*** old/src/share/vm/opto/compile.cpp	Wed Aug 12 15:10:31 2009
--- new/src/share/vm/opto/compile.cpp	Wed Aug 12 15:10:30 2009

*** 1543,1573 ****
--- 1543,1578 ----
    // Set loop opts counter
    loop_opts_cnt = num_loop_opts();
    if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
      {
        TracePhase t2("idealLoop", &_t_idealLoop, true);
-       PhaseIdealLoop ideal_loop( igvn, NULL, true );
        loop_opts_cnt--;
        if (major_progress()) print_method("PhaseIdealLoop 1", 2);
        if (failing())  return;
      }
      // Loop opts pass if partial peeling occurred in previous pass
      if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
        TracePhase t3("idealLoop", &_t_idealLoop, true);
-       PhaseIdealLoop ideal_loop( igvn, NULL, false );
        loop_opts_cnt--;
        if (major_progress()) print_method("PhaseIdealLoop 2", 2);
        if (failing())  return;
      }
      // Loop opts pass for loop-unrolling before CCP
      if(major_progress() && (loop_opts_cnt > 0)) {
        TracePhase t4("idealLoop", &_t_idealLoop, true);
-       PhaseIdealLoop ideal_loop( igvn, NULL, false );
        loop_opts_cnt--;
        if (major_progress()) print_method("PhaseIdealLoop 3", 2);
      }
+     if (!failing()) {
+       // Verify that last round of loop opts produced a valid graph
+       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
+       PhaseIdealLoop::verify(igvn);
      }
+   }
    if (failing())  return;
  
    // Conditional Constant Propagation;
    PhaseCCP ccp( &igvn );
    assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");

*** 1595,1611 ****
--- 1600,1624 ----
    if(loop_opts_cnt > 0) {
      debug_only( int cnt = 0; );
      while(major_progress() && (loop_opts_cnt > 0)) {
        TracePhase t2("idealLoop", &_t_idealLoop, true);
        assert( cnt++ < 40, "infinite cycle in loop optimization" );
-       PhaseIdealLoop ideal_loop( igvn, NULL, true );
        loop_opts_cnt--;
        if (major_progress()) print_method("PhaseIdealLoop iterations", 2);
        if (failing())  return;
      }
    }
+ 
    {
+     // Verify that all previous optimizations produced a valid graph
+     // at least to this point, even if no loop optimizations were done.
+     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
+     PhaseIdealLoop::verify(igvn);
+   }
+ 
+   {
      NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
      PhaseMacroExpand  mex(igvn);
      if (mex.expand_macro_nodes()) {
        assert(failing(), "must bail out w/ explicit message");
        return;