/*

 * Copyright (c) 1999, 2015, 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 "opto/addnode.hpp"

#include "opto/callnode.hpp"

#include "opto/cfgnode.hpp"

#include "opto/compile.hpp"

#include "opto/convertnode.hpp"

#include "opto/locknode.hpp"

#include "opto/memnode.hpp"

#include "opto/mulnode.hpp"

#include "opto/node.hpp"

#include "opto/parse.hpp"

#include "opto/phaseX.hpp"

#include "opto/rootnode.hpp"

#include "opto/runtime.hpp"

#include "opto/type.hpp"

//--------------------gen_stub-------------------------------

void GraphKit::gen_stub(address C_function,

                        const char *name,

                        int is_fancy_jump,

                        bool pass_tls,

                        bool return_pc) {

  ResourceMark rm;

  const TypeTuple *jdomain = C->tf()->domain();

  const TypeTuple *jrange  = C->tf()->range();

  // The procedure start

  StartNode* start = new StartNode(root(), jdomain);

  _gvn.set_type_bottom(start);

  // Make a map, with JVM state

  uint parm_cnt = jdomain->cnt();

  uint max_map = MAX2(2*parm_cnt+1, jrange->cnt());

  // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces

  assert(SynchronizationEntryBCI == InvocationEntryBci, "");

  JVMState* jvms = new (C) JVMState(0);

  jvms->set_bci(InvocationEntryBci);

  jvms->set_monoff(max_map);

  jvms->set_scloff(max_map);

  jvms->set_endoff(max_map);

  {

    SafePointNode *map = new SafePointNode( max_map, jvms );

    jvms->set_map(map);

    set_jvms(jvms);

    assert(map == this->map(), "kit.map is set");

  }

  // Make up the parameters

  uint i;

  for( i = 0; i < parm_cnt; i++ )

    map()->init_req(i, _gvn.transform(new ParmNode(start, i)));

  for( ; i<map()->req(); i++ )

    map()->init_req(i, top());      // For nicer debugging

  // GraphKit requires memory to be a MergeMemNode:

  set_all_memory(map()->memory());

  // Get base of thread-local storage area

  Node* thread = _gvn.transform( new ThreadLocalNode() );

  const int NoAlias = Compile::AliasIdxBot;

  Node* adr_last_Java_pc = basic_plus_adr(top(),

                                            thread,

                                            in_bytes(JavaThread::frame_anchor_offset()) +

                                            in_bytes(JavaFrameAnchor::last_Java_pc_offset()));

#if defined(SPARC)

  Node* adr_flags = basic_plus_adr(top(),

                                   thread,

                                   in_bytes(JavaThread::frame_anchor_offset()) +

                                   in_bytes(JavaFrameAnchor::flags_offset()));

#endif /* defined(SPARC) */

  // Drop in the last_Java_sp.  last_Java_fp is not touched.

  // Always do this after the other "last_Java_frame" fields are set since

  // as soon as last_Java_sp != NULL the has_last_Java_frame is true and

  // users will look at the other fields.

  //

  Node *adr_sp = basic_plus_adr(top(), thread, in_bytes(JavaThread::last_Java_sp_offset()));

  Node *last_sp = basic_plus_adr(top(), frameptr(), (intptr_t) STACK_BIAS);

  store_to_memory(NULL, adr_sp, last_sp, T_ADDRESS, NoAlias, MemNode::unordered);

  // Set _thread_in_native

  // The order of stores into TLS is critical!  Setting _thread_in_native MUST

  // be last, because a GC is allowed at any time after setting it and the GC

  // will require last_Java_pc and last_Java_sp.

  //-----------------------------

  // Compute signature for C call.  Varies from the Java signature!

  const Type **fields = TypeTuple::fields(2*parm_cnt+2);

  uint cnt = TypeFunc::Parms;

  // The C routines gets the base of thread-local storage passed in as an

  // extra argument.  Not all calls need it, but its cheap to add here.

  for (uint pcnt = cnt; pcnt < parm_cnt; pcnt++, cnt++) {

    fields[cnt] = jdomain->field_at(pcnt);

  }

  fields[cnt++] = TypeRawPtr::BOTTOM; // Thread-local storage

  // Also pass in the caller's PC, if asked for.

  if (return_pc) {

    fields[cnt++] = TypeRawPtr::BOTTOM; // Return PC

  }

  const TypeTuple* domain = TypeTuple::make(cnt,fields);

  // The C routine we are about to call cannot return an oop; it can block on

  // exit and a GC will trash the oop while it sits in C-land.  Instead, we

  // return the oop through TLS for runtime calls.

  // Also, C routines returning integer subword values leave the high

  // order bits dirty; these must be cleaned up by explicit sign extension.

  const Type* retval = (jrange->cnt() == TypeFunc::Parms) ? Type::TOP : jrange->field_at(TypeFunc::Parms);

  // Make a private copy of jrange->fields();

  const Type **rfields = TypeTuple::fields(jrange->cnt() - TypeFunc::Parms);

  // Fixup oop returns

  int retval_ptr = retval->isa_oop_ptr();

  if (retval_ptr) {

    assert( pass_tls, "Oop must be returned thru TLS" );

    // Fancy-jumps return address; others return void

    rfields[TypeFunc::Parms] = is_fancy_jump ? TypeRawPtr::BOTTOM : Type::TOP;

  } else if (retval->isa_int()) { // Returning any integer subtype?

    // "Fatten" byte, char & short return types to 'int' to show that

    // the native C code can return values with junk high order bits.

    // We'll sign-extend it below later.

    rfields[TypeFunc::Parms] = TypeInt::INT; // It's "dirty" and needs sign-ext

  } else if (jrange->cnt() >= TypeFunc::Parms+1) { // Else copy other types

    rfields[TypeFunc::Parms] = jrange->field_at(TypeFunc::Parms);

    if (jrange->cnt() == TypeFunc::Parms+2) {

      rfields[TypeFunc::Parms+1] = jrange->field_at(TypeFunc::Parms+1);

    }

  }

  const TypeTuple* range = TypeTuple::make(jrange->cnt(),rfields);

  // Final C signature

  const TypeFunc *c_sig = TypeFunc::make(domain,range);

  //-----------------------------

  // Make the call node

  CallRuntimeNode *call = new CallRuntimeNode(c_sig, C_function, name, TypePtr::BOTTOM);

  //-----------------------------

  // Fix-up the debug info for the call

  call->set_jvms( new (C) JVMState(0) );

  call->jvms()->set_bci(0);

  call->jvms()->set_offsets(cnt);

  // Set fixed predefined input arguments

  cnt = 0;

  for (i = 0; i < TypeFunc::Parms; i++)

    call->init_req(cnt++, map()->in(i));

  // A little too aggressive on the parm copy; return address is not an input

  call->set_req(TypeFunc::ReturnAdr, top());

  for (; i < parm_cnt; i++) { // Regular input arguments

    call->init_req(cnt++, map()->in(i));

  }

  call->init_req( cnt++, thread );

  if( return_pc )             // Return PC, if asked for

    call->init_req( cnt++, returnadr() );

  _gvn.transform_no_reclaim(call);

  //-----------------------------

  // Now set up the return results

  set_control( _gvn.transform( new ProjNode(call,TypeFunc::Control)) );

  set_i_o(     _gvn.transform( new ProjNode(call,TypeFunc::I_O    )) );

  set_all_memory_call(call);

  if (range->cnt() > TypeFunc::Parms) {

    Node* retnode = _gvn.transform( new ProjNode(call,TypeFunc::Parms) );

    // C-land is allowed to return sub-word values.  Convert to integer type.

    assert( retval != Type::TOP, "" );

    if (retval == TypeInt::BOOL) {

      retnode = _gvn.transform( new AndINode(retnode, intcon(0xFF)) );

    } else if (retval == TypeInt::CHAR) {

      retnode = _gvn.transform( new AndINode(retnode, intcon(0xFFFF)) );

    } else if (retval == TypeInt::BYTE) {

      retnode = _gvn.transform( new LShiftINode(retnode, intcon(24)) );

      retnode = _gvn.transform( new RShiftINode(retnode, intcon(24)) );

    } else if (retval == TypeInt::SHORT) {

      retnode = _gvn.transform( new LShiftINode(retnode, intcon(16)) );

      retnode = _gvn.transform( new RShiftINode(retnode, intcon(16)) );

    }

    map()->set_req( TypeFunc::Parms, retnode );

  }

  //-----------------------------

  // Clear last_Java_sp

  store_to_memory(NULL, adr_sp, null(), T_ADDRESS, NoAlias, MemNode::unordered);

  // Clear last_Java_pc and (optionally)_flags

  store_to_memory(NULL, adr_last_Java_pc, null(), T_ADDRESS, NoAlias, MemNode::unordered);

#if defined(SPARC)

  store_to_memory(NULL, adr_flags, intcon(0), T_INT, NoAlias, MemNode::unordered);

#endif /* defined(SPARC) */

#if (defined(IA64) && !defined(AIX))

  Node* adr_last_Java_fp = basic_plus_adr(top(), thread, in_bytes(JavaThread::last_Java_fp_offset()));

  store_to_memory(NULL, adr_last_Java_fp, null(), T_ADDRESS, NoAlias, MemNode::unordered);

#endif

  // For is-fancy-jump, the C-return value is also the branch target

  Node* target = map()->in(TypeFunc::Parms);

  // Runtime call returning oop in TLS?  Fetch it out

  if( pass_tls ) {

    Node* adr = basic_plus_adr(top(), thread, in_bytes(JavaThread::vm_result_offset()));

    Node* vm_result = make_load(NULL, adr, TypeOopPtr::BOTTOM, T_OBJECT, NoAlias, MemNode::unordered);

    map()->set_req(TypeFunc::Parms, vm_result); // vm_result passed as result

    // clear thread-local-storage(tls)

    store_to_memory(NULL, adr, null(), T_ADDRESS, NoAlias, MemNode::unordered);

  }

  //-----------------------------

  // check exception

  Node* adr = basic_plus_adr(top(), thread, in_bytes(Thread::pending_exception_offset()));

  Node* pending = make_load(NULL, adr, TypeOopPtr::BOTTOM, T_OBJECT, NoAlias, MemNode::unordered);

  Node* exit_memory = reset_memory();

  Node* cmp = _gvn.transform( new CmpPNode(pending, null()) );

  Node* bo  = _gvn.transform( new BoolNode(cmp, BoolTest::ne) );

  IfNode   *iff = create_and_map_if(control(), bo, PROB_MIN, COUNT_UNKNOWN);

  Node* if_null     = _gvn.transform( new IfFalseNode(iff) );

  Node* if_not_null = _gvn.transform( new IfTrueNode(iff)  );

  assert (StubRoutines::forward_exception_entry() != NULL, "must be generated before");

  Node *exc_target = makecon(TypeRawPtr::make( StubRoutines::forward_exception_entry() ));

  Node *to_exc = new TailCallNode(if_not_null,

                                  i_o(),

                                  exit_memory,

                                  frameptr(),

                                  returnadr(),

                                  exc_target, null());

  root()->add_req(_gvn.transform(to_exc));  // bind to root to keep live

  C->init_start(start);

  //-----------------------------

  // If this is a normal subroutine return, issue the return and be done.

  switch( is_fancy_jump ) {

  case 0:                       // Make a return instruction

    // Return to caller, free any space for return address

    ret = new ReturnNode(TypeFunc::Parms, if_null,

                         i_o(),

                         exit_memory,

                         frameptr(),

                         returnadr());

    if (C->tf()->range()->cnt() > TypeFunc::Parms)

      ret->add_req( map()->in(TypeFunc::Parms) );

    break;

  case 1:    // This is a fancy tail-call jump.  Jump to computed address.

    // Jump to new callee; leave old return address alone.

    ret = new TailCallNode(if_null,

                           i_o(),

                           exit_memory,

                           frameptr(),

                           returnadr(),

                           target, map()->in(TypeFunc::Parms));

    break;

  case 2:                       // Pop return address & jump

    // Throw away old return address; jump to new computed address

    //assert(C_function == CAST_FROM_FN_PTR(address, OptoRuntime::rethrow_C), "fancy_jump==2 only for rethrow");

    ret = new TailJumpNode(if_null,

                               i_o(),

                               exit_memory,

                               frameptr(),

                               target, map()->in(TypeFunc::Parms));

    break;

  default:

    ShouldNotReachHere();

  }

  root()->add_req(_gvn.transform(ret));

}