/*

 * Copyright (c) 1997, 2012, 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/assembler.hpp"

#include "asm/assembler.inline.hpp"

#include "compiler/disassembler.hpp"

#include "gc_interface/collectedHeap.inline.hpp"

#include "interpreter/interpreter.hpp"

#include "memory/cardTableModRefBS.hpp"

#include "memory/resourceArea.hpp"

#include "prims/methodHandles.hpp"

#include "runtime/biasedLocking.hpp"

#include "runtime/interfaceSupport.hpp"

#include "runtime/objectMonitor.hpp"

#include "runtime/os.hpp"

#include "runtime/sharedRuntime.hpp"

#include "runtime/stubRoutines.hpp"

#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"

#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"

#include "gc_implementation/g1/heapRegion.hpp"

#ifdef PRODUCT

#define BLOCK_COMMENT(str) /* nothing */

#define STOP(error) stop(error)

#else

#define BLOCK_COMMENT(str) block_comment(str)

#define STOP(error) block_comment(error); stop(error)

#endif

#define BIND(label) bind(label); BLOCK_COMMENT(#label ":")

#ifdef ASSERT

bool AbstractAssembler::pd_check_instruction_mark() { return true; }

#endif

static Assembler::Condition reverse[] = {

    Assembler::noOverflow     /* overflow      = 0x0 */ ,

    Assembler::overflow       /* noOverflow    = 0x1 */ ,

    Assembler::aboveEqual     /* carrySet      = 0x2, below         = 0x2 */ ,

    Assembler::below          /* aboveEqual    = 0x3, carryClear    = 0x3 */ ,

    Assembler::notZero        /* zero          = 0x4, equal         = 0x4 */ ,

    Assembler::zero           /* notZero       = 0x5, notEqual      = 0x5 */ ,

    Assembler::above          /* belowEqual    = 0x6 */ ,

    Assembler::belowEqual     /* above         = 0x7 */ ,

    Assembler::positive       /* negative      = 0x8 */ ,

    Assembler::negative       /* positive      = 0x9 */ ,

    Assembler::noParity       /* parity        = 0xa */ ,

    Assembler::parity         /* noParity      = 0xb */ ,

    Assembler::greaterEqual   /* less          = 0xc */ ,

    Assembler::less           /* greaterEqual  = 0xd */ ,

    Assembler::greater        /* lessEqual     = 0xe */ ,

    Assembler::lessEqual      /* greater       = 0xf, */

};

// Implementation of MacroAssembler

// First all the versions that have distinct versions depending on 32/64 bit

// Unless the difference is trivial (1 line or so).

#ifndef _LP64

// 32bit versions

Address MacroAssembler::as_Address(AddressLiteral adr) {

  return Address(adr.target(), adr.rspec());

}

Address MacroAssembler::as_Address(ArrayAddress adr) {

  return Address::make_array(adr);

}

int MacroAssembler::biased_locking_enter(Register lock_reg,

                                         Register obj_reg,

                                         Register swap_reg,

                                         Register tmp_reg,

                                         bool swap_reg_contains_mark,

                                         Label& done,

                                         Label* slow_case,

                                         BiasedLockingCounters* counters) {

  assert(UseBiasedLocking, "why call this otherwise?");

  assert(swap_reg == rax, "swap_reg must be rax, for cmpxchg");

  assert_different_registers(lock_reg, obj_reg, swap_reg);

  if (PrintBiasedLockingStatistics && counters == NULL)

    counters = BiasedLocking::counters();

  bool need_tmp_reg = false;

  if (tmp_reg == noreg) {

    need_tmp_reg = true;

    tmp_reg = lock_reg;

  } else {

    assert_different_registers(lock_reg, obj_reg, swap_reg, tmp_reg);

  }

  assert(markOopDesc::age_shift == markOopDesc::lock_bits + markOopDesc::biased_lock_bits, "biased locking makes assumptions about bit layout");

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

  Address klass_addr     (obj_reg, oopDesc::klass_offset_in_bytes());

  Address saved_mark_addr(lock_reg, 0);

  // Biased locking

  // See whether the lock is currently biased toward our thread and

  // whether the epoch is still valid

  // Note that the runtime guarantees sufficient alignment of JavaThread

  // pointers to allow age to be placed into low bits

  // First check to see whether biasing is even enabled for this object

  Label cas_label;

  int null_check_offset = -1;

  if (!swap_reg_contains_mark) {

    null_check_offset = offset();

    movl(swap_reg, mark_addr);

  }

  if (need_tmp_reg) {

    push(tmp_reg);

  }

  movl(tmp_reg, swap_reg);

  andl(tmp_reg, markOopDesc::biased_lock_mask_in_place);

  cmpl(tmp_reg, markOopDesc::biased_lock_pattern);

  if (need_tmp_reg) {

    pop(tmp_reg);

  }

  jcc(Assembler::notEqual, cas_label);

  // The bias pattern is present in the object's header. Need to check

  // whether the bias owner and the epoch are both still current.

  // Note that because there is no current thread register on x86 we

  // need to store off the mark word we read out of the object to

  // avoid reloading it and needing to recheck invariants below. This

  // store is unfortunate but it makes the overall code shorter and

  // simpler.

  movl(saved_mark_addr, swap_reg);

  if (need_tmp_reg) {

    push(tmp_reg);

  }

  get_thread(tmp_reg);

  xorl(swap_reg, tmp_reg);

  if (swap_reg_contains_mark) {

    null_check_offset = offset();

  }

  movl(tmp_reg, klass_addr);

  xorl(swap_reg, Address(tmp_reg, Klass::prototype_header_offset()));

  andl(swap_reg, ~((int) markOopDesc::age_mask_in_place));

  if (need_tmp_reg) {

    pop(tmp_reg);

  }

  if (counters != NULL) {

    cond_inc32(Assembler::zero,

               ExternalAddress((address)counters->biased_lock_entry_count_addr()));

  }

  jcc(Assembler::equal, done);

  Label try_revoke_bias;

  Label try_rebias;

  // At this point we know that the header has the bias pattern and

  // that we are not the bias owner in the current epoch. We need to

  // figure out more details about the state of the header in order to

  // know what operations can be legally performed on the object's

  // header.

  // If the low three bits in the xor result aren't clear, that means

  // the prototype header is no longer biased and we have to revoke

  // the bias on this object.

  testl(swap_reg, markOopDesc::biased_lock_mask_in_place);

  jcc(Assembler::notZero, try_revoke_bias);

  // Biasing is still enabled for this data type. See whether the

  // epoch of the current bias is still valid, meaning that the epoch

  // bits of the mark word are equal to the epoch bits of the

  // prototype header. (Note that the prototype header's epoch bits

  // only change at a safepoint.) If not, attempt to rebias the object

  // toward the current thread. Note that we must be absolutely sure

  // that the current epoch is invalid in order to do this because

  // otherwise the manipulations it performs on the mark word are

  // illegal.

  testl(swap_reg, markOopDesc::epoch_mask_in_place);

  jcc(Assembler::notZero, try_rebias);

  // The epoch of the current bias is still valid but we know nothing

  // about the owner; it might be set or it might be clear. Try to

  // acquire the bias of the object using an atomic operation. If this

  // fails we will go in to the runtime to revoke the object's bias.

  // Note that we first construct the presumed unbiased header so we

  // don't accidentally blow away another thread's valid bias.

  movl(swap_reg, saved_mark_addr);

  andl(swap_reg,

       markOopDesc::biased_lock_mask_in_place | markOopDesc::age_mask_in_place | markOopDesc::epoch_mask_in_place);

  if (need_tmp_reg) {

    push(tmp_reg);

  }

  get_thread(tmp_reg);

  orl(tmp_reg, swap_reg);

  if (os::is_MP()) {

    lock();

  }

  cmpxchgptr(tmp_reg, Address(obj_reg, 0));

  if (need_tmp_reg) {

    pop(tmp_reg);

  }

  // If the biasing toward our thread failed, this means that

  // another thread succeeded in biasing it toward itself and we

  // need to revoke that bias. The revocation will occur in the

  // interpreter runtime in the slow case.

  if (counters != NULL) {

    cond_inc32(Assembler::zero,

               ExternalAddress((address)counters->anonymously_biased_lock_entry_count_addr()));

  }

  if (slow_case != NULL) {

    jcc(Assembler::notZero, *slow_case);

  }

  jmp(done);

  bind(try_rebias);

  // At this point we know the epoch has expired, meaning that the

  // current "bias owner", if any, is actually invalid. Under these

  // circumstances _only_, we are allowed to use the current header's

  // value as the comparison value when doing the cas to acquire the

  // bias in the current epoch. In other words, we allow transfer of

  // the bias from one thread to another directly in this situation.

  //

  // FIXME: due to a lack of registers we currently blow away the age

  // bits in this situation. Should attempt to preserve them.

  if (need_tmp_reg) {

    push(tmp_reg);

  }

  get_thread(tmp_reg);

  movl(swap_reg, klass_addr);

  orl(tmp_reg, Address(swap_reg, Klass::prototype_header_offset()));

  movl(swap_reg, saved_mark_addr);

  if (os::is_MP()) {

    lock();

  }

  cmpxchgptr(tmp_reg, Address(obj_reg, 0));

  if (need_tmp_reg) {

    pop(tmp_reg);

  }

  // If the biasing toward our thread failed, then another thread

  // succeeded in biasing it toward itself and we need to revoke that

  // bias. The revocation will occur in the runtime in the slow case.

  if (counters != NULL) {

    cond_inc32(Assembler::zero,

               ExternalAddress((address)counters->rebiased_lock_entry_count_addr()));

  }

  if (slow_case != NULL) {

    jcc(Assembler::notZero, *slow_case);

  }

  jmp(done);

  bind(try_revoke_bias);

  // The prototype mark in the klass doesn't have the bias bit set any

  // more, indicating that objects of this data type are not supposed

  // to be biased any more. We are going to try to reset the mark of

  // this object to the prototype value and fall through to the

  // CAS-based locking scheme. Note that if our CAS fails, it means

  // that another thread raced us for the privilege of revoking the

  // bias of this particular object, so it's okay to continue in the

  // normal locking code.

  //

  // FIXME: due to a lack of registers we currently blow away the age

  // bits in this situation. Should attempt to preserve them.

  movl(swap_reg, saved_mark_addr);

  if (need_tmp_reg) {

    push(tmp_reg);

  }

  movl(tmp_reg, klass_addr);

  movl(tmp_reg, Address(tmp_reg, Klass::prototype_header_offset()));

  if (os::is_MP()) {

    lock();

  }

  cmpxchgptr(tmp_reg, Address(obj_reg, 0));

  if (need_tmp_reg) {

    pop(tmp_reg);

  }

  // Fall through to the normal CAS-based lock, because no matter what

  // the result of the above CAS, some thread must have succeeded in

  // removing the bias bit from the object's header.

  if (counters != NULL) {

    cond_inc32(Assembler::zero,

               ExternalAddress((address)counters->revoked_lock_entry_count_addr()));

  }

  bind(cas_label);

  return null_check_offset;

}

void MacroAssembler::call_VM_leaf_base(address entry_point,

                                       int number_of_arguments) {

  call(RuntimeAddress(entry_point));

  increment(rsp, number_of_arguments * wordSize);

}

void MacroAssembler::cmpklass(Address src1, Metadata* obj) {

  cmp_literal32(src1, (int32_t)obj, metadata_Relocation::spec_for_immediate());

}

void MacroAssembler::cmpklass(Register src1, Metadata* obj) {

  cmp_literal32(src1, (int32_t)obj, metadata_Relocation::spec_for_immediate());

}

void MacroAssembler::cmpoop(Address src1, jobject obj) {

  cmp_literal32(src1, (int32_t)obj, oop_Relocation::spec_for_immediate());

}

void MacroAssembler::cmpoop(Register src1, jobject obj) {

  cmp_literal32(src1, (int32_t)obj, oop_Relocation::spec_for_immediate());

}

void MacroAssembler::extend_sign(Register hi, Register lo) {

  // According to Intel Doc. AP-526, "Integer Divide", p.18.

  if (VM_Version::is_P6() && hi == rdx && lo == rax) {

    cdql();

  } else {

    movl(hi, lo);

    sarl(hi, 31);

  }

}

void MacroAssembler::jC2(Register tmp, Label& L) {

  // set parity bit if FPU flag C2 is set (via rax)

  save_rax(tmp);

  fwait(); fnstsw_ax();

  sahf();

  restore_rax(tmp);

  // branch

  jcc(Assembler::parity, L);

}

void MacroAssembler::jnC2(Register tmp, Label& L) {

  // set parity bit if FPU flag C2 is set (via rax)

  save_rax(tmp);

  fwait(); fnstsw_ax();

  sahf();

  restore_rax(tmp);

  // branch

  jcc(Assembler::noParity, L);

}

// 32bit can do a case table jump in one instruction but we no longer allow the base

// to be installed in the Address class

void MacroAssembler::jump(ArrayAddress entry) {

  jmp(as_Address(entry));

}

// Note: y_lo will be destroyed

void MacroAssembler::lcmp2int(Register x_hi, Register x_lo, Register y_hi, Register y_lo) {

  // Long compare for Java (semantics as described in JVM spec.)

  Label high, low, done;

  cmpl(x_hi, y_hi);

  jcc(Assembler::less, low);

  jcc(Assembler::greater, high);

  // x_hi is the return register

  xorl(x_hi, x_hi);

  cmpl(x_lo, y_lo);

  jcc(Assembler::below, low);

  jcc(Assembler::equal, done);

  bind(high);

  xorl(x_hi, x_hi);

  increment(x_hi);

  jmp(done);

  bind(low);

  xorl(x_hi, x_hi);

  decrementl(x_hi);

  bind(done);

}

void MacroAssembler::lea(Register dst, AddressLiteral src) {

    mov_literal32(dst, (int32_t)src.target(), src.rspec());

}

void MacroAssembler::lea(Address dst, AddressLiteral adr) {

  // leal(dst, as_Address(adr));

  // see note in movl as to why we must use a move

  mov_literal32(dst, (int32_t) adr.target(), adr.rspec());

}

void MacroAssembler::leave() {

  mov(rsp, rbp);

  pop(rbp);

}

void MacroAssembler::lmul(int x_rsp_offset, int y_rsp_offset) {

  // Multiplication of two Java long values stored on the stack

  // as illustrated below. Result is in rdx:rax.

  //

  // rsp ---> [  ??  ] \               \

  //            ....    | y_rsp_offset  |

  //          [ y_lo ] /  (in bytes)    | x_rsp_offset

  //          [ y_hi ]                  | (in bytes)

  //            ....                    |

  //          [ x_lo ]                 /

  //          [ x_hi ]

  //            ....

  //

  // Basic idea: lo(result) = lo(x_lo * y_lo)

  //             hi(result) = hi(x_lo * y_lo) + lo(x_hi * y_lo) + lo(x_lo * y_hi)

  Address x_hi(rsp, x_rsp_offset + wordSize); Address x_lo(rsp, x_rsp_offset);

  Address y_hi(rsp, y_rsp_offset + wordSize); Address y_lo(rsp, y_rsp_offset);

  Label quick;

  // load x_hi, y_hi and check if quick

  // multiplication is possible

  movl(rbx, x_hi);

  movl(rcx, y_hi);

  movl(rax, rbx);

  orl(rbx, rcx);                                 // rbx, = 0 <=> x_hi = 0 and y_hi = 0

  jcc(Assembler::zero, quick);                   // if rbx, = 0 do quick multiply

  // do full multiplication

  // 1st step

  mull(y_lo);                                    // x_hi * y_lo

  movl(rbx, rax);                                // save lo(x_hi * y_lo) in rbx,

  // 2nd step

  movl(rax, x_lo);

  mull(rcx);                                     // x_lo * y_hi

  addl(rbx, rax);                                // add lo(x_lo * y_hi) to rbx,

  // 3rd step

  bind(quick);                                   // note: rbx, = 0 if quick multiply!

  movl(rax, x_lo);

  mull(y_lo);                                    // x_lo * y_lo

  addl(rdx, rbx);                                // correct hi(x_lo * y_lo)

}

void MacroAssembler::lneg(Register hi, Register lo) {

  negl(lo);

  adcl(hi, 0);

  negl(hi);

}

void MacroAssembler::lshl(Register hi, Register lo) {

  // Java shift left long support (semantics as described in JVM spec., p.305)

  // (basic idea for shift counts s >= n: x << s == (x << n) << (s - n))

  // shift value is in rcx !

  assert(hi != rcx, "must not use rcx");

  assert(lo != rcx, "must not use rcx");

  const Register s = rcx;                        // shift count

  const int      n = BitsPerWord;

  Label L;

  andl(s, 0x3f);                                 // s := s & 0x3f (s < 0x40)

  cmpl(s, n);                                    // if (s < n)

  jcc(Assembler::less, L);                       // else (s >= n)

  movl(hi, lo);                                  // x := x << n

  xorl(lo, lo);

  // Note: subl(s, n) is not needed since the Intel shift instructions work rcx mod n!

  bind(L);                                       // s (mod n) < n

  shldl(hi, lo);                                 // x := x << s

  shll(lo);

}

void MacroAssembler::lshr(Register hi, Register lo, bool sign_extension) {

  // Java shift right long support (semantics as described in JVM spec., p.306 & p.310)

  // (basic idea for shift counts s >= n: x >> s == (x >> n) >> (s - n))

  assert(hi != rcx, "must not use rcx");

  assert(lo != rcx, "must not use rcx");

  const Register s = rcx;                        // shift count

  const int      n = BitsPerWord;

  Label L;

  andl(s, 0x3f);                                 // s := s & 0x3f (s < 0x40)

  cmpl(s, n);                                    // if (s < n)

  jcc(Assembler::less, L);                       // else (s >= n)

  movl(lo, hi);                                  // x := x >> n

  if (sign_extension) sarl(hi, 31);

  else                xorl(hi, hi);

  // Note: subl(s, n) is not needed since the Intel shift instructions work rcx mod n!

  bind(L);                                       // s (mod n) < n

  shrdl(lo, hi);                                 // x := x >> s

  if (sign_extension) sarl(hi);

  else                shrl(hi);

}

void MacroAssembler::movoop(Register dst, jobject obj) {

  mov_literal32(dst, (int32_t)obj, oop_Relocation::spec_for_immediate());

}

void MacroAssembler::movoop(Address dst, jobject obj) {

  mov_literal32(dst, (int32_t)obj, oop_Relocation::spec_for_immediate());

}

void MacroAssembler::mov_metadata(Register dst, Metadata* obj) {

  mov_literal32(dst, (int32_t)obj, metadata_Relocation::spec_for_immediate());

}

void MacroAssembler::mov_metadata(Address dst, Metadata* obj) {

  mov_literal32(dst, (int32_t)obj, metadata_Relocation::spec_for_immediate());

}

void MacroAssembler::movptr(Register dst, AddressLiteral src) {

  if (src.is_lval()) {

    mov_literal32(dst, (intptr_t)src.target(), src.rspec());

  } else {

    movl(dst, as_Address(src));

  }

}

void MacroAssembler::movptr(ArrayAddress dst, Register src) {

  movl(as_Address(dst), src);

}

void MacroAssembler::movptr(Register dst, ArrayAddress src) {

  movl(dst, as_Address(src));

}