1 //===- IntervalPartition.cpp - Interval Partition module code ----*- C++ -*--=//
3 // This file contains the definition of the cfg::IntervalPartition class, which
4 // calculates and represent the interval partition of a method.
6 //===----------------------------------------------------------------------===//
8 #include "llvm/Analysis/IntervalIterator.h"
12 //===----------------------------------------------------------------------===//
13 // IntervalPartition Implementation
14 //===----------------------------------------------------------------------===//
16 template <class T> static inline void deleter(T *Ptr) { delete Ptr; }
18 // Destructor - Free memory
19 IntervalPartition::~IntervalPartition() {
20 for_each(begin(), end(), deleter<cfg::Interval>);
23 // addNodeToInterval - This method exists to assist the generic ProcessNode
24 // with the task of adding a node to the new interval, depending on the
25 // type of the source node. In the case of a CFG source graph (BasicBlock
26 // case), the BasicBlock itself is added to the interval.
28 inline void IntervalPartition::addNodeToInterval(Interval *Int, BasicBlock *BB){
29 Int->Nodes.push_back(BB);
30 IntervalMap.insert(make_pair(BB, Int));
33 // addNodeToInterval - This method exists to assist the generic ProcessNode
34 // with the task of adding a node to the new interval, depending on the
35 // type of the source node. In the case of a CFG source graph (BasicBlock
36 // case), the BasicBlock itself is added to the interval. In the case of
37 // an IntervalPartition source graph (Interval case), all of the member
38 // BasicBlocks are added to the interval.
40 inline void IntervalPartition::addNodeToInterval(Interval *Int, Interval *I) {
41 // Add all of the nodes in I as new nodes in Int.
42 copy(I->Nodes.begin(), I->Nodes.end(), back_inserter(Int->Nodes));
44 // Add mappings for all of the basic blocks in I to the IntervalPartition
45 for (Interval::node_iterator It = I->Nodes.begin(), End = I->Nodes.end();
47 IntervalMap.insert(make_pair(*It, Int));
51 // ProcessNode - This method is called by ProcessInterval to add nodes to the
52 // interval being constructed, and it is also called recursively as it walks
53 // the source graph. A node is added to the current interval only if all of
54 // its predecessors are already in the graph. This also takes care of keeping
55 // the successor set of an interval up to date.
57 // This method is templated because it may operate on two different source
58 // graphs: a basic block graph, or a preexisting interval graph.
60 template<class NodeTy, class OrigContainer>
61 void IntervalPartition::ProcessNode(Interval *Int,
62 NodeTy *Node, OrigContainer *OC) {
63 assert(Int && "Null interval == bad!");
64 assert(Node && "Null Node == bad!");
66 BasicBlock *NodeHeader = getNodeHeader(Node);
67 Interval *CurInt = getBlockInterval(NodeHeader);
68 if (CurInt == Int) { // Already in this interval...
70 } else if (CurInt != 0) { // In another interval, add as successor
71 if (!Int->isSuccessor(NodeHeader)) // Add only if not already in set
72 Int->Successors.push_back(NodeHeader);
73 } else { // Otherwise, not in interval yet
74 for (typename NodeTy::pred_iterator I = pred_begin(Node),
75 E = pred_end(Node); I != E; ++I) {
76 if (!Int->contains(*I)) { // If pred not in interval, we can't be
77 if (!Int->isSuccessor(NodeHeader)) // Add only if not already in set
78 Int->Successors.push_back(NodeHeader);
79 return; // See you later
83 // If we get here, then all of the predecessors of BB are in the interval
84 // already. In this case, we must add BB to the interval!
85 addNodeToInterval(Int, Node);
87 if (Int->isSuccessor(NodeHeader)) {
88 // If we were in the successor list from before... remove from succ list
89 Int->Successors.erase(remove(Int->Successors.begin(),
90 Int->Successors.end(), NodeHeader),
91 Int->Successors.end());
94 // Now that we have discovered that Node is in the interval, perhaps some of
95 // its successors are as well?
96 for (typename NodeTy::succ_iterator It = succ_begin(Node),
97 End = succ_end(Node); It != End; ++It)
98 ProcessNode(Int, getSourceGraphNode(OC, *It), OC);
103 // ProcessInterval - This method is used during the construction of the
104 // interval graph. It walks through the source graph, recursively creating
105 // an interval per invokation until the entire graph is covered. This uses
106 // the ProcessNode method to add all of the nodes to the interval.
108 // This method is templated because it may operate on two different source
109 // graphs: a basic block graph, or a preexisting interval graph.
111 template<class NodeTy, class OrigContainer>
112 void IntervalPartition::ProcessInterval(NodeTy *Node, OrigContainer *OC) {
113 BasicBlock *Header = getNodeHeader(Node);
114 if (getBlockInterval(Header)) return; // Interval already constructed?
116 // Create a new interval and add the interval to our current set
117 Interval *Int = new Interval(Header);
118 IntervalList.push_back(Int);
119 IntervalMap.insert(make_pair(Header, Int));
121 // Check all of our successors to see if they are in the interval...
122 for (typename NodeTy::succ_iterator I = succ_begin(Node), E = succ_end(Node);
124 ProcessNode(Int, getSourceGraphNode(OC, *I), OC);
126 // Build all of the successor intervals of this interval now...
127 for(Interval::succ_iterator I = Int->Successors.begin(),
128 E = Int->Successors.end(); I != E; ++I) {
129 ProcessInterval(getSourceGraphNode(OC, *I), OC);
135 // updatePredecessors - Interval generation only sets the successor fields of
136 // the interval data structures. After interval generation is complete,
137 // run through all of the intervals and propogate successor info as
140 void IntervalPartition::updatePredecessors(cfg::Interval *Int) {
141 BasicBlock *Header = Int->getHeaderNode();
142 for (Interval::succ_iterator I = Int->Successors.begin(),
143 E = Int->Successors.end(); I != E; ++I)
144 getBlockInterval(*I)->Predecessors.push_back(Header);
149 // IntervalPartition ctor - Build the first level interval partition for the
150 // specified method...
152 IntervalPartition::IntervalPartition(Method *M) {
153 BasicBlock *MethodStart = M->getBasicBlocks().front();
154 assert(MethodStart && "Cannot operate on prototypes!");
156 ProcessInterval(MethodStart, M);
157 RootInterval = getBlockInterval(MethodStart);
159 // Now that we know all of the successor information, propogate this to the
160 // predecessors for each block...
161 for(iterator I = begin(), E = end(); I != E; ++I)
162 updatePredecessors(*I);
166 // IntervalPartition ctor - Build a reduced interval partition from an
167 // existing interval graph. This takes an additional boolean parameter to
168 // distinguish it from a copy constructor. Always pass in false for now.
170 IntervalPartition::IntervalPartition(IntervalPartition &I, bool) {
171 Interval *MethodStart = I.getRootInterval();
172 assert(MethodStart && "Cannot operate on empty IntervalPartitions!");
174 ProcessInterval(MethodStart, &I);
175 RootInterval = getBlockInterval(*MethodStart->Nodes.begin());
177 // Now that we know all of the successor information, propogate this to the
178 // predecessors for each block...
179 for(iterator I = begin(), E = end(); I != E; ++I)
180 updatePredecessors(*I);