Mercurial > jdk8-mips64-public > hotspot / file diff

     1.1 --- a/src/share/vm/opto/node.cpp	Thu May 15 22:40:43 2008 -0700
     1.2 +++ b/src/share/vm/opto/node.cpp	Thu May 15 22:43:11 2008 -0700
     1.3 @@ -1043,6 +1043,9 @@
     1.4    assert(this->is_CFG(), "expecting control");
     1.5    assert(sub != NULL && sub->is_CFG(), "expecting control");
     1.6  
     1.7 +  // detect dead cycle without regions
     1.8 +  int iterations_without_region_limit = DominatorSearchLimit;
     1.9 +
    1.10    Node* orig_sub = sub;
    1.11    nlist.clear();
    1.12    bool this_dominates = false;
    1.13 @@ -1057,6 +1060,7 @@
    1.14          // Region nodes were visited. Continue walk up to Start or Root
    1.15          // to make sure that it did not walk in a cycle.
    1.16          this_dominates = true; // first time meet
    1.17 +        iterations_without_region_limit = DominatorSearchLimit; // Reset
    1.18        } else {
    1.19          return false;          // already met before: walk in a cycle
    1.20        }
    1.21 @@ -1069,19 +1073,20 @@
    1.22        return false; // Conservative answer for dead code
    1.23  
    1.24      if (sub == up && sub->is_Loop()) {
    1.25 -      up = sub->in(0); // in(LoopNode::EntryControl);
    1.26 -    } else if (sub == up && sub->is_Region()) {
    1.27 +      up = sub->in(1); // in(LoopNode::EntryControl);
    1.28 +    } else if (sub == up && sub->is_Region() && sub->req() == 3) {
    1.29 +      iterations_without_region_limit = DominatorSearchLimit; // Reset
    1.30        uint i = 1;
    1.31 -      if (nlist.size() == 0) {
    1.32 +      uint size = nlist.size();
    1.33 +      if (size == 0) {
    1.34          // No Region nodes (except Loops) were visited before.
    1.35          // Take first valid path on the way up to 'this'.
    1.36 -      } else if (nlist.at(nlist.size() - 1) == sub) {
    1.37 +      } else if (nlist.at(size - 1) == sub) {
    1.38          // This Region node was just visited. Take other path.
    1.39          i = region_input + 1;
    1.40          nlist.pop();
    1.41        } else {
    1.42          // Was this Region node visited before?
    1.43 -        uint size = nlist.size();
    1.44          for (uint j = 0; j < size; j++) {
    1.45            if (nlist.at(j) == sub) {
    1.46              return false; // The Region node was visited before. Give up.
    1.47 @@ -1104,8 +1109,9 @@
    1.48      }
    1.49      if (sub == up)
    1.50        return false;    // some kind of tight cycle
    1.51 -    if (orig_sub == up)
    1.52 -      return false;    // walk in a cycle
    1.53 +
    1.54 +    if (--iterations_without_region_limit < 0)
    1.55 +      return false;    // dead cycle
    1.56  
    1.57      sub = up;
    1.58    }