/*

 * Copyright (c) 1998, 2011, 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 "compiler/compileLog.hpp"

#include "interpreter/linkResolver.hpp"

#include "memory/universe.inline.hpp"

#include "oops/objArrayKlass.hpp"

#include "opto/addnode.hpp"

#include "opto/memnode.hpp"

#include "opto/parse.hpp"

#include "opto/rootnode.hpp"

#include "opto/runtime.hpp"

#include "opto/subnode.hpp"

#include "runtime/deoptimization.hpp"

#include "runtime/handles.inline.hpp"

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

// Helper methods for _get* and _put* bytecodes

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

bool Parse::static_field_ok_in_clinit(ciField *field, ciMethod *method) {

  // Could be the field_holder's <clinit> method, or <clinit> for a subklass.

  // Better to check now than to Deoptimize as soon as we execute

  assert( field->is_static(), "Only check if field is static");

  // is_being_initialized() is too generous.  It allows access to statics

  // by threads that are not running the <clinit> before the <clinit> finishes.

  // return field->holder()->is_being_initialized();

  // The following restriction is correct but conservative.

  // It is also desirable to allow compilation of methods called from <clinit>

  // but this generated code will need to be made safe for execution by

  // other threads, or the transition from interpreted to compiled code would

  // need to be guarded.

  ciInstanceKlass *field_holder = field->holder();

  bool access_OK = false;

  if (method->holder()->is_subclass_of(field_holder)) {

    if (method->is_static()) {

      if (method->name() == ciSymbol::class_initializer_name()) {

        // OK to access static fields inside initializer

        access_OK = true;

      }

    } else {

      if (method->name() == ciSymbol::object_initializer_name()) {

        // It's also OK to access static fields inside a constructor,

        // because any thread calling the constructor must first have

        // synchronized on the class by executing a '_new' bytecode.

        access_OK = true;

      }

    }

  }

  return access_OK;

}

void Parse::do_field_access(bool is_get, bool is_field) {

  bool will_link;

  ciField* field = iter().get_field(will_link);

  assert(will_link, "getfield: typeflow responsibility");

  ciInstanceKlass* field_holder = field->holder();

  if (is_field == field->is_static()) {

    // Interpreter will throw java_lang_IncompatibleClassChangeError

    // Check this before allowing <clinit> methods to access static fields

    uncommon_trap(Deoptimization::Reason_unhandled,

                  Deoptimization::Action_none);

    return;

  }

  if (!is_field && !field_holder->is_initialized()) {

    if (!static_field_ok_in_clinit(field, method())) {

      uncommon_trap(Deoptimization::Reason_uninitialized,

                    Deoptimization::Action_reinterpret,

                    NULL, "!static_field_ok_in_clinit");

      return;

    }

  }

  assert(field->will_link(method()->holder(), bc()), "getfield: typeflow responsibility");

  // Note:  We do not check for an unloaded field type here any more.

  // Generate code for the object pointer.

  Node* obj;

  if (is_field) {

    int obj_depth = is_get ? 0 : field->type()->size();

    obj = do_null_check(peek(obj_depth), T_OBJECT);

    // Compile-time detect of null-exception?

    if (stopped())  return;

#ifdef ASSERT

    const TypeInstPtr *tjp = TypeInstPtr::make(TypePtr::NotNull, iter().get_declared_field_holder());

    assert(_gvn.type(obj)->higher_equal(tjp), "cast_up is no longer needed");

#endif

    if (is_get) {

      --_sp;  // pop receiver before getting

      do_get_xxx(obj, field, is_field);

    } else {

      do_put_xxx(obj, field, is_field);

      --_sp;  // pop receiver after putting

    }

  } else {

    const TypeInstPtr* tip = TypeInstPtr::make(field_holder->java_mirror());

    obj = _gvn.makecon(tip);

    if (is_get) {

      do_get_xxx(obj, field, is_field);

    } else {

      do_put_xxx(obj, field, is_field);

    }

  }

}

void Parse::do_get_xxx(Node* obj, ciField* field, bool is_field) {

  // Does this field have a constant value?  If so, just push the value.

  if (field->is_constant()) {

    if (field->is_static()) {

      // final static field

      if (push_constant(field->constant_value()))

        return;

    }

    else {

      // final non-static field of a trusted class (classes in

      // java.lang.invoke and sun.invoke packages and subpackages).

      if (obj->is_Con()) {

        const TypeOopPtr* oop_ptr = obj->bottom_type()->isa_oopptr();

        ciObject* constant_oop = oop_ptr->const_oop();

        ciConstant constant = field->constant_value_of(constant_oop);

        if (push_constant(constant, true))

          return;

      }

    }

  }

  ciType* field_klass = field->type();

  bool is_vol = field->is_volatile();

  // Compute address and memory type.

  int offset = field->offset_in_bytes();

  const TypePtr* adr_type = C->alias_type(field)->adr_type();

  Node *adr = basic_plus_adr(obj, obj, offset);

  BasicType bt = field->layout_type();

  // Build the resultant type of the load

  const Type *type;

  bool must_assert_null = false;

  if( bt == T_OBJECT ) {

    if (!field->type()->is_loaded()) {

      type = TypeInstPtr::BOTTOM;

      must_assert_null = true;

    } else if (field->is_constant() && field->is_static()) {

      // This can happen if the constant oop is non-perm.

      ciObject* con = field->constant_value().as_object();

      // Do not "join" in the previous type; it doesn't add value,

      // and may yield a vacuous result if the field is of interface type.

      type = TypeOopPtr::make_from_constant(con)->isa_oopptr();

      assert(type != NULL, "field singleton type must be consistent");

    } else {

      type = TypeOopPtr::make_from_klass(field_klass->as_klass());

    }

  } else {

    type = Type::get_const_basic_type(bt);

  }

  // Build the load.

  Node* ld = make_load(NULL, adr, type, bt, adr_type, is_vol);

  // Adjust Java stack

  if (type2size[bt] == 1)

    push(ld);

  else

    push_pair(ld);

  if (must_assert_null) {

    // Do not take a trap here.  It's possible that the program

    // will never load the field's class, and will happily see

    // null values in this field forever.  Don't stumble into a

    // trap for such a program, or we might get a long series

    // of useless recompilations.  (Or, we might load a class

    // which should not be loaded.)  If we ever see a non-null

    // value, we will then trap and recompile.  (The trap will

    // not need to mention the class index, since the class will

    // already have been loaded if we ever see a non-null value.)

    // uncommon_trap(iter().get_field_signature_index());

#ifndef PRODUCT

    if (PrintOpto && (Verbose || WizardMode)) {

      method()->print_name(); tty->print_cr(" asserting nullness of field at bci: %d", bci());

    }

#endif

    if (C->log() != NULL) {

      C->log()->elem("assert_null reason='field' klass='%d'",

                     C->log()->identify(field->type()));

    }

    // If there is going to be a trap, put it at the next bytecode:

    set_bci(iter().next_bci());

    do_null_assert(peek(), T_OBJECT);

    set_bci(iter().cur_bci()); // put it back

  }

  // If reference is volatile, prevent following memory ops from

  // floating up past the volatile read.  Also prevents commoning

  // another volatile read.

  if (field->is_volatile()) {

    // Memory barrier includes bogus read of value to force load BEFORE membar

    insert_mem_bar(Op_MemBarAcquire, ld);

  }

}

void Parse::do_put_xxx(Node* obj, ciField* field, bool is_field) {

  bool is_vol = field->is_volatile();

  // If reference is volatile, prevent following memory ops from

  // floating down past the volatile write.  Also prevents commoning

  // another volatile read.

  if (is_vol)  insert_mem_bar(Op_MemBarRelease);

  // Compute address and memory type.

  int offset = field->offset_in_bytes();

  const TypePtr* adr_type = C->alias_type(field)->adr_type();

  Node* adr = basic_plus_adr(obj, obj, offset);

  BasicType bt = field->layout_type();

  // Value to be stored

  Node* val = type2size[bt] == 1 ? pop() : pop_pair();

  // Round doubles before storing

  if (bt == T_DOUBLE)  val = dstore_rounding(val);

  // Store the value.

  Node* store;

  if (bt == T_OBJECT) {

    const TypeOopPtr* field_type;

    if (!field->type()->is_loaded()) {

      field_type = TypeInstPtr::BOTTOM;

    } else {

      field_type = TypeOopPtr::make_from_klass(field->type()->as_klass());

    }

    store = store_oop_to_object( control(), obj, adr, adr_type, val, field_type, bt);

  } else {

    store = store_to_memory( control(), adr, val, bt, adr_type, is_vol );

  }

  // If reference is volatile, prevent following volatiles ops from

  // floating up before the volatile write.

  if (is_vol) {

    // First place the specific membar for THIS volatile index. This first

    // membar is dependent on the store, keeping any other membars generated

    // below from floating up past the store.

    int adr_idx = C->get_alias_index(adr_type);

    insert_mem_bar_volatile(Op_MemBarVolatile, adr_idx, store);

    // Now place a membar for AliasIdxBot for the unknown yet-to-be-parsed

    // volatile alias indices. Skip this if the membar is redundant.

    if (adr_idx != Compile::AliasIdxBot) {

      insert_mem_bar_volatile(Op_MemBarVolatile, Compile::AliasIdxBot, store);

    }

    // Finally, place alias-index-specific membars for each volatile index

    // that isn't the adr_idx membar. Typically there's only 1 or 2.

    for( int i = Compile::AliasIdxRaw; i < C->num_alias_types(); i++ ) {

      if (i != adr_idx && C->alias_type(i)->is_volatile()) {

        insert_mem_bar_volatile(Op_MemBarVolatile, i, store);

      }

    }

  }

  // If the field is final, the rules of Java say we are in <init> or <clinit>.

  // Note the presence of writes to final non-static fields, so that we

  // can insert a memory barrier later on to keep the writes from floating

  // out of the constructor.

  if (is_field && field->is_final()) {

    set_wrote_final(true);

  }

}

bool Parse::push_constant(ciConstant constant, bool require_constant) {

  switch (constant.basic_type()) {

  case T_BOOLEAN:  push( intcon(constant.as_boolean()) ); break;

  case T_INT:      push( intcon(constant.as_int())     ); break;

  case T_CHAR:     push( intcon(constant.as_char())    ); break;

  case T_BYTE:     push( intcon(constant.as_byte())    ); break;

  case T_SHORT:    push( intcon(constant.as_short())   ); break;

  case T_FLOAT:    push( makecon(TypeF::make(constant.as_float())) );  break;

  case T_DOUBLE:   push_pair( makecon(TypeD::make(constant.as_double())) );  break;

  case T_LONG:     push_pair( longcon(constant.as_long()) ); break;

  case T_ARRAY:

  case T_OBJECT: {

    // cases:

    //   can_be_constant    = (oop not scavengable || ScavengeRootsInCode != 0)

    //   should_be_constant = (oop not scavengable || ScavengeRootsInCode >= 2)

    // An oop is not scavengable if it is in the perm gen.

    ciObject* oop_constant = constant.as_object();

    if (oop_constant->is_null_object()) {

      push( zerocon(T_OBJECT) );

      break;

    } else if (require_constant || oop_constant->should_be_constant()) {

      push( makecon(TypeOopPtr::make_from_constant(oop_constant, require_constant)) );

      break;

    } else {

      // we cannot inline the oop, but we can use it later to narrow a type

      return false;

    }

  }

  case T_ILLEGAL: {

    // Invalid ciConstant returned due to OutOfMemoryError in the CI

    assert(C->env()->failing(), "otherwise should not see this");

    // These always occur because of object types; we are going to

    // bail out anyway, so make the stack depths match up

    push( zerocon(T_OBJECT) );

    return false;

  }

  default:

    ShouldNotReachHere();

    return false;

  }

  // success

  return true;

}

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

void Parse::do_anewarray() {

  bool will_link;

  ciKlass* klass = iter().get_klass(will_link);

  // Uncommon Trap when class that array contains is not loaded

  // we need the loaded class for the rest of graph; do not

  // initialize the container class (see Java spec)!!!

  assert(will_link, "anewarray: typeflow responsibility");

  ciObjArrayKlass* array_klass = ciObjArrayKlass::make(klass);

  // Check that array_klass object is loaded

  if (!array_klass->is_loaded()) {

    // Generate uncommon_trap for unloaded array_class

    uncommon_trap(Deoptimization::Reason_unloaded,

                  Deoptimization::Action_reinterpret,

                  array_klass);

    return;

  }

  kill_dead_locals();

  const TypeKlassPtr* array_klass_type = TypeKlassPtr::make(array_klass);

  Node* count_val = pop();

  Node* obj = new_array(makecon(array_klass_type), count_val, 1);

  push(obj);

}

void Parse::do_newarray(BasicType elem_type) {

  kill_dead_locals();

  Node*   count_val = pop();

  const TypeKlassPtr* array_klass = TypeKlassPtr::make(ciTypeArrayKlass::make(elem_type));

  Node*   obj = new_array(makecon(array_klass), count_val, 1);

  // Push resultant oop onto stack

  push(obj);

}

// Expand simple expressions like new int[3][5] and new Object[2][nonConLen].

// Also handle the degenerate 1-dimensional case of anewarray.

Node* Parse::expand_multianewarray(ciArrayKlass* array_klass, Node* *lengths, int ndimensions, int nargs) {

  Node* length = lengths[0];

  assert(length != NULL, "");

  Node* array = new_array(makecon(TypeKlassPtr::make(array_klass)), length, nargs);

  if (ndimensions > 1) {

    jint length_con = find_int_con(length, -1);

    guarantee(length_con >= 0, "non-constant multianewarray");

    ciArrayKlass* array_klass_1 = array_klass->as_obj_array_klass()->element_klass()->as_array_klass();

    const TypePtr* adr_type = TypeAryPtr::OOPS;

    const TypeOopPtr*    elemtype = _gvn.type(array)->is_aryptr()->elem()->make_oopptr();

    const intptr_t header   = arrayOopDesc::base_offset_in_bytes(T_OBJECT);

    for (jint i = 0; i < length_con; i++) {

      Node*    elem   = expand_multianewarray(array_klass_1, &lengths[1], ndimensions-1, nargs);

      intptr_t offset = header + ((intptr_t)i << LogBytesPerHeapOop);

      Node*    eaddr  = basic_plus_adr(array, offset);

      store_oop_to_array(control(), array, eaddr, adr_type, elem, elemtype, T_OBJECT);

    }

  }

  return array;

}

void Parse::do_multianewarray() {

  int ndimensions = iter().get_dimensions();

  // the m-dimensional array

  bool will_link;

  ciArrayKlass* array_klass = iter().get_klass(will_link)->as_array_klass();

  assert(will_link, "multianewarray: typeflow responsibility");

  // Note:  Array classes are always initialized; no is_initialized check.

  kill_dead_locals();

  // get the lengths from the stack (first dimension is on top)

  length[ndimensions] = NULL;  // terminating null for make_runtime_call

  int j;

  for (j = ndimensions-1; j >= 0 ; j--) length[j] = pop();

  // The original expression was of this form: new T[length0][length1]...

  // It is often the case that the lengths are small (except the last).

  // If that happens, use the fast 1-d creator a constant number of times.

  const jint expand_limit = MIN2((juint)MultiArrayExpandLimit, (juint)100);

  jint expand_count = 1;        // count of allocations in the expansion

  jint expand_fanout = 1;       // running total fanout

  for (j = 0; j < ndimensions-1; j++) {

    jint dim_con = find_int_con(length[j], -1);

    expand_fanout *= dim_con;

    expand_count  += expand_fanout; // count the level-J sub-arrays

    if (dim_con <= 0

        || dim_con > expand_limit

        || expand_count > expand_limit) {

      expand_count = 0;

      break;

    }

  }

  // Can use multianewarray instead of [a]newarray if only one dimension,

  // or if all non-final dimensions are small constants.

  if (ndimensions == 1 || (1 <= expand_count && expand_count <= expand_limit)) {

    Node* obj = NULL;

    // Set the original stack and the reexecute bit for the interpreter

    // to reexecute the multianewarray bytecode if deoptimization happens.

    // Do it unconditionally even for one dimension multianewarray.

    // Note: the reexecute bit will be set in GraphKit::add_safepoint_edges()

    // when AllocateArray node for newarray is created.

    { PreserveReexecuteState preexecs(this);

      _sp += ndimensions;

      // Pass 0 as nargs since uncommon trap code does not need to restore stack.

      obj = expand_multianewarray(array_klass, &length[0], ndimensions, 0);

    } //original reexecute and sp are set back here

    push(obj);

    return;

  }

  address fun = NULL;

  switch (ndimensions) {

  case 2: fun = OptoRuntime::multianewarray2_Java(); break;

  case 3: fun = OptoRuntime::multianewarray3_Java(); break;

  case 4: fun = OptoRuntime::multianewarray4_Java(); break;

  case 5: fun = OptoRuntime::multianewarray5_Java(); break;

  };

  Node* res = _gvn.transform(new (C, 1) ProjNode(c, TypeFunc::Parms));

  const Type* type = TypeOopPtr::make_from_klass_raw(array_klass);

  // Improve the type:  We know it's not null, exact, and of a given length.

  type = type->is_ptr()->cast_to_ptr_type(TypePtr::NotNull);

  type = type->is_aryptr()->cast_to_exactness(true);

  const TypeInt* ltype = _gvn.find_int_type(length[0]);

  if (ltype != NULL)

    type = type->is_aryptr()->cast_to_size(ltype);