1020 
1021   // Known constants can be compared exactly
1022   // Null can be distinguished from any NotNull pointers
1023   // Unknown inputs makes an unknown result
1024   if( r0->singleton() ) {
1025     intptr_t bits0 = r0->get_con();
1026     if( r1->singleton() )
1027       return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
1028     return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1029   } else if( r1->singleton() ) {
1030     intptr_t bits1 = r1->get_con();
1031     return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1032   } else
1033     return TypeInt::CC;
1034 }
1035 
1036 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
1037   // Return the klass node for (indirect load from OopHandle)
1038   //   LoadBarrier?(LoadP(LoadP(AddP(foo:Klass, #java_mirror))))
1039   //   or null if not matching.
1040   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1041     n = bs->step_over_gc_barrier(n);
1042 
1043   if (n->Opcode() != Op_LoadP) return nullptr;
1044 
1045   const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1046   if (!tp || tp->instance_klass() != phase->C->env()->Class_klass()) return nullptr;
1047 
1048   Node* adr = n->in(MemNode::Address);
1049   // First load from OopHandle: ((OopHandle)mirror)->resolve(); may need barrier.
1050   if (adr->Opcode() != Op_LoadP || !phase->type(adr)->isa_rawptr()) return nullptr;
1051   adr = adr->in(MemNode::Address);
1052 
1053   intptr_t off = 0;
1054   Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off);
1055   if (k == nullptr)  return nullptr;
1056   const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr();
1057   if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return nullptr;
1058 
1059   // We've found the klass node of a Java mirror load.
1060   return k;
1061 }
1062 

1020 
1021   // Known constants can be compared exactly
1022   // Null can be distinguished from any NotNull pointers
1023   // Unknown inputs makes an unknown result
1024   if( r0->singleton() ) {
1025     intptr_t bits0 = r0->get_con();
1026     if( r1->singleton() )
1027       return bits0 == r1->get_con() ? TypeInt::CC_EQ : TypeInt::CC_GT;
1028     return ( r1->_ptr == TypePtr::NotNull && bits0==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1029   } else if( r1->singleton() ) {
1030     intptr_t bits1 = r1->get_con();
1031     return ( r0->_ptr == TypePtr::NotNull && bits1==0 ) ? TypeInt::CC_GT : TypeInt::CC;
1032   } else
1033     return TypeInt::CC;
1034 }
1035 
1036 static inline Node* isa_java_mirror_load(PhaseGVN* phase, Node* n) {
1037   // Return the klass node for (indirect load from OopHandle)
1038   //   LoadBarrier?(LoadP(LoadP(AddP(foo:Klass, #java_mirror))))
1039   //   or null if not matching.



1040   if (n->Opcode() != Op_LoadP) return nullptr;
1041 
1042   const TypeInstPtr* tp = phase->type(n)->isa_instptr();
1043   if (!tp || tp->instance_klass() != phase->C->env()->Class_klass()) return nullptr;
1044 
1045   Node* adr = n->in(MemNode::Address);
1046   // First load from OopHandle: ((OopHandle)mirror)->resolve(); may need barrier.
1047   if (adr->Opcode() != Op_LoadP || !phase->type(adr)->isa_rawptr()) return nullptr;
1048   adr = adr->in(MemNode::Address);
1049 
1050   intptr_t off = 0;
1051   Node* k = AddPNode::Ideal_base_and_offset(adr, phase, off);
1052   if (k == nullptr)  return nullptr;
1053   const TypeKlassPtr* tkp = phase->type(k)->isa_klassptr();
1054   if (!tkp || off != in_bytes(Klass::java_mirror_offset())) return nullptr;
1055 
1056   // We've found the klass node of a Java mirror load.
1057   return k;
1058 }
1059