VtableStub* VtableStubs::lookup(bool is_vtable_stub, int vtable_index) {
  MutexLocker ml(VtableStubs_lock);
  unsigned hash = VtableStubs::hash(is_vtable_stub, vtable_index);
  VtableStub* s = _table[hash];
  while( s && !s->matches(is_vtable_stub, vtable_index)) s = s->next();
  return s;
}

void VtableStubs::vtable_stub_do(void f(VtableStub*)) {
    for (int i = 0; i < N; i++) {
        for (VtableStub* s = _table[i]; s != NULL; s = s->next()) {
            f(s);
        }
    }
}

VtableStub* VtableStubs::stub_containing(address pc) {
  // Note: No locking needed since any change to the data structure
  //       happens with an atomic store into it (we don't care about
  //       consistency with the _number_of_vtable_stubs counter).
  for (int i = 0; i < N; i++) {
    for (VtableStub* s = _table[i]; s != NULL; s = s->next()) {
      if (s->contains(pc)) return s;
    }
  }
  return NULL;
}

bool CompiledIC::is_icholder_entry(address entry) {
  CodeBlob* cb = CodeCache::find_blob_unsafe(entry);
  if (cb != NULL && cb->is_adapter_blob()) {
    return true;
  }
  // itable stubs also use CompiledICHolder
  if (cb != NULL && cb->is_vtable_blob()) {
    VtableStub* s = VtableStubs::entry_point(entry);
    return (s != NULL) && s->is_itable_stub();
  }

  return false;
}

VtableStub* VtableStubs::create_itable_stub(int vtable_index, int receiver_location) {  
  const int i486_code_length = VtableStub::pd_code_size_limit(false);
  VtableStub* s = new(i486_code_length) VtableStub(false, vtable_index, receiver_location);
  ResourceMark rm;
  MacroAssembler* masm = new MacroAssembler(new CodeBuffer(s->entry_point(), i486_code_length));
  
  // Entry arguments:
  //  eax: Interface
  //  ecx: Receiver
  
  // get receiver (need to skip return address on top of stack)
  COMPILER1_ONLY(assert(receiver_location == 0, "receiver is always in ecx - no location info needed");)
 
#ifdef COMPILER2
    if( receiver_location < SharedInfo::stack0 ) {

address VtableStubs::create_stub(bool is_vtable_stub, int vtable_index, methodOop method) {
  assert(vtable_index >= 0, "must be positive");

  VtableStub* s = ShareVtableStubs ? lookup(is_vtable_stub, vtable_index) : NULL;
  if (s == NULL) {
    if (is_vtable_stub) {
      s = create_vtable_stub(vtable_index);
    } else {
      s = create_itable_stub(vtable_index);
    }
    enter(is_vtable_stub, vtable_index, s);
    if (PrintAdapterHandlers) {
      tty->print_cr("Decoding VtableStub %s[%d]@%d",
                    is_vtable_stub? "vtbl": "itbl", vtable_index, VtableStub::receiver_location());
      Disassembler::decode(s->code_begin(), s->code_end());
    }
  }
  return s->entry_point();
}

VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {
  const int code_length = VtableStub::pd_code_size_limit(true);
  VtableStub* s = new(code_length) VtableStub(true, vtable_index);
  // Can be NULL if there is no free space in the code cache.
  if (s == NULL) {
    return NULL;
  }

  ResourceMark rm;
  CodeBuffer cb(s->entry_point(), code_length);
  MacroAssembler* masm = new MacroAssembler(&cb);

  assert(VtableStub::receiver_location() == R0->as_VMReg(), "receiver expected in R0");

  const Register tmp = Rtemp; // Rtemp OK, should be free at call sites

  address npe_addr = __ pc();
  __ load_klass(tmp, R0);

  {
  int entry_offset = in_bytes(Klass::vtable_start_offset()) + vtable_index * vtableEntry::size_in_bytes();
  int method_offset = vtableEntry::method_offset_in_bytes() + entry_offset;

  assert ((method_offset & (wordSize - 1)) == 0, "offset should be aligned");
  int offset_mask = AARCH64_ONLY(0xfff << LogBytesPerWord) NOT_AARCH64(0xfff);
  if (method_offset & ~offset_mask) {
    __ add(tmp, tmp, method_offset & ~offset_mask);
  }
  __ ldr(Rmethod, Address(tmp, method_offset & offset_mask));
  }

  address ame_addr = __ pc();
#ifdef AARCH64
  __ ldr(tmp, Address(Rmethod, Method::from_compiled_offset()));
  __ br(tmp);
#else
  __ ldr(PC, Address(Rmethod, Method::from_compiled_offset()));
#endif // AARCH64

  masm->flush();

  if (PrintMiscellaneous && (WizardMode || Verbose)) {
    tty->print_cr("vtable #%d at " PTR_FORMAT "[%d] left over: %d",
                  vtable_index, p2i(s->entry_point()),
                  (int)(s->code_end() - s->entry_point()),
                  (int)(s->code_end() - __ pc()));
  }
  guarantee(__ pc() <= s->code_end(), "overflowed buffer");
  // FIXME ARM: need correct 'slop' - below is x86 code
  // shut the door on sizing bugs
  //int slop = 8;  // 32-bit offset is this much larger than a 13-bit one
  //assert(vtable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset");

  s->set_exception_points(npe_addr, ame_addr);
  return s;
}

address VtableStubs::find_stub(bool is_vtable_stub, int vtable_index) {
  assert(vtable_index >= 0, "must be positive");

  VtableStub* s = ShareVtableStubs ? lookup(is_vtable_stub, vtable_index) : NULL;
  if (s == NULL) {
    if (is_vtable_stub) {
      s = create_vtable_stub(vtable_index);
    } else {
      s = create_itable_stub(vtable_index);
    }

    // Creation of vtable or itable can fail if there is not enough free space in the code cache.
    if (s == NULL) {
      return NULL;
    }

    enter(is_vtable_stub, vtable_index, s);
    if (PrintAdapterHandlers) {
      tty->print_cr("Decoding VtableStub %s[%d]@%d",
                    is_vtable_stub? "vtbl": "itbl", vtable_index, VtableStub::receiver_location());
      Disassembler::decode(s->code_begin(), s->code_end());
    }
    // Notify JVMTI about this stub. The event will be recorded by the enclosing
    // JvmtiDynamicCodeEventCollector and posted when this thread has released
    // all locks.
    if (JvmtiExport::should_post_dynamic_code_generated()) {
      JvmtiExport::post_dynamic_code_generated_while_holding_locks(is_vtable_stub? "vtable stub": "itable stub",
                                                                   s->code_begin(), s->code_end());
    }
  }
  return s->entry_point();
}

VtableStub* VtableStubs::create_itable_stub(int vtable_index) {
  const int   code_length = VtableStub::pd_code_size_limit(false);
  VtableStub *s = new(code_length) VtableStub(false, vtable_index);
  if (s == NULL) { // Indicates OOM in the code cache.
    return NULL;
  }

  ResourceMark    rm;
  CodeBuffer      cb(s->entry_point(), code_length);
  MacroAssembler *masm = new MacroAssembler(&cb);
  address start_pc;
  int     padding_bytes = 0;

#if (!defined(PRODUCT) && defined(COMPILER2))
  if (CountCompiledCalls) {
    // Count unused bytes
    //                  worst case             actual size
    padding_bytes += __ load_const_size() - __ load_const_optimized_rtn_len(Z_R1_scratch, (long)SharedRuntime::nof_megamorphic_calls_addr(), true);

    // Use generic emitter for direct memory increment.
    // Use Z_tmp_1 as scratch register for generic emitter.
    __ add2mem_32((Z_R1_scratch), 1, Z_tmp_1);
  }
#endif

  assert(VtableStub::receiver_location() == Z_R2->as_VMReg(), "receiver expected in Z_ARG1");

  // Entry arguments:
  //  Z_method: Interface
  //  Z_ARG1:   Receiver
  const Register rcvr_klass = Z_tmp_1;    // Used to compute itable_entry_addr.
                                          // Use extra reg to avoid re-load.
  const Register vtable_len = Z_tmp_2;    // Used to compute itable_entry_addr.
  const Register itable_entry_addr = Z_R1_scratch;
  const Register itable_interface  = Z_R0_scratch;

  // Get receiver klass.
  // Must do an explicit check if implicit checks are disabled.
  address npe_addr = __ pc(); // npe == NULL ptr exception
  __ null_check(Z_ARG1, Z_R1_scratch, oopDesc::klass_offset_in_bytes());
  __ load_klass(rcvr_klass, Z_ARG1);

  // Load start of itable entries into itable_entry.
  __ z_llgf(vtable_len, Address(rcvr_klass, InstanceKlass::vtable_length_offset()));
  __ z_sllg(vtable_len, vtable_len, exact_log2(vtableEntry::size_in_bytes()));

  // Loop over all itable entries until desired interfaceOop(Rinterface) found.
  const int vtable_base_offset = in_bytes(InstanceKlass::vtable_start_offset());
  // Count unused bytes.
  start_pc = __ pc();
  __ add2reg_with_index(itable_entry_addr, vtable_base_offset + itableOffsetEntry::interface_offset_in_bytes(), rcvr_klass, vtable_len);
  padding_bytes += 20 - (__ pc() - start_pc);

  const int itable_offset_search_inc = itableOffsetEntry::size() * wordSize;
  Label search;
  __ bind(search);

  // Handle IncompatibleClassChangeError in itable stubs.
  // If the entry is NULL then we've reached the end of the table
  // without finding the expected interface, so throw an exception.
  NearLabel   throw_icce;
  __ load_and_test_long(itable_interface, Address(itable_entry_addr));
  __ z_bre(throw_icce); // Throw the exception out-of-line.
  // Count unused bytes.
  start_pc = __ pc();
  __ add2reg(itable_entry_addr, itable_offset_search_inc);
  padding_bytes += 20 - (__ pc() - start_pc);
  __ z_cgr(itable_interface, Z_method);
  __ z_brne(search);

  // Entry found. Itable_entry_addr points to the subsequent entry (itable_offset_search_inc too far).
  // Get offset of vtable for interface.

  const Register vtable_offset = Z_R1_scratch;
  const Register itable_method = rcvr_klass;   // Calculated before.

  const int vtable_offset_offset = (itableOffsetEntry::offset_offset_in_bytes() -
                                    itableOffsetEntry::interface_offset_in_bytes()) -
                                   itable_offset_search_inc;
  __ z_llgf(vtable_offset, vtable_offset_offset, itable_entry_addr);

  // Compute itableMethodEntry and get method and entry point for compiler.
  const int method_offset = (itableMethodEntry::size() * wordSize * vtable_index) +
                            itableMethodEntry::method_offset_in_bytes();

  __ z_lg(Z_method, method_offset, vtable_offset, itable_method);

#ifndef PRODUCT
  if (DebugVtables) {
    Label ok1;
    __ z_ltgr(Z_method, Z_method);
    __ z_brne(ok1);
    __ stop("method is null",103);
    __ bind(ok1);
  }
#endif

  address ame_addr = __ pc();
  // Must do an explicit check if implicit checks are disabled.
  if (!ImplicitNullChecks) {
//.........这里部分代码省略.........

VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {
  const int aarch64_code_length = VtableStub::pd_code_size_limit(true);
  VtableStub* s = new(aarch64_code_length) VtableStub(true, vtable_index);
  ResourceMark rm;
  CodeBuffer cb(s->entry_point(), aarch64_code_length);
  MacroAssembler* masm = new MacroAssembler(&cb);

#ifndef PRODUCT
  if (CountCompiledCalls) {
    __ lea(r19, ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
    __ incrementw(Address(r19));
  }
#endif

  // get receiver (need to skip return address on top of stack)
  assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");

  // get receiver klass
  address npe_addr = __ pc();
  __ load_klass(r19, j_rarg0);

#ifndef PRODUCT
  if (DebugVtables) {
    Label L;
    // check offset vs vtable length
    __ ldrw(rscratch1, Address(r19, Klass::vtable_length_offset()));
    __ cmpw(rscratch1, vtable_index * vtableEntry::size());
    __ br(Assembler::GT, L);
    __ enter();
    __ mov(r2, vtable_index);
    __ call_VM(noreg,
               CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), j_rarg0, r2);
    __ leave();
    __ bind(L);
  }
#endif // PRODUCT

  __ lookup_virtual_method(r19, vtable_index, rmethod);

  if (DebugVtables) {
    Label L;
    __ cbz(rmethod, L);
    __ ldr(rscratch1, Address(rmethod, Method::from_compiled_offset()));
    __ cbnz(rscratch1, L);
    __ stop("Vtable entry is NULL");
    __ bind(L);
  }
  // r0: receiver klass
  // rmethod: Method*
  // r2: receiver
  address ame_addr = __ pc();
  __ ldr(rscratch1, Address(rmethod, Method::from_compiled_offset()));
  __ br(rscratch1);

  __ flush();

  if (PrintMiscellaneous && (WizardMode || Verbose)) {
    tty->print_cr("vtable #%d at " PTR_FORMAT "[%d] left over: %d",
                  vtable_index, p2i(s->entry_point()),
                  (int)(s->code_end() - s->entry_point()),
                  (int)(s->code_end() - __ pc()));
  }
  guarantee(__ pc() <= s->code_end(), "overflowed buffer");

  s->set_exception_points(npe_addr, ame_addr);
  return s;
}

VtableStub* VtableStubs::create_itable_stub(int itable_index) {
  // Note well: pd_code_size_limit is the absolute minimum we can get away with.  If you
  //            add code here, bump the code stub size returned by pd_code_size_limit!
  const int i486_code_length = VtableStub::pd_code_size_limit(false);
  VtableStub* s = new(i486_code_length) VtableStub(false, itable_index);
  // Can be NULL if there is no free space in the code cache.
  if (s == NULL) {
    return NULL;
  }

  ResourceMark rm;
  CodeBuffer cb(s->entry_point(), i486_code_length);
  MacroAssembler* masm = new MacroAssembler(&cb);

  // Entry arguments:
  //  rax,: Interface
  //  rcx: Receiver

#ifndef PRODUCT
  if (CountCompiledCalls) {
    __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
  }
#endif /* PRODUCT */
  // get receiver (need to skip return address on top of stack)

  assert(VtableStub::receiver_location() == rcx->as_VMReg(), "receiver expected in rcx");

  // get receiver klass (also an implicit null-check)
  address npe_addr = __ pc();
  __ movptr(rsi, Address(rcx, oopDesc::klass_offset_in_bytes()));

  // Most registers are in use; we'll use rax, rbx, rsi, rdi
  // (If we need to make rsi, rdi callee-save, do a push/pop here.)
  const Register method = rbx;
  Label throw_icce;

  // Get Method* and entrypoint for compiler
  __ lookup_interface_method(// inputs: rec. class, interface, itable index
                             rsi, rax, itable_index,
                             // outputs: method, scan temp. reg
                             method, rdi,
                             throw_icce);

  // method (rbx): Method*
  // rcx: receiver

#ifdef ASSERT
  if (DebugVtables) {
      Label L1;
      __ cmpptr(method, (int32_t)NULL_WORD);
      __ jcc(Assembler::equal, L1);
      __ cmpptr(Address(method, Method::from_compiled_offset()), (int32_t)NULL_WORD);
      __ jcc(Assembler::notZero, L1);
      __ stop("Method* is null");
      __ bind(L1);
    }
#endif // ASSERT

  address ame_addr = __ pc();
  __ jmp(Address(method, Method::from_compiled_offset()));

  __ bind(throw_icce);
  __ jump(RuntimeAddress(StubRoutines::throw_IncompatibleClassChangeError_entry()));
  masm->flush();

  if (PrintMiscellaneous && (WizardMode || Verbose)) {
    tty->print_cr("itable #%d at "PTR_FORMAT"[%d] left over: %d",
                  itable_index, s->entry_point(),
                  (int)(s->code_end() - s->entry_point()),
                  (int)(s->code_end() - __ pc()));
  }
  guarantee(__ pc() <= s->code_end(), "overflowed buffer");
  // shut the door on sizing bugs
  int slop = 3;  // 32-bit offset is this much larger than an 8-bit one
  assert(itable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset");

  s->set_exception_points(npe_addr, ame_addr);
  return s;
}

VtableStub* VtableStubs::create_itable_stub(int itable_index) {
  // Note well: pd_code_size_limit is the absolute minimum we can get
  // away with.  If you add code here, bump the code stub size
  // returned by pd_code_size_limit!
  const int amd64_code_length = VtableStub::pd_code_size_limit(false);
  VtableStub* s = new(amd64_code_length) VtableStub(false, itable_index);
  ResourceMark rm;
  CodeBuffer cb(s->entry_point(), amd64_code_length);
  MacroAssembler* masm = new MacroAssembler(&cb);

#ifndef PRODUCT
  if (CountCompiledCalls) {
    __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
  }
#endif

  // Entry arguments:
  //  rax: Interface
  //  j_rarg0: Receiver

  // Free registers (non-args) are rax (interface), rbx

  // get receiver (need to skip return address on top of stack)

  assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");
  // get receiver klass (also an implicit null-check)
  address npe_addr = __ pc();

  // Most registers are in use; we'll use rax, rbx, r10, r11
  // (various calling sequences use r[cd]x, r[sd]i, r[89]; stay away from them)
  __ load_klass(r10, j_rarg0);

  // If we take a trap while this arg is on the stack we will not
  // be able to walk the stack properly. This is not an issue except
  // when there are mistakes in this assembly code that could generate
  // a spurious fault. Ask me how I know...

  const Register method = rbx;
  Label throw_icce;

  // Get methodOop and entrypoint for compiler
  __ lookup_interface_method(// inputs: rec. class, interface, itable index
                             r10, rax, itable_index,
                             // outputs: method, scan temp. reg
                             method, r11,
                             throw_icce);

  // method (rbx): methodOop
  // j_rarg0: receiver

#ifdef ASSERT
  if (DebugVtables) {
    Label L2;
    __ cmpptr(method, (int32_t)NULL_WORD);
    __ jcc(Assembler::equal, L2);
    __ cmpptr(Address(method, methodOopDesc::from_compiled_offset()), (int32_t)NULL_WORD);
    __ jcc(Assembler::notZero, L2);
    __ stop("compiler entrypoint is null");
    __ bind(L2);
  }
#endif // ASSERT

  // rbx: methodOop
  // j_rarg0: receiver
  address ame_addr = __ pc();
  __ jmp(Address(method, methodOopDesc::from_compiled_offset()));

  __ bind(throw_icce);
  __ jump(RuntimeAddress(StubRoutines::throw_IncompatibleClassChangeError_entry()));

  __ flush();

  if (PrintMiscellaneous && (WizardMode || Verbose)) {
    tty->print_cr("itable #%d at "PTR_FORMAT"[%d] left over: %d",
                  itable_index, s->entry_point(),
                  (int)(s->code_end() - s->entry_point()),
                  (int)(s->code_end() - __ pc()));
  }
  guarantee(__ pc() <= s->code_end(), "overflowed buffer");
  // shut the door on sizing bugs
  int slop = 3;  // 32-bit offset is this much larger than an 8-bit one
  assert(itable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset");

  s->set_exception_points(npe_addr, ame_addr);
  return s;
}

// NOTE:  %%%% if any change is made to this stub make sure that the function
//             pd_code_size_limit is changed to ensure the correct size for VtableStub
VtableStub* VtableStubs::create_itable_stub(int itable_index) {
  const int sparc_code_length = VtableStub::pd_code_size_limit(false);
  VtableStub* s = new(sparc_code_length) VtableStub(false, itable_index);
  // Can be NULL if there is no free space in the code cache.
  if (s == NULL) {
    return NULL;
  }

  ResourceMark rm;
  CodeBuffer cb(s->entry_point(), sparc_code_length);
  MacroAssembler* masm = new MacroAssembler(&cb);

  Register G3_Klass = G3_scratch;
  Register G5_interface = G5;  // Passed in as an argument
  Label search;

  // Entry arguments:
  //  G5_interface: Interface
  //  O0:           Receiver
  assert(VtableStub::receiver_location() == O0->as_VMReg(), "receiver expected in O0");

  // get receiver klass (also an implicit null-check)
  address npe_addr = __ pc();
  __ load_klass(O0, G3_Klass);

  // Push a new window to get some temp registers.  This chops the head of all
  // my 64-bit %o registers in the LION build, but this is OK because no longs
  // are passed in the %o registers.  Instead, longs are passed in G1 and G4
  // and so those registers are not available here.
  __ save(SP,-frame::register_save_words*wordSize,SP);

#ifndef PRODUCT
  if (CountCompiledCalls) {
    __ inc_counter(SharedRuntime::nof_megamorphic_calls_addr(), L0, L1);
  }
#endif /* PRODUCT */

  Label throw_icce;

  Register L5_method = L5;
  __ lookup_interface_method(// inputs: rec. class, interface, itable index
                             G3_Klass, G5_interface, itable_index,
                             // outputs: method, scan temp. reg
                             L5_method, L2, L3,
                             throw_icce);

#ifndef PRODUCT
  if (DebugVtables) {
    Label L01;
    __ br_notnull_short(L5_method, Assembler::pt, L01);
    __ stop("Method* is null");
    __ bind(L01);
  }
#endif

  // If the following load is through a NULL pointer, we'll take an OS
  // exception that should translate into an AbstractMethodError.  We need the
  // window count to be correct at that time.
  __ restore(L5_method, 0, G5_method);
  // Restore registers *before* the AME point.

  address ame_addr = __ pc();   // if the vtable entry is null, the method is abstract
  __ ld_ptr(G5_method, in_bytes(Method::from_compiled_offset()), G3_scratch);

  // G5_method:  Method*
  // O0:         Receiver
  // G3_scratch: entry point
  __ JMP(G3_scratch, 0);
  __ delayed()->nop();

  __ bind(throw_icce);
  AddressLiteral icce(StubRoutines::throw_IncompatibleClassChangeError_entry());
  __ jump_to(icce, G3_scratch);
  __ delayed()->restore();

  masm->flush();

  if (PrintMiscellaneous && (WizardMode || Verbose)) {
    tty->print_cr("itable #%d at " PTR_FORMAT "[%d] left over: %d",
                  itable_index, p2i(s->entry_point()),
                  (int)(s->code_end() - s->entry_point()),
                  (int)(s->code_end() - __ pc()));
  }
  guarantee(__ pc() <= s->code_end(), "overflowed buffer");
  // shut the door on sizing bugs
  int slop = 2*BytesPerInstWord;  // 32-bit offset is this much larger than a 13-bit one
  assert(itable_index > 10 || __ pc() + slop <= s->code_end(), "room for sethi;add");

  s->set_exception_points(npe_addr, ame_addr);
  return s;
}

VtableStub* VtableStubs::create_itable_stub(int itable_index) {
  // PPC port: use fixed size.
  const int code_length = VtableStub::pd_code_size_limit(false);
  VtableStub* s = new (code_length) VtableStub(false, itable_index);

  // Can be NULL if there is no free space in the code cache.
  if (s == NULL) {
    return NULL;
  }

  ResourceMark rm;
  CodeBuffer cb(s->entry_point(), code_length);
  MacroAssembler* masm = new MacroAssembler(&cb);
  address start_pc;

#ifndef PRODUCT
  if (CountCompiledCalls) {
    int offs = __ load_const_optimized(R11_scratch1, SharedRuntime::nof_megamorphic_calls_addr(), R12_scratch2, true);
    __ lwz(R12_scratch2, offs, R11_scratch1);
    __ addi(R12_scratch2, R12_scratch2, 1);
    __ stw(R12_scratch2, offs, R11_scratch1);
  }
#endif

  assert(VtableStub::receiver_location() == R3_ARG1->as_VMReg(), "receiver expected in R3_ARG1");

  // Entry arguments:
  //  R19_method: Interface
  //  R3_ARG1:    Receiver

  Label L_no_such_interface;
  const Register rcvr_klass = R11_scratch1,
                 interface  = R12_scratch2,
                 tmp1       = R21_tmp1,
                 tmp2       = R22_tmp2;

  address npe_addr = __ pc(); // npe = null pointer exception
  __ load_klass_with_trap_null_check(rcvr_klass, R3_ARG1);

  // Receiver subtype check against REFC.
  __ ld(interface, CompiledICHolder::holder_klass_offset(), R19_method);
  __ lookup_interface_method(rcvr_klass, interface, noreg,
                             R0, tmp1, tmp2,
                             L_no_such_interface, /*return_method=*/ false);

  // Get Method* and entrypoint for compiler
  __ ld(interface, CompiledICHolder::holder_metadata_offset(), R19_method);
  __ lookup_interface_method(rcvr_klass, interface, itable_index,
                             R19_method, tmp1, tmp2,
                             L_no_such_interface, /*return_method=*/ true);

#ifndef PRODUCT
  if (DebugVtables) {
    Label ok;
    __ cmpd(CCR0, R19_method, 0);
    __ bne(CCR0, ok);
    __ stop("method is null", 103);
    __ bind(ok);
  }
#endif

  // If the vtable entry is null, the method is abstract.
  address ame_addr = __ pc(); // ame = abstract method error

  // Must do an explicit check if implicit checks are disabled.
  assert(!MacroAssembler::needs_explicit_null_check(in_bytes(Method::from_compiled_offset())), "sanity");
  if (!ImplicitNullChecks || !os::zero_page_read_protected()) {
    if (TrapBasedNullChecks) {
      __ trap_null_check(R19_method);
    } else {
      __ cmpdi(CCR0, R19_method, 0);
      __ beq(CCR0, L_no_such_interface);
    }
  }
  __ ld(R12_scratch2, in_bytes(Method::from_compiled_offset()), R19_method);
  __ mtctr(R12_scratch2);
  __ bctr();

  // Handle IncompatibleClassChangeError in itable stubs.
  // More detailed error message.
  // We force resolving of the call site by jumping to the "handle
  // wrong method" stub, and so let the interpreter runtime do all the
  // dirty work.
  __ bind(L_no_such_interface);
  __ load_const_optimized(R11_scratch1, SharedRuntime::get_handle_wrong_method_stub(), R12_scratch2);
  __ mtctr(R11_scratch1);
  __ bctr();

  masm->flush();

  guarantee(__ pc() <= s->code_end(), "overflowed buffer");

  s->set_exception_points(npe_addr, ame_addr);
  return s;
}

static void find(intptr_t x, bool print_pc) {
  address addr = (address)x;

  CodeBlob* b = CodeCache::find_blob_unsafe(addr);
  if (b != NULL) {
    if (b->is_buffer_blob()) {
      // the interpreter is generated into a buffer blob
      InterpreterCodelet* i = Interpreter::codelet_containing(addr);
      if (i != NULL) {
        i->print();
        return;
      }
      if (Interpreter::contains(addr)) {
        tty->print_cr(INTPTR_FORMAT " is pointing into interpreter code (not bytecode specific)", addr);
        return;
      }
      //
      if (AdapterHandlerLibrary::contains(b)) {
        AdapterHandlerLibrary::print_handler(b);
      }
      // the stubroutines are generated into a buffer blob
      StubCodeDesc* d = StubCodeDesc::desc_for(addr);
      if (d != NULL) {
        d->print();
        if (print_pc) tty->cr();
        return;
      }
      if (StubRoutines::contains(addr)) {
        tty->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) stub routine", addr);
        return;
      }
      // the InlineCacheBuffer is using stubs generated into a buffer blob
      if (InlineCacheBuffer::contains(addr)) {
        tty->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
        return;
      }
      VtableStub* v = VtableStubs::stub_containing(addr);
      if (v != NULL) {
        v->print();
        return;
      }
    }
    if (print_pc && b->is_nmethod()) {
      ResourceMark rm;
      tty->print("%#p: Compiled ", addr);
      ((nmethod*)b)->method()->print_value_on(tty);
      tty->print("  = (CodeBlob*)" INTPTR_FORMAT, b);
      tty->cr();
      return;
    }
    if ( b->is_nmethod()) {
      if (b->is_zombie()) {
        tty->print_cr(INTPTR_FORMAT " is zombie nmethod", b);
      } else if (b->is_not_entrant()) {
        tty->print_cr(INTPTR_FORMAT " is non-entrant nmethod", b);
      }
    }
    b->print();
    return;
  }

  if (Universe::heap()->is_in(addr)) {
    HeapWord* p = Universe::heap()->block_start(addr);
    bool print = false;
    // If we couldn't find it it just may mean that heap wasn't parseable
    // See if we were just given an oop directly
    if (p != NULL && Universe::heap()->block_is_obj(p)) {
      print = true;
    } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
      p = (HeapWord*) addr;
      print = true;
    }
    if (print) {
      oop(p)->print();
      if (p != (HeapWord*)x && oop(p)->is_constMethod() &&
          constMethodOop(p)->contains(addr)) {
        Thread *thread = Thread::current();
        HandleMark hm(thread);
        methodHandle mh (thread, constMethodOop(p)->method());
        if (!mh->is_native()) {
          tty->print_cr("bci_from(%p) = %d; print_codes():",
                        addr, mh->bci_from(address(x)));
          mh->print_codes();
        }
      }
      return;
    }
  } else if (Universe::heap()->is_in_reserved(addr)) {
    tty->print_cr(INTPTR_FORMAT " is an unallocated location in the heap", addr);
    return;
  }

  if (JNIHandles::is_global_handle((jobject) addr)) {
    tty->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
    return;
  }
  if (JNIHandles::is_weak_global_handle((jobject) addr)) {
    tty->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
    return;
  }
//.........这里部分代码省略.........