JDK14/Java14源码在线阅读

//
// Copyright (c) 2015, 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.
//
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// questions.
//

source_hpp %{

#include "gc/z/c2/zBarrierSetC2.hpp"
#include "gc/z/zThreadLocalData.hpp"

%}

source %{

static void z_load_barrier(MacroAssembler& _masm, const MachNode* node, Address ref_addr, Register ref, Register tmp, bool weak) {
  ZLoadBarrierStubC2* const stub = ZLoadBarrierStubC2::create(node, ref_addr, ref, tmp, weak);
  __ testptr(ref, Address(r15_thread, ZThreadLocalData::address_bad_mask_offset()));
  __ jcc(Assembler::notZero, *stub->entry());
  __ bind(*stub->continuation());
}

static void z_load_barrier_slow_path(MacroAssembler& _masm, const MachNode* node, Address ref_addr, Register ref, Register tmp) {
  ZLoadBarrierStubC2* const stub = ZLoadBarrierStubC2::create(node, ref_addr, ref, tmp, false /* weak */);
  __ jmp(*stub->entry());
  __ bind(*stub->continuation());
}

%}

// Load Pointer
instruct zLoadP(rRegP dst, memory mem, rFlagsReg cr)
%{
  predicate(UseZGC && n->as_Load()->barrier_data() == ZLoadBarrierStrong);
  match(Set dst (LoadP mem));
  effect(KILL cr, TEMP dst);

  ins_cost(125);

  format %{ "movq     $dst, $mem" %}

  ins_encode %{
    __ movptr($dst$$Register, $mem$$Address);
    if (barrier_data() != ZLoadBarrierElided) {
      z_load_barrier(_masm, this, $mem$$Address, $dst$$Register, noreg /* tmp */, false /* weak */);
    }
  %}

  ins_pipe(ialu_reg_mem);
%}

// Load Weak Pointer
instruct zLoadWeakP(rRegP dst, memory mem, rFlagsReg cr)
%{
  predicate(UseZGC && n->as_Load()->barrier_data() == ZLoadBarrierWeak);
  match(Set dst (LoadP mem));
  effect(KILL cr, TEMP dst);

  ins_cost(125);

  format %{ "movq     $dst, $mem" %}

  ins_encode %{
    __ movptr($dst$$Register, $mem$$Address);
    z_load_barrier(_masm, this, $mem$$Address, $dst$$Register, noreg /* tmp */, true /* weak */);
  %}

  ins_pipe(ialu_reg_mem);
%}

instruct zCompareAndExchangeP(memory mem, rax_RegP oldval, rRegP newval, rRegP tmp, rFlagsReg cr) %{
  match(Set oldval (CompareAndExchangeP mem (Binary oldval newval)));
  predicate(UseZGC && n->as_LoadStore()->barrier_data() == ZLoadBarrierStrong);
  effect(KILL cr, TEMP tmp);

  format %{ "lock\n\t"
            "cmpxchgq $newval, $mem" %}

  ins_encode %{
    if (barrier_data() != ZLoadBarrierElided) {
      __ movptr($tmp$$Register, $oldval$$Register);
    }
    __ lock();
    __ cmpxchgptr($newval$$Register, $mem$$Address);
    if (barrier_data() != ZLoadBarrierElided) {
      Label good;
      __ testptr($oldval$$Register, Address(r15_thread, ZThreadLocalData::address_bad_mask_offset()));
      __ jcc(Assembler::zero, good);
      z_load_barrier_slow_path(_masm, this, $mem$$Address, $oldval$$Register, $tmp$$Register);
      __ movptr($oldval$$Register, $tmp$$Register);
      __ lock();
      __ cmpxchgptr($newval$$Register, $mem$$Address);
      __ bind(good);
    }
  %}

  ins_pipe(pipe_cmpxchg);
%}

instruct zCompareAndSwapP(rRegI res, memory mem, rRegP newval, rRegP tmp, rFlagsReg cr, rax_RegP oldval) %{
  match(Set res (CompareAndSwapP mem (Binary oldval newval)));
  match(Set res (WeakCompareAndSwapP mem (Binary oldval newval)));
  predicate(UseZGC && n->as_LoadStore()->barrier_data() == ZLoadBarrierStrong);
  effect(KILL cr, KILL oldval, TEMP tmp);

  format %{ "lock\n\t"
            "cmpxchgq $newval, $mem\n\t"
            "sete     $res\n\t"
            "movzbl   $res, $res" %}

  ins_encode %{
    if (barrier_data() != ZLoadBarrierElided) {
      __ movptr($tmp$$Register, $oldval$$Register);
    }
    __ lock();
    __ cmpxchgptr($newval$$Register, $mem$$Address);
    if (barrier_data() != ZLoadBarrierElided) {
      Label good;
      __ testptr($oldval$$Register, Address(r15_thread, ZThreadLocalData::address_bad_mask_offset()));
      __ jcc(Assembler::zero, good);
      z_load_barrier_slow_path(_masm, this, $mem$$Address, $oldval$$Register, $tmp$$Register);
      __ movptr($oldval$$Register, $tmp$$Register);
      __ lock();
      __ cmpxchgptr($newval$$Register, $mem$$Address);
      __ bind(good);
      __ cmpptr($tmp$$Register, $oldval$$Register);
    }
    __ setb(Assembler::equal, $res$$Register);

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