/*

 * Copyright (c) 1998, 2019, Oracle and/or its affiliates. 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.

 *

 */

#include "precompiled.hpp"

#include "ci/ciReplay.hpp"

#include "classfile/systemDictionary.hpp"

#include "classfile/vmSymbols.hpp"

#include "compiler/compileBroker.hpp"

#include "compiler/compileLog.hpp"

#include "interpreter/linkResolver.hpp"

#include "jfr/jfrEvents.hpp"

#include "oops/objArrayKlass.hpp"

#include "opto/callGenerator.hpp"

#include "opto/parse.hpp"

#include "runtime/handles.inline.hpp"

#include "utilities/events.hpp"

//=============================================================================

//------------------------------InlineTree-------------------------------------

InlineTree::InlineTree(Compile* c,

                       const InlineTree *caller_tree, ciMethod* callee,

                       JVMState* caller_jvms, int caller_bci,

                       float site_invoke_ratio, int max_inline_level) :

  C(c),

  _caller_jvms(caller_jvms),

  _method(callee),

  _caller_tree((InlineTree*) caller_tree),

  _count_inline_bcs(method()->code_size_for_inlining()),

  _site_invoke_ratio(site_invoke_ratio),

  _max_inline_level(max_inline_level),

  _subtrees(c->comp_arena(), 2, 0, NULL),

  _msg(NULL)

{

#ifndef PRODUCT

  _count_inlines = 0;

  _forced_inline = false;

#endif

  if (_caller_jvms != NULL) {

    // Keep a private copy of the caller_jvms:

    _caller_jvms = new (C) JVMState(caller_jvms->method(), caller_tree->caller_jvms());

    _caller_jvms->set_bci(caller_jvms->bci());

    assert(!caller_jvms->should_reexecute(), "there should be no reexecute bytecode with inlining");

  }

  assert(_caller_jvms->same_calls_as(caller_jvms), "consistent JVMS");

  assert((caller_tree == NULL ? 0 : caller_tree->stack_depth() + 1) == stack_depth(), "correct (redundant) depth parameter");

  assert(caller_bci == this->caller_bci(), "correct (redundant) bci parameter");

  // Update hierarchical counts, count_inline_bcs() and count_inlines()

  InlineTree *caller = (InlineTree *)caller_tree;

  for( ; caller != NULL; caller = ((InlineTree *)(caller->caller_tree())) ) {

    caller->_count_inline_bcs += count_inline_bcs();

    NOT_PRODUCT(caller->_count_inlines++;)

  }

}

/**

 *  Return true when EA is ON and a java constructor is called or

 *  a super constructor is called from an inlined java constructor.

 *  Also return true for boxing methods.

 *  Also return true for methods returning Iterator (including Iterable::iterator())

 *  that is essential for forall-loops performance.

 */

static bool is_init_with_ea(ciMethod* callee_method,

                            ciMethod* caller_method, Compile* C) {

  if (!C->do_escape_analysis() || !EliminateAllocations) {

    return false; // EA is off

  }

  if (callee_method->is_initializer()) {

    return true; // constuctor

  }

  if (caller_method->is_initializer() &&

      caller_method != C->method() &&

      caller_method->holder()->is_subclass_of(callee_method->holder())) {

    return true; // super constructor is called from inlined constructor

  }

  if (C->eliminate_boxing() && callee_method->is_boxing_method()) {

    return true;

  }

  ciType *retType = callee_method->signature()->return_type();

  ciKlass *iter = C->env()->Iterator_klass();

  if(retType->is_loaded() && iter->is_loaded() && retType->is_subtype_of(iter)) {

    return true;

  }

  return false;

}

/**

 *  Force inlining unboxing accessor.

 */

static bool is_unboxing_method(ciMethod* callee_method, Compile* C) {

  return C->eliminate_boxing() && callee_method->is_unboxing_method();

}

// positive filter: should callee be inlined?

bool InlineTree::should_inline(ciMethod* callee_method, ciMethod* caller_method,

                               int caller_bci, ciCallProfile& profile,

                               WarmCallInfo* wci_result) {

  // Allows targeted inlining

  if (C->directive()->should_inline(callee_method)) {

    *wci_result = *(WarmCallInfo::always_hot());

    if (C->print_inlining() && Verbose) {

      CompileTask::print_inline_indent(inline_level());

      tty->print_cr("Inlined method is hot: ");

    }

    set_msg("force inline by CompileCommand");

    _forced_inline = true;

    return true;

  }

  if (callee_method->force_inline()) {

      set_msg("force inline by annotation");

      _forced_inline = true;

      return true;

  }

#ifndef PRODUCT

  int inline_depth = inline_level()+1;

  if (ciReplay::should_inline(C->replay_inline_data(), callee_method, caller_bci, inline_depth)) {

    set_msg("force inline by ciReplay");

    _forced_inline = true;

    return true;

  }

#endif

  int size = callee_method->code_size_for_inlining();

  // Check for too many throws (and not too huge)

  if(callee_method->interpreter_throwout_count() > InlineThrowCount &&

     size < InlineThrowMaxSize ) {

    wci_result->set_profit(wci_result->profit() * 100);

    if (C->print_inlining() && Verbose) {

      CompileTask::print_inline_indent(inline_level());

      tty->print_cr("Inlined method with many throws (throws=%d):", callee_method->interpreter_throwout_count());

    }

    set_msg("many throws");

    return true;

  }

  int default_max_inline_size = C->max_inline_size();

  int inline_small_code_size  = InlineSmallCode / 4;

  int max_inline_size         = default_max_inline_size;

  int call_site_count  = method()->scale_count(profile.count());

  int invoke_count     = method()->interpreter_invocation_count();

  assert(invoke_count != 0, "require invocation count greater than zero");

  int freq = call_site_count / invoke_count;

  // bump the max size if the call is frequent

  if ((freq >= InlineFrequencyRatio) ||

      (call_site_count >= InlineFrequencyCount) ||

      is_unboxing_method(callee_method, C) ||

      is_init_with_ea(callee_method, caller_method, C)) {

    max_inline_size = C->freq_inline_size();

    if (size <= max_inline_size && TraceFrequencyInlining) {

      CompileTask::print_inline_indent(inline_level());

      tty->print_cr("Inlined frequent method (freq=%d count=%d):", freq, call_site_count);

      CompileTask::print_inline_indent(inline_level());

      callee_method->print();

      tty->cr();

    }

  } else {

    // Not hot.  Check for medium-sized pre-existing nmethod at cold sites.

    if (callee_method->has_compiled_code() &&

        callee_method->instructions_size() > inline_small_code_size) {

      set_msg("already compiled into a medium method");

      return false;

    }

  }

  if (size > max_inline_size) {

    if (max_inline_size > default_max_inline_size) {

      set_msg("hot method too big");

    } else {

      set_msg("too big");

    }

    return false;

  }

  return true;

}

// negative filter: should callee NOT be inlined?

bool InlineTree::should_not_inline(ciMethod *callee_method,

                                   ciMethod* caller_method,

                                   JVMState* jvms,

                                   WarmCallInfo* wci_result) {

  const char* fail_msg = NULL;

  // First check all inlining restrictions which are required for correctness

  if (callee_method->is_abstract()) {

    fail_msg = "abstract method"; // // note: we allow ik->is_abstract()

  } else if (!callee_method->holder()->is_initialized() &&

             // access allowed in the context of static initializer

             C->needs_clinit_barrier(callee_method->holder(), caller_method)) {

    fail_msg = "method holder not initialized";

  } else if (callee_method->is_native()) {

    fail_msg = "native method";

  } else if (callee_method->dont_inline()) {

    fail_msg = "don't inline by annotation";

  }

  // one more inlining restriction

  if (fail_msg == NULL && callee_method->has_unloaded_classes_in_signature()) {

    fail_msg = "unloaded signature classes";

  }

  if (fail_msg != NULL) {

    set_msg(fail_msg);

    return true;

  }

  // ignore heuristic controls on inlining

  if (C->directive()->should_inline(callee_method)) {

    set_msg("force inline by CompileCommand");

    return false;

  }

  if (C->directive()->should_not_inline(callee_method)) {

    set_msg("disallowed by CompileCommand");

    return true;

  }

#ifndef PRODUCT

  int caller_bci = jvms->bci();

  int inline_depth = inline_level()+1;

  if (ciReplay::should_inline(C->replay_inline_data(), callee_method, caller_bci, inline_depth)) {

    set_msg("force inline by ciReplay");

    return false;

  }

  if (ciReplay::should_not_inline(C->replay_inline_data(), callee_method, caller_bci, inline_depth)) {

    set_msg("disallowed by ciReplay");

    return true;

  }

  if (ciReplay::should_not_inline(callee_method)) {

    set_msg("disallowed by ciReplay");

    return true;

  }

#endif

  if (callee_method->force_inline()) {

    set_msg("force inline by annotation");

    return false;

  }

  // Now perform checks which are heuristic

  if (is_unboxing_method(callee_method, C)) {

    // Inline unboxing methods.

    return false;

  }

  if (callee_method->has_compiled_code() &&

      callee_method->instructions_size() > InlineSmallCode) {

    set_msg("already compiled into a big method");

    return true;

  }

  // don't inline exception code unless the top method belongs to an

  // exception class

  if (caller_tree() != NULL &&

      callee_method->holder()->is_subclass_of(C->env()->Throwable_klass())) {

    const InlineTree *top = this;

    while (top->caller_tree() != NULL) top = top->caller_tree();

    ciInstanceKlass* k = top->method()->holder();

    if (!k->is_subclass_of(C->env()->Throwable_klass())) {

      set_msg("exception method");

      return true;

    }

  }

  // use frequency-based objections only for non-trivial methods

  if (callee_method->code_size() <= MaxTrivialSize) {

    return false;

  }

  // don't use counts with -Xcomp

  if (UseInterpreter) {

    if (!callee_method->has_compiled_code() &&

        !callee_method->was_executed_more_than(0)) {

      set_msg("never executed");

      return true;

    }

    if (is_init_with_ea(callee_method, caller_method, C)) {

      // Escape Analysis: inline all executed constructors

      return false;

    } else {

      intx counter_high_value;

      // Tiered compilation uses a different "high value" than non-tiered compilation.

      // Determine the right value to use.

      if (TieredCompilation) {

        counter_high_value = InvocationCounter::count_limit / 2;

      } else {

        counter_high_value = CompileThreshold / 2;

      }

      if (!callee_method->was_executed_more_than(MIN2(MinInliningThreshold, counter_high_value))) {

        set_msg("executed < MinInliningThreshold times");

        return true;

      }

    }

  }

  return false;

}

bool InlineTree::is_not_reached(ciMethod* callee_method, ciMethod* caller_method, int caller_bci, ciCallProfile& profile) {

  if (!UseInterpreter) {

    return false; // -Xcomp

  }

  if (profile.count() > 0) {

    return false; // reachable according to profile

  }

  if (!callee_method->was_executed_more_than(0)) {

    return true; // callee was never executed

  }

  if (caller_method->is_not_reached(caller_bci)) {

    return true; // call site not resolved

  }

  if (profile.count() == -1) {

    return false; // immature profile; optimistically treat as reached

  }

  assert(profile.count() == 0, "sanity");

  // Profile info is scarce.

  // Try to guess: check if the call site belongs to a start block.

  // Call sites in a start block should be reachable if no exception is thrown earlier.

  ciMethodBlocks* caller_blocks = caller_method->get_method_blocks();

  bool is_start_block = caller_blocks->block_containing(caller_bci)->start_bci() == 0;

  if (is_start_block) {

    return false; // treat the call reached as part of start block

  }

  return true; // give up and treat the call site as not reached

}

//-----------------------------try_to_inline-----------------------------------

// return true if ok

// Relocated from "InliningClosure::try_to_inline"

bool InlineTree::try_to_inline(ciMethod* callee_method, ciMethod* caller_method,

                               int caller_bci, JVMState* jvms, ciCallProfile& profile,

                               WarmCallInfo* wci_result, bool& should_delay) {

  if (ClipInlining && (int)count_inline_bcs() >= DesiredMethodLimit) {

    if (!callee_method->force_inline() || !IncrementalInline) {

      set_msg("size > DesiredMethodLimit");

      return false;

    } else if (!C->inlining_incrementally()) {

      should_delay = true;

    }

  }

  _forced_inline = false; // Reset

  if (!should_inline(callee_method, caller_method, caller_bci, profile,

                     wci_result)) {

    return false;

  }

  if (should_not_inline(callee_method, caller_method, jvms, wci_result)) {

    return false;

  }

  if (InlineAccessors && callee_method->is_accessor()) {

    // accessor methods are not subject to any of the following limits.

    set_msg("accessor");

    return true;

  }

  // suppress a few checks for accessors and trivial methods

  if (callee_method->code_size() > MaxTrivialSize) {

    // don't inline into giant methods

    if (C->over_inlining_cutoff()) {

      if ((!callee_method->force_inline() && !caller_method->is_compiled_lambda_form())

          || !IncrementalInline) {

        set_msg("NodeCountInliningCutoff");

        return false;

      } else {

        should_delay = true;

      }

    }

    if (!UseInterpreter &&

        is_init_with_ea(callee_method, caller_method, C)) {

      // Escape Analysis stress testing when running Xcomp:

      // inline constructors even if they are not reached.

    } else if (forced_inline()) {

      // Inlining was forced by CompilerOracle, ciReplay or annotation

    } else if (is_not_reached(callee_method, caller_method, caller_bci, profile)) {

      // don't inline unreached call sites

       set_msg("call site not reached");

       return false;

    }

  }

  if (!C->do_inlining() && InlineAccessors) {

    set_msg("not an accessor");

    return false;

  }

  // Limit inlining depth in case inlining is forced or

  // _max_inline_level was increased to compensate for lambda forms.

  if (inline_level() > MaxForceInlineLevel) {

    set_msg("MaxForceInlineLevel");

    return false;

  }

  if (inline_level() > _max_inline_level) {

    if (!callee_method->force_inline() || !IncrementalInline) {

      set_msg("inlining too deep");

      return false;

    } else if (!C->inlining_incrementally()) {

      should_delay = true;

    }

  }

  // detect direct and indirect recursive inlining

  {

    // count the current method and the callee

    const bool is_compiled_lambda_form = callee_method->is_compiled_lambda_form();

    int inline_level = 0;

    if (!is_compiled_lambda_form) {

      if (method() == callee_method) {

        inline_level++;

      }

    }

    // count callers of current method and callee

    Node* callee_argument0 = is_compiled_lambda_form ? jvms->map()->argument(jvms, 0)->uncast() : NULL;

    for (JVMState* j = jvms->caller(); j != NULL && j->has_method(); j = j->caller()) {

      if (j->method() == callee_method) {

        if (is_compiled_lambda_form) {

          // Since compiled lambda forms are heavily reused we allow recursive inlining.  If it is truly

          // a recursion (using the same "receiver") we limit inlining otherwise we can easily blow the

          // compiler stack.

          Node* caller_argument0 = j->map()->argument(j, 0)->uncast();

          if (caller_argument0 == callee_argument0) {

            inline_level++;

          }

        } else {

          inline_level++;

        }

      }

    }

    if (inline_level > MaxRecursiveInlineLevel) {

      set_msg("recursive inlining is too deep");

      return false;

    }

  }

  int size = callee_method->code_size_for_inlining();

  if (ClipInlining && (int)count_inline_bcs() + size >= DesiredMethodLimit) {

    if (!callee_method->force_inline() || !IncrementalInline) {

      set_msg("size > DesiredMethodLimit");

      return false;

    } else if (!C->inlining_incrementally()) {

      should_delay = true;

    }

  }

  // ok, inline this method

  return true;

}

//------------------------------pass_initial_checks----------------------------

bool InlineTree::pass_initial_checks(ciMethod* caller_method, int caller_bci, ciMethod* callee_method) {

  // Check if a callee_method was suggested

  if (callee_method == NULL) {