New file due to the Intervals.h splitup

llvm-svn: 66

llvm/lib/Analysis/IntervalPartition.cpp

@@ -0,0 +1,181 @@
+//===- IntervalPartition.cpp - Interval Partition module code ----*- C++ -*--=//
+//
+// This file contains the definition of the cfg::IntervalPartition class, which
+// calculates and represent the interval partition of a method.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/IntervalIterator.h"
+
+using namespace cfg;
+
+//===----------------------------------------------------------------------===//
+// IntervalPartition Implementation
+//===----------------------------------------------------------------------===//
+
+template <class T> static inline void deleter(T *Ptr) { delete Ptr; }
+
+// Destructor - Free memory
+IntervalPartition::~IntervalPartition() {
+  for_each(begin(), end(), deleter<cfg::Interval>);
+}
+
+// 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));
+}
+
+// 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));
+
+  // 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));
+}
+
+
+// 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 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(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);
+    
+    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(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<class NodeTy, class OrigContainer>
+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->getHeaderNode();
+  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);
+}