/*
 * Copyright (c) 2003, 2023, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2014, Red Hat Inc. All rights reserved.
 * Copyright (c) 2020, 2022, Huawei Technologies Co., Ltd. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
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 */

#include "precompiled.hpp"
#include "interpreter/interpreter.hpp"
#include "oops/constMethod.hpp"
#include "oops/klass.inline.hpp"
#include "oops/method.hpp"
#include "runtime/frame.inline.hpp"
#include "utilities/align.hpp"
#include "utilities/debug.hpp"
#include "utilities/macros.hpp"

int AbstractInterpreter::BasicType_as_index(BasicType type) {
  int i = 0;
  switch (type) {
    case T_BOOLEAN: i = 0; break;
    case T_CHAR   : i = 1; break;
    case T_BYTE   : i = 2; break;
    case T_SHORT  : i = 3; break;
    case T_INT    : i = 4; break;
    case T_LONG   : i = 5; break;
    case T_VOID   : i = 6; break;
    case T_FLOAT  : i = 7; break;
    case T_DOUBLE : i = 8; break;
    case T_OBJECT : i = 9; break;
    case T_ARRAY  : i = 9; break;
    default       : ShouldNotReachHere();
  }
  assert(0 <= i && i < AbstractInterpreter::number_of_result_handlers,
         "index out of bounds");
  return i;
}

// How much stack a method activation needs in words.
int AbstractInterpreter::size_top_interpreter_activation(Method* method) {
  const int entry_size = frame::interpreter_frame_monitor_size();

  // total overhead size: entry_size + (saved fp thru expr stack
  // bottom).  be sure to change this if you add/subtract anything
  // to/from the overhead area
  const int overhead_size =
    -(frame::interpreter_frame_initial_sp_offset) + entry_size;

  const int stub_code = frame::entry_frame_after_call_words;
  assert_cond(method != nullptr);
  const int method_stack = (method->max_locals() + method->max_stack()) *
                           Interpreter::stackElementWords;
  return (overhead_size + method_stack + stub_code);
}

// asm based interpreter deoptimization helpers
int AbstractInterpreter::size_activation(int max_stack,
                                         int temps,
                                         int extra_args,
                                         int monitors,
                                         int callee_params,
                                         int callee_locals,
                                         bool is_top_frame) {
  // Note: This calculation must exactly parallel the frame setup
  // in TemplateInterpreterGenerator::generate_method_entry.

  // fixed size of an interpreter frame:
  int overhead = frame::sender_sp_offset -
                 frame::interpreter_frame_initial_sp_offset;
  // Our locals were accounted for by the caller (or last_frame_adjust
  // on the transition) Since the callee parameters already account
  // for the callee's params we only need to account for the extra
  // locals.
  int size = overhead +
             (callee_locals - callee_params) * Interpreter::stackElementWords +
             monitors * frame::interpreter_frame_monitor_size() +
             // On the top frame, at all times SP <= ESP, and SP is
             // 16-aligned.  We ensure this by adjusting SP on method
             // entry and re-entry to allow room for the maximum size of
             // the expression stack.  When we call another method we bump
             // SP so that no stack space is wasted.  So, only on the top
             // frame do we need to allow max_stack words.
             (is_top_frame ? max_stack : temps + extra_args);

  // On riscv we always keep the stack pointer 16-aligned, so we
  // must round up here.
  size = align_up(size, 2);

  return size;
}

void AbstractInterpreter::layout_activation(Method* method,
                                            int tempcount,
                                            int popframe_extra_args,
                                            int moncount,
                                            int caller_actual_parameters,
                                            int callee_param_count,
                                            int callee_locals,
                                            frame* caller,
                                            frame* interpreter_frame,
                                            bool is_top_frame,
                                            bool is_bottom_frame) {
  // The frame interpreter_frame is guaranteed to be the right size,
  // as determined by a previous call to the size_activation() method.
  // It is also guaranteed to be walkable even though it is in a
  // skeletal state

  const int max_locals = method->max_locals() * Interpreter::stackElementWords;
  const int params = method->size_of_parameters() * Interpreter::stackElementWords;
  const int extra_locals = max_locals - params;

#ifdef ASSERT
  assert(caller->sp() == interpreter_frame->sender_sp(), "Frame not properly walkable");
#endif

  interpreter_frame->interpreter_frame_set_method(method);
  // NOTE the difference in using sender_sp and interpreter_frame_sender_sp
  // interpreter_frame_sender_sp is the original sp of the caller (the unextended_sp)
  // and sender_sp is fp
  intptr_t* const locals = caller->is_interpreted_frame()
    ? caller->interpreter_frame_last_sp() + caller_actual_parameters - 1
    : interpreter_frame->sender_sp() + max_locals - 1;

#ifdef ASSERT
  if (caller->is_interpreted_frame()) {
    assert(locals < caller->fp() + frame::interpreter_frame_initial_sp_offset, "bad placement");
  }
#endif

  interpreter_frame->interpreter_frame_set_locals(locals);
  BasicObjectLock* montop = interpreter_frame->interpreter_frame_monitor_begin();
  BasicObjectLock* monbot = montop - moncount;
  interpreter_frame->interpreter_frame_set_monitor_end(monbot);

  // Set last_sp
  intptr_t* last_sp = (intptr_t*) monbot -
    tempcount*Interpreter::stackElementWords -
    popframe_extra_args;
  interpreter_frame->interpreter_frame_set_last_sp(last_sp);

  // We have to add extra reserved slots to max_stack. There are 3 users of the extra slots,
  // none of which are at the same time, so we just need to make sure there is enough room
  // for the biggest user:
  //   -reserved slot for excepton handler
  //   -reserved slot for JSR292. Method::extra_stack_entries() is the size.
  //   -reserved slot for TraceBytecodes
  int max_stack = method->constMethod()->max_stack() + MAX2(3, Method::extra_stack_entries());
  intptr_t* extended_sp = (intptr_t*) monbot -
                          (max_stack * Interpreter::stackElementWords) -
                          popframe_extra_args;
  extended_sp = align_down(extended_sp, StackAlignmentInBytes);
  interpreter_frame->interpreter_frame_set_extended_sp(extended_sp);

  // All frames but the initial (oldest) interpreter frame we fill in have
  // a value for sender_sp that allows walking the stack but isn't
  // truly correct. Correct the value here.
  if (extra_locals != 0 && interpreter_frame->sender_sp() == interpreter_frame->interpreter_frame_sender_sp()) {
    interpreter_frame->set_interpreter_frame_sender_sp(caller->sp() + extra_locals);
  }

  *interpreter_frame->interpreter_frame_cache_addr() = method->constants()->cache();
  *interpreter_frame->interpreter_frame_mirror_addr() = method->method_holder()->java_mirror();
}