3 files changed, 38 insertions, 14 deletions

diff --git a/backend/src/ir/function.cpp b/backend/src/ir/function.cpp
index deb65ef..3767d9c 100644
--- a/backend/src/ir/function.cpp
+++ b/backend/src/ir/function.cpp
@@ -260,14 +260,23 @@ namespace ir {
         jumpToNext = &bb;
         return;
       }
-      const BranchInstruction &insn = cast<BranchInstruction>(*last);
-      if (insn.getOpcode() == OP_BRA) {
+      ir::BasicBlock::iterator it = --bb.end();
+      uint32_t handledInsns = 0;
+      while ((handledInsns < 2 && it != bb.end()) &&
+             static_cast<ir::BranchInstruction *>(&*it)->getOpcode() == OP_BRA) {
+        const BranchInstruction &insn = cast<BranchInstruction>(*it);
+        if (insn.getOpcode() != OP_BRA)
+          break;
         const LabelIndex label = insn.getLabelIndex();
         BasicBlock *target = this->blocks[label];
         GBE_ASSERT(target != NULL);
         target->predecessors.insert(&bb);
         bb.successors.insert(target);
-        if ( insn.isPredicated() == true) jumpToNext = &bb;
+        if (insn.isPredicated() == true) jumpToNext = &bb;
+        // If we are going to handle the second bra, this bra must be a predicated bra
+        GBE_ASSERT(handledInsns == 0 || insn.isPredicated() == true);
+        --it;
+        ++handledInsns;
       }
     });
   }
@@ -324,7 +333,9 @@ namespace ir {
   BasicBlock::BasicBlock(Function &fn) : needEndif(true), needIf(true), endifLabel(0),
                                          matchingEndifLabel(0), matchingElseLabel(0),
                                          thisElseLabel(0), belongToStructure(false),
-                                         isStructureExit(false), matchingStructureEntry(NULL),
+                                         isStructureExit(false), isLoopExit(false),
+                                         hasExtraBra(false),
+                                         matchingStructureEntry(NULL),
                                          fn(fn) {
     this->nextBlock = this->prevBlock = NULL;
   }
diff --git a/backend/src/ir/function.hpp b/backend/src/ir/function.hpp
index d0b595e..0f145c5 100644
--- a/backend/src/ir/function.hpp
+++ b/backend/src/ir/function.hpp
@@ -122,6 +122,11 @@ namespace ir {
      * identified structure. so if isStructureExit is false then matchingStructureEntry
      * is meaningless. */
     bool isStructureExit;
+    /* This block is an exit point of a loop block. It may not be exit point of
+       the large structure block. */
+    bool isLoopExit;
+    /* This block has an extra branch in the end of the block. */
+    bool hasExtraBra;
     BasicBlock *matchingStructureEntry;
     /* variable liveout is for if-else structure liveness analysis. eg. we have an sequence of
      * bbs of 0, 1, 2, 3, 4 and the CFG is as below:
diff --git a/backend/src/ir/structural_analysis.cpp b/backend/src/ir/structural_analysis.cpp
index 040a7e0..1e98629 100644
--- a/backend/src/ir/structural_analysis.cpp
+++ b/backend/src/ir/structural_analysis.cpp
@@ -59,20 +59,24 @@ namespace analysis
   }
   void ControlTree::handleSelfLoopNode(Node *loopnode, ir::LabelIndex& whileLabel)
   {
+              //NodeList::iterator child_iter = (*it)->children.begin();
     ir::BasicBlock *pbb = loopnode->getExit();
-    ir::BranchInstruction* pinsn = static_cast<ir::BranchInstruction *>(pbb->getLastInstruction());
-    ir::Register reg = pinsn->getPredicateIndex();
+    GBE_ASSERT(pbb->isLoopExit);
     ir::BasicBlock::iterator it = pbb->end();
     it--;
+    if (pbb->hasExtraBra)
+      it--;
+    ir::BranchInstruction* pinsn = static_cast<ir::BranchInstruction *>(&*it);
+    ir::Register reg = pinsn->getPredicateIndex();
     /* since this node is an while node, so we remove the BRA instruction at the bottom of the exit BB of 'node',
      * and insert WHILE instead
      */
-    pbb->erase(it);
     whileLabel = pinsn->getLabelIndex();
     ir::Instruction insn = ir::WHILE(whileLabel, reg);
     ir::Instruction* p_new_insn = pbb->getParent().newInstruction(insn);
-    pbb->append(*p_new_insn);
+    pbb->insertAt(it, *p_new_insn);
     pbb->whileLabel = whileLabel;
+    pbb->erase(it);
   }
 
   /* recursive mark the bbs' variable needEndif, the bbs all belong to node.*/
@@ -257,11 +261,15 @@ namespace analysis
     for(size_t i = 0; i < blocks.size(); ++i)
     {
       bbs[i] = blocks[i];
-      if(bbs[i]->getLastInstruction()->getOpcode() != ir::OP_BRA && i != blocks.size() - 1)
+      if(i != blocks.size() -1 &&
+         (bbs[i]->getLastInstruction()->getOpcode() != ir::OP_BRA ||
+         (bbs[i]->isStructureExit && bbs[i]->isLoopExit)))
       {
         ir::Instruction insn = ir::BRA(bbs[i]->getNextBlock()->getLabelIndex());
         ir::Instruction* pNewInsn = bbs[i]->getParent().newInstruction(insn);
         bbs[i]->append(*pNewInsn);
+        if (bbs[i]->isStructureExit && bbs[i]->isLoopExit)
+          bbs[i]->hasExtraBra = true;
       }
     }
 
@@ -337,6 +345,9 @@ namespace analysis
           it--;
 
           bbs[i]->erase(it);
+
+          if (bbs[i]->hasExtraBra)
+            bbs[i]->hasExtraBra = false;
         }
       }
     }
@@ -346,7 +357,6 @@ namespace analysis
     fn->sortLabels();
     fn->computeCFG();
 
-#if 1
     it = begin;
     while(it != end)
     {
@@ -384,9 +394,8 @@ namespace analysis
 
           case SelfLoop:
             {
-              NodeList::iterator child_iter = (*it)->children.begin();
               ir::LabelIndex whilelabel;
-              handleSelfLoopNode(*child_iter, whilelabel);
+              handleSelfLoopNode(*it, whilelabel);
             }
             break;
 
@@ -397,7 +406,6 @@ namespace analysis
 
       it++;
     }
-#endif
 
   }
 
@@ -868,7 +876,7 @@ namespace analysis
         Node* p = new SelfLoopNode(node);
 
         p->canBeHandled = true;
-
+        node->getExit()->isLoopExit = true;
         return insertNode(p);
       }
       else