/*

 * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.

 * Copyright (c) 2012, 2018 SAP SE. 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 "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"

#include "utilities/align.hpp"

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

  const Register temp_reg = R12_scratch2;

  Label Lmiss;

  verify_oop(receiver);

  MacroAssembler::null_check(receiver, oopDesc::klass_offset_in_bytes(), &Lmiss);

  load_klass(temp_reg, receiver);

  if (TrapBasedICMissChecks && TrapBasedNullChecks) {

    trap_ic_miss_check(temp_reg, iCache);

  } else {

    Label Lok;

    cmpd(CCR0, temp_reg, iCache);

    beq(CCR0, Lok);

    bind(Lmiss);

    //load_const_optimized(temp_reg, SharedRuntime::get_ic_miss_stub(), R0);

    calculate_address_from_global_toc(temp_reg, SharedRuntime::get_ic_miss_stub(), true, true, false);

    mtctr(temp_reg);

    bctr();

    align(32, 12);

    bind(Lok);

  }

}

void C1_MacroAssembler::explicit_null_check(Register base) {

  Unimplemented();

}

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

  // Avoid stack bang as first instruction. It may get overwritten by patch_verified_entry.

  const Register return_pc = R20;

  mflr(return_pc);

  // Make sure there is enough stack space for this method's activation.

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

  generate_stack_overflow_check(bang_size_in_bytes);

  std(return_pc, _abi(lr), R1_SP);     // SP->lr = return_pc

  push_frame(frame_size_in_bytes, R0); // SP -= frame_size_in_bytes

}

void C1_MacroAssembler::verified_entry() {

  if (C1Breakpoint) illtrap();

  // build frame

}

void C1_MacroAssembler::lock_object(Register Rmark, Register Roop, Register Rbox, Register Rscratch, Label& slow_case) {

  assert_different_registers(Rmark, Roop, Rbox, Rscratch);

  Label done, cas_failed, slow_int;

  // The following move must be the first instruction of emitted since debug

  // information may be generated for it.

  // Load object header.

  ld(Rmark, oopDesc::mark_offset_in_bytes(), Roop);

  verify_oop(Roop);

  // Save object being locked into the BasicObjectLock...

  std(Roop, BasicObjectLock::obj_offset_in_bytes(), Rbox);

  if (UseBiasedLocking) {

    biased_locking_enter(CCR0, Roop, Rmark, Rscratch, R0, done, &slow_int);

  }

  // ... and mark it unlocked.

  ori(Rmark, Rmark, markWord::unlocked_value);

  // Save unlocked object header into the displaced header location on the stack.

  std(Rmark, BasicLock::displaced_header_offset_in_bytes(), Rbox);

  // Compare object markWord with Rmark and if equal exchange Rscratch with object markWord.

  assert(oopDesc::mark_offset_in_bytes() == 0, "cas must take a zero displacement");

  cmpxchgd(/*flag=*/CCR0,

           /*current_value=*/Rscratch,

           /*compare_value=*/Rmark,

           /*exchange_value=*/Rbox,

           /*where=*/Roop/*+0==mark_offset_in_bytes*/,

           MacroAssembler::MemBarRel | MacroAssembler::MemBarAcq,

           MacroAssembler::cmpxchgx_hint_acquire_lock(),

           noreg,

           &cas_failed,

           /*check without membar and ldarx first*/true);

  // If compare/exchange succeeded we found an unlocked object and we now have locked it

  // hence we are done.

  b(done);

  bind(slow_int);

  b(slow_case); // far

  bind(cas_failed);

  // We did not find an unlocked object so see if this is a recursive case.

  sub(Rscratch, Rscratch, R1_SP);

  load_const_optimized(R0, (~(os::vm_page_size()-1) | markWord::lock_mask_in_place));

  and_(R0/*==0?*/, Rscratch, R0);

  std(R0/*==0, perhaps*/, BasicLock::displaced_header_offset_in_bytes(), Rbox);

  bne(CCR0, slow_int);

  bind(done);

}

void C1_MacroAssembler::unlock_object(Register Rmark, Register Roop, Register Rbox, Label& slow_case) {

  assert_different_registers(Rmark, Roop, Rbox);

  Label slow_int, done;

  Address mark_addr(Roop, oopDesc::mark_offset_in_bytes());

  assert(mark_addr.disp() == 0, "cas must take a zero displacement");

  if (UseBiasedLocking) {

    // Load the object out of the BasicObjectLock.

    ld(Roop, BasicObjectLock::obj_offset_in_bytes(), Rbox);

    verify_oop(Roop);

    biased_locking_exit(CCR0, Roop, R0, done);

  }

  // Test first it it is a fast recursive unlock.

  ld(Rmark, BasicLock::displaced_header_offset_in_bytes(), Rbox);

  cmpdi(CCR0, Rmark, 0);

  beq(CCR0, done);

  if (!UseBiasedLocking) {

    // Load object.

    ld(Roop, BasicObjectLock::obj_offset_in_bytes(), Rbox);

    verify_oop(Roop);

  }

  // Check if it is still a light weight lock, this is is true if we see

  // the stack address of the basicLock in the markWord of the object.

  cmpxchgd(/*flag=*/CCR0,

           /*current_value=*/R0,

           /*compare_value=*/Rbox,

           /*exchange_value=*/Rmark,

           /*where=*/Roop,

           MacroAssembler::MemBarRel,

           MacroAssembler::cmpxchgx_hint_release_lock(),

           noreg,

           &slow_int);

  b(done);

  bind(slow_int);

  b(slow_case); // far

  // Done

  bind(done);

}

void C1_MacroAssembler::try_allocate(

  Register obj,                        // result: pointer to object after successful allocation

  Register var_size_in_bytes,          // object size in bytes if unknown at compile time; invalid otherwise

  int      con_size_in_bytes,          // object size in bytes if   known at compile time

  Register t1,                         // temp register, must be global register for incr_allocated_bytes

  Register t2,                         // temp register

  Label&   slow_case                   // continuation point if fast allocation fails

) {

  if (UseTLAB) {

    tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case);

  } else {

    eden_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case);

    RegisterOrConstant size_in_bytes = var_size_in_bytes->is_valid()

                                       ? RegisterOrConstant(var_size_in_bytes)

                                       : RegisterOrConstant(con_size_in_bytes);

    incr_allocated_bytes(size_in_bytes, t1, t2);

  }

}

void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {

  assert_different_registers(obj, klass, len, t1, t2);

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

    ld(t1, in_bytes(Klass::prototype_header_offset()), klass);

  } else {

    load_const_optimized(t1, (intx)markWord::prototype().value());

  }

  std(t1, oopDesc::mark_offset_in_bytes(), obj);

  store_klass(obj, klass);

  if (len->is_valid()) {

    stw(len, arrayOopDesc::length_offset_in_bytes(), obj);

  } else if (UseCompressedClassPointers) {

    // Otherwise length is in the class gap.

    store_klass_gap(obj);

  }

}

void C1_MacroAssembler::initialize_body(Register base, Register index) {

  assert_different_registers(base, index);

  srdi(index, index, LogBytesPerWord);

  clear_memory_doubleword(base, index);

}

void C1_MacroAssembler::initialize_body(Register obj, Register tmp1, Register tmp2,

                                        int obj_size_in_bytes, int hdr_size_in_bytes) {

  const int index = (obj_size_in_bytes - hdr_size_in_bytes) / HeapWordSize;

  // 2x unrolled loop is shorter with more than 9 HeapWords.

  if (index <= 9) {

    clear_memory_unrolled(obj, index, R0, hdr_size_in_bytes);

  } else {

    const Register base_ptr = tmp1,

                   cnt_dwords = tmp2;

    addi(base_ptr, obj, hdr_size_in_bytes); // Compute address of first element.

    clear_memory_doubleword(base_ptr, cnt_dwords, R0, index);

  }

}

void C1_MacroAssembler::allocate_object(

  Register obj,                        // result: pointer to object after successful allocation

  Register t1,                         // temp register

  Register t2,                         // temp register

  Register t3,                         // temp register

  int      hdr_size,                   // object header size in words

  int      obj_size,                   // object size in words

  Register klass,                      // object klass

  Label&   slow_case                   // continuation point if fast allocation fails

) {

  assert_different_registers(obj, t1, t2, t3, klass);

  // allocate space & initialize header

  if (!is_simm16(obj_size * wordSize)) {

    // Would need to use extra register to load

    // object size => go the slow case for now.

    b(slow_case);

    return;

  }

  try_allocate(obj, noreg, obj_size * wordSize, t2, t3, slow_case);

  initialize_object(obj, klass, noreg, obj_size * HeapWordSize, t1, t2);

}

void C1_MacroAssembler::initialize_object(

  Register obj,                        // result: pointer to object after successful allocation

  Register klass,                      // object klass

  Register var_size_in_bytes,          // object size in bytes if unknown at compile time; invalid otherwise

  int      con_size_in_bytes,          // object size in bytes if   known at compile time

  Register t1,                         // temp register

  Register t2                          // temp register

  ) {

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

  initialize_header(obj, klass, noreg, t1, t2);

#ifdef ASSERT

  {

    lwz(t1, in_bytes(Klass::layout_helper_offset()), klass);

    if (var_size_in_bytes != noreg) {

      cmpw(CCR0, t1, var_size_in_bytes);

    } else {

      cmpwi(CCR0, t1, con_size_in_bytes);

    }

    asm_assert_eq("bad size in initialize_object", 0x753);

  }

#endif

  // Initialize body.

  if (var_size_in_bytes != noreg) {

    // Use a loop.

    addi(t1, obj, hdr_size_in_bytes);                // Compute address of first element.

    addi(t2, var_size_in_bytes, -hdr_size_in_bytes); // Compute size of body.

    initialize_body(t1, t2);

  } else if (con_size_in_bytes > hdr_size_in_bytes) {

    // Use a loop.

    initialize_body(obj, t1, t2, con_size_in_bytes, hdr_size_in_bytes);

  }

  if (CURRENT_ENV->dtrace_alloc_probes()) {

    Unimplemented();

//    assert(obj == O0, "must be");

//    call(CAST_FROM_FN_PTR(address, Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)),

//         relocInfo::runtime_call_type);

  }

  verify_oop(obj);

}

void C1_MacroAssembler::allocate_array(

  Register obj,                        // result: pointer to array after successful allocation

  Register len,                        // array length

  Register t1,                         // temp register

  Register t2,                         // temp register

  Register t3,                         // temp register

  int      hdr_size,                   // object header size in words

  int      elt_size,                   // element size in bytes

  Register klass,                      // object klass

  Label&   slow_case                   // continuation point if fast allocation fails

) {

  assert_different_registers(obj, len, t1, t2, t3, klass);

  // Determine alignment mask.

  assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");

  int log2_elt_size = exact_log2(elt_size);

  // Check for negative or excessive length.

  size_t max_length = max_array_allocation_length >> log2_elt_size;

  if (UseTLAB) {

    size_t max_tlab = align_up(ThreadLocalAllocBuffer::max_size() >> log2_elt_size, 64*K);

    if (max_tlab < max_length) { max_length = max_tlab; }

  }

  load_const_optimized(t1, max_length);

  cmpld(CCR0, len, t1);

  bc_far_optimized(Assembler::bcondCRbiIs1, bi0(CCR0, Assembler::greater), slow_case);

  // compute array size

  // note: If 0 <= len <= max_length, len*elt_size + header + alignment is

  //       smaller or equal to the largest integer; also, since top is always

  //       aligned, we can do the alignment here instead of at the end address

  //       computation.

  const Register arr_size = t1;

  Register arr_len_in_bytes = len;

  if (elt_size != 1) {

    sldi(t1, len, log2_elt_size);

    arr_len_in_bytes = t1;

  }

  addi(arr_size, arr_len_in_bytes, hdr_size * wordSize + MinObjAlignmentInBytesMask); // Add space for header & alignment.

  clrrdi(arr_size, arr_size, LogMinObjAlignmentInBytes);                              // Align array size.

  // Allocate space & initialize header.

  if (UseTLAB) {

    tlab_allocate(obj, arr_size, 0, t2, slow_case);

  } else {

    eden_allocate(obj, arr_size, 0, t2, t3, slow_case);

  }

  initialize_header(obj, klass, len, t2, t3);

  // Initialize body.

  const Register base  = t2;

  const Register index = t3;

  addi(base, obj, hdr_size * wordSize);               // compute address of first element

  addi(index, arr_size, -(hdr_size * wordSize));      // compute index = number of bytes to clear

  initialize_body(base, index);

  if (CURRENT_ENV->dtrace_alloc_probes()) {

    Unimplemented();

    //assert(obj == O0, "must be");

    //call(CAST_FROM_FN_PTR(address, Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)),

    //     relocInfo::runtime_call_type);

  }

  verify_oop(obj);

}

#ifndef PRODUCT

void C1_MacroAssembler::verify_stack_oop(int stack_offset) {

  verify_oop_addr((RegisterOrConstant)(stack_offset + STACK_BIAS), R1_SP, "broken oop in stack slot");

}

void C1_MacroAssembler::verify_not_null_oop(Register r) {

  Label not_null;

  cmpdi(CCR0, r, 0);

  bne(CCR0, not_null);

  stop("non-null oop required");

  bind(not_null);

  if (!VerifyOops) return;

  verify_oop(r);

}

#endif // PRODUCT

void C1_MacroAssembler::null_check(Register r, Label* Lnull) {

  if (TrapBasedNullChecks) { // SIGTRAP based

    trap_null_check(r);

  } else { // explicit

    //const address exception_entry = Runtime1::entry_for(Runtime1::throw_null_pointer_exception_id);

    assert(Lnull != NULL, "must have Label for explicit check");

    cmpdi(CCR0, r, 0);

    bc_far_optimized(Assembler::bcondCRbiIs1, bi0(CCR0, Assembler::equal), *Lnull);

  }

}

address C1_MacroAssembler::call_c_with_frame_resize(address dest, int frame_resize) {

  if (frame_resize) { resize_frame(-frame_resize, R0); }

#if defined(ABI_ELFv2)

  address return_pc = call_c(dest, relocInfo::runtime_call_type);

#else

  address return_pc = call_c(CAST_FROM_FN_PTR(FunctionDescriptor*, dest), relocInfo::runtime_call_type);

#endif

  if (frame_resize) { resize_frame(frame_resize, R0); }

  return return_pc;

}