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| -rw-r--r-- | include/llvm/Analysis/IntervalIterator.h | 223 | ||||
| -rw-r--r-- | include/llvm/Analysis/IntervalPartition.h | 123 |
2 files changed, 346 insertions, 0 deletions
diff --git a/include/llvm/Analysis/IntervalIterator.h b/include/llvm/Analysis/IntervalIterator.h new file mode 100644 index 0000000000..ec70c8782d --- /dev/null +++ b/include/llvm/Analysis/IntervalIterator.h @@ -0,0 +1,223 @@ +//===- IntervalIterator.h - Interval Iterator Declaration --------*- C++ -*--=// +// +// This file defines an iterator that enumerates the intervals in a control flow +// graph of some sort. This iterator is parametric, allowing iterator over the +// following types of graphs: +// +// TODO +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_INTERVAL_ITERATOR_H +#define LLVM_INTERVAL_ITERATOR_H + +#include "llvm/Analysis/IntervalPartition.h" +#include "llvm/Method.h" +#include "llvm/CFG.h" +#include <stack> +#include <set> +#include <algorithm> + +namespace cfg { + +// TODO: Provide an interval iterator that codifies the internals of +// IntervalPartition. Inside, it would have a stack of Interval*'s, and would +// walk the interval partition in depth first order. IntervalPartition would +// then be a client of this iterator. The iterator should work on Method*, +// const Method*, IntervalPartition*, and const IntervalPartition*. +// + + +// getNodeHeader - Given a source graph node and the source graph, return the +// BasicBlock that is the header node. This is the opposite of +// getSourceGraphNode. +// +inline BasicBlock *getNodeHeader(BasicBlock *BB) { return BB; } +inline BasicBlock *getNodeHeader(Interval *I) { return I->getHeaderNode(); } + +// getSourceGraphNode - Given a BasicBlock and the source graph, return the +// source graph node that corresponds to the BasicBlock. This is the opposite +// of getNodeHeader. +// +inline BasicBlock *getSourceGraphNode(Method *, BasicBlock *BB) { + return BB; +} +inline Interval *getSourceGraphNode(IntervalPartition *IP, BasicBlock *BB) { + return IP->getBlockInterval(BB); +} + +// addNodeToInterval - This method exists to assist the generic ProcessNode +// with the task of adding a node to the new interval, depending on the +// type of the source node. In the case of a CFG source graph (BasicBlock +// case), the BasicBlock itself is added to the interval. +// +inline void addNodeToInterval(Interval *Int, BasicBlock *BB){ + Int->Nodes.push_back(BB); +} + +// addNodeToInterval - This method exists to assist the generic ProcessNode +// with the task of adding a node to the new interval, depending on the +// type of the source node. In the case of a CFG source graph (BasicBlock +// case), the BasicBlock itself is added to the interval. In the case of +// an IntervalPartition source graph (Interval case), all of the member +// BasicBlocks are added to the interval. +// +inline void addNodeToInterval(Interval *Int, Interval *I) { + // Add all of the nodes in I as new nodes in Int. + copy(I->Nodes.begin(), I->Nodes.end(), back_inserter(Int->Nodes)); +} + + +template<class NodeTy, class OrigContainer_t> +class IntervalIterator { + stack<pair<Interval, typename Interval::succ_iterator> > IntStack; + set<BasicBlock*> Visited; + OrigContainer_t *OrigContainer; +public: + typedef BasicBlock* _BB; + + typedef IntervalIterator<NodeTy, OrigContainer_t> _Self; + typedef forward_iterator_tag iterator_category; + + IntervalIterator() {} // End iterator, empty stack + IntervalIterator(Method *M) { + OrigContainer = M; + if (!ProcessInterval(M->getBasicBlocks().front())) { + assert(0 && "ProcessInterval should never fail for first interval!"); + } + } + + IntervalIterator(IntervalPartition &IP) { + OrigContainer = &IP; + if (!ProcessInterval(IP.getRootInterval())) { + assert(0 && "ProcessInterval should never fail for first interval!"); + } + } + + inline bool operator==(const _Self& x) const { return IntStack == x.IntStack; } + inline bool operator!=(const _Self& x) const { return !operator==(x); } + + inline Interval &operator*() const { return IntStack.top(); } + inline Interval *operator->() const { return &(operator*()); } + + inline _Self& operator++() { // Preincrement + do { + // All of the intervals on the stack have been visited. Try visiting their + // successors now. + Interval &CurInt = IntStack.top().first; + Interval::iterator &SuccIt = IntStack.top().second,End = succ_end(&CurInt); + + for (; SuccIt != End; ++SuccIt) // Loop over all interval successors + if (ProcessInterval(*SuccIt)) // Found a new interval! + return *this; // Use it! + + // We ran out of successors for this interval... pop off the stack + IntStack.pop(); + } while (!IntStack.empty()); + + return *this; + } + inline _Self operator++(int) { // Postincrement + _Self tmp = *this; ++*this; return tmp; + } + +private: + // ProcessInterval - This method is used during the construction of the + // interval graph. It walks through the source graph, recursively creating + // an interval per invokation until the entire graph is covered. This uses + // the ProcessNode method to add all of the nodes to the interval. + // + // This method is templated because it may operate on two different source + // graphs: a basic block graph, or a preexisting interval graph. + // + bool ProcessInterval(NodeTy *Node) { + BasicBlock *Header = getNodeHeader(Node); + if (Visited.count(Header)) return false; + + Interval Int(Header); + Visited.insert(Header); // The header has now been visited! + + // Check all of our successors to see if they are in the interval... + for (typename NodeTy::succ_iterator I = succ_begin(Node), E = succ_end(Node); + I != E; ++I) + ProcessNode(&Int, getSourceGraphNode(OrigContainer, *I)); + + IntStack.push(make_pair(Int, succ_begin(&Int))); + return true; + } + + // ProcessNode - This method is called by ProcessInterval to add nodes to the + // interval being constructed, and it is also called recursively as it walks + // the source graph. A node is added to the current interval only if all of + // its predecessors are already in the graph. This also takes care of keeping + // the successor set of an interval up to date. + // + // This method is templated because it may operate on two different source + // graphs: a basic block graph, or a preexisting interval graph. + // + void ProcessNode(Interval *Int, NodeTy *Node) { + assert(Int && "Null interval == bad!"); + assert(Node && "Null Node == bad!"); + + BasicBlock *NodeHeader = getNodeHeader(Node); + + if (Visited.count(NodeHeader)) { // Node already been visited? + if (Int->contains(NodeHeader)) { // Already in this interval... + return; + } else { // In another interval, add as successor + if (!Int->isSuccessor(NodeHeader)) // Add only if not already in set + Int->Successors.push_back(NodeHeader); + } + } else { // Otherwise, not in interval yet + for (typename NodeTy::pred_iterator I = pred_begin(Node), + E = pred_end(Node); I != E; ++I) { + if (!Int->contains(*I)) { // If pred not in interval, we can't be + if (!Int->isSuccessor(NodeHeader)) // Add only if not already in set + Int->Successors.push_back(NodeHeader); + return; // See you later + } + } + + // If we get here, then all of the predecessors of BB are in the interval + // already. In this case, we must add BB to the interval! + addNodeToInterval(Int, Node); + Visited.insert(NodeHeader); // The node has now been visited! + + if (Int->isSuccessor(NodeHeader)) { + // If we were in the successor list from before... remove from succ list + Int->Successors.erase(remove(Int->Successors.begin(), + Int->Successors.end(), NodeHeader), + Int->Successors.end()); + } + + // Now that we have discovered that Node is in the interval, perhaps some + // of its successors are as well? + for (typename NodeTy::succ_iterator It = succ_begin(Node), + End = succ_end(Node); It != End; ++It) + ProcessNode(Int, getSourceGraphNode(OrigContainer, *It)); + } + } +}; + +typedef IntervalIterator<BasicBlock, Method> method_interval_iterator; +typedef IntervalIterator<Interval, IntervalPartition> interval_part_interval_iterator; + + +inline method_interval_iterator intervals_begin(Method *M) { + return method_interval_iterator(M); +} +inline method_interval_iterator intervals_end(Method *M) { + return method_interval_iterator(); +} + +inline interval_part_interval_iterator intervals_begin(IntervalPartition &IP) { + return interval_part_interval_iterator(IP); +} + +inline interval_part_interval_iterator intervals_end(IntervalPartition &IP) { + return interval_part_interval_iterator(); +} + +} // End namespace cfg + +#endif diff --git a/include/llvm/Analysis/IntervalPartition.h b/include/llvm/Analysis/IntervalPartition.h new file mode 100644 index 0000000000..fd24b2fb98 --- /dev/null +++ b/include/llvm/Analysis/IntervalPartition.h @@ -0,0 +1,123 @@ +//===- IntervalPartition.h - Interval partition Calculation ------*- C++ -*--=// +// +// This file contains the declaration of the cfg::IntervalPartition class, which +// calculates and represents the interval partition of a method, or a +// preexisting interval partition. +// +// In this way, the interval partition may be used to reduce a flow graph down +// to its degenerate single node interval partition (unless it is irreducible). +// +// TODO: The IntervalPartition class should take a bool parameter that tells +// whether it should add the "tails" of an interval to an interval itself or if +// they should be represented as distinct intervals. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_INTERVAL_PARTITION_H +#define LLVM_INTERVAL_PARTITION_H + +#include "llvm/Analysis/Interval.h" +#include <map> + +class Method; + +namespace cfg { + +//===----------------------------------------------------------------------===// +// +// IntervalPartition - This class builds and holds an "interval partition" for +// a method. This partition divides the control flow graph into a set of +// maximal intervals, as defined with the properties above. Intuitively, a +// BasicBlock is a (possibly nonexistent) loop with a "tail" of non looping +// nodes following it. +// +class IntervalPartition { + typedef map<BasicBlock*, Interval*> IntervalMapTy; + IntervalMapTy IntervalMap; + + typedef vector<Interval*> IntervalListTy; + IntervalListTy IntervalList; + Interval *RootInterval; + +public: + typedef IntervalListTy::iterator iterator; + +public: + // IntervalPartition ctor - Build the partition for the specified method + IntervalPartition(Method *M); + + // IntervalPartition ctor - Build a reduced interval partition from an + // existing interval graph. This takes an additional boolean parameter to + // distinguish it from a copy constructor. Always pass in false for now. + // + IntervalPartition(IntervalPartition &I, bool); + + // Destructor - Free memory + ~IntervalPartition(); + + // getRootInterval() - Return the root interval that contains the starting + // block of the method. + inline Interval *getRootInterval() { return RootInterval; } + + // isDegeneratePartition() - Returns true if the interval partition contains + // a single interval, and thus cannot be simplified anymore. + bool isDegeneratePartition() { return size() == 1; } + + // TODO: isIrreducible - look for triangle graph. + + // getBlockInterval - Return the interval that a basic block exists in. + inline Interval *getBlockInterval(BasicBlock *BB) { + IntervalMapTy::iterator I = IntervalMap.find(BB); + return I != IntervalMap.end() ? I->second : 0; + } + + // Iterators to iterate over all of the intervals in the method + inline iterator begin() { return IntervalList.begin(); } + inline iterator end() { return IntervalList.end(); } + inline unsigned size() { return IntervalList.size(); } + +private: + // ProcessInterval - This method is used during the construction of the + // interval graph. It walks through the source graph, recursively creating + // an interval per invokation until the entire graph is covered. This uses + // the ProcessNode method to add all of the nodes to the interval. + // + // This method is templated because it may operate on two different source + // graphs: a basic block graph, or a preexisting interval graph. + // + template<class NodeTy, class OrigContainer> + void ProcessInterval(NodeTy *Node, OrigContainer *OC); + + // ProcessNode - This method is called by ProcessInterval to add nodes to the + // interval being constructed, and it is also called recursively as it walks + // the source graph. A node is added to the current interval only if all of + // its predecessors are already in the graph. This also takes care of keeping + // the successor set of an interval up to date. + // + // This method is templated because it may operate on two different source + // graphs: a basic block graph, or a preexisting interval graph. + // + template<class NodeTy, class OrigContainer> + void ProcessNode(Interval *Int, NodeTy *Node, OrigContainer *OC); + + // addNodeToInterval - This method exists to assist the generic ProcessNode + // with the task of adding a node to the new interval, depending on the + // type of the source node. In the case of a CFG source graph (BasicBlock + // case), the BasicBlock itself is added to the interval. In the case of + // an IntervalPartition source graph (Interval case), all of the member + // BasicBlocks are added to the interval. + // + inline void addNodeToInterval(Interval *Int, Interval *I); + inline void addNodeToInterval(Interval *Int, BasicBlock *BB); + + // updatePredecessors - Interval generation only sets the successor fields of + // the interval data structures. After interval generation is complete, + // run through all of the intervals and propogate successor info as + // predecessor info. + // + void updatePredecessors(Interval *Int); +}; + +} // End namespace cfg + +#endif |