interp_masm_x86_64.cpp

/*
 * Copyright 2003-2007 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */

#include "incls/_precompiled.incl"
#include "incls/_interp_masm_x86_64.cpp.incl"


// Implementation of InterpreterMacroAssembler

void InterpreterMacroAssembler::call_VM_leaf_base(address entry_point,
                                                  int number_of_arguments) {
  // interpreter specific
  //
  // Note: No need to save/restore bcp & locals (r13 & r14) pointer
  //       since these are callee saved registers and no blocking/
  //       GC can happen in leaf calls.
  // Further Note: DO NOT save/restore bcp/locals. If a caller has
  // already saved them so that it can use esi/edi as temporaries
  // then a save/restore here will DESTROY the copy the caller
  // saved! There used to be a save_bcp() that only happened in
  // the ASSERT path (no restore_bcp). Which caused bizarre failures
  // when jvm built with ASSERTs.
#ifdef ASSERT
  {
    Label L;
    cmpq(Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize), (int)NULL_WORD);
    jcc(Assembler::equal, L);
    stop("InterpreterMacroAssembler::call_VM_leaf_base:"
         " last_sp != NULL");
    bind(L);
  }
#endif
  // super call
  MacroAssembler::call_VM_leaf_base(entry_point, number_of_arguments);
  // interpreter specific
  // Used to ASSERT that r13/r14 were equal to frame's bcp/locals
  // but since they may not have been saved (and we don't want to
  // save thme here (see note above) the assert is invalid.
}

void InterpreterMacroAssembler::call_VM_base(Register oop_result,
                                             Register java_thread,
                                             Register last_java_sp,
                                             address  entry_point,
                                             int      number_of_arguments,
                                             bool     check_exceptions) {
  // interpreter specific
  //
  // Note: Could avoid restoring locals ptr (callee saved) - however doesn't
  //       really make a difference for these runtime calls, since they are
  //       slow anyway. Btw., bcp must be saved/restored since it may change
  //       due to GC.
  // assert(java_thread == noreg , "not expecting a precomputed java thread");
  save_bcp();
#ifdef ASSERT
  {
    Label L;
    cmpq(Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize), (int)NULL_WORD);
    jcc(Assembler::equal, L);
    stop("InterpreterMacroAssembler::call_VM_leaf_base:"
         " last_sp != NULL");
    bind(L);
  }
#endif /* ASSERT */
  // super call
  MacroAssembler::call_VM_base(oop_result, noreg, last_java_sp,
                               entry_point, number_of_arguments,
                               check_exceptions);
  // interpreter specific
  restore_bcp();
  restore_locals();
}


void InterpreterMacroAssembler::check_and_handle_popframe(Register java_thread) {
  if (JvmtiExport::can_pop_frame()) {
    Label L;
    // Initiate popframe handling only if it is not already being
    // processed.  If the flag has the popframe_processing bit set, it
    // means that this code is called *during* popframe handling - we
    // don't want to reenter.
    // This method is only called just after the call into the vm in
    // call_VM_base, so the arg registers are available.
    movl(c_rarg0, Address(r15_thread, JavaThread::popframe_condition_offset()));
    testl(c_rarg0, JavaThread::popframe_pending_bit);
    jcc(Assembler::zero, L);
    testl(c_rarg0, JavaThread::popframe_processing_bit);
    jcc(Assembler::notZero, L);
    // Call Interpreter::remove_activation_preserving_args_entry() to get the
    // address of the same-named entrypoint in the generated interpreter code.
    call_VM_leaf(CAST_FROM_FN_PTR(address, Interpreter::remove_activation_preserving_args_entry));
    jmp(rax);
    bind(L);
  }
}


void InterpreterMacroAssembler::load_earlyret_value(TosState state) {
  movq(rcx, Address(r15_thread, JavaThread::jvmti_thread_state_offset()));
  const Address tos_addr(rcx, JvmtiThreadState::earlyret_tos_offset());
  const Address oop_addr(rcx, JvmtiThreadState::earlyret_oop_offset());
  const Address val_addr(rcx, JvmtiThreadState::earlyret_value_offset());
  switch (state) {
    case atos: movq(rax, oop_addr);
               movptr(oop_addr, NULL_WORD);
               verify_oop(rax, state);              break;
    case ltos: movq(rax, val_addr);                 break;
    case btos:                                   // fall through
    case ctos:                                   // fall through
    case stos:                                   // fall through
    case itos: movl(rax, val_addr);                 break;
    case ftos: movflt(xmm0, val_addr);              break;
    case dtos: movdbl(xmm0, val_addr);              break;
    case vtos: /* nothing to do */                  break;
    default  : ShouldNotReachHere();
  }
  // Clean up tos value in the thread object
  movl(tos_addr,  (int) ilgl);
  movl(val_addr,  (int) NULL_WORD);
}


void InterpreterMacroAssembler::check_and_handle_earlyret(Register java_thread) {
  if (JvmtiExport::can_force_early_return()) {
    Label L;
    movq(c_rarg0, Address(r15_thread, JavaThread::jvmti_thread_state_offset()));
    testq(c_rarg0, c_rarg0);
    jcc(Assembler::zero, L); // if (thread->jvmti_thread_state() == NULL) exit;

    // Initiate earlyret handling only if it is not already being processed.
    // If the flag has the earlyret_processing bit set, it means that this code
    // is called *during* earlyret handling - we don't want to reenter.
    movl(c_rarg0, Address(c_rarg0, JvmtiThreadState::earlyret_state_offset()));
    cmpl(c_rarg0, JvmtiThreadState::earlyret_pending);
    jcc(Assembler::notEqual, L);

    // Call Interpreter::remove_activation_early_entry() to get the address of the
    // same-named entrypoint in the generated interpreter code.
    movq(c_rarg0, Address(r15_thread, JavaThread::jvmti_thread_state_offset()));
    movl(c_rarg0, Address(c_rarg0, JvmtiThreadState::earlyret_tos_offset()));
    call_VM_leaf(CAST_FROM_FN_PTR(address, Interpreter::remove_activation_early_entry), c_rarg0);
    jmp(rax);
    bind(L);
  }
}


void InterpreterMacroAssembler::get_unsigned_2_byte_index_at_bcp(
  Register reg,
  int bcp_offset) {
  assert(bcp_offset >= 0, "bcp is still pointing to start of bytecode");
  movl(reg, Address(r13, bcp_offset));
  bswapl(reg);
  shrl(reg, 16);
}


void InterpreterMacroAssembler::get_cache_and_index_at_bcp(Register cache,
                                                           Register index,
                                                           int bcp_offset) {
  assert(bcp_offset > 0, "bcp is still pointing to start of bytecode");
  assert(cache != index, "must use different registers");
  load_unsigned_word(index, Address(r13, bcp_offset));
  movq(cache, Address(rbp, frame::interpreter_frame_cache_offset * wordSize));
  assert(sizeof(ConstantPoolCacheEntry) == 4 * wordSize, "adjust code below");
  // convert from field index to ConstantPoolCacheEntry index
  shll(index, 2);
}


void InterpreterMacroAssembler::get_cache_entry_pointer_at_bcp(Register cache,
                                                               Register tmp,
                                                               int bcp_offset) {
  assert(bcp_offset > 0, "bcp is still pointing to start of bytecode");
  assert(cache != tmp, "must use different register");
  load_unsigned_word(tmp, Address(r13, bcp_offset));
  assert(sizeof(ConstantPoolCacheEntry) == 4 * wordSize, "adjust code below");
  // convert from field index to ConstantPoolCacheEntry index
  // and from word offset to byte offset
  shll(tmp, 2 + LogBytesPerWord);
  movq(cache, Address(rbp, frame::interpreter_frame_cache_offset * wordSize));
  // skip past the header
  addq(cache, in_bytes(constantPoolCacheOopDesc::base_offset()));
  addq(cache, tmp);  // construct pointer to cache entry
}


// Generate a subtype check: branch to ok_is_subtype if sub_klass is a
// subtype of super_klass.
//
// Args:
//      rax: superklass
//      Rsub_klass: subklass
//
// Kills:
//      rcx, rdi
void InterpreterMacroAssembler::gen_subtype_check(Register Rsub_klass,
                                                  Label& ok_is_subtype) {
  assert(Rsub_klass != rax, "rax holds superklass");
  assert(Rsub_klass != r14, "r14 holds locals");
  assert(Rsub_klass != r13, "r13 holds bcp");
  assert(Rsub_klass != rcx, "rcx holds 2ndary super array length");
  assert(Rsub_klass != rdi, "rdi holds 2ndary super array scan ptr");

  Label not_subtype, loop;

  // Profile the not-null value's klass.
  profile_typecheck(rcx, Rsub_klass, rdi); // blows rcx, rdi

  // Load the super-klass's check offset into rcx
  movl(rcx, Address(rax, sizeof(oopDesc) +
                    Klass::super_check_offset_offset_in_bytes()));
  // Load from the sub-klass's super-class display list, or a 1-word
  // cache of the secondary superclass list, or a failing value with a
  // sentinel offset if the super-klass is an interface or
  // exceptionally deep in the Java hierarchy and we have to scan the
  // secondary superclass list the hard way.  See if we get an
  // immediate positive hit
  cmpq(rax, Address(Rsub_klass, rcx, Address::times_1));
  jcc(Assembler::equal,ok_is_subtype);

  // Check for immediate negative hit
  cmpl(rcx, sizeof(oopDesc) + Klass::secondary_super_cache_offset_in_bytes());
  jcc( Assembler::notEqual, not_subtype );
  // Check for self
  cmpq(Rsub_klass, rax);
  jcc(Assembler::equal, ok_is_subtype);

  // Now do a linear scan of the secondary super-klass chain.
  movq(rdi, Address(Rsub_klass, sizeof(oopDesc) +
                    Klass::secondary_supers_offset_in_bytes()));
  // rdi holds the objArrayOop of secondary supers.
  // Load the array length
  movl(rcx, Address(rdi, arrayOopDesc::length_offset_in_bytes()));
  // Skip to start of data; also clear Z flag incase rcx is zero
  addq(rdi, arrayOopDesc::base_offset_in_bytes(T_OBJECT));
  // Scan rcx words at [rdi] for occurance of rax
  // Set NZ/Z based on last compare

  // this part is kind tricky, as values in supers array could be 32 or 64 bit wide
  // and we store values in objArrays always encoded, thus we need to encode value
  // before repne
  if (UseCompressedOops) {
    encode_heap_oop(rax);
    repne_scanl();
    // Not equal?
    jcc(Assembler::notEqual, not_subtype);
    // decode heap oop here for movq
    decode_heap_oop(rax);
  } else {
    repne_scanq();
    jcc(Assembler::notEqual, not_subtype);
  }
  // Must be equal but missed in cache.  Update cache.
  movq(Address(Rsub_klass, sizeof(oopDesc) +
               Klass::secondary_super_cache_offset_in_bytes()), rax);
  jmp(ok_is_subtype);

  bind(not_subtype);
  // decode heap oop here for miss
  if (UseCompressedOops) decode_heap_oop(rax);
  profile_typecheck_failed(rcx); // blows rcx
}


// Java Expression Stack

#ifdef ASSERT
// Verifies that the stack tag matches.  Must be called before the stack
// value is popped off the stack.
void InterpreterMacroAssembler::verify_stack_tag(frame::Tag t) {
  if (TaggedStackInterpreter) {
    frame::Tag tag = t;
    if (t == frame::TagCategory2) {
      tag = frame::TagValue;
      Label hokay;
      cmpq(Address(rsp, 3*wordSize), (int)tag);
      jcc(Assembler::equal, hokay);
      stop("Java Expression stack tag high value is bad");
      bind(hokay);
    }
    Label okay;
    cmpq(Address(rsp, wordSize), (int)tag);
    jcc(Assembler::equal, okay);
    // Also compare if the stack value is zero, then the tag might
    // not have been set coming from deopt.
    cmpq(Address(rsp, 0), 0);
    jcc(Assembler::equal, okay);
    stop("Java Expression stack tag value is bad");
    bind(okay);
  }
}
#endif // ASSERT

void InterpreterMacroAssembler::pop_ptr(Register r) {
  debug_only(verify_stack_tag(frame::TagReference));
  popq(r);
  if (TaggedStackInterpreter) addq(rsp, 1 * wordSize);
}

void InterpreterMacroAssembler::pop_ptr(Register r, Register tag) {
  popq(r);
  if (TaggedStackInterpreter) popq(tag);
}

void InterpreterMacroAssembler::pop_i(Register r) {
  // XXX can't use popq currently, upper half non clean
  debug_only(verify_stack_tag(frame::TagValue));
  movl(r, Address(rsp, 0));
  addq(rsp, wordSize);
  if (TaggedStackInterpreter) addq(rsp, 1 * wordSize);
}

void InterpreterMacroAssembler::pop_l(Register r) {
  debug_only(verify_stack_tag(frame::TagCategory2));
  movq(r, Address(rsp, 0));
  addq(rsp, 2 * Interpreter::stackElementSize());
}

void InterpreterMacroAssembler::pop_f(XMMRegister r) {
  debug_only(verify_stack_tag(frame::TagValue));
  movflt(r, Address(rsp, 0));
  addq(rsp, wordSize);
  if (TaggedStackInterpreter) addq(rsp, 1 * wordSize);
}

void InterpreterMacroAssembler::pop_d(XMMRegister r) {
  debug_only(verify_stack_tag(frame::TagCategory2));
  movdbl(r, Address(rsp, 0));
  addq(rsp, 2 * Interpreter::stackElementSize());
}

void InterpreterMacroAssembler::push_ptr(Register r) {
  if (TaggedStackInterpreter) pushq(frame::TagReference);
  pushq(r);
}

void InterpreterMacroAssembler::push_ptr(Register r, Register tag) {
  if (TaggedStackInterpreter) pushq(tag);
  pushq(r);
}

void InterpreterMacroAssembler::push_i(Register r) {
  if (TaggedStackInterpreter) pushq(frame::TagValue);
  pushq(r);
}

void InterpreterMacroAssembler::push_l(Register r) {
  if (TaggedStackInterpreter) {
    pushq(frame::TagValue);
    subq(rsp, 1 * wordSize);
    pushq(frame::TagValue);
    subq(rsp, 1 * wordSize);
  } else {
    subq(rsp, 2 * wordSize);
  }
  movq(Address(rsp, 0), r);
}

void InterpreterMacroAssembler::push_f(XMMRegister r) {
  if (TaggedStackInterpreter) pushq(frame::TagValue);
  subq(rsp, wordSize);
  movflt(Address(rsp, 0), r);
}

void InterpreterMacroAssembler::push_d(XMMRegister r) {
  if (TaggedStackInterpreter) {
    pushq(frame::TagValue);
    subq(rsp, 1 * wordSize);
    pushq(frame::TagValue);
    subq(rsp, 1 * wordSize);
  } else {
    subq(rsp, 2 * wordSize);
  }
  movdbl(Address(rsp, 0), r);
}

void InterpreterMacroAssembler::pop(TosState state) {
  switch (state) {
  case atos: pop_ptr();                 break;
  case btos:
  case ctos:
  case stos:
  case itos: pop_i();                   break;
  case ltos: pop_l();                   break;
  case ftos: pop_f();                   break;
  case dtos: pop_d();                   break;
  case vtos: /* nothing to do */        break;
  default:   ShouldNotReachHere();
  }
  verify_oop(rax, state);
}

void InterpreterMacroAssembler::push(TosState state) {
  verify_oop(rax, state);
  switch (state) {
  case atos: push_ptr();                break;
  case btos:
  case ctos:
  case stos:
  case itos: push_i();                  break;
  case ltos: push_l();                  break;
  case ftos: push_f();                  break;
  case dtos: push_d();                  break;
  case vtos: /* nothing to do */        break;
  default  : ShouldNotReachHere();
  }
}


// Tagged stack helpers for swap and dup
void InterpreterMacroAssembler::load_ptr_and_tag(int n, Register val,
                                                 Register tag) {
  movq(val, Address(rsp, Interpreter::expr_offset_in_bytes(n)));
  if (TaggedStackInterpreter) {
    movq(tag, Address(rsp, Interpreter::expr_tag_offset_in_bytes(n)));
  }
}

void InterpreterMacroAssembler::store_ptr_and_tag(int n, Register val,
                                                  Register tag) {
  movq(Address(rsp, Interpreter::expr_offset_in_bytes(n)), val);
  if (TaggedStackInterpreter) {
    movq(Address(rsp, Interpreter::expr_tag_offset_in_bytes(n)), tag);
  }
}


// Tagged local support
void InterpreterMacroAssembler::tag_local(frame::Tag tag, int n) {
  if (TaggedStackInterpreter) {
    if (tag == frame::TagCategory2) {
      mov64(Address(r14, Interpreter::local_tag_offset_in_bytes(n+1)),
           (intptr_t)frame::TagValue);
      mov64(Address(r14, Interpreter::local_tag_offset_in_bytes(n)),
           (intptr_t)frame::TagValue);
    } else {
      mov64(Address(r14, Interpreter::local_tag_offset_in_bytes(n)), (intptr_t)tag);
    }
  }
}

void InterpreterMacroAssembler::tag_local(frame::Tag tag, Register idx) {
  if (TaggedStackInterpreter) {
    if (tag == frame::TagCategory2) {
      mov64(Address(r14, idx, Address::times_8,
                  Interpreter::local_tag_offset_in_bytes(1)), (intptr_t)frame::TagValue);
      mov64(Address(r14, idx, Address::times_8,
                  Interpreter::local_tag_offset_in_bytes(0)), (intptr_t)frame::TagValue);
    } else {
      mov64(Address(r14, idx, Address::times_8, Interpreter::local_tag_offset_in_bytes(0)),
           (intptr_t)tag);
    }
  }
}

void InterpreterMacroAssembler::tag_local(Register tag, Register idx) {
  if (TaggedStackInterpreter) {
    // can only be TagValue or TagReference
    movq(Address(r14, idx, Address::times_8, Interpreter::local_tag_offset_in_bytes(0)), tag);
  }
}


void InterpreterMacroAssembler::tag_local(Register tag, int n) {
  if (TaggedStackInterpreter) {
    // can only be TagValue or TagReference
    movq(Address(r14, Interpreter::local_tag_offset_in_bytes(n)), tag);
  }
}

#ifdef ASSERT
void InterpreterMacroAssembler::verify_local_tag(frame::Tag tag, int n) {
  if (TaggedStackInterpreter) {
     frame::Tag t = tag;
    if (tag == frame::TagCategory2) {
      Label nbl;
      t = frame::TagValue;  // change to what is stored in locals
      cmpq(Address(r14, Interpreter::local_tag_offset_in_bytes(n+1)), (int)t);
      jcc(Assembler::equal, nbl);
      stop("Local tag is bad for long/double");
      bind(nbl);
    }
    Label notBad;
    cmpq(Address(r14, Interpreter::local_tag_offset_in_bytes(n)), (int)t);
    jcc(Assembler::equal, notBad);
    // Also compare if the local value is zero, then the tag might
    // not have been set coming from deopt.
    cmpq(Address(r14, Interpreter::local_offset_in_bytes(n)), 0);
    jcc(Assembler::equal, notBad);
    stop("Local tag is bad");
    bind(notBad);
  }
}

void InterpreterMacroAssembler::verify_local_tag(frame::Tag tag, Register idx) {
  if (TaggedStackInterpreter) {
    frame::Tag t = tag;
    if (tag == frame::TagCategory2) {
      Label nbl;
      t = frame::TagValue;  // change to what is stored in locals
      cmpq(Address(r14, idx, Address::times_8, Interpreter::local_tag_offset_in_bytes(1)), (int)t);
      jcc(Assembler::equal, nbl);
      stop("Local tag is bad for long/double");
      bind(nbl);
    }
    Label notBad;
    cmpq(Address(r14, idx, Address::times_8, Interpreter::local_tag_offset_in_bytes(0)), (int)t);
    jcc(Assembler::equal, notBad);
    // Also compare if the local value is zero, then the tag might
    // not have been set coming from deopt.
    cmpq(Address(r14, idx, Address::times_8, Interpreter::local_offset_in_bytes(0)), 0);
    jcc(Assembler::equal, notBad);
    stop("Local tag is bad");
    bind(notBad);
  }
}
#endif // ASSERT


void InterpreterMacroAssembler::super_call_VM_leaf(address entry_point) {
  MacroAssembler::call_VM_leaf_base(entry_point, 0);
}


void InterpreterMacroAssembler::super_call_VM_leaf(address entry_point,
                                                   Register arg_1) {
  if (c_rarg0 != arg_1) {
    movq(c_rarg0, arg_1);
  }
  MacroAssembler::call_VM_leaf_base(entry_point, 1);
}


void InterpreterMacroAssembler::super_call_VM_leaf(address entry_point,
                                                   Register arg_1,
                                                   Register arg_2) {
  assert(c_rarg0 != arg_2, "smashed argument");
  assert(c_rarg1 != arg_1, "smashed argument");
  if (c_rarg0 != arg_1) {
    movq(c_rarg0, arg_1);
  }
  if (c_rarg1 != arg_2) {
    movq(c_rarg1, arg_2);
  }
  MacroAssembler::call_VM_leaf_base(entry_point, 2);
}

void InterpreterMacroAssembler::super_call_VM_leaf(address entry_point,
                                                   Register arg_1,
                                                   Register arg_2,
                                                   Register arg_3) {
  assert(c_rarg0 != arg_2, "smashed argument");
  assert(c_rarg0 != arg_3, "smashed argument");
  assert(c_rarg1 != arg_1, "smashed argument");
  assert(c_rarg1 != arg_3, "smashed argument");
  assert(c_rarg2 != arg_1, "smashed argument");
  assert(c_rarg2 != arg_2, "smashed argument");
  if (c_rarg0 != arg_1) {
    movq(c_rarg0, arg_1);
  }
  if (c_rarg1 != arg_2) {
    movq(c_rarg1, arg_2);
  }
  if (c_rarg2 != arg_3) {
    movq(c_rarg2, arg_3);
  }
  MacroAssembler::call_VM_leaf_base(entry_point, 3);
}

// Jump to from_interpreted entry of a call unless single stepping is possible
// in this thread in which case we must call the i2i entry
void InterpreterMacroAssembler::jump_from_interpreted(Register method, Register temp) {
  // set sender sp
  leaq(r13, Address(rsp, wordSize));
  // record last_sp
  movq(Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize), r13);

  if (JvmtiExport::can_post_interpreter_events()) {
    Label run_compiled_code;
    // JVMTI events, such as single-stepping, are implemented partly by avoiding running
    // compiled code in threads for which the event is enabled.  Check here for
    // interp_only_mode if these events CAN be enabled.
    get_thread(temp);
    // interp_only is an int, on little endian it is sufficient to test the byte only
    // Is a cmpl faster (ce
    cmpb(Address(temp, JavaThread::interp_only_mode_offset()), 0);
    jcc(Assembler::zero, run_compiled_code);
    jmp(Address(method, methodOopDesc::interpreter_entry_offset()));
    bind(run_compiled_code);
  }

  jmp(Address(method, methodOopDesc::from_interpreted_offset()));

}


// The following two routines provide a hook so that an implementation
// can schedule the dispatch in two parts.  amd64 does not do this.
void InterpreterMacroAssembler::dispatch_prolog(TosState state, int step) {
  // Nothing amd64 specific to be done here
}

void InterpreterMacroAssembler::dispatch_epilog(TosState state, int step) {
  dispatch_next(state, step);
}

void InterpreterMacroAssembler::dispatch_base(TosState state,
                                              address* table,
                                              bool verifyoop) {
  verify_FPU(1, state);
  if (VerifyActivationFrameSize) {
    Label L;
    movq(rcx, rbp);
    subq(rcx, rsp);
    int min_frame_size =
      (frame::link_offset - frame::interpreter_frame_initial_sp_offset) *
      wordSize;
    cmpq(rcx, min_frame_size);
    jcc(Assembler::greaterEqual, L);
    stop("broken stack frame");
    bind(L);
  }
  if (verifyoop) {
    verify_oop(rax, state);
  }
  lea(rscratch1, ExternalAddress((address)table));
  jmp(Address(rscratch1, rbx, Address::times_8));
}

void InterpreterMacroAssembler::dispatch_only(TosState state) {
  dispatch_base(state, Interpreter::dispatch_table(state));
}

void InterpreterMacroAssembler::dispatch_only_normal(TosState state) {
  dispatch_base(state, Interpreter::normal_table(state));
}

void InterpreterMacroAssembler::dispatch_only_noverify(TosState state) {
  dispatch_base(state, Interpreter::normal_table(state), false);
}


void InterpreterMacroAssembler::dispatch_next(TosState state, int step) {
  // load next bytecode (load before advancing r13 to prevent AGI)
  load_unsigned_byte(rbx, Address(r13, step));
  // advance r13
  incrementq(r13, step);
  dispatch_base(state, Interpreter::dispatch_table(state));
}

void InterpreterMacroAssembler::dispatch_via(TosState state, address* table) {
  // load current bytecode
  load_unsigned_byte(rbx, Address(r13, 0));
  dispatch_base(state, table);
}

// remove activation
//
// Unlock the receiver if this is a synchronized method.
// Unlock any Java monitors from syncronized blocks.
// Remove the activation from the stack.
//
// If there are locked Java monitors
//    If throw_monitor_exception
//       throws IllegalMonitorStateException
//    Else if install_monitor_exception
//       installs IllegalMonitorStateException
//    Else
//       no error processing
void InterpreterMacroAssembler::remove_activation(
        TosState state,
        Register ret_addr,
        bool throw_monitor_exception,
        bool install_monitor_exception,
        bool notify_jvmdi) {
  // Note: Registers rdx xmm0 may be in use for the
  // result check if synchronized method
  Label unlocked, unlock, no_unlock;

  // get the value of _do_not_unlock_if_synchronized into rdx
  const Address do_not_unlock_if_synchronized(r15_thread,
    in_bytes(JavaThread::do_not_unlock_if_synchronized_offset()));
  movbool(rdx, do_not_unlock_if_synchronized);
  movbool(do_not_unlock_if_synchronized, false); // reset the flag

 // get method access flags
  movq(rbx, Address(rbp, frame::interpreter_frame_method_offset * wordSize));
  movl(rcx, Address(rbx, methodOopDesc::access_flags_offset()));
  testl(rcx, JVM_ACC_SYNCHRONIZED);
  jcc(Assembler::zero, unlocked);

  // Don't unlock anything if the _do_not_unlock_if_synchronized flag
  // is set.
  testbool(rdx);
  jcc(Assembler::notZero, no_unlock);

  // unlock monitor
  push(state); // save result

  // BasicObjectLock will be first in list, since this is a
  // synchronized method. However, need to check that the object has
  // not been unlocked by an explicit monitorexit bytecode.
  const Address monitor(rbp, frame::interpreter_frame_initial_sp_offset *
                        wordSize - (int) sizeof(BasicObjectLock));
  // We use c_rarg1 so that if we go slow path it will be the correct
  // register for unlock_object to pass to VM directly
  leaq(c_rarg1, monitor); // address of first monitor

  movq(rax, Address(c_rarg1, BasicObjectLock::obj_offset_in_bytes()));
  testq(rax, rax);
  jcc(Assembler::notZero, unlock);

  pop(state);
  if (throw_monitor_exception) {
    // Entry already unlocked, need to throw exception
    call_VM(noreg, CAST_FROM_FN_PTR(address,
                   InterpreterRuntime::throw_illegal_monitor_state_exception));
    should_not_reach_here();
  } else {
    // Monitor already unlocked during a stack unroll. If requested,
    // install an illegal_monitor_state_exception.  Continue with
    // stack unrolling.
    if (install_monitor_exception) {
      call_VM(noreg, CAST_FROM_FN_PTR(address,
                     InterpreterRuntime::new_illegal_monitor_state_exception));
    }
    jmp(unlocked);
  }

  bind(unlock);
  unlock_object(c_rarg1);
  pop(state);

  // Check that for block-structured locking (i.e., that all locked
  // objects has been unlocked)
  bind(unlocked);

  // rax: Might contain return value

  // Check that all monitors are unlocked
  {
    Label loop, exception, entry, restart;
    const int entry_size = frame::interpreter_frame_monitor_size() * wordSize;
    const Address monitor_block_top(
        rbp, frame::interpreter_frame_monitor_block_top_offset * wordSize);
    const Address monitor_block_bot(
        rbp, frame::interpreter_frame_initial_sp_offset * wordSize);

    bind(restart);
    // We use c_rarg1 so that if we go slow path it will be the correct
    // register for unlock_object to pass to VM directly
    movq(c_rarg1, monitor_block_top); // points to current entry, starting
                                  // with top-most entry
    leaq(rbx, monitor_block_bot); // points to word before bottom of
                                  // monitor block
    jmp(entry);

    // Entry already locked, need to throw exception
    bind(exception);

    if (throw_monitor_exception) {
      // Throw exception
      MacroAssembler::call_VM(noreg,
                              CAST_FROM_FN_PTR(address, InterpreterRuntime::
                                   throw_illegal_monitor_state_exception));
      should_not_reach_here();
    } else {
      // Stack unrolling. Unlock object and install illegal_monitor_exception.
      // Unlock does not block, so don't have to worry about the frame.
      // We don't have to preserve c_rarg1 since we are going to throw an exception.

      push(state);
      unlock_object(c_rarg1);
      pop(state);

      if (install_monitor_exception) {
        call_VM(noreg, CAST_FROM_FN_PTR(address,
                                        InterpreterRuntime::
                                        new_illegal_monitor_state_exception));
      }

      jmp(restart);
    }

    bind(loop);
    // check if current entry is used
    cmpq(Address(c_rarg1, BasicObjectLock::obj_offset_in_bytes()), (int) NULL);
    jcc(Assembler::notEqual, exception);

    addq(c_rarg1, entry_size); // otherwise advance to next entry
    bind(entry);
    cmpq(c_rarg1, rbx); // check if bottom reached
    jcc(Assembler::notEqual, loop); // if not at bottom then check this entry
  }

  bind(no_unlock);

  // jvmti support
  if (notify_jvmdi) {
    notify_method_exit(state, NotifyJVMTI);    // preserve TOSCA
  } else {
    notify_method_exit(state, SkipNotifyJVMTI); // preserve TOSCA
  }

  // remove activation
  // get sender sp
  movq(rbx,
       Address(rbp, frame::interpreter_frame_sender_sp_offset * wordSize));
  leave();                           // remove frame anchor
  popq(ret_addr);                    // get return address
  movq(rsp, rbx);                    // set sp to sender sp
}

// Lock object
//
// Args:
//      c_rarg1: BasicObjectLock to be used for locking
//
// Kills:
//      rax
//      c_rarg0, c_rarg1, c_rarg2, c_rarg3, .. (param regs)
//      rscratch1, rscratch2 (scratch regs)
void InterpreterMacroAssembler::lock_object(Register lock_reg) {
  assert(lock_reg == c_rarg1, "The argument is only for looks. It must be c_rarg1");

  if (UseHeavyMonitors) {
    call_VM(noreg,
            CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorenter),
            lock_reg);
  } else {
    Label done;

    const Register swap_reg = rax; // Must use rax for cmpxchg instruction
    const Register obj_reg = c_rarg3; // Will contain the oop

    const int obj_offset = BasicObjectLock::obj_offset_in_bytes();
    const int lock_offset = BasicObjectLock::lock_offset_in_bytes ();
    const int mark_offset = lock_offset +
                            BasicLock::displaced_header_offset_in_bytes();

    Label slow_case;

    // Load object pointer into obj_reg %c_rarg3
    movq(obj_reg, Address(lock_reg, obj_offset));

    if (UseBiasedLocking) {
      biased_locking_enter(lock_reg, obj_reg, swap_reg, rscratch1, false, done, &slow_case);
    }

    // Load immediate 1 into swap_reg %rax
    movl(swap_reg, 1);

    // Load (object->mark() | 1) into swap_reg %rax
    orq(swap_reg, Address(obj_reg, 0));

    // Save (object->mark() | 1) into BasicLock's displaced header
    movq(Address(lock_reg, mark_offset), swap_reg);

    assert(lock_offset == 0,
           "displached header must be first word in BasicObjectLock");

    if (os::is_MP()) lock();
    cmpxchgq(lock_reg, Address(obj_reg, 0));
    if (PrintBiasedLockingStatistics) {
      cond_inc32(Assembler::zero,
                 ExternalAddress((address) BiasedLocking::fast_path_entry_count_addr()));
    }
    jcc(Assembler::zero, done);

    // Test if the oopMark is an obvious stack pointer, i.e.,
    //  1) (mark & 7) == 0, and
    //  2) rsp <= mark < mark + os::pagesize()
    //
    // These 3 tests can be done by evaluating the following
    // expression: ((mark - rsp) & (7 - os::vm_page_size())),
    // assuming both stack pointer and pagesize have their
    // least significant 3 bits clear.
    // NOTE: the oopMark is in swap_reg %rax as the result of cmpxchg
    subq(swap_reg, rsp);
    andq(swap_reg, 7 - os::vm_page_size());

    // Save the test result, for recursive case, the result is zero
    movq(Address(lock_reg, mark_offset), swap_reg);

    if (PrintBiasedLockingStatistics) {
      cond_inc32(Assembler::zero,
                 ExternalAddress((address) BiasedLocking::fast_path_entry_count_addr()));
    }
    jcc(Assembler::zero, done);

    bind(slow_case);

    // Call the runtime routine for slow case
    call_VM(noreg,
            CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorenter),
            lock_reg);

    bind(done);
  }
}


// Unlocks an object. Used in monitorexit bytecode and
// remove_activation.  Throws an IllegalMonitorException if object is
// not locked by current thread.
//
// Args:
//      c_rarg1: BasicObjectLock for lock
//
// Kills:
//      rax
//      c_rarg0, c_rarg1, c_rarg2, c_rarg3, ... (param regs)
//      rscratch1, rscratch2 (scratch regs)
void InterpreterMacroAssembler::unlock_object(Register lock_reg) {
  assert(lock_reg == c_rarg1, "The argument is only for looks. It must be rarg1");

  if (UseHeavyMonitors) {
    call_VM(noreg,
            CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorexit),
            lock_reg);
  } else {
    Label done;

    const Register swap_reg   = rax;  // Must use rax for cmpxchg instruction
    const Register header_reg = c_rarg2;  // Will contain the old oopMark
    const Register obj_reg    = c_rarg3;  // Will contain the oop

    save_bcp(); // Save in case of exception

    // Convert from BasicObjectLock structure to object and BasicLock
    // structure Store the BasicLock address into %rax
    leaq(swap_reg, Address(lock_reg, BasicObjectLock::lock_offset_in_bytes()));

    // Load oop into obj_reg(%c_rarg3)
    movq(obj_reg, Address(lock_reg, BasicObjectLock::obj_offset_in_bytes()));

    // Free entry
    movptr(Address(lock_reg, BasicObjectLock::obj_offset_in_bytes()), NULL_WORD);

    if (UseBiasedLocking) {
      biased_locking_exit(obj_reg, header_reg, done);
    }

    // Load the old header from BasicLock structure
    movq(header_reg, Address(swap_reg,
                             BasicLock::displaced_header_offset_in_bytes()));

    // Test for recursion
    testq(header_reg, header_reg);

    // zero for recursive case
    jcc(Assembler::zero, done);

    // Atomic swap back the old header
    if (os::is_MP()) lock();
    cmpxchgq(header_reg, Address(obj_reg, 0));

    // zero for recursive case
    jcc(Assembler::zero, done);

    // Call the runtime routine for slow case.
    movq(Address(lock_reg, BasicObjectLock::obj_offset_in_bytes()),
         obj_reg); // restore obj
    call_VM(noreg,
            CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorexit),
            lock_reg);

    bind(done);

    restore_bcp();
  }
}


void InterpreterMacroAssembler::test_method_data_pointer(Register mdp,
                                                         Label& zero_continue) {
  assert(ProfileInterpreter, "must be profiling interpreter");
  movq(mdp, Address(rbp, frame::interpreter_frame_mdx_offset * wordSize));
  testq(mdp, mdp);
  jcc(Assembler::zero, zero_continue);
}


// Set the method data pointer for the current bcp.
void InterpreterMacroAssembler::set_method_data_pointer_for_bcp() {
  assert(ProfileInterpreter, "must be profiling interpreter");
  Label zero_continue;
  pushq(rax);
  pushq(rbx);

  get_method(rbx);
  // Test MDO to avoid the call if it is NULL.
  movq(rax, Address(rbx, in_bytes(methodOopDesc::method_data_offset())));
  testq(rax, rax);
  jcc(Assembler::zero, zero_continue);

  // rbx: method
  // r13: bcp
  call_VM_leaf(CAST_FROM_FN_PTR(address, InterpreterRuntime::bcp_to_di), rbx, r13);
  // rax: mdi

  movq(rbx, Address(rbx, in_bytes(methodOopDesc::method_data_offset())));
  testq(rbx, rbx);
  jcc(Assembler::zero, zero_continue);
  addq(rbx, in_bytes(methodDataOopDesc::data_offset()));
  addq(rbx, rax);
  movq(Address(rbp, frame::interpreter_frame_mdx_offset * wordSize), rbx);

  bind(zero_continue);
  popq(rbx);
  popq(rax);
}

void InterpreterMacroAssembler::verify_method_data_pointer() {
  assert(ProfileInterpreter, "must be profiling interpreter");
#ifdef ASSERT
  Label verify_continue;
  pushq(rax);
  pushq(rbx);
  pushq(c_rarg3);
  pushq(c_rarg2);
  test_method_data_pointer(c_rarg3, verify_continue); // If mdp is zero, continue
  get_method(rbx);

  // If the mdp is valid, it will point to a DataLayout header which is
  // consistent with the bcp.  The converse is highly probable also.
  load_unsigned_word(c_rarg2,
                     Address(c_rarg3, in_bytes(DataLayout::bci_offset())));
  addq(c_rarg2, Address(rbx, methodOopDesc::const_offset()));
  leaq(c_rarg2, Address(c_rarg2, constMethodOopDesc::codes_offset()));
  cmpq(c_rarg2, r13);
  jcc(Assembler::equal, verify_continue);
  // rbx: method
  // r13: bcp
  // c_rarg3: mdp
  call_VM_leaf(CAST_FROM_FN_PTR(address, InterpreterRuntime::verify_mdp),
               rbx, r13, c_rarg3);
  bind(verify_continue);
  popq(c_rarg2);
  popq(c_rarg3);
  popq(rbx);
  popq(rax);
#endif // ASSERT
}


void InterpreterMacroAssembler::set_mdp_data_at(Register mdp_in,
                                                int constant,
                                                Register value) {
  assert(ProfileInterpreter, "must be profiling interpreter");
  Address data(mdp_in, constant);
  movq(data, value);
}


void InterpreterMacroAssembler::increment_mdp_data_at(Register mdp_in,
                                                      int constant,
                                                      bool decrement) {
  // Counter address
  Address data(mdp_in, constant);

  increment_mdp_data_at(data, decrement);
}

void InterpreterMacroAssembler::increment_mdp_data_at(Address data,
                                                      bool decrement) {
  assert(ProfileInterpreter, "must be profiling interpreter");

  if (decrement) {
    // Decrement the register.  Set condition codes.
    addq(data, -DataLayout::counter_increment);
    // If the decrement causes the counter to overflow, stay negative
    Label L;
    jcc(Assembler::negative, L);
    addq(data, DataLayout::counter_increment);
    bind(L);
  } else {
    assert(DataLayout::counter_increment == 1,
           "flow-free idiom only works with 1");
    // Increment the register.  Set carry flag.
    addq(data, DataLayout::counter_increment);
    // If the increment causes the counter to overflow, pull back by 1.
    sbbq(data, 0);
  }
}


void InterpreterMacroAssembler::increment_mdp_data_at(Register mdp_in,
                                                      Register reg,
                                                      int constant,
                                                      bool decrement) {
  Address data(mdp_in, reg, Address::times_1, constant);

  increment_mdp_data_at(data, decrement);
}

void InterpreterMacroAssembler::set_mdp_flag_at(Register mdp_in,
                                                int flag_byte_constant) {
  assert(ProfileInterpreter, "must be profiling interpreter");
  int header_offset = in_bytes(DataLayout::header_offset());
  int header_bits = DataLayout::flag_mask_to_header_mask(flag_byte_constant);
  // Set the flag
  orl(Address(mdp_in, header_offset), header_bits);
}



void InterpreterMacroAssembler::test_mdp_data_at(Register mdp_in,
                                                 int offset,
                                                 Register value,
                                                 Register test_value_out,
                                                 Label& not_equal_continue) {
  assert(ProfileInterpreter, "must be profiling interpreter");
  if (test_value_out == noreg) {
    cmpq(value, Address(mdp_in, offset));
  } else {
    // Put the test value into a register, so caller can use it:
    movq(test_value_out, Address(mdp_in, offset));
    cmpq(test_value_out, value);
  }
  jcc(Assembler::notEqual, not_equal_continue);
}


void InterpreterMacroAssembler::update_mdp_by_offset(Register mdp_in,
                                                     int offset_of_disp) {
  assert(ProfileInterpreter, "must be profiling interpreter");
  Address disp_address(mdp_in, offset_of_disp);
  addq(mdp_in, disp_address);
  movq(Address(rbp, frame::interpreter_frame_mdx_offset * wordSize), mdp_in);
}


void InterpreterMacroAssembler::update_mdp_by_offset(Register mdp_in,
                                                     Register reg,
                                                     int offset_of_disp) {
  assert(ProfileInterpreter, "must be profiling interpreter");
  Address disp_address(mdp_in, reg, Address::times_1, offset_of_disp);
  addq(mdp_in, disp_address);
  movq(Address(rbp, frame::interpreter_frame_mdx_offset * wordSize), mdp_in);
}


void InterpreterMacroAssembler::update_mdp_by_constant(Register mdp_in,
                                                       int constant) {
  assert(ProfileInterpreter, "must be profiling interpreter");
  addq(mdp_in, constant);
  movq(Address(rbp, frame::interpreter_frame_mdx_offset * wordSize), mdp_in);
}


void InterpreterMacroAssembler::update_mdp_for_ret(Register return_bci) {
  assert(ProfileInterpreter, "must be profiling interpreter");
  pushq(return_bci); // save/restore across call_VM
  call_VM(noreg,
          CAST_FROM_FN_PTR(address, InterpreterRuntime::update_mdp_for_ret),
          return_bci);
  popq(return_bci);
}


void InterpreterMacroAssembler::profile_taken_branch(Register mdp,
                                                     Register bumped_count) {
  if (ProfileInterpreter) {
    Label profile_continue;

    // If no method data exists, go to profile_continue.
    // Otherwise, assign to mdp
    test_method_data_pointer(mdp, profile_continue);

    // We are taking a branch.  Increment the taken count.
    // We inline increment_mdp_data_at to return bumped_count in a register
    //increment_mdp_data_at(mdp, in_bytes(JumpData::taken_offset()));
    Address data(mdp, in_bytes(JumpData::taken_offset()));
    movq(bumped_count, data);
    assert(DataLayout::counter_increment == 1,
            "flow-free idiom only works with 1");
    addq(bumped_count, DataLayout::counter_increment);
    sbbq(bumped_count, 0);
    movq(data, bumped_count); // Store back out

    // The method data pointer needs to be updated to reflect the new target.
    update_mdp_by_offset(mdp, in_bytes(JumpData::displacement_offset()));
    bind(profile_continue);
  }
}


void InterpreterMacroAssembler::profile_not_taken_branch(Register mdp) {
  if (ProfileInterpreter) {
    Label profile_continue;

    // If no method data exists, go to profile_continue.
    test_method_data_pointer(mdp, profile_continue);

    // We are taking a branch.  Increment the not taken count.
    increment_mdp_data_at(mdp, in_bytes(BranchData::not_taken_offset()));

    // The method data pointer needs to be updated to correspond to
    // the next bytecode
    update_mdp_by_constant(mdp, in_bytes(BranchData::branch_data_size()));
    bind(profile_continue);
  }
}


void InterpreterMacroAssembler::profile_call(Register mdp) {
  if (ProfileInterpreter) {
    Label profile_continue;

    // If no method data exists, go to profile_continue.
    test_method_data_pointer(mdp, profile_continue);

    // We are making a call.  Increment the count.
    increment_mdp_data_at(mdp, in_bytes(CounterData::count_offset()));

    // The method data pointer needs to be updated to reflect the new target.
    update_mdp_by_constant(mdp, in_bytes(CounterData::counter_data_size()));
    bind(profile_continue);
  }
}


void InterpreterMacroAssembler::profile_final_call(Register mdp) {
  if (ProfileInterpreter) {
    Label profile_continue;

    // If no method data exists, go to profile_continue.
    test_method_data_pointer(mdp, profile_continue);

    // We are making a call.  Increment the count.
    increment_mdp_data_at(mdp, in_bytes(CounterData::count_offset()));

    // The method data pointer needs to be updated to reflect the new target.
    update_mdp_by_constant(mdp,
                           in_bytes(VirtualCallData::
                                    virtual_call_data_size()));
    bind(profile_continue);
  }
}


void InterpreterMacroAssembler::profile_virtual_call(Register receiver,
                                                     Register mdp,
                                                     Register reg2) {
  if (ProfileInterpreter) {
    Label profile_continue;

    // If no method data exists, go to profile_continue.
    test_method_data_pointer(mdp, profile_continue);

    // We are making a call.  Increment the count.
    increment_mdp_data_at(mdp, in_bytes(CounterData::count_offset()));

    // Record the receiver type.
    record_klass_in_profile(receiver, mdp, reg2);

    // The method data pointer needs to be updated to reflect the new target.
    update_mdp_by_constant(mdp,
                           in_bytes(VirtualCallData::
                                    virtual_call_data_size()));
    bind(profile_continue);
  }
}

// This routine creates a state machine for updating the multi-row
// type profile at a virtual call site (or other type-sensitive bytecode).
// The machine visits each row (of receiver/count) until the receiver type
// is found, or until it runs out of rows.  At the same time, it remembers
// the location of the first empty row.  (An empty row records null for its
// receiver, and can be allocated for a newly-observed receiver type.)
// Because there are two degrees of freedom in the state, a simple linear
// search will not work; it must be a decision tree.  Hence this helper
// function is recursive, to generate the required tree structured code.
// It's the interpreter, so we are trading off code space for speed.
// See below for example code.
void InterpreterMacroAssembler::record_klass_in_profile_helper(
                                        Register receiver, Register mdp,
                                        Register reg2,
                                        int start_row, Label& done) {
  int last_row = VirtualCallData::row_limit() - 1;
  assert(start_row <= last_row, "must be work left to do");
  // Test this row for both the receiver and for null.
  // Take any of three different outcomes:
  //   1. found receiver => increment count and goto done
  //   2. found null => keep looking for case 1, maybe allocate this cell
  //   3. found something else => keep looking for cases 1 and 2
  // Case 3 is handled by a recursive call.
  for (int row = start_row; row <= last_row; row++) {
    Label next_test;
    bool test_for_null_also = (row == start_row);

    // See if the receiver is receiver[n].
    int recvr_offset = in_bytes(VirtualCallData::receiver_offset(row));
    test_mdp_data_at(mdp, recvr_offset, receiver,
                     (test_for_null_also ? reg2 : noreg),
                     next_test);
    // (Reg2 now contains the receiver from the CallData.)

    // The receiver is receiver[n].  Increment count[n].
    int count_offset = in_bytes(VirtualCallData::receiver_count_offset(row));
    increment_mdp_data_at(mdp, count_offset);
    jmp(done);
    bind(next_test);

    if (test_for_null_also) {
      // Failed the equality check on receiver[n]...  Test for null.
      testq(reg2, reg2);
      if (start_row == last_row) {
        // The only thing left to do is handle the null case.
        jcc(Assembler::notZero, done);
        break;
      }
      // Since null is rare, make it be the branch-taken case.
      Label found_null;
      jcc(Assembler::zero, found_null);

      // Put all the "Case 3" tests here.
      record_klass_in_profile_helper(receiver, mdp, reg2, start_row + 1, done);

      // Found a null.  Keep searching for a matching receiver,
      // but remember that this is an empty (unused) slot.
      bind(found_null);
    }
  }

  // In the fall-through case, we found no matching receiver, but we
  // observed the receiver[start_row] is NULL.

  // Fill in the receiver field and increment the count.
  int recvr_offset = in_bytes(VirtualCallData::receiver_offset(start_row));
  set_mdp_data_at(mdp, recvr_offset, receiver);
  int count_offset = in_bytes(VirtualCallData::receiver_count_offset(start_row));
  movl(reg2, DataLayout::counter_increment);
  set_mdp_data_at(mdp, count_offset, reg2);
  jmp(done);
}

// Example state machine code for three profile rows:
//   // main copy of decision tree, rooted at row[1]
//   if (row[0].rec == rec) { row[0].incr(); goto done; }
//   if (row[0].rec != NULL) {
//     // inner copy of decision tree, rooted at row[1]
//     if (row[1].rec == rec) { row[1].incr(); goto done; }
//     if (row[1].rec != NULL) {
//       // degenerate decision tree, rooted at row[2]
//       if (row[2].rec == rec) { row[2].incr(); goto done; }
//       if (row[2].rec != NULL) { goto done; } // overflow
//       row[2].init(rec); goto done;
//     } else {
//       // remember row[1] is empty
//       if (row[2].rec == rec) { row[2].incr(); goto done; }
//       row[1].init(rec); goto done;
//     }
//   } else {
//     // remember row[0] is empty
//     if (row[1].rec == rec) { row[1].incr(); goto done; }
//     if (row[2].rec == rec) { row[2].incr(); goto done; }
//     row[0].init(rec); goto done;
//   }

void InterpreterMacroAssembler::record_klass_in_profile(Register receiver,
                                                        Register mdp,
                                                        Register reg2) {
  assert(ProfileInterpreter, "must be profiling");
  Label done;

  record_klass_in_profile_helper(receiver, mdp, reg2, 0, done);

  bind (done);
}

void InterpreterMacroAssembler::profile_ret(Register return_bci,
                                            Register mdp) {
  if (ProfileInterpreter) {
    Label profile_continue;
    uint row;

    // If no method data exists, go to profile_continue.
    test_method_data_pointer(mdp, profile_continue);

    // Update the total ret count.
    increment_mdp_data_at(mdp, in_bytes(CounterData::count_offset()));

    for (row = 0; row < RetData::row_limit(); row++) {
      Label next_test;

      // See if return_bci is equal to bci[n]:
      test_mdp_data_at(mdp,
                       in_bytes(RetData::bci_offset(row)),
                       return_bci, noreg,
                       next_test);

      // return_bci is equal to bci[n].  Increment the count.
      increment_mdp_data_at(mdp, in_bytes(RetData::bci_count_offset(row)));

      // The method data pointer needs to be updated to reflect the new target.
      update_mdp_by_offset(mdp,
                           in_bytes(RetData::bci_displacement_offset(row)));
      jmp(profile_continue);
      bind(next_test);
    }

    update_mdp_for_ret(return_bci);

    bind(profile_continue);
  }
}


void InterpreterMacroAssembler::profile_null_seen(Register mdp) {
  if (ProfileInterpreter) {
    Label profile_continue;

    // If no method data exists, go to profile_continue.
    test_method_data_pointer(mdp, profile_continue);

    // The method data pointer needs to be updated.
    int mdp_delta = in_bytes(BitData::bit_data_size());
    if (TypeProfileCasts) {
      mdp_delta = in_bytes(VirtualCallData::virtual_call_data_size());
    }
    update_mdp_by_constant(mdp, mdp_delta);

    bind(profile_continue);
  }
}


void InterpreterMacroAssembler::profile_typecheck_failed(Register mdp) {
  if (ProfileInterpreter && TypeProfileCasts) {
    Label profile_continue;

    // If no method data exists, go to profile_continue.
    test_method_data_pointer(mdp, profile_continue);

    int count_offset = in_bytes(CounterData::count_offset());
    // Back up the address, since we have already bumped the mdp.
    count_offset -= in_bytes(VirtualCallData::virtual_call_data_size());

    // *Decrement* the counter.  We expect to see zero or small negatives.
    increment_mdp_data_at(mdp, count_offset, true);

    bind (profile_continue);
  }
}


void InterpreterMacroAssembler::profile_typecheck(Register mdp, Register klass, Register reg2) {
  if (ProfileInterpreter) {
    Label profile_continue;

    // If no method data exists, go to profile_continue.
    test_method_data_pointer(mdp, profile_continue);

    // The method data pointer needs to be updated.
    int mdp_delta = in_bytes(BitData::bit_data_size());
    if (TypeProfileCasts) {
      mdp_delta = in_bytes(VirtualCallData::virtual_call_data_size());

      // Record the object type.
      record_klass_in_profile(klass, mdp, reg2);
    }
    update_mdp_by_constant(mdp, mdp_delta);

    bind(profile_continue);
  }
}


void InterpreterMacroAssembler::profile_switch_default(Register mdp) {
  if (ProfileInterpreter) {
    Label profile_continue;

    // If no method data exists, go to profile_continue.
    test_method_data_pointer(mdp, profile_continue);

    // Update the default case count
    increment_mdp_data_at(mdp,
                          in_bytes(MultiBranchData::default_count_offset()));

    // The method data pointer needs to be updated.
    update_mdp_by_offset(mdp,
                         in_bytes(MultiBranchData::
                                  default_displacement_offset()));

    bind(profile_continue);
  }
}


void InterpreterMacroAssembler::profile_switch_case(Register index,
                                                    Register mdp,
                                                    Register reg2) {
  if (ProfileInterpreter) {
    Label profile_continue;

    // If no method data exists, go to profile_continue.
    test_method_data_pointer(mdp, profile_continue);

    // Build the base (index * per_case_size_in_bytes()) +
    // case_array_offset_in_bytes()
    movl(reg2, in_bytes(MultiBranchData::per_case_size()));
    imulq(index, reg2); // XXX l ?
    addq(index, in_bytes(MultiBranchData::case_array_offset())); // XXX l ?

    // Update the case count
    increment_mdp_data_at(mdp,
                          index,
                          in_bytes(MultiBranchData::relative_count_offset()));

    // The method data pointer needs to be updated.
    update_mdp_by_offset(mdp,
                         index,
                         in_bytes(MultiBranchData::
                                  relative_displacement_offset()));

    bind(profile_continue);
  }
}


void InterpreterMacroAssembler::verify_oop(Register reg, TosState state) {
  if (state == atos) {
    MacroAssembler::verify_oop(reg);
  }
}

void InterpreterMacroAssembler::verify_FPU(int stack_depth, TosState state) {
}


void InterpreterMacroAssembler::notify_method_entry() {
  // Whenever JVMTI is interp_only_mode, method entry/exit events are sent to
  // track stack depth.  If it is possible to enter interp_only_mode we add
  // the code to check if the event should be sent.
  if (JvmtiExport::can_post_interpreter_events()) {
    Label L;
    movl(rdx, Address(r15_thread, JavaThread::interp_only_mode_offset()));
    testl(rdx, rdx);
    jcc(Assembler::zero, L);
    call_VM(noreg, CAST_FROM_FN_PTR(address,
                                    InterpreterRuntime::post_method_entry));
    bind(L);
  }

  {
    SkipIfEqual skip(this, &DTraceMethodProbes, false);
    get_method(c_rarg1);
    call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_entry),
                 r15_thread, c_rarg1);
  }
}


void InterpreterMacroAssembler::notify_method_exit(
    TosState state, NotifyMethodExitMode mode) {
  // Whenever JVMTI is interp_only_mode, method entry/exit events are sent to
  // track stack depth.  If it is possible to enter interp_only_mode we add
  // the code to check if the event should be sent.
  if (mode == NotifyJVMTI && JvmtiExport::can_post_interpreter_events()) {
    Label L;
    // Note: frame::interpreter_frame_result has a dependency on how the
    // method result is saved across the call to post_method_exit. If this
    // is changed then the interpreter_frame_result implementation will
    // need to be updated too.
    push(state);
    movl(rdx, Address(r15_thread, JavaThread::interp_only_mode_offset()));
    testl(rdx, rdx);
    jcc(Assembler::zero, L);
    call_VM(noreg,
            CAST_FROM_FN_PTR(address, InterpreterRuntime::post_method_exit));
    bind(L);
    pop(state);
  }

  {
    SkipIfEqual skip(this, &DTraceMethodProbes, false);
    push(state);
    get_method(c_rarg1);
    call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_exit),
                 r15_thread, c_rarg1);
    pop(state);
  }
}