src/hotspot/share/opto/subnode.cpp

rev 52049 : JDK11-only: Use WB-based acmp barrier

*** 892,905 ****
      return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
    } else
      return TypeInt::CC;
  }
  
! static inline Node* isa_java_mirror_load_helper(PhaseGVN* phase, Node* n) {
    // Return the klass node for (indirect load from OopHandle)
    //   LoadP(LoadP(AddP(foo:Klass, #java_mirror)))
    //   or NULL if not matching.
    if (n->Opcode() != Op_LoadP) return NULL;
  
    const TypeInstPtr* tp = phase->type(n)->isa_instptr();
    if (!tp || tp->klass() != phase->C->env()->Class_klass()) return NULL;
  
--- 892,910 ----
      return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
    } else
      return TypeInt::CC;
  }
  
! static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
    // Return the klass node for (indirect load from OopHandle)
    //   LoadP(LoadP(AddP(foo:Klass, #java_mirror)))
    //   or NULL if not matching.
+ 
+ #if INCLUDE_SHENANDOAHGC
+   n = ShenandoahBarrierNode::skip_through_barrier(n);
+ #endif
+ 
    if (n->Opcode() != Op_LoadP) return NULL;
  
    const TypeInstPtr* tp = phase->type(n)->isa_instptr();
    if (!tp || tp->klass() != phase->C->env()->Class_klass()) return NULL;
  
*** 916,954 ****
  
    // We've found the klass node of a Java mirror load.
    return k;
  }
  
- static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
-   if (!UseShenandoahGC) {
-     if (n->Opcode() == Op_LoadP) {
-       return isa_java_mirror_load_helper(phase, n);
-     }
-   } else {
- #if INCLUDE_SHENANDOAHGC
-     if (n->is_ShenandoahBarrier() &&
-                n->in(ShenandoahBarrierNode::ValueIn)->Opcode() == Op_LoadP) {
-       // When Shenandoah is enabled acmp is compiled as:
-       // if (a != b) {
-       //   a = read_barrier(a);
-       //   b = read_barrier(b);
-       //   if (a == b) {
-       //     ..
-       //   } else {
-       //     ..
-       //   }
-       // } else  {
-       //
-       // Recognize that pattern here for the second comparison
-       return isa_java_mirror_load_helper(phase, n->in(ShenandoahBarrierNode::ValueIn));
-     }
- #endif
-   }
- 
-   return NULL;
- }
- 
  static inline Node* isa_const_java_mirror(PhaseGVN* phase, Node* n) {
    // for ConP(Foo.class) return ConP(Foo.klass)
    // otherwise return NULL
    if (!n->is_Con()) return NULL;
  
--- 921,930 ----
*** 969,1031 ****
    // return the ConP(Foo.klass)
    assert(mirror_type->is_klass(), "mirror_type should represent a Klass*");
    return phase->makecon(TypeKlassPtr::make(mirror_type->as_klass()));
  }
  
- #if INCLUDE_SHENANDOAHGC
- bool CmpPNode::shenandoah_optimize_java_mirror_cmp(PhaseGVN *phase, bool can_reshape) {
-   assert(UseShenandoahGC, "shenandoah only");
-   if (in(1)->is_ShenandoahBarrier()) {
-     // For this pattern:
-     // if (a != b) {
-     //   a = read_barrier(a);
-     //   b = read_barrier(b);
-     //   if (a == b) {
-     //     ..
-     //   } else {
-     //     ..
-     //  }
-     // } else  {
-     //
-     // Change the second test to a.klass == b.klass and replace the
-     // first compare by that new test if possible.
-     if (can_reshape) {
-       for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
-         Node* u = fast_out(i);
-         if (u->is_Bool()) {
-           for (DUIterator_Fast jmax, j = u->fast_outs(jmax); j < jmax; j++) {
-             Node* uu = u->fast_out(j);
-             if (uu->is_If() &&
-                 uu->in(0) != NULL &&
-                 uu->in(0)->is_Proj() &&
-                 uu->in(0)->in(0)->is_MemBar() &&
-                 uu->in(0)->in(0)->in(0) != NULL &&
-                 uu->in(0)->in(0)->in(0)->Opcode() == Op_IfTrue) {
-               Node* iff = uu->in(0)->in(0)->in(0)->in(0);
-               if (iff->in(1) != NULL &&
-                   iff->in(1)->is_Bool() &&
-                   iff->in(1)->as_Bool()->_test._test == BoolTest::ne &&
-                   iff->in(1)->in(1) != NULL &&
-                   iff->in(1)->in(1)->Opcode() == Op_CmpP) {
-                 Node* cmp = iff->in(1)->in(1);
-                 if (in(1)->in(ShenandoahBarrierNode::ValueIn) == cmp->in(1) &&
-                     (!in(2)->is_ShenandoahBarrier() || in(2)->in(ShenandoahBarrierNode::ValueIn) == cmp->in(2))) {
-                   PhaseIterGVN* igvn = phase->is_IterGVN();
-                   igvn->replace_input_of(iff->in(1), 1, this);
-                   return true;
-                 }
-               }
-             }
-           }
-         }
-       }
-     }
-   }
-   return false;
- }
- #endif
- 
  //------------------------------Ideal------------------------------------------
  // Normalize comparisons between Java mirror loads to compare the klass instead.
  //
  // Also check for the case of comparing an unknown klass loaded from the primary
  // super-type array vs a known klass with no subtypes.  This amounts to
--- 945,954 ----
*** 1079,1097 ****
      Node* k1 = isa_java_mirror_load(phase, in(1));
      Node* k2 = isa_java_mirror_load(phase, in(2));
      Node* conk2 = isa_const_java_mirror(phase, in(2));
  
      if (k1 && (k2 || conk2)) {
-       if (!UseShenandoahGC SHENANDOAHGC_ONLY(|| shenandoah_optimize_java_mirror_cmp(phase, can_reshape))) {
          Node* lhs = k1;
          Node* rhs = (k2 != NULL) ? k2 : conk2;
          this->set_req(1, lhs);
          this->set_req(2, rhs);
          return this;
        }
      }
-   }
  
    // Constant pointer on right?
    const TypeKlassPtr* t2 = phase->type(in(2))->isa_klassptr();
    if (t2 == NULL || !t2->klass_is_exact())
      return NULL;
--- 1002,1018 ----