From ed465bc265d9661c080b72604fa92593ae0cc2ca Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Wed, 20 Jun 2001 22:44:32 +0000 Subject: [PATCH] Add capability to build a derived interval graph git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Analysis/Interval.h | 76 +++++++++++- lib/Analysis/Interval.cpp | 197 ++++++++++++++++++++++++------- 2 files changed, 225 insertions(+), 48 deletions(-) diff --git a/include/llvm/Analysis/Interval.h b/include/llvm/Analysis/Interval.h index a17e655c9e4..3c22f6dc7ca 100644 --- a/include/llvm/Analysis/Interval.h +++ b/include/llvm/Analysis/Interval.h @@ -1,7 +1,11 @@ //===- llvm/Analysis/Intervals.h - Interval partition Calculation-*- C++ -*--=// // // This file contains the declaration of the cfg::IntervalPartition class, which -// calculates and represent the interval partition of a method. +// 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). // //===----------------------------------------------------------------------===// @@ -64,6 +68,28 @@ private: // Only accessable by IntervalPartition class }; +// succ_begin/succ_end - define global functions so that Intervals may be used +// just like BasicBlocks can with the succ_* functions, and *::succ_iterator. +// +inline Interval::succ_iterator succ_begin(Interval *I) { + return I->Successors.begin(); +} +inline Interval::succ_iterator succ_end(Interval *I) { + return I->Successors.end(); +} + +// pred_begin/pred_end - define global functions so that Intervals may be used +// just like BasicBlocks can with the pred_* functions, and *::pred_iterator. +// +inline Interval::pred_iterator pred_begin(Interval *I) { + return I->Predecessors.begin(); +} +inline Interval::pred_iterator pred_end(Interval *I) { + return I->Predecessors.end(); +} + + + // 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 @@ -85,6 +111,12 @@ 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); + // getRootInterval() - Return the root interval that contains the starting // block of the method inline Interval *getRootInterval() { return RootInterval; } @@ -102,9 +134,45 @@ public: inline iterator end() { return IntervalList.end(); } private: - void ProcessInterval(BasicBlock *Header); - void ProcessBasicBlock(Interval *I, BasicBlock *BB); - void UpdateSuccessors(Interval *Int); + // 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 + 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 + 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 diff --git a/lib/Analysis/Interval.cpp b/lib/Analysis/Interval.cpp index f1737fc39af..ac4846ae620 100644 --- a/lib/Analysis/Interval.cpp +++ b/lib/Analysis/Interval.cpp @@ -10,76 +10,185 @@ #include "llvm/BasicBlock.h" #include "llvm/CFG.h" -void cfg::IntervalPartition::UpdateSuccessors(cfg::Interval *Int) { - BasicBlock *Header = Int->HeaderNode; - for (cfg::Interval::succ_iterator I = Int->Successors.begin(), - E = Int->Successors.end(); I != E; ++I) - getBlockInterval(*I)->Predecessors.push_back(Header); -} +using namespace cfg; -// IntervalPartition ctor - Build the partition for the specified method -cfg::IntervalPartition::IntervalPartition(Method *M) { - BasicBlock *MethodStart = M->getBasicBlocks().front(); - assert(MethodStart && "Cannot operate on prototypes!"); +// 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 static BasicBlock *getNodeHeader(BasicBlock *BB) { return BB; } +inline static BasicBlock *getNodeHeader(Interval *I) { return I->HeaderNode; } - ProcessInterval(MethodStart); - RootInterval = getBlockInterval(MethodStart); - // Now that we know all of the successor information, propogate this to the - // predecessors for each block... - for(iterator I = begin(), E = end(); I != E; ++I) - UpdateSuccessors(*I); +// 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 static BasicBlock *getSourceGraphNode(Method *, BasicBlock *BB) { + return BB; +} +inline static Interval *getSourceGraphNode(IntervalPartition *IP, + BasicBlock *BB) { + return IP->getBlockInterval(BB); } -void cfg::IntervalPartition::ProcessInterval(BasicBlock *Header) { - if (getBlockInterval(Header)) return; // Interval already constructed - Interval *Int = new Interval(Header); - IntervalList.push_back(Int); // Add the interval to our current set - IntervalMap.insert(make_pair(Header, Int)); +// 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 IntervalPartition::addNodeToInterval(Interval *Int, BasicBlock *BB){ + Int->Nodes.push_back(BB); + IntervalMap.insert(make_pair(BB, Int)); +} - // Check all of our successors to see if they are in the interval... - for (succ_iterator I = succ_begin(Header), E = succ_end(Header); I != E; ++I) - ProcessBasicBlock(Int, *I); +// 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 IntervalPartition::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)); - // Build all of the successor intervals of this interval now... - for(Interval::succ_iterator I = Int->Successors.begin(), - E = Int->Successors.end(); I != E; ++I) - ProcessInterval(*I); + // Add mappings for all of the basic blocks in I to the IntervalPartition + for (Interval::node_iterator It = I->Nodes.begin(), End = I->Nodes.end(); + It != End; ++It) + IntervalMap.insert(make_pair(*It, Int)); } -void cfg::IntervalPartition::ProcessBasicBlock(Interval *Int, BasicBlock *BB) { - assert(Int && "Null interval == bad!"); - assert(BB && "Null interval == bad!"); - Interval *CurInt = getBlockInterval(BB); +// 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 +void IntervalPartition::ProcessNode(Interval *Int, + NodeTy *Node, OrigContainer *OC) { + assert(Int && "Null interval == bad!"); + assert(Node && "Null Node == bad!"); + + BasicBlock *NodeHeader = getNodeHeader(Node); + Interval *CurInt = getBlockInterval(NodeHeader); if (CurInt == Int) { // Already in this interval... return; } else if (CurInt != 0) { // In another interval, add as successor - if (!Int->isSuccessor(BB)) // Add only if not already in set - Int->Successors.push_back(BB); + if (!Int->isSuccessor(NodeHeader)) // Add only if not already in set + Int->Successors.push_back(NodeHeader); } else { // Otherwise, not in interval yet - for (pred_iterator I = pred_begin(BB), E = pred_end(BB); I != E; ++I) { + 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(BB)) // Add only if not already in set - Int->Successors.push_back(BB); + 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! - Int->Nodes.push_back(BB); - IntervalMap.insert(make_pair(BB, Int)); + addNodeToInterval(Int, Node); - if (Int->isSuccessor(BB)) { + if (Int->isSuccessor(NodeHeader)) { // If we were in the successor list from before... remove from succ list - remove(Int->Successors.begin(), Int->Successors.end(), BB); + Int->Successors.erase(remove(Int->Successors.begin(), + Int->Successors.end(), NodeHeader), + Int->Successors.end()); } - // Now that we have discovered that BB is in the interval, perhaps some of + // Now that we have discovered that Node is in the interval, perhaps some of // its successors are as well? - for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I) - ProcessBasicBlock(Int, *I); + for (typename NodeTy::succ_iterator It = succ_begin(Node), + End = succ_end(Node); It != End; ++It) + ProcessNode(Int, getSourceGraphNode(OC, *It), OC); } } + + +// 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 +void IntervalPartition::ProcessInterval(NodeTy *Node, OrigContainer *OC) { + BasicBlock *Header = getNodeHeader(Node); + if (getBlockInterval(Header)) return; // Interval already constructed? + + // Create a new interval and add the interval to our current set + Interval *Int = new Interval(Header); + IntervalList.push_back(Int); + IntervalMap.insert(make_pair(Header, Int)); + + // 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(OC, *I), OC); + + // Build all of the successor intervals of this interval now... + for(Interval::succ_iterator I = Int->Successors.begin(), + E = Int->Successors.end(); I != E; ++I) { + ProcessInterval(getSourceGraphNode(OC, *I), OC); + } +} + + + +// 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 IntervalPartition::updatePredecessors(cfg::Interval *Int) { + BasicBlock *Header = Int->HeaderNode; + for (Interval::succ_iterator I = Int->Successors.begin(), + E = Int->Successors.end(); I != E; ++I) + getBlockInterval(*I)->Predecessors.push_back(Header); +} + + + +// IntervalPartition ctor - Build the first level interval partition for the +// specified method... +// +IntervalPartition::IntervalPartition(Method *M) { + BasicBlock *MethodStart = M->getBasicBlocks().front(); + assert(MethodStart && "Cannot operate on prototypes!"); + + ProcessInterval(MethodStart, M); + RootInterval = getBlockInterval(MethodStart); + + // Now that we know all of the successor information, propogate this to the + // predecessors for each block... + for(iterator I = begin(), E = end(); I != E; ++I) + updatePredecessors(*I); +} + + +// 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(IntervalPartition &I, bool) { + Interval *MethodStart = I.getRootInterval(); + assert(MethodStart && "Cannot operate on empty IntervalPartitions!"); + + ProcessInterval(MethodStart, &I); + RootInterval = getBlockInterval(*MethodStart->Nodes.begin()); + + // Now that we know all of the successor information, propogate this to the + // predecessors for each block... + for(iterator I = begin(), E = end(); I != E; ++I) + updatePredecessors(*I); +} -- 2.34.1