From 18c9f915f2dbaeb64f19c862dcbf645fae76740c Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Fri, 6 Jul 2001 16:56:17 +0000 Subject: [PATCH] * Added comments * Made iterators inherit from appropriate iterator base class * Abstracted out graphs from depth first iterator * Add "Inverse" traversal of CFG git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/CFG.h | 166 ++++++++++++++++++++++++++-------------- include/llvm/CFGdecls.h | 32 ++++++-- 2 files changed, 133 insertions(+), 65 deletions(-) diff --git a/include/llvm/CFG.h b/include/llvm/CFG.h index 5f207b5cfe9..73fbc164539 100644 --- a/include/llvm/CFG.h +++ b/include/llvm/CFG.h @@ -12,24 +12,22 @@ // 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 #include +#include #include "llvm/Method.h" #include "llvm/BasicBlock.h" #include "llvm/InstrTypes.h" -//===----------------------------------------------------------------------===// -// Interface -//===----------------------------------------------------------------------===// - -#include "llvm/CFGdecls.h" // See this file for concise interface info - namespace cfg { //===----------------------------------------------------------------------===// @@ -41,19 +39,14 @@ namespace cfg { // template // Predecessor Iterator -class PredIterator { - const _Ptr BB; +class PredIterator : public std::bidirectional_iterator<_Ptr, ptrdiff_t> { + _Ptr *BB; _USE_iterator It; public: typedef PredIterator<_Ptr,_USE_iterator> _Self; - typedef bidirectional_iterator_tag iterator_category; - typedef _Ptr &reference; - typedef unsigned difference_type; - typedef _Ptr value_type; - typedef _Ptr pointer; - inline void advancePastConstPool() { + // TODO: This is bad // Loop to ignore constant pool references while (It != BB->use_end() && ((!(*It)->isInstruction()) || @@ -61,10 +54,10 @@ public: ++It; } - inline PredIterator(_Ptr bb) : BB(bb), It(bb->use_begin()) { + inline PredIterator(_Ptr *bb) : BB(bb), It(bb->use_begin()) { advancePastConstPool(); } - inline PredIterator(_Ptr bb, bool) : BB(bb), It(bb->use_end()) {} + 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); } @@ -108,17 +101,12 @@ inline pred_const_iterator pred_end(const BasicBlock *BB) { // template // Successor Iterator -class SuccIterator { +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 - typedef bidirectional_iterator_tag iterator_category; - typedef _BB &reference; - typedef unsigned difference_type; - typedef _BB value_type; - typedef _BB pointer; inline SuccIterator(_Term T) : Term(T), idx(0) {} // begin iterator inline SuccIterator(_Term T, bool) @@ -128,7 +116,7 @@ public: 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 pointer operator->() const { return operator*(); } inline _Self& operator++() { ++idx; return *this; } // Preincrement inline _Self operator++(int) { // Postincrement @@ -155,44 +143,99 @@ inline succ_const_iterator succ_end(const BasicBlock *BB) { } +//===----------------------------------------------------------------------===// +// 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 // -template -class DFIterator { // BasicBlock Depth First Iterator - set Visited; // All of the blocks visited so far... +// BasicBlock Depth First Iterator +template +class DFIterator : public std::forward_iterator { + typedef typename GI::NodeType NodeType; + typedef typename GI::ChildIteratorType ChildItTy; + + set 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 > VisitStack; + stack > VisitStack; const bool Reverse; // Iterate over children before self? private: void reverseEnterNode() { - pair &Top = VisitStack.top(); - BBType *BB = Top.first; - SuccItTy &It = Top.second; - for (; It != succ_end(BB); ++It) { - BBType *Child = *It; + pair &Top = VisitStack.top(); + NodeType *BB = Top.first; + ChildItTy &It = Top.second; + for (; It != GI::child_end(BB); ++It) { + NodeType *Child = *It; if (!Visited.count(Child)) { Visited.insert(Child); - VisitStack.push(make_pair(Child, succ_begin(Child))); + VisitStack.push(make_pair(Child, GI::child_begin(Child))); reverseEnterNode(); return; } } } public: - typedef DFIterator _Self; + typedef DFIterator _Self; - typedef forward_iterator_tag iterator_category; - typedef BBType *pointer; - typedef BBType &reference; - typedef void difference_type; - typedef BBType *value_type; - - inline DFIterator(BBType *BB, bool reverse) : Reverse(reverse) { + inline DFIterator(NodeType *BB, bool reverse) : Reverse(reverse) { Visited.insert(BB); - VisitStack.push(make_pair(BB, succ_begin(BB))); + VisitStack.push(make_pair(BB, GI::child_begin(BB))); if (Reverse) reverseEnterNode(); } inline DFIterator() { /* End is when stack is empty */ } @@ -210,26 +253,26 @@ public: // 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 NodeType *operator->() const { return operator*(); } inline _Self& operator++() { // Preincrement if (Reverse) { // Reverse Depth First Iterator - if (VisitStack.top().second == succ_end(VisitStack.top().first)) + if (VisitStack.top().second == GI::child_end(VisitStack.top().first)) VisitStack.pop(); if (!VisitStack.empty()) reverseEnterNode(); } else { // Normal Depth First Iterator do { - pair &Top = VisitStack.top(); - BBType *BB = Top.first; - SuccItTy &It = Top.second; + pair &Top = VisitStack.top(); + NodeType *BB = Top.first; + ChildItTy &It = Top.second; - while (It != succ_end(BB)) { - BBType *Next = *It++; + while (It != GI::child_end(BB)) { + 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, succ_begin(Next))); + VisitStack.push(make_pair(Next, GI::child_begin(Next))); return *this; } } @@ -275,12 +318,27 @@ inline df_const_iterator df_end(const BasicBlock*) { } + +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 POIterator { +class POIterator : public std::forward_iterator { set 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 @@ -298,12 +356,6 @@ class POIterator { public: typedef POIterator _Self; - typedef forward_iterator_tag iterator_category; - typedef BBType *pointer; - typedef BBType &reference; - typedef void difference_type; - typedef BBType *value_type; - inline POIterator(BBType *BB) { Visited.insert(BB); VisitStack.push(make_pair(BB, succ_begin(BB))); diff --git a/include/llvm/CFGdecls.h b/include/llvm/CFGdecls.h index 32007d89f6f..8d4152fea0a 100644 --- a/include/llvm/CFGdecls.h +++ b/include/llvm/CFGdecls.h @@ -31,8 +31,8 @@ namespace cfg { // Forward declare iterator class template... template class PredIterator; -typedef PredIterator pred_iterator; -typedef PredIterator pred_iterator; +typedef PredIterator pred_const_iterator; inline pred_iterator pred_begin( BasicBlock *BB); @@ -51,9 +51,9 @@ inline pred_const_iterator pred_end (const BasicBlock *BB); // Forward declare iterator class template... template class SuccIterator; -typedef SuccIterator succ_iterator; +typedef SuccIterator succ_iterator; typedef SuccIterator succ_const_iterator; + const BasicBlock> succ_const_iterator; inline succ_iterator succ_begin( BasicBlock *BB); inline succ_const_iterator succ_begin(const BasicBlock *BB); @@ -69,13 +69,17 @@ inline succ_const_iterator succ_end (const BasicBlock *BB); // reverse depth first ordering, depending on the value passed to the df_begin // method. // +struct BasicBlockGraph; +struct ConstBasicBlockGraph; +struct InverseBasicBlockGraph; +struct ConstInverseBasicBlockGraph; // Forward declare iterator class template... -template class DFIterator; +template class DFIterator; -typedef DFIterator df_iterator; -typedef DFIterator df_const_iterator; +// Normal Depth First Iterator Definitions (Forward and Reverse) +typedef DFIterator< BasicBlockGraph> df_iterator; +typedef DFIterator df_const_iterator; inline df_iterator df_begin( Method *M, bool Reverse = false); inline df_const_iterator df_begin(const Method *M, bool Reverse = false); @@ -88,6 +92,18 @@ inline df_iterator df_end ( BasicBlock *BB); inline df_const_iterator df_end (const BasicBlock *BB); +// Inverse Depth First Iterator Definitions (Forward and Reverse) - Traverse +// predecessors instead of successors... +// +typedef DFIterator< InverseBasicBlockGraph> idf_iterator; +typedef DFIterator idf_const_iterator; + +inline idf_iterator idf_begin( BasicBlock *BB, bool Reverse = false); +inline idf_const_iterator idf_begin(const BasicBlock *BB, bool Reverse = false); +inline idf_iterator idf_end ( BasicBlock *BB); +inline idf_const_iterator idf_end (const BasicBlock *BB); + + //===--------------------------------------------------------------------===// // Post Order CFG iterator code //===--------------------------------------------------------------------===//