/*

 * Copyright (c) 2018, 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 "asm/macroAssembler.inline.hpp"

#include "gc/g1/g1BarrierSet.hpp"

#include "gc/g1/g1BarrierSetAssembler.hpp"

#include "gc/g1/g1BarrierSetRuntime.hpp"

#include "gc/g1/g1CardTable.hpp"

#include "gc/g1/g1ThreadLocalData.hpp"

#include "gc/g1/heapRegion.hpp"

#include "interpreter/interp_masm.hpp"

#include "runtime/sharedRuntime.hpp"

#include "utilities/macros.hpp"

#ifdef COMPILER1

#include "c1/c1_LIRAssembler.hpp"

#include "c1/c1_MacroAssembler.hpp"

#include "gc/g1/c1/g1BarrierSetC1.hpp"

#endif

#define __ masm->

void G1BarrierSetAssembler::gen_write_ref_array_pre_barrier(MacroAssembler* masm, DecoratorSet decorators,

                                                            Register addr, Register count) {

  bool dest_uninitialized = (decorators & AS_DEST_NOT_INITIALIZED) != 0;

  // With G1, don't generate the call if we statically know that the target in uninitialized

  if (!dest_uninitialized) {

    Register tmp = O5;

    assert_different_registers(addr, count, tmp);

    Label filtered;

    // Is marking active?

    if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {

      __ ld(G2, in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset()), tmp);

    } else {

      guarantee(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");

      __ ldsb(G2, in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset()), tmp);

    }

    // Is marking active?

    __ cmp_and_br_short(tmp, G0, Assembler::equal, Assembler::pt, filtered);

    __ save_frame(0);

    // Save the necessary global regs... will be used after.

    if (addr->is_global()) {

      __ mov(addr, L0);

    }

    if (count->is_global()) {

      __ mov(count, L1);

    }

    __ mov(addr->after_save(), O0);

    // Get the count into O1

    address slowpath = UseCompressedOops ? CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_array_pre_narrow_oop_entry)

                                         : CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_array_pre_oop_entry);

    __ call(slowpath);

    __ delayed()->mov(count->after_save(), O1);

    if (addr->is_global()) {

      __ mov(L0, addr);

    }

    if (count->is_global()) {

      __ mov(L1, count);

    }

    __ restore();

    __ bind(filtered);

    DEBUG_ONLY(__ set(0xDEADC0DE, tmp);) // we have killed tmp

  }

}

void G1BarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,

                                                             Register addr, Register count, Register tmp) {

  // Get some new fresh output registers.

  __ save_frame(0);

  __ mov(addr->after_save(), O0);

  __ call(CAST_FROM_FN_PTR(address, G1BarrierSetRuntime::write_ref_array_post_entry));

  __ delayed()->mov(count->after_save(), O1);

  __ restore();

}

#undef __

static address satb_log_enqueue_with_frame = NULL;

static u_char* satb_log_enqueue_with_frame_end = NULL;

static address satb_log_enqueue_frameless = NULL;

static u_char* satb_log_enqueue_frameless_end = NULL;

static int EnqueueCodeSize = 128 DEBUG_ONLY( + 256); // Instructions?

static void generate_satb_log_enqueue(bool with_frame) {

  BufferBlob* bb = BufferBlob::create("enqueue_with_frame", EnqueueCodeSize);

  CodeBuffer buf(bb);

  MacroAssembler masm(&buf);

#define __ masm.

  address start = __ pc();

  Register pre_val;

  Label refill, restart;

  if (with_frame) {

    __ save_frame(0);

    pre_val = I0;  // Was O0 before the save.

  } else {

    pre_val = O0;

  }

  int satb_q_index_byte_offset = in_bytes(G1ThreadLocalData::satb_mark_queue_index_offset());

  int satb_q_buf_byte_offset = in_bytes(G1ThreadLocalData::satb_mark_queue_buffer_offset());

  assert(in_bytes(SATBMarkQueue::byte_width_of_index()) == sizeof(intptr_t) &&

         in_bytes(SATBMarkQueue::byte_width_of_buf()) == sizeof(intptr_t),

         "check sizes in assembly below");

  __ bind(restart);

  // Load the index into the SATB buffer. SATBMarkQueue::_index is a size_t

  // so ld_ptr is appropriate.

  __ ld_ptr(G2_thread, satb_q_index_byte_offset, L0);

  // index == 0?

  __ cmp_and_brx_short(L0, G0, Assembler::equal, Assembler::pn, refill);

  __ ld_ptr(G2_thread, satb_q_buf_byte_offset, L1);

  __ sub(L0, oopSize, L0);

  __ st_ptr(pre_val, L1, L0);  // [_buf + index] := I0

  if (!with_frame) {

    // Use return-from-leaf

    __ retl();

    __ delayed()->st_ptr(L0, G2_thread, satb_q_index_byte_offset);

  } else {

    // Not delayed.

    __ st_ptr(L0, G2_thread, satb_q_index_byte_offset);

  }

  if (with_frame) {

    __ ret();

    __ delayed()->restore();

  }

  __ bind(refill);

  address handle_zero =

    CAST_FROM_FN_PTR(address,

                     &SATBMarkQueueSet::handle_zero_index_for_thread);

  // This should be rare enough that we can afford to save all the

  // scratch registers that the calling context might be using.

  __ mov(G1_scratch, L0);

  __ mov(G3_scratch, L1);

  __ mov(G4, L2);

  // We need the value of O0 above (for the write into the buffer), so we

  // save and restore it.

  __ mov(O0, L3);

  // Since the call will overwrite O7, we save and restore that, as well.

  __ mov(O7, L4);

  __ call_VM_leaf(L5, handle_zero, G2_thread);

  __ mov(L0, G1_scratch);

  __ mov(L1, G3_scratch);

  __ mov(L2, G4);

  __ mov(L3, O0);

  __ br(Assembler::always, /*annul*/false, Assembler::pt, restart);

  __ delayed()->mov(L4, O7);

  if (with_frame) {

    satb_log_enqueue_with_frame = start;

    satb_log_enqueue_with_frame_end = __ pc();

  } else {

    satb_log_enqueue_frameless = start;

    satb_log_enqueue_frameless_end = __ pc();

  }

#undef __

}

#define __ masm->

void G1BarrierSetAssembler::g1_write_barrier_pre(MacroAssembler* masm,

                                                 Register obj,

                                                 Register index,

                                                 int offset,

                                                 Register pre_val,

                                                 Register tmp,

                                                 bool preserve_o_regs) {

  Label filtered;

  if (obj == noreg) {

    // We are not loading the previous value so make

    // sure that we don't trash the value in pre_val

    // with the code below.

    assert_different_registers(pre_val, tmp);

  } else {

    // We will be loading the previous value

    // in this code so...

    assert(offset == 0 || index == noreg, "choose one");

    assert(pre_val == noreg, "check this code");

  }

  // Is marking active?

  if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {

    __ ld(G2, in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset()), tmp);

  } else {

    guarantee(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");

    __ ldsb(G2, in_bytes(G1ThreadLocalData::satb_mark_queue_active_offset()), tmp);

  }

  // Is marking active?

  __ cmp_and_br_short(tmp, G0, Assembler::equal, Assembler::pt, filtered);

  // Do we need to load the previous value?

  if (obj != noreg) {

    // Load the previous value...

    if (index == noreg) {

      if (Assembler::is_simm13(offset)) {

        __ load_heap_oop(obj, offset, tmp);

      } else {

        __ set(offset, tmp);

        __ load_heap_oop(obj, tmp, tmp);

      }

    } else {

      __ load_heap_oop(obj, index, tmp);

    }

    // Previous value has been loaded into tmp

    pre_val = tmp;

  }

  assert(pre_val != noreg, "must have a real register");

  // Is the previous value null?

  __ cmp_and_brx_short(pre_val, G0, Assembler::equal, Assembler::pt, filtered);

  // OK, it's not filtered, so we'll need to call enqueue.  In the normal

  // case, pre_val will be a scratch G-reg, but there are some cases in

  // which it's an O-reg.  In the first case, do a normal call.  In the

  // latter, do a save here and call the frameless version.

  guarantee(pre_val->is_global() || pre_val->is_out(),

            "Or we need to think harder.");

  if (pre_val->is_global() && !preserve_o_regs) {

    __ call(satb_log_enqueue_with_frame);

    __ delayed()->mov(pre_val, O0);

  } else {

    __ save_frame(0);

    __ call(satb_log_enqueue_frameless);

    __ delayed()->mov(pre_val->after_save(), O0);

    __ restore();

  }

  __ bind(filtered);

}

#undef __

static address dirty_card_log_enqueue = 0;

static u_char* dirty_card_log_enqueue_end = 0;

// This gets to assume that o0 contains the object address.

static void generate_dirty_card_log_enqueue(jbyte* byte_map_base) {

  BufferBlob* bb = BufferBlob::create("dirty_card_enqueue", EnqueueCodeSize*2);

  CodeBuffer buf(bb);

  MacroAssembler masm(&buf);

#define __ masm.

  address start = __ pc();

  Label not_already_dirty, restart, refill, young_card;

  __ srlx(O0, CardTable::card_shift, O0);

  AddressLiteral addrlit(byte_map_base);

  __ set(addrlit, O1); // O1 := <card table base>

  __ ldub(O0, O1, O2); // O2 := [O0 + O1]

  __ cmp_and_br_short(O2, G1CardTable::g1_young_card_val(), Assembler::equal, Assembler::pt, young_card);

  __ membar(Assembler::Membar_mask_bits(Assembler::StoreLoad));

  __ ldub(O0, O1, O2); // O2 := [O0 + O1]

  assert(G1CardTable::dirty_card_val() == 0, "otherwise check this code");

  __ cmp_and_br_short(O2, G0, Assembler::notEqual, Assembler::pt, not_already_dirty);

  __ bind(young_card);

  // We didn't take the branch, so we're already dirty: return.

  // Use return-from-leaf

  __ retl();

  __ delayed()->nop();

  // Not dirty.

  __ bind(not_already_dirty);

  // Get O0 + O1 into a reg by itself

  __ add(O0, O1, O3);

  // First, dirty it.

  __ stb(G0, O3, G0);  // [cardPtr] := 0  (i.e., dirty).

  int dirty_card_q_index_byte_offset = in_bytes(G1ThreadLocalData::dirty_card_queue_index_offset());

  int dirty_card_q_buf_byte_offset = in_bytes(G1ThreadLocalData::dirty_card_queue_buffer_offset());

  __ bind(restart);

  // Load the index into the update buffer. DirtyCardQueue::_index is

  // a size_t so ld_ptr is appropriate here.

  __ ld_ptr(G2_thread, dirty_card_q_index_byte_offset, L0);

  // index == 0?

  __ cmp_and_brx_short(L0, G0, Assembler::equal, Assembler::pn, refill);

  __ ld_ptr(G2_thread, dirty_card_q_buf_byte_offset, L1);

  __ sub(L0, oopSize, L0);

  __ st_ptr(O3, L1, L0);  // [_buf + index] := I0

  // Use return-from-leaf

  __ retl();

  __ delayed()->st_ptr(L0, G2_thread, dirty_card_q_index_byte_offset);

  __ bind(refill);

  address handle_zero =

    CAST_FROM_FN_PTR(address,

                     &DirtyCardQueueSet::handle_zero_index_for_thread);

  // This should be rare enough that we can afford to save all the

  // scratch registers that the calling context might be using.

  __ mov(G1_scratch, L3);

  __ mov(G3_scratch, L5);

  // We need the value of O3 above (for the write into the buffer), so we

  // save and restore it.

  __ mov(O3, L6);

  // Since the call will overwrite O7, we save and restore that, as well.

  __ mov(O7, L4);

  __ call_VM_leaf(L7_thread_cache, handle_zero, G2_thread);

  __ mov(L3, G1_scratch);

  __ mov(L5, G3_scratch);

  __ mov(L6, O3);

  __ br(Assembler::always, /*annul*/false, Assembler::pt, restart);

  __ delayed()->mov(L4, O7);

  dirty_card_log_enqueue = start;

  dirty_card_log_enqueue_end = __ pc();

  // XXX Should have a guarantee here about not going off the end!

  // Does it already do so?  Do an experiment...

#undef __

}

#define __ masm->

void G1BarrierSetAssembler::g1_write_barrier_post(MacroAssembler* masm, Register store_addr, Register new_val, Register tmp) {

  Label filtered;

  MacroAssembler* post_filter_masm = masm;

  if (new_val == G0) return;

  G1BarrierSet* bs = barrier_set_cast<G1BarrierSet>(BarrierSet::barrier_set());

  // If the "store_addr" register is an "in" or "local" register, move it to

  // a scratch reg so we can pass it as an argument.

  bool use_scr = !(store_addr->is_global() || store_addr->is_out());

  // Pick a scratch register different from "tmp".

  Register scr = (tmp == G1_scratch ? G3_scratch : G1_scratch);

  // Make sure we use up the delay slot!

  if (use_scr) {

    post_filter_masm->mov(store_addr, scr);

  } else {

    post_filter_masm->nop();

  }

  __ save_frame(0);

  __ call(dirty_card_log_enqueue);

  if (use_scr) {

    __ delayed()->mov(scr, O0);

  } else {

    __ delayed()->mov(store_addr->after_save(), O0);

  }

  __ restore();

  __ bind(filtered);

}

void G1BarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,

                                         Register val, Address dst, Register tmp) {

  bool in_heap = (decorators & IN_HEAP) != 0;

  bool in_concurrent_root = (decorators & IN_CONCURRENT_ROOT) != 0;

  bool needs_pre_barrier = in_heap || in_concurrent_root;

  // No need for post barrier if storing NULL

  bool needs_post_barrier = val != G0 && in_heap;

  bool on_array = (decorators & IN_HEAP_ARRAY) != 0;

  bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;

  bool precise = on_array || on_anonymous;

  Register index = dst.has_index() ? dst.index() : noreg;

  int disp = dst.has_disp() ? dst.disp() : 0;

  if (needs_pre_barrier) {

    // Load and record the previous value.

    g1_write_barrier_pre(masm, dst.base(), index, disp,

                         noreg /* pre_val */,

                         tmp, true /*preserve_o_regs*/);

  }

  Register new_val = val;

  if (needs_post_barrier) {

    // G1 barrier needs uncompressed oop for region cross check.

    if (UseCompressedOops && val != G0) {

      new_val = tmp;

      __ mov(val, new_val);

    }

  }

  BarrierSetAssembler::store_at(masm, decorators, type, val, dst, tmp);

  if (needs_post_barrier) {

    Register base = dst.base();

    if (precise) {

      if (!dst.has_index()) {

        __ add(base, disp, base);

      } else {

        assert(!dst.has_disp(), "not supported yet");

        __ add(base, index, base);

      }

    }

    g1_write_barrier_post(masm, base, new_val, tmp);

  }

}

void G1BarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,

                                    Address src, Register dst, Register tmp) {

  bool on_oop = type == T_OBJECT || type == T_ARRAY;

  bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;

  bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0;

  bool on_reference = on_weak || on_phantom;

  // Load the value of the referent field.

  ModRefBarrierSetAssembler::load_at(masm, decorators, type, src, dst, tmp);

  if (on_oop && on_reference) {

    // Generate the G1 pre-barrier code to log the value of

    // the referent field in an SATB buffer. Note with

    // these parameters the pre-barrier does not generate

    // the load of the previous value

    Register pre_val = dst;

    bool saved = false;

    if (pre_val->is_in()) {

      // The g1_write_barrier_pre method assumes that the pre_val

      // is not in an input register.

      __ save_frame_and_mov(0, pre_val, O0);

      pre_val = O0;

      saved = true;

    }

    g1_write_barrier_pre(masm, noreg /* obj */, noreg /* index */, 0 /* offset */,

                         pre_val /* pre_val */,

                         tmp /* tmp */,

                         true /* preserve_o_regs */);

    if (saved) {

      __ restore();

    }

  }

}

void G1BarrierSetAssembler::barrier_stubs_init() {

  if (dirty_card_log_enqueue == 0) {

    G1BarrierSet* bs = barrier_set_cast<G1BarrierSet>(BarrierSet::barrier_set());

    CardTable *ct = bs->card_table();

    generate_dirty_card_log_enqueue(ct->byte_map_base());

    assert(dirty_card_log_enqueue != 0, "postcondition.");

  }

  if (satb_log_enqueue_with_frame == 0) {

    generate_satb_log_enqueue(true);

    assert(satb_log_enqueue_with_frame != 0, "postcondition.");

  }

  if (satb_log_enqueue_frameless == 0) {

    generate_satb_log_enqueue(false);

    assert(satb_log_enqueue_frameless != 0, "postcondition.");

  }

}