList(iplist<DSNode, ilist_traits> &L2,
ilist_iterator<DSNode> first,
ilist_iterator<DSNode> last) {}
};
template<>
struct ilist_traits<const DSNode> : public ilist_traits<DSNode> {};
//===----------------------------------------------------------------------===//
// Define inline DSNodeHandle functions that depend on the definition of DSNode
//
inline DSNode *DSNodeHandle::getNode() const {
// Disabling this assertion because it is failing on a "magic" struct
// in named (from bind). The fourth field is an array of length 0,
// presumably used to create struct instances of different sizes.
assert((!N ||
N->isNodeCompletelyFolded() ||
(N->Size == 0 && Offset == 0) ||
(int(Offset) >= 0 && Offset < N->Size) ||
(int(Offset) < 0 && -int(Offset) < int(N->Size)) ||
N->isForwarding()) && "Node handle offset out of range!");
if (N == 0 || !N->isForwarding())
return N;
return HandleForwarding();
}
inline void DSNodeHandle::setTo(DSNode *n, unsigned NewOffset) const {
assert(!n || !n->isForwarding() && "Cannot set node to a forwarded node!");
if (N) getNode()->NumReferrers--;
N = n;
Offset = NewOffset;
if (N) {
N->NumReferrers++;
if (Offset >= N->Size) {
assert((Offset == 0 || N->Size == 1) &&
"Pointer to non-collapsed node with invalid offset!");
Offset = 0;
}
}
assert(!N || ((N->NodeType & DSNode::DEAD) == 0));
assert((!N || Offset < N->Size || (N->Size == 0 && Offset == 0) ||
N->isForwarding()) && "Node handle offset out of range!");
}
inline bool DSNodeHandle::hasLink(unsigned Num) const {
assert(N && "DSNodeHandle does not point to a node yet!");
return getNode()->hasLink(Num+Offset);
}
/// 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 Off) const {
assert(N && "DSNodeHandle does not point to a node yet!");
return getNode()->getLink(Offset+Off);
}
inline DSNodeHandle &DSNodeHandle::getLink(unsigned Off) {
assert(N && "DSNodeHandle does not point to a node yet!");
return getNode()->getLink(Off+Offset);
}
inline void DSNodeHandle::setLink(unsigned Off, const DSNodeHandle &NH) {
assert(N && "DSNodeHandle does not point to a node yet!");
getNode()->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 Off, const DSNodeHandle &Node) {
assert(N && "DSNodeHandle does not point to a node yet!");
getNode()->addEdgeTo(Off+Offset, Node);
}
/// mergeWith - Merge the logical node pointed to by 'this' with the node
/// pointed to by 'N'.
///
inline void DSNodeHandle::mergeWith(const DSNodeHandle &Node) const {
if (!isNull())
getNode()->mergeWith(Node, Offset);
else { // No node to merge with, so just point to Node
Offset = 0;
DSNode *NN = Node.getNode();
setTo(NN, Node.getOffset());
}
}
} // End llvm namespace
#endif