/*

 * Copyright (c) 2008, 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 "c1/c1_MacroAssembler.hpp"

#include "c1/c1_Runtime1.hpp"

#include "classfile/systemDictionary.hpp"

#include "gc/shared/collectedHeap.hpp"

#include "interpreter/interpreter.hpp"

#include "oops/arrayOop.hpp"

#include "oops/markWord.hpp"

#include "runtime/basicLock.hpp"

#include "runtime/biasedLocking.hpp"

#include "runtime/os.hpp"

#include "runtime/sharedRuntime.hpp"

#include "runtime/stubRoutines.hpp"

// Note: Rtemp usage is this file should not impact C2 and should be

// correct as long as it is not implicitly used in lower layers (the

// arm [macro]assembler) and used with care in the other C1 specific

// files.

void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {

  Label verified;

  load_klass(Rtemp, receiver);

  cmp(Rtemp, iCache);

  b(verified, eq); // jump over alignment no-ops

  jump(SharedRuntime::get_ic_miss_stub(), relocInfo::runtime_call_type);

  align(CodeEntryAlignment);

  bind(verified);

}

void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes) {

  assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");

  assert((frame_size_in_bytes % StackAlignmentInBytes) == 0, "frame size should be aligned");

  arm_stack_overflow_check(bang_size_in_bytes, Rtemp);

  // FP can no longer be used to memorize SP. It may be modified

  // if this method contains a methodHandle call site

  raw_push(FP, LR);

  sub_slow(SP, SP, frame_size_in_bytes);

}

void C1_MacroAssembler::remove_frame(int frame_size_in_bytes) {

  add_slow(SP, SP, frame_size_in_bytes);

  raw_pop(FP, LR);

}

void C1_MacroAssembler::verified_entry() {

  if (C1Breakpoint) {

    breakpoint();

  }

}

// Puts address of allocated object into register `obj` and end of allocated object into register `obj_end`.

void C1_MacroAssembler::try_allocate(Register obj, Register obj_end, Register tmp1, Register tmp2,

                                     RegisterOrConstant size_expression, Label& slow_case) {

  if (UseTLAB) {

    tlab_allocate(obj, obj_end, tmp1, size_expression, slow_case);

  } else {

    eden_allocate(obj, obj_end, tmp1, tmp2, size_expression, slow_case);

  }

}

void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register tmp) {

  assert_different_registers(obj, klass, len, tmp);

  if(UseBiasedLocking && !len->is_valid()) {

    ldr(tmp, Address(klass, Klass::prototype_header_offset()));

  } else {

    mov(tmp, (intptr_t)markWord::prototype().value());

  }

  str(tmp, Address(obj, oopDesc::mark_offset_in_bytes()));

  str(klass, Address(obj, oopDesc::klass_offset_in_bytes()));

  if (len->is_valid()) {

    str_32(len, Address(obj, arrayOopDesc::length_offset_in_bytes()));

  }

}

// Cleans object body [base..obj_end]. Clobbers `base` and `tmp` registers.

void C1_MacroAssembler::initialize_body(Register base, Register obj_end, Register tmp) {

  zero_memory(base, obj_end, tmp);

}

void C1_MacroAssembler::initialize_object(Register obj, Register obj_end, Register klass,

                                          Register len, Register tmp1, Register tmp2,

                                          RegisterOrConstant header_size, int obj_size_in_bytes,

                                          bool is_tlab_allocated)

{

  assert_different_registers(obj, obj_end, klass, len, tmp1, tmp2);

  initialize_header(obj, klass, len, tmp1);

  const Register ptr = tmp2;

  if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) {

    if (obj_size_in_bytes >= 0 && obj_size_in_bytes <= 8 * BytesPerWord) {

      mov(tmp1, 0);

      const int base = instanceOopDesc::header_size() * HeapWordSize;

      for (int i = base; i < obj_size_in_bytes; i += wordSize) {

        str(tmp1, Address(obj, i));

      }

    } else {

      assert(header_size.is_constant() || header_size.as_register() == ptr, "code assumption");

      add(ptr, obj, header_size);

      initialize_body(ptr, obj_end, tmp1);

    }

  }

  // StoreStore barrier required after complete initialization

  // (headers + content zeroing), before the object may escape.

  membar(MacroAssembler::StoreStore, tmp1);

}

void C1_MacroAssembler::allocate_object(Register obj, Register tmp1, Register tmp2, Register tmp3,

                                        int header_size, int object_size,

                                        Register klass, Label& slow_case) {

  assert_different_registers(obj, tmp1, tmp2, tmp3, klass, Rtemp);

  assert(header_size >= 0 && object_size >= header_size, "illegal sizes");

  const int object_size_in_bytes = object_size * BytesPerWord;

  const Register obj_end = tmp1;

  const Register len = noreg;

  if (Assembler::is_arith_imm_in_range(object_size_in_bytes)) {

    try_allocate(obj, obj_end, tmp2, tmp3, object_size_in_bytes, slow_case);

  } else {

    // Rtemp should be free at c1 LIR level

    mov_slow(Rtemp, object_size_in_bytes);

    try_allocate(obj, obj_end, tmp2, tmp3, Rtemp, slow_case);

  }

  initialize_object(obj, obj_end, klass, len, tmp2, tmp3, instanceOopDesc::header_size() * HeapWordSize, object_size_in_bytes, /* is_tlab_allocated */ UseTLAB);

}

void C1_MacroAssembler::allocate_array(Register obj, Register len,

                                       Register tmp1, Register tmp2, Register tmp3,

                                       int header_size, int element_size,

                                       Register klass, Label& slow_case) {

  assert_different_registers(obj, len, tmp1, tmp2, tmp3, klass, Rtemp);

  const int header_size_in_bytes = header_size * BytesPerWord;

  const int scale_shift = exact_log2(element_size);

  const Register obj_size = Rtemp; // Rtemp should be free at c1 LIR level

  cmp_32(len, max_array_allocation_length);

  b(slow_case, hs);

  bool align_header = ((header_size_in_bytes | element_size) & MinObjAlignmentInBytesMask) != 0;

  assert(align_header || ((header_size_in_bytes & MinObjAlignmentInBytesMask) == 0), "must be");

  assert(align_header || ((element_size & MinObjAlignmentInBytesMask) == 0), "must be");

  mov(obj_size, header_size_in_bytes + (align_header ? (MinObjAlignmentInBytes - 1) : 0));

  add_ptr_scaled_int32(obj_size, obj_size, len, scale_shift);

  if (align_header) {

    align_reg(obj_size, obj_size, MinObjAlignmentInBytes);

  }

  try_allocate(obj, tmp1, tmp2, tmp3, obj_size, slow_case);

  initialize_object(obj, tmp1, klass, len, tmp2, tmp3, header_size_in_bytes, -1, /* is_tlab_allocated */ UseTLAB);

}

int C1_MacroAssembler::lock_object(Register hdr, Register obj,

                                   Register disp_hdr, Register tmp1,

                                   Label& slow_case) {

  Label done, fast_lock, fast_lock_done;

  int null_check_offset = 0;

  const Register tmp2 = Rtemp; // Rtemp should be free at c1 LIR level

  assert_different_registers(hdr, obj, disp_hdr, tmp1, tmp2);

  assert(BasicObjectLock::lock_offset_in_bytes() == 0, "ajust this code");

  const int obj_offset = BasicObjectLock::obj_offset_in_bytes();

  const int mark_offset = BasicLock::displaced_header_offset_in_bytes();

  if (UseBiasedLocking) {

    // load object

    str(obj, Address(disp_hdr, obj_offset));

    null_check_offset = biased_locking_enter(obj, hdr/*scratched*/, tmp1, false, tmp2, done, slow_case);

  }

  assert(oopDesc::mark_offset_in_bytes() == 0, "Required by atomic instructions");

  if (!UseBiasedLocking) {

    null_check_offset = offset();

  }

  // On MP platforms the next load could return a 'stale' value if the memory location has been modified by another thread.

  // That would be acceptable as ether CAS or slow case path is taken in that case.

  // Must be the first instruction here, because implicit null check relies on it

  ldr(hdr, Address(obj, oopDesc::mark_offset_in_bytes()));

  str(obj, Address(disp_hdr, obj_offset));

  tst(hdr, markWord::unlocked_value);

  b(fast_lock, ne);

  // Check for recursive locking

  // See comments in InterpreterMacroAssembler::lock_object for

  // explanations on the fast recursive locking check.

  // -1- test low 2 bits

  movs(tmp2, AsmOperand(hdr, lsl, 30));

  // -2- test (hdr - SP) if the low two bits are 0

  sub(tmp2, hdr, SP, eq);

  movs(tmp2, AsmOperand(tmp2, lsr, exact_log2(os::vm_page_size())), eq);

  // If 'eq' then OK for recursive fast locking: store 0 into a lock record.

  str(tmp2, Address(disp_hdr, mark_offset), eq);

  b(fast_lock_done, eq);

  // else need slow case

  b(slow_case);

  bind(fast_lock);

  // Save previous object header in BasicLock structure and update the header

  str(hdr, Address(disp_hdr, mark_offset));

  cas_for_lock_acquire(hdr, disp_hdr, obj, tmp2, slow_case);

  bind(fast_lock_done);

#ifndef PRODUCT

  if (PrintBiasedLockingStatistics) {

    cond_atomic_inc32(al, BiasedLocking::fast_path_entry_count_addr());

  }

#endif // !PRODUCT

  bind(done);

  return null_check_offset;

}

void C1_MacroAssembler::unlock_object(Register hdr, Register obj,

                                      Register disp_hdr, Register tmp,

                                      Label& slow_case) {

  // Note: this method is not using its 'tmp' argument

  assert_different_registers(hdr, obj, disp_hdr, Rtemp);

  Register tmp2 = Rtemp;

  assert(BasicObjectLock::lock_offset_in_bytes() == 0, "ajust this code");

  const int obj_offset = BasicObjectLock::obj_offset_in_bytes();

  const int mark_offset = BasicLock::displaced_header_offset_in_bytes();

  Label done;

  if (UseBiasedLocking) {

    // load object

    ldr(obj, Address(disp_hdr, obj_offset));

    biased_locking_exit(obj, hdr, done);

  }

  assert(oopDesc::mark_offset_in_bytes() == 0, "Required by atomic instructions");

  // Load displaced header and object from the lock

  ldr(hdr, Address(disp_hdr, mark_offset));

  // If hdr is NULL, we've got recursive locking and there's nothing more to do

  cbz(hdr, done);

  if(!UseBiasedLocking) {

    // load object

    ldr(obj, Address(disp_hdr, obj_offset));

  }

  // Restore the object header

  cas_for_lock_release(disp_hdr, hdr, obj, tmp2, slow_case);

  bind(done);

}

#ifndef PRODUCT

void C1_MacroAssembler::verify_stack_oop(int stack_offset) {

  if (!VerifyOops) return;

  verify_oop_addr(Address(SP, stack_offset));

}

void C1_MacroAssembler::verify_not_null_oop(Register r) {

  Label not_null;

  cbnz(r, not_null);

  stop("non-null oop required");

  bind(not_null);

  if (!VerifyOops) return;

  verify_oop(r);

}

#endif // !PRODUCT