llvm-6502/include/llvm/Analysis/DataStructure.h
2002-08-21 17:09:45 +00:00

487 lines
18 KiB
C++

//===- DataStructure.h - Build data structure graphs -------------*- C++ -*--=//
//
// Implement the LLVM data structure analysis library.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_DATA_STRUCTURE_H
#define LLVM_ANALYSIS_DATA_STRUCTURE_H
#include "llvm/Pass.h"
#include "llvm/GlobalValue.h"
#include "Support/HashExtras.h"
#include "Support/hash_set"
#include <set>
#include <string>
class Type;
class GlobalValue;
class DSNode; // Each node in the graph
class DSGraph; // A graph for a function
class GlobalDSGraph; // A common graph for globals in a program
class DSNodeIterator; // Data structure graph traversal iterator
class LocalDataStructures; // A collection of local graphs for a program
class BUDataStructures; // A collection of bu graphs for a program
class TDDataStructures; // A collection of td graphs for a program
//===----------------------------------------------------------------------===//
// DSNodeHandle - Implement a "handle" to a data structure node that takes care
// of all of the add/un'refing of the node to prevent the backpointers in the
// graph from getting out of date.
//
class DSNodeHandle {
DSNode *N;
public:
// Allow construction, destruction, and assignment...
DSNodeHandle(DSNode *n = 0) : N(0) { operator=(n); }
DSNodeHandle(const DSNodeHandle &H) : N(0) { operator=(H.N); }
~DSNodeHandle() { operator=(0); }
DSNodeHandle &operator=(const DSNodeHandle &H) {operator=(H.N); return *this;}
// Assignment of DSNode*, implement all of the add/un'refing (defined later)
inline DSNodeHandle &operator=(DSNode *n);
// Allow automatic, implicit, conversion to DSNode*
operator DSNode*() { return N; }
operator const DSNode*() const { return N; }
operator const DSNode*() { return N; }
operator bool() const { return N != 0; }
operator bool() { return N != 0; }
bool operator<(const DSNodeHandle &H) const { // Allow sorting
return N < H.N;
}
bool operator==(const DSNodeHandle &H) const { return N == H.N; }
bool operator!=(const DSNodeHandle &H) const { return N != H.N; }
bool operator==(const DSNode *Node) const { return N == Node; }
bool operator!=(const DSNode *Node) const { return N != Node; }
bool operator==(DSNode *Node) const { return N == Node; }
bool operator!=(DSNode *Node) const { return N != Node; }
// Avoid having comparisons to null cause errors...
bool operator==(int X) const {
assert(X == 0 && "Bad comparison!");
return operator==((DSNode*)0);
}
bool operator!=(int X) const { return !operator==(X); }
// Allow explicit conversion to DSNode...
DSNode *get() { return N; }
const DSNode *get() const { return N; }
// Allow this to be treated like a pointer...
DSNode *operator->() { return N; }
const DSNode *operator->() const { return N; }
};
//===----------------------------------------------------------------------===//
// DSNode - Data structure node class
//
// This class keeps track of a node's type, and the fields in the data
// structure.
//
//
class DSNode {
const Type *Ty;
std::vector<DSNodeHandle> Links;
std::vector<DSNodeHandle*> Referrers;
// Globals - The list of global values that are merged into this node.
std::vector<GlobalValue*> Globals;
void operator=(const DSNode &); // DO NOT IMPLEMENT
public:
enum NodeTy {
ShadowNode = 0, // Nothing is known about this node...
ScalarNode = 1 << 0, // Scalar of the current function contains this value
AllocaNode = 1 << 1, // This node was allocated with alloca
NewNode = 1 << 2, // This node was allocated with malloc
GlobalNode = 1 << 3, // This node was allocated by a global var decl
SubElement = 1 << 4, // This node is a part of some other node
CastNode = 1 << 5, // This node is accessed in unsafe ways
Incomplete = 1 << 6, // This node may not be complete
};
// 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. Scalar and Alloca markers go away
// when function graphs are inlined.
//
unsigned char NodeType;
DSNode(enum NodeTy NT, const Type *T);
DSNode(const DSNode &);
~DSNode() {
#ifndef NDEBUG
dropAllReferences(); // Only needed to satisfy assertion checks...
#endif
assert(Referrers.empty() && "Referrers to dead node exist!");
}
// Iterator for graph interface...
typedef DSNodeIterator iterator;
inline iterator begin(); // Defined in DataStructureGraph.h
inline iterator end();
// Accessors
const Type *getType() const { return Ty; }
unsigned getNumLinks() const { return Links.size(); }
DSNode *getLink(unsigned i) {
assert(i < getNumLinks() && "Field links access out of range...");
return Links[i];
}
const DSNode *getLink(unsigned i) const {
assert(i < getNumLinks() && "Field links access out of range...");
return Links[i];
}
void setLink(unsigned i, DSNode *N) {
assert(i < getNumLinks() && "Field links access out of range...");
Links[i] = N;
}
// 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);
const std::vector<GlobalValue*> &getGlobals() const { return Globals; }
std::vector<GlobalValue*> &getGlobals() { return Globals; }
// addEdgeTo - Add an edge from the current node to the specified node. This
// can cause merging of nodes in the graph.
//
void addEdgeTo(unsigned LinkNo, DSNode *N);
void addEdgeTo(DSNode *N) {
assert(getNumLinks() == 1 && "Must specify a field number to add edge if "
" more than one field exists!");
addEdgeTo(0, N);
}
// mergeWith - Merge this node into the specified node, moving all links to
// and from the argument node into the current node. The specified node may
// be a null pointer (in which case, nothing happens).
//
void mergeWith(DSNode *N);
// addReferrer - Keep the referrer set up to date...
void addReferrer(DSNodeHandle *H) { Referrers.push_back(H); }
void removeReferrer(DSNodeHandle *H);
const std::vector<DSNodeHandle*> &getReferrers() const { return Referrers; }
void print(std::ostream &O, const DSGraph *G) const;
void dump() const;
std::string getCaption(const DSGraph *G) const;
void dropAllReferences() {
Links.clear();
}
};
inline DSNodeHandle &DSNodeHandle::operator=(DSNode *n) {
if (N) N->removeReferrer(this);
N = n;
if (N) N->addReferrer(this);
return *this;
}
// DSGraph - The graph that represents a function.
//
class DSGraph {
friend class GlobalDSGraph;
protected:
Function &Func;
std::vector<DSNode*> Nodes;
DSNodeHandle RetNode; // Node that gets returned...
std::map<Value*, DSNodeHandle> ValueMap;
// GlobalsGraph -- Reference to the common graph of globally visible objects.
// This includes GlobalValues, New nodes, Cast nodes, and Calls.
//
GlobalDSGraph* GlobalsGraph;
// FunctionCalls - This vector maintains a single entry for each call
// instruction in the current graph. Each call entry contains DSNodeHandles
// that refer to the arguments that are passed into the function call. The
// first entry in the vector is the scalar that holds the return value for the
// call, the second is the function scalar being invoked, and the rest are
// pointer arguments to the function.
//
std::vector<std::vector<DSNodeHandle> > FunctionCalls;
// OrigFunctionCalls - This vector retains a copy of the original function
// calls of the current graph. This is needed to support top-down inlining
// after bottom-up inlining is complete, since the latter deletes call nodes.
//
std::vector<std::vector<DSNodeHandle> > OrigFunctionCalls;
// PendingCallers - This vector records all unresolved callers of the
// current function, i.e., ones whose graphs have not been inlined into
// the current graph. As long as there are unresolved callers, the nodes
// for formal arguments in the current graph cannot be eliminated, and
// nodes in the graph reachable from the formal argument nodes or
// global variable nodes must be considered incomplete.
std::set<Function*> PendingCallers;
protected:
// Define the interface only accessable to DataStructure
friend class LocalDataStructures;
friend class BUDataStructures;
friend class TDDataStructures;
DSGraph(Function &F, GlobalDSGraph* GlobalsG); // Compute the local DSGraph
DSGraph(const DSGraph &DSG); // Copy ctor
virtual ~DSGraph();
// clone all the call nodes and save the copies in OrigFunctionCalls
void saveOrigFunctionCalls() {
assert(OrigFunctionCalls.size() == 0 && "Do this only once!");
OrigFunctionCalls = FunctionCalls;
}
// get the saved copies of the original function call nodes
std::vector<std::vector<DSNodeHandle> > &getOrigFunctionCalls() {
return OrigFunctionCalls;
}
void operator=(const DSGraph &); // DO NOT IMPLEMENT
public:
Function &getFunction() const { return Func; }
// getNodes - Get a vector of all the nodes in the graph
//
const std::vector<DSNode*>& getNodes() const { return Nodes; }
std::vector<DSNode*>& getNodes() { return Nodes; }
// getValueMap - Get a map that describes what the nodes the scalars in this
// function point to...
//
std::map<Value*, DSNodeHandle> &getValueMap() { return ValueMap; }
const std::map<Value*, DSNodeHandle> &getValueMap() const { return ValueMap;}
std::vector<std::vector<DSNodeHandle> > &getFunctionCalls() {
return FunctionCalls;
}
const std::vector<std::vector<DSNodeHandle> > &getFunctionCalls() const {
return FunctionCalls;
}
const DSNode *getRetNode() const { return RetNode; }
DSNode *getRetNode() { return RetNode; }
unsigned getGraphSize() const {
return Nodes.size();
}
void print(std::ostream &O) const;
void dump() const;
// maskNodeTypes - Apply a mask to all of the node types in the graph. This
// is useful for clearing out markers like Scalar or Incomplete.
//
void maskNodeTypes(unsigned char Mask);
void maskIncompleteMarkers() { maskNodeTypes(~DSNode::Incomplete); }
// markIncompleteNodes - Traverse the graph, identifying nodes that may be
// modified by other functions that have not been resolved yet. This marks
// nodes that are reachable through three sources of "unknownness":
// Global Variables, Function Calls, and Incoming Arguments
//
// For any node that may have unknown components (because something outside
// the scope of current analysis may have modified it), the 'Incomplete' flag
// is added to the NodeType.
//
void markIncompleteNodes(bool markFormalArgs = true);
// removeTriviallyDeadNodes - After the graph has been constructed, this
// method removes all unreachable nodes that are created because they got
// merged with other nodes in the graph.
//
void removeTriviallyDeadNodes(bool KeepAllGlobals = false);
// removeDeadNodes - Use a more powerful reachability analysis to eliminate
// subgraphs that are unreachable. This often occurs because the data
// structure doesn't "escape" into it's caller, and thus should be eliminated
// from the caller's graph entirely. This is only appropriate to use when
// inlining graphs.
//
void removeDeadNodes(bool KeepAllGlobals = false, bool KeepCalls = true);
// AddCaller - add a known caller node into the graph and mark it pending.
// getCallers - get a vector of the functions that call this one
// getCallersPending - get a matching vector of bools indicating if each
// caller's DSGraph has been resolved into this one.
//
void addCaller(Function& caller) {
PendingCallers.insert(&caller);
}
std::set<Function*>& getPendingCallers() {
return PendingCallers;
}
// cloneInto - Clone the specified DSGraph into the current graph, returning
// the Return node of the graph. The translated ValueMap for the old function
// is filled into the OldValMap member.
// If StripScalars (StripAllocas) is set to true, Scalar (Alloca) markers
// are removed from the graph as the graph is being cloned.
// If CopyCallers is set to true, the PendingCallers list is copied.
// If CopyOrigCalls is set to true, the OrigFunctionCalls list is copied.
//
DSNode *cloneInto(const DSGraph &G, std::map<Value*, DSNodeHandle> &OldValMap,
std::map<const DSNode*, DSNode*>& OldNodeMap,
bool StripScalars = false, bool StripAllocas = false,
bool CopyCallers = true, bool CopyOrigCalls = true);
// cloneGlobalInto - Clone the given global node (or the node for the given
// GlobalValue) from the GlobalsGraph and all its target links (recursively).
//
DSNode* cloneGlobalInto(const DSNode* GNode);
DSNode* cloneGlobalInto(GlobalValue* GV) {
assert(!GV || (((DSGraph*) GlobalsGraph)->ValueMap[GV] != 0));
return GV? cloneGlobalInto(((DSGraph*) GlobalsGraph)->ValueMap[GV]) : 0;
}
private:
bool isNodeDead(DSNode *N);
};
// GlobalDSGraph - A common graph for all the globals and their outgoing links
// to externally visible nodes. This includes GlobalValues, New nodes,
// Cast nodes, and Calls. This graph can only be used by one of the
// individual function graphs, and it goes away when they all go away.
//
class GlobalDSGraph : public DSGraph {
hash_set<const DSGraph*> Referrers;
void addReference(const DSGraph* referrer);
void removeReference(const DSGraph* referrer);
friend class DSGraph; // give access to Referrers
GlobalDSGraph(const GlobalDSGraph &GlobalDSG); // Do not implement
// Helper function for cloneGlobals and cloneCalls
DSNode* cloneNodeInto(DSNode *OldNode,
std::map<const DSNode*, DSNode*> &NodeCache,
bool GlobalsAreFinal = false);
public:
GlobalDSGraph(); // Create an empty DSGraph
virtual ~GlobalDSGraph();
void cloneGlobals(DSGraph& Graph, bool CloneCalls = false);
void cloneCalls (DSGraph& Graph);
};
// LocalDataStructures - The analysis that computes the local data structure
// graphs for all of the functions in the program.
//
// FIXME: This should be a Function pass that can be USED by a Pass, and would
// be automatically preserved. Until we can do that, this is a Pass.
//
class LocalDataStructures : public Pass {
// DSInfo, one graph for each function
std::map<const Function*, DSGraph*> DSInfo;
public:
~LocalDataStructures() { releaseMemory(); }
virtual bool run(Module &M);
// getDSGraph - Return the data structure graph for the specified function.
DSGraph &getDSGraph(const Function &F) const {
std::map<const Function*, DSGraph*>::const_iterator I = DSInfo.find(&F);
assert(I != DSInfo.end() && "Function not in module!");
return *I->second;
}
// print - Print out the analysis results...
void print(std::ostream &O, const Module *M) const;
// If the pass pipeline is done with this pass, we can release our memory...
virtual void releaseMemory();
// getAnalysisUsage - This obviously provides a data structure graph.
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
}
};
// BUDataStructures - The analysis that computes the interprocedurally closed
// data structure graphs for all of the functions in the program. This pass
// only performs a "Bottom Up" propogation (hence the name).
//
class BUDataStructures : public Pass {
// DSInfo, one graph for each function
std::map<const Function*, DSGraph*> DSInfo;
public:
~BUDataStructures() { releaseMemory(); }
virtual bool run(Module &M);
// getDSGraph - Return the data structure graph for the specified function.
DSGraph &getDSGraph(const Function &F) const {
std::map<const Function*, DSGraph*>::const_iterator I = DSInfo.find(&F);
assert(I != DSInfo.end() && "Function not in module!");
return *I->second;
}
// print - Print out the analysis results...
void print(std::ostream &O, const Module *M) const;
// If the pass pipeline is done with this pass, we can release our memory...
virtual void releaseMemory();
// getAnalysisUsage - This obviously provides a data structure graph.
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
AU.addRequired<LocalDataStructures>();
}
private:
DSGraph &calculateGraph(Function &F);
};
// TDDataStructures - Analysis that computes new data structure graphs
// for each function using the closed graphs for the callers computed
// by the bottom-up pass.
//
class TDDataStructures : public Pass {
// DSInfo, one graph for each function
std::map<const Function*, DSGraph*> DSInfo;
public:
~TDDataStructures() { releaseMemory(); }
virtual bool run(Module &M);
// getDSGraph - Return the data structure graph for the specified function.
DSGraph &getDSGraph(const Function &F) const {
std::map<const Function*, DSGraph*>::const_iterator I = DSInfo.find(&F);
assert(I != DSInfo.end() && "Function not in module!");
return *I->second;
}
// print - Print out the analysis results...
void print(std::ostream &O, const Module *M) const;
// If the pass pipeline is done with this pass, we can release our memory...
virtual void releaseMemory();
// getAnalysisUsage - This obviously provides a data structure graph.
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
AU.addRequired<BUDataStructures>();
}
private:
DSGraph &calculateGraph(Function &F);
void pushGraphIntoCallee(DSGraph &callerGraph, DSGraph &calleeGraph,
std::map<Value*, DSNodeHandle> &OldValMap,
std::map<const DSNode*, DSNode*> &OldNodeMap);
};
#endif