shenandoahBarrierSetC2.cpp

/*
 * Copyright (c) 2018, 2019, Red Hat, Inc. All rights reserved.
 *
 * 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
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 */

#include "precompiled.hpp"
#include "gc_implementation/shenandoah/shenandoahBarrierSet.hpp"
#include "gc_implementation/shenandoah/shenandoahRuntime.hpp"
#include "gc_implementation/shenandoah/c2/shenandoahBarrierSetC2.hpp"
#include "gc_implementation/shenandoah/c2/shenandoahSupport.hpp"
#include "opto/type.hpp"
#include "runtime/thread.hpp"

ShenandoahBarrierSetC2* ShenandoahBarrierSetC2::bsc2() {
  return ShenandoahBarrierSet::barrier_set()->bsc2();
}

bool ShenandoahBarrierSetC2::is_shenandoah_lrb_call(Node* call) {
  if (!call->is_CallLeaf()) {
    return false;
  }

  address entry_point = call->as_CallLeaf()->entry_point();
  return (entry_point == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier)) ||
         (entry_point == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_narrow));
}

bool ShenandoahBarrierSetC2::is_shenandoah_state_load(Node* n) {
  if (!n->is_Load()) return false;
  const int state_offset = in_bytes(JavaThread::gc_state_offset());
  return n->in(2)->is_AddP() && n->in(2)->in(2)->Opcode() == Op_ThreadLocal
         && n->in(2)->in(3)->is_Con()
         && n->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == state_offset;
}

const TypeFunc* ShenandoahBarrierSetC2::shenandoah_load_reference_barrier_Type() {
  const Type **fields = TypeTuple::fields(2);
  fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value
  fields[TypeFunc::Parms+1] = TypeRawPtr::BOTTOM;   // original load address

  const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+2, fields);

  // create result type (range)
  fields = TypeTuple::fields(1);
  fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL;
  const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+1, fields);

  return TypeFunc::make(domain, range);
}

Node* ShenandoahBarrierSetC2::step_over_gc_barrier(Node* c) {
  if (c->Opcode() == Op_ShenandoahLoadReferenceBarrier) {
    return c->in(ShenandoahLoadReferenceBarrierNode::ValueIn);
  }
  return c;
}

Node* ShenandoahBarrierSetC2::load_reference_barrier(GraphKit* kit, Node* n) const {
  if (ShenandoahLoadRefBarrier) {
    return kit->gvn().transform(new (kit->C) ShenandoahLoadReferenceBarrierNode(NULL, n));
  } else {
    return n;
  }
}