llvm-6502/include/llvm/CFG.h
Chris Lattner bd8364aed7 * Add assertions
* Add a nodeVisited method to the DF interator


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362 91177308-0d34-0410-b5e6-96231b3b80d8
2001-08-23 17:05:59 +00:00

457 lines
14 KiB
C++

//===-- llvm/CFG.h - CFG definitions and useful classes ----------*- C++ -*--=//
//
// This file contains the class definitions useful for operating on the control
// flow graph.
//
// Currently it contains functionality for these three applications:
//
// 1. Iterate over the predecessors of a basic block:
// pred_iterator, pred_const_iterator, pred_begin, pred_end
// 2. Iterate over the successors of a basic block:
// succ_iterator, succ_const_iterator, succ_begin, succ_end
// 3. Iterate over the basic blocks of a method in depth first ordering or
// reverse depth first order. df_iterator, df_const_iterator,
// df_begin, df_end. df_begin takes an arg to specify reverse or not.
// 4. Iterator over the basic blocks of a method in post order.
// 5. Iterator over a method in reverse post order.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CFG_H
#define LLVM_CFG_H
#include "llvm/CFGdecls.h" // See this file for concise interface info
#include <set>
#include <stack>
#include <iterator>
#include "llvm/Method.h"
#include "llvm/BasicBlock.h"
#include "llvm/InstrTypes.h"
namespace cfg {
//===----------------------------------------------------------------------===//
// Implementation
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
// Basic Block Predecessor Iterator
//
template <class _Ptr, class _USE_iterator> // Predecessor Iterator
class PredIterator : public std::bidirectional_iterator<_Ptr, ptrdiff_t> {
_Ptr *BB;
_USE_iterator It;
public:
typedef PredIterator<_Ptr,_USE_iterator> _Self;
inline void advancePastConstPool() {
// TODO: This is bad
// Loop to ignore constant pool references
while (It != BB->use_end() &&
((!(*It)->isInstruction()) ||
!(((Instruction*)(*It))->isTerminator())))
++It;
}
inline PredIterator(_Ptr *bb) : BB(bb), It(bb->use_begin()) {
advancePastConstPool();
}
inline PredIterator(_Ptr *bb, bool) : BB(bb), It(bb->use_end()) {}
inline bool operator==(const _Self& x) const { return It == x.It; }
inline bool operator!=(const _Self& x) const { return !operator==(x); }
inline pointer operator*() const {
return (*It)->castInstructionAsserting()->getParent();
}
inline pointer *operator->() const { return &(operator*()); }
inline _Self& operator++() { // Preincrement
++It; advancePastConstPool();
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;
}
};
inline pred_iterator pred_begin( BasicBlock *BB) {
return pred_iterator(BB);
}
inline pred_const_iterator pred_begin(const BasicBlock *BB) {
return pred_const_iterator(BB);
}
inline pred_iterator pred_end( BasicBlock *BB) {
return pred_iterator(BB,true);
}
inline pred_const_iterator pred_end(const BasicBlock *BB) {
return pred_const_iterator(BB,true);
}
//===----------------------------------------------------------------------===//
// Basic Block Successor Iterator
//
template <class _Term, class _BB> // Successor Iterator
class SuccIterator : public std::bidirectional_iterator<_BB, ptrdiff_t> {
const _Term Term;
unsigned idx;
public:
typedef SuccIterator<_Term, _BB> _Self;
// TODO: This can be random access iterator, need operator+ and stuff tho
inline SuccIterator(_Term T) : Term(T), idx(0) { // begin iterator
assert(T && "getTerminator returned null!");
}
inline SuccIterator(_Term T, bool) // end iterator
: Term(T), idx(Term->getNumSuccessors()) {
assert(T && "getTerminator returned null!");
}
inline bool operator==(const _Self& x) const { return idx == x.idx; }
inline bool operator!=(const _Self& x) const { return !operator==(x); }
inline pointer operator*() const { return Term->getSuccessor(idx); }
inline pointer operator->() const { return operator*(); }
inline _Self& operator++() { ++idx; return *this; } // Preincrement
inline _Self operator++(int) { // Postincrement
_Self tmp = *this; ++*this; return tmp;
}
inline _Self& operator--() { --idx; return *this; } // Predecrement
inline _Self operator--(int) { // Postdecrement
_Self tmp = *this; --*this; return tmp;
}
};
inline succ_iterator succ_begin( BasicBlock *BB) {
return succ_iterator(BB->getTerminator());
}
inline succ_const_iterator succ_begin(const BasicBlock *BB) {
return succ_const_iterator(BB->getTerminator());
}
inline succ_iterator succ_end( BasicBlock *BB) {
return succ_iterator(BB->getTerminator(),true);
}
inline succ_const_iterator succ_end(const BasicBlock *BB) {
return succ_const_iterator(BB->getTerminator(),true);
}
//===----------------------------------------------------------------------===//
// Graph Type Declarations
//
// BasicBlockGraph - Represent a standard traversal of a CFG
// ConstBasicBlockGraph - Represent a standard traversal of a const CFG
// InverseBasicBlockGraph - Represent a inverse traversal of a CFG
// ConstInverseBasicBlockGraph - Represent a inverse traversal of a const CFG
//
// An Inverse traversal of a graph is where we chase predecessors, instead of
// successors.
//
struct BasicBlockGraph {
typedef BasicBlock NodeType;
typedef succ_iterator ChildIteratorType;
static inline ChildIteratorType child_begin(NodeType *N) {
return succ_begin(N);
}
static inline ChildIteratorType child_end(NodeType *N) {
return succ_end(N);
}
};
struct ConstBasicBlockGraph {
typedef const BasicBlock NodeType;
typedef succ_const_iterator ChildIteratorType;
static inline ChildIteratorType child_begin(NodeType *N) {
return succ_begin(N);
}
static inline ChildIteratorType child_end(NodeType *N) {
return succ_end(N);
}
};
struct InverseBasicBlockGraph {
typedef BasicBlock NodeType;
typedef pred_iterator ChildIteratorType;
static inline ChildIteratorType child_begin(NodeType *N) {
return pred_begin(N);
}
static inline ChildIteratorType child_end(NodeType *N) {
return pred_end(N);
}
};
struct ConstInverseBasicBlockGraph {
typedef const BasicBlock NodeType;
typedef pred_const_iterator ChildIteratorType;
static inline ChildIteratorType child_begin(NodeType *N) {
return pred_begin(N);
}
static inline ChildIteratorType child_end(NodeType *N) {
return pred_end(N);
}
};
//===----------------------------------------------------------------------===//
// Depth First Iterator
//
// Generic Depth First Iterator
template<class GI>
class DFIterator : public std::forward_iterator<typename GI::NodeType,
ptrdiff_t> {
typedef typename GI::NodeType NodeType;
typedef typename GI::ChildIteratorType ChildItTy;
set<NodeType *> Visited; // All of the blocks visited so far...
// VisitStack - Used to maintain the ordering. Top = current block
// First element is node pointer, second is the 'next child' to visit
stack<pair<NodeType *, ChildItTy> > VisitStack;
const bool Reverse; // Iterate over children before self?
private:
void reverseEnterNode() {
pair<NodeType *, ChildItTy> &Top = VisitStack.top();
NodeType *Node = Top.first;
ChildItTy &It = Top.second;
for (; It != GI::child_end(Node); ++It) {
NodeType *Child = *It;
if (!Visited.count(Child)) {
Visited.insert(Child);
VisitStack.push(make_pair(Child, GI::child_begin(Child)));
reverseEnterNode();
return;
}
}
}
public:
typedef DFIterator<GI> _Self;
inline DFIterator(NodeType *Node, bool reverse) : Reverse(reverse) {
Visited.insert(Node);
VisitStack.push(make_pair(Node, GI::child_begin(Node)));
if (Reverse) reverseEnterNode();
}
inline DFIterator() { /* End is when stack is empty */ }
inline bool operator==(const _Self& x) const {
return VisitStack == x.VisitStack;
}
inline bool operator!=(const _Self& x) const { return !operator==(x); }
inline pointer operator*() const {
return VisitStack.top().first;
}
// This is a nonstandard operator-> that dereferences the pointer an extra
// time... so that you can actually call methods ON the Node, because
// the contained type is a pointer. This allows BBIt->getTerminator() f.e.
//
inline NodeType *operator->() const { return operator*(); }
inline _Self& operator++() { // Preincrement
if (Reverse) { // Reverse Depth First Iterator
if (VisitStack.top().second == GI::child_end(VisitStack.top().first))
VisitStack.pop();
if (!VisitStack.empty())
reverseEnterNode();
} else { // Normal Depth First Iterator
do {
pair<NodeType *, ChildItTy> &Top = VisitStack.top();
NodeType *Node = Top.first;
ChildItTy &It = Top.second;
while (It != GI::child_end(Node)) {
NodeType *Next = *It++;
if (!Visited.count(Next)) { // Has our next sibling been visited?
// No, do it now.
Visited.insert(Next);
VisitStack.push(make_pair(Next, GI::child_begin(Next)));
return *this;
}
}
// Oops, ran out of successors... go up a level on the stack.
VisitStack.pop();
} while (!VisitStack.empty());
}
return *this;
}
inline _Self operator++(int) { // Postincrement
_Self tmp = *this; ++*this; return tmp;
}
// nodeVisited - return true if this iterator has already visited the
// specified node. This is public, and will probably be used to iterate over
// nodes that a depth first iteration did not find: ie unreachable nodes.
//
inline bool nodeVisited(NodeType *Node) const {
return Visited.count(Node) != 0;
}
};
inline df_iterator df_begin(Method *M, bool Reverse = false) {
return df_iterator(M->front(), Reverse);
}
inline df_const_iterator df_begin(const Method *M, bool Reverse = false) {
return df_const_iterator(M->front(), Reverse);
}
inline df_iterator df_end(Method*) {
return df_iterator();
}
inline df_const_iterator df_end(const Method*) {
return df_const_iterator();
}
inline df_iterator df_begin(BasicBlock *BB, bool Reverse = false) {
return df_iterator(BB, Reverse);
}
inline df_const_iterator df_begin(const BasicBlock *BB, bool Reverse = false) {
return df_const_iterator(BB, Reverse);
}
inline df_iterator df_end(BasicBlock*) {
return df_iterator();
}
inline df_const_iterator df_end(const BasicBlock*) {
return df_const_iterator();
}
inline idf_iterator idf_begin(BasicBlock *BB, bool Reverse = false) {
return idf_iterator(BB, Reverse);
}
inline idf_const_iterator idf_begin(const BasicBlock *BB, bool Reverse = false) {
return idf_const_iterator(BB, Reverse);
}
inline idf_iterator idf_end(BasicBlock*) {
return idf_iterator();
}
inline idf_const_iterator idf_end(const BasicBlock*) {
return idf_const_iterator();
}
//===----------------------------------------------------------------------===//
// Post Order CFG iterator code
//
template<class BBType, class SuccItTy>
class POIterator : public std::forward_iterator<BBType, ptrdiff_t> {
set<BBType *> Visited; // All of the blocks visited so far...
// VisitStack - Used to maintain the ordering. Top = current block
// First element is basic block pointer, second is the 'next child' to visit
stack<pair<BBType *, SuccItTy> > VisitStack;
void traverseChild() {
while (VisitStack.top().second != succ_end(VisitStack.top().first)) {
BBType *BB = *VisitStack.top().second++;
if (!Visited.count(BB)) { // If the block is not visited...
Visited.insert(BB);
VisitStack.push(make_pair(BB, succ_begin(BB)));
}
}
}
public:
typedef POIterator<BBType, SuccItTy> _Self;
inline POIterator(BBType *BB) {
Visited.insert(BB);
VisitStack.push(make_pair(BB, succ_begin(BB)));
traverseChild();
}
inline POIterator() { /* End is when stack is empty */ }
inline bool operator==(const _Self& x) const {
return VisitStack == x.VisitStack;
}
inline bool operator!=(const _Self& x) const { return !operator==(x); }
inline pointer operator*() const {
return VisitStack.top().first;
}
// This is a nonstandard operator-> that dereferences the pointer an extra
// time... so that you can actually call methods ON the BasicBlock, because
// the contained type is a pointer. This allows BBIt->getTerminator() f.e.
//
inline BBType *operator->() const { return operator*(); }
inline _Self& operator++() { // Preincrement
VisitStack.pop();
if (!VisitStack.empty())
traverseChild();
return *this;
}
inline _Self operator++(int) { // Postincrement
_Self tmp = *this; ++*this; return tmp;
}
};
inline po_iterator po_begin( Method *M) {
return po_iterator(M->front());
}
inline po_const_iterator po_begin(const Method *M) {
return po_const_iterator(M->front());
}
inline po_iterator po_end ( Method *M) {
return po_iterator();
}
inline po_const_iterator po_end (const Method *M) {
return po_const_iterator();
}
inline po_iterator po_begin( BasicBlock *BB) {
return po_iterator(BB);
}
inline po_const_iterator po_begin(const BasicBlock *BB) {
return po_const_iterator(BB);
}
inline po_iterator po_end ( BasicBlock *BB) {
return po_iterator();
}
inline po_const_iterator po_end (const BasicBlock *BB) {
return po_const_iterator();
}
//===----------------------------------------------------------------------===//
// Reverse Post Order CFG iterator code
//
class ReversePostOrderTraversal {
vector<BasicBlock*> Blocks; // Block list in normal PO order
inline void Initialize(BasicBlock *BB) {
copy(po_begin(BB), po_end(BB), back_inserter(Blocks));
}
public:
inline ReversePostOrderTraversal(Method *M) {
Initialize(M->front());
}
inline ReversePostOrderTraversal(BasicBlock *BB) {
Initialize(BB);
}
// Because we want a reverse post order, use reverse iterators from the vector
inline rpo_iterator begin() { return Blocks.rbegin(); }
inline rpo_iterator end() { return Blocks.rend(); }
};
} // End namespace cfg
#endif