Subzero: Loop Invariant Code Motion

src/IceLoopAnalyzer.cpp

 //===- subzero/src/IceLoopAnalyzer.cpp - Loop Analysis --------------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 36 matching lines @@
 
   // Allocate memory ahead of time. This is why a vector is used instead of a
   // stack which doesn't support reserving (or bulk erasure used below).
   AllNodes.reserve(Nodes.size());
   WorkStack.reserve(Nodes.size());
   LoopStack.reserve(Nodes.size());
 
   // Create the LoopNodes from the function's CFG
   for (CfgNode *Node : Nodes)
     AllNodes.emplace_back(Node);
+  computeLoopNestDepth();
 }
 
 void LoopAnalyzer::computeLoopNestDepth() {
   assert(AllNodes.size() == Func->getNodes().size());
   assert(NextIndex == FirstDefinedIndex);
   assert(NumDeletedNodes == 0);
 
   while (NumDeletedNodes < AllNodes.size()) {
     // Prepare to run Tarjan's
     for (LoopNode &Node : AllNodes)
@@ skipping 67 matching lines @@
   // Reaching here means a loop has been found! It consists of the nodes on the
   // top of the stack, down until the current node being processed, Node, is
   // found.
   for (auto It = LoopStack.rbegin(); It != LoopStack.rend(); ++It) {
     (*It)->setOnStack(false);
     (*It)->incrementLoopNestDepth();
     // Remove the loop from the stack and delete the head node
     if (*It == &Node) {
       (*It)->setDeleted();
       ++NumDeletedNodes;
+      CfgVector<SizeT> LoopNodes;
+      for (auto LoopIter = It.base() - 1; LoopIter != LoopStack.end();
+           ++LoopIter) {
+        LoopNodes.push_back((*LoopIter)->getNode()->getIndex());
+      }
+      Loops[(*It)->getNode()->getIndex()] = LoopNodes;
       LoopStack.erase(It.base() - 1, LoopStack.end());
       break;
     }
   }
 
   return nullptr;
 }
 
 } // end of namespace Ice