src/share/vm/opto/ifnode.cpp

*** 21,30 ****
--- 21,31 ----
   * questions.
   *
   */
  
  #include "precompiled.hpp"
+ #include "ci/ciTypeFlow.hpp"
  #include "memory/allocation.inline.hpp"
  #include "opto/addnode.hpp"
  #include "opto/castnode.hpp"
  #include "opto/cfgnode.hpp"
  #include "opto/connode.hpp"
*** 766,776 ****
  }
  
  // Do this If and the dominating If both branch out to an uncommon trap
  bool IfNode::has_only_uncommon_traps(ProjNode* proj, ProjNode*& success, ProjNode*& fail, PhaseIterGVN* igvn) {
    ProjNode* otherproj = proj->other_if_proj();
!   CallStaticJavaNode* dom_unc = otherproj->is_uncommon_trap_proj(Deoptimization::Reason_none);
  
    if (otherproj->outcnt() == 1 && dom_unc != NULL) {
      CallStaticJavaNode* unc = NULL;
      ProjNode* unc_proj = uncommon_trap_proj(unc);
      if (unc_proj != NULL && unc_proj->outcnt() == 1) {
--- 767,783 ----
  }
  
  // Do this If and the dominating If both branch out to an uncommon trap
  bool IfNode::has_only_uncommon_traps(ProjNode* proj, ProjNode*& success, ProjNode*& fail, PhaseIterGVN* igvn) {
    ProjNode* otherproj = proj->other_if_proj();
!   // Dominating uncommon trap must have 'Reason_unstable_if' to ensure re-execution of folded Ifs
!   CallStaticJavaNode* dom_unc = otherproj->is_uncommon_trap_proj(Deoptimization::Reason_unstable_if);
! 
!   // We need to re-execute the check after deoptimization
!   if (!dom_unc->jvms()->should_reexecute()) {
!     return false;
!   }
  
    if (otherproj->outcnt() == 1 && dom_unc != NULL) {
      CallStaticJavaNode* unc = NULL;
      ProjNode* unc_proj = uncommon_trap_proj(unc);
      if (unc_proj != NULL && unc_proj->outcnt() == 1) {
*** 782,797 ****
          }
          assert(r->has_phi() == NULL, "simple region shouldn't have a phi");
        } else if (dom_unc->in(0) != otherproj || unc->in(0) != unc_proj) {
          return false;
        }
        // See merge_uncommon_traps: the reason of the uncommon trap
        // will be changed and the state of the dominating If will be
        // used. Checked that we didn't apply this transformation in a
        // previous compilation and it didn't cause too many traps
!       if (!igvn->C->too_many_traps(dom_unc->jvms()->method(), dom_unc->jvms()->bci(), Deoptimization::Reason_unstable_fused_if) &&
!           !igvn->C->too_many_traps(dom_unc->jvms()->method(), dom_unc->jvms()->bci(), Deoptimization::Reason_range_check)) {
          success = unc_proj;
          fail = unc_proj->other_if_proj();
          return true;
        }
      }
--- 789,820 ----
          }
          assert(r->has_phi() == NULL, "simple region shouldn't have a phi");
        } else if (dom_unc->in(0) != otherproj || unc->in(0) != unc_proj) {
          return false;
        }
+ 
+       // Check if the bci of the dominating uncommon trap dominates the bci
+       // of the dominated uncommon trap. Otherwise we may not re-execute
+       // the dominated check after deoptimization from the merged uncommon trap.
+       ciMethod* method = unc->jvms()->method();
+       ciMethod* dom_method = dom_unc->jvms()->method();
+       if (method != dom_method) {
+         return false;
+       }
+       ciTypeFlow* flow = dom_method->get_flow_analysis();
+       int bci = unc->jvms()->bci();
+       int dom_bci = dom_unc->jvms()->bci();
+       if (!flow->is_dominated_by(bci, dom_bci)) {
+         return false;
+       }
+ 
        // See merge_uncommon_traps: the reason of the uncommon trap
        // will be changed and the state of the dominating If will be
        // used. Checked that we didn't apply this transformation in a
        // previous compilation and it didn't cause too many traps
!       if (!igvn->C->too_many_traps(dom_method, dom_bci, Deoptimization::Reason_unstable_fused_if) &&
!           !igvn->C->too_many_traps(dom_method, dom_bci, Deoptimization::Reason_range_check)) {
          success = unc_proj;
          fail = unc_proj->other_if_proj();
          return true;
        }
      }