/*

 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.

 * Copyright (c) 2012, 2015 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/assembler.inline.hpp"

#include "gc/shared/cardTableBarrierSet.hpp"

#include "gc/shared/collectedHeap.inline.hpp"

#include "interpreter/interpreter.hpp"

#include "memory/resourceArea.hpp"

#include "prims/methodHandles.hpp"

#include "runtime/biasedLocking.hpp"

#include "runtime/interfaceSupport.inline.hpp"

#include "runtime/objectMonitor.hpp"

#include "runtime/os.hpp"

#include "runtime/sharedRuntime.hpp"

#include "runtime/stubRoutines.hpp"

#include "utilities/macros.hpp"

#ifdef PRODUCT

#define BLOCK_COMMENT(str) // nothing

#else

#define BLOCK_COMMENT(str) block_comment(str)

#endif

int AbstractAssembler::code_fill_byte() {

  return 0x00;                  // illegal instruction 0x00000000

}

// Patch instruction `inst' at offset `inst_pos' to refer to

// `dest_pos' and return the resulting instruction.  We should have

// pcs, not offsets, but since all is relative, it will work out fine.

int Assembler::patched_branch(int dest_pos, int inst, int inst_pos) {

  int m = 0; // mask for displacement field

  int v = 0; // new value for displacement field

  switch (inv_op_ppc(inst)) {

  case b_op:  m = li(-1); v = li(disp(dest_pos, inst_pos)); break;

  case bc_op: m = bd(-1); v = bd(disp(dest_pos, inst_pos)); break;

    default: ShouldNotReachHere();

  }

  return inst & ~m | v;

}

// Return the offset, relative to _code_begin, of the destination of

// the branch inst at offset pos.

int Assembler::branch_destination(int inst, int pos) {

  int r = 0;

  switch (inv_op_ppc(inst)) {

    case b_op:  r = bxx_destination_offset(inst, pos); break;

    case bc_op: r = inv_bd_field(inst, pos); break;

    default: ShouldNotReachHere();

  }

  return r;

}

// Low-level andi-one-instruction-macro.

void Assembler::andi(Register a, Register s, const long ui16) {

  if (is_power_of_2_long(((jlong) ui16)+1)) {

    // pow2minus1

    clrldi(a, s, 64-log2_long((((jlong) ui16)+1)));

  } else if (is_power_of_2_long((jlong) ui16)) {

    // pow2

    rlwinm(a, s, 0, 31-log2_long((jlong) ui16), 31-log2_long((jlong) ui16));

  } else if (is_power_of_2_long((jlong)-ui16)) {

    // negpow2

    clrrdi(a, s, log2_long((jlong)-ui16));

  } else {

    assert(is_uimm(ui16, 16), "must be 16-bit unsigned immediate");

    andi_(a, s, ui16);

  }

}

// RegisterOrConstant version.

void Assembler::ld(Register d, RegisterOrConstant roc, Register s1) {

  if (roc.is_constant()) {

    if (s1 == noreg) {

      int simm16_rest = load_const_optimized(d, roc.as_constant(), noreg, true);

      Assembler::ld(d, simm16_rest, d);

    } else if (is_simm(roc.as_constant(), 16)) {

      Assembler::ld(d, roc.as_constant(), s1);

    } else {

      load_const_optimized(d, roc.as_constant());

      Assembler::ldx(d, d, s1);

    }

  } else {

    if (s1 == noreg)

      Assembler::ld(d, 0, roc.as_register());

    else

      Assembler::ldx(d, roc.as_register(), s1);

  }

}

void Assembler::lwa(Register d, RegisterOrConstant roc, Register s1) {

  if (roc.is_constant()) {

    if (s1 == noreg) {

      int simm16_rest = load_const_optimized(d, roc.as_constant(), noreg, true);

      Assembler::lwa(d, simm16_rest, d);

    } else if (is_simm(roc.as_constant(), 16)) {

      Assembler::lwa(d, roc.as_constant(), s1);

    } else {

      load_const_optimized(d, roc.as_constant());

      Assembler::lwax(d, d, s1);

    }

  } else {

    if (s1 == noreg)

      Assembler::lwa(d, 0, roc.as_register());

    else

      Assembler::lwax(d, roc.as_register(), s1);

  }

}

void Assembler::lwz(Register d, RegisterOrConstant roc, Register s1) {

  if (roc.is_constant()) {

    if (s1 == noreg) {

      int simm16_rest = load_const_optimized(d, roc.as_constant(), noreg, true);

      Assembler::lwz(d, simm16_rest, d);

    } else if (is_simm(roc.as_constant(), 16)) {

      Assembler::lwz(d, roc.as_constant(), s1);

    } else {

      load_const_optimized(d, roc.as_constant());

      Assembler::lwzx(d, d, s1);

    }

  } else {

    if (s1 == noreg)

      Assembler::lwz(d, 0, roc.as_register());

    else

      Assembler::lwzx(d, roc.as_register(), s1);

  }

}

void Assembler::lha(Register d, RegisterOrConstant roc, Register s1) {

  if (roc.is_constant()) {

    if (s1 == noreg) {

      int simm16_rest = load_const_optimized(d, roc.as_constant(), noreg, true);

      Assembler::lha(d, simm16_rest, d);

    } else if (is_simm(roc.as_constant(), 16)) {

      Assembler::lha(d, roc.as_constant(), s1);

    } else {

      load_const_optimized(d, roc.as_constant());

      Assembler::lhax(d, d, s1);

    }

  } else {

    if (s1 == noreg)

      Assembler::lha(d, 0, roc.as_register());

    else

      Assembler::lhax(d, roc.as_register(), s1);

  }

}

void Assembler::lhz(Register d, RegisterOrConstant roc, Register s1) {

  if (roc.is_constant()) {

    if (s1 == noreg) {

      int simm16_rest = load_const_optimized(d, roc.as_constant(), noreg, true);

      Assembler::lhz(d, simm16_rest, d);

    } else if (is_simm(roc.as_constant(), 16)) {

      Assembler::lhz(d, roc.as_constant(), s1);

    } else {

      load_const_optimized(d, roc.as_constant());

      Assembler::lhzx(d, d, s1);

    }

  } else {

    if (s1 == noreg)

      Assembler::lhz(d, 0, roc.as_register());

    else

      Assembler::lhzx(d, roc.as_register(), s1);

  }

}

void Assembler::lbz(Register d, RegisterOrConstant roc, Register s1) {

  if (roc.is_constant()) {

    if (s1 == noreg) {

      int simm16_rest = load_const_optimized(d, roc.as_constant(), noreg, true);

      Assembler::lbz(d, simm16_rest, d);

    } else if (is_simm(roc.as_constant(), 16)) {

      Assembler::lbz(d, roc.as_constant(), s1);

    } else {

      load_const_optimized(d, roc.as_constant());

      Assembler::lbzx(d, d, s1);

    }

  } else {

    if (s1 == noreg)

      Assembler::lbz(d, 0, roc.as_register());

    else

      Assembler::lbzx(d, roc.as_register(), s1);

  }

}

void Assembler::std(Register d, RegisterOrConstant roc, Register s1, Register tmp) {

  if (roc.is_constant()) {

    if (s1 == noreg) {

      guarantee(tmp != noreg, "Need tmp reg to encode large constants");

      int simm16_rest = load_const_optimized(tmp, roc.as_constant(), noreg, true);

      Assembler::std(d, simm16_rest, tmp);

    } else if (is_simm(roc.as_constant(), 16)) {

      Assembler::std(d, roc.as_constant(), s1);

    } else {

      guarantee(tmp != noreg, "Need tmp reg to encode large constants");

      load_const_optimized(tmp, roc.as_constant());

      Assembler::stdx(d, tmp, s1);

    }

  } else {

    if (s1 == noreg)

      Assembler::std(d, 0, roc.as_register());

    else

      Assembler::stdx(d, roc.as_register(), s1);

  }

}

void Assembler::stw(Register d, RegisterOrConstant roc, Register s1, Register tmp) {

  if (roc.is_constant()) {

    if (s1 == noreg) {

      guarantee(tmp != noreg, "Need tmp reg to encode large constants");

      int simm16_rest = load_const_optimized(tmp, roc.as_constant(), noreg, true);

      Assembler::stw(d, simm16_rest, tmp);

    } else if (is_simm(roc.as_constant(), 16)) {

      Assembler::stw(d, roc.as_constant(), s1);

    } else {

      guarantee(tmp != noreg, "Need tmp reg to encode large constants");

      load_const_optimized(tmp, roc.as_constant());

      Assembler::stwx(d, tmp, s1);

    }

  } else {

    if (s1 == noreg)

      Assembler::stw(d, 0, roc.as_register());

    else

      Assembler::stwx(d, roc.as_register(), s1);

  }

}

void Assembler::sth(Register d, RegisterOrConstant roc, Register s1, Register tmp) {

  if (roc.is_constant()) {

    if (s1 == noreg) {

      guarantee(tmp != noreg, "Need tmp reg to encode large constants");

      int simm16_rest = load_const_optimized(tmp, roc.as_constant(), noreg, true);

      Assembler::sth(d, simm16_rest, tmp);

    } else if (is_simm(roc.as_constant(), 16)) {

      Assembler::sth(d, roc.as_constant(), s1);

    } else {

      guarantee(tmp != noreg, "Need tmp reg to encode large constants");

      load_const_optimized(tmp, roc.as_constant());

      Assembler::sthx(d, tmp, s1);

    }

  } else {

    if (s1 == noreg)

      Assembler::sth(d, 0, roc.as_register());

    else

      Assembler::sthx(d, roc.as_register(), s1);

  }

}

void Assembler::stb(Register d, RegisterOrConstant roc, Register s1, Register tmp) {

  if (roc.is_constant()) {

    if (s1 == noreg) {

      guarantee(tmp != noreg, "Need tmp reg to encode large constants");

      int simm16_rest = load_const_optimized(tmp, roc.as_constant(), noreg, true);

      Assembler::stb(d, simm16_rest, tmp);

    } else if (is_simm(roc.as_constant(), 16)) {

      Assembler::stb(d, roc.as_constant(), s1);

    } else {

      guarantee(tmp != noreg, "Need tmp reg to encode large constants");

      load_const_optimized(tmp, roc.as_constant());

      Assembler::stbx(d, tmp, s1);

    }

  } else {

    if (s1 == noreg)

      Assembler::stb(d, 0, roc.as_register());

    else

      Assembler::stbx(d, roc.as_register(), s1);

  }

}

void Assembler::add(Register d, RegisterOrConstant roc, Register s1) {

  if (roc.is_constant()) {

    intptr_t c = roc.as_constant();

    assert(is_simm(c, 16), "too big");

    addi(d, s1, (int)c);

  }

  else add(d, roc.as_register(), s1);

}

void Assembler::subf(Register d, RegisterOrConstant roc, Register s1) {

  if (roc.is_constant()) {

    intptr_t c = roc.as_constant();

    assert(is_simm(-c, 16), "too big");

    addi(d, s1, (int)-c);

  }

  else subf(d, roc.as_register(), s1);

}

void Assembler::cmpd(ConditionRegister d, RegisterOrConstant roc, Register s1) {

  if (roc.is_constant()) {

    intptr_t c = roc.as_constant();

    assert(is_simm(c, 16), "too big");

    cmpdi(d, s1, (int)c);

  }

  else cmpd(d, roc.as_register(), s1);

}

// Load a 64 bit constant. Patchable.

void Assembler::load_const(Register d, long x, Register tmp) {

  // 64-bit value: x = xa xb xc xd

  int xa = (x >> 48) & 0xffff;

  int xb = (x >> 32) & 0xffff;

  int xc = (x >> 16) & 0xffff;

  int xd = (x >>  0) & 0xffff;

  if (tmp == noreg) {

    Assembler::lis( d, (int)(short)xa);

    Assembler::ori( d, d, (unsigned int)xb);

    Assembler::sldi(d, d, 32);

    Assembler::oris(d, d, (unsigned int)xc);

    Assembler::ori( d, d, (unsigned int)xd);

  } else {

    // exploit instruction level parallelism if we have a tmp register

    assert_different_registers(d, tmp);

    Assembler::lis(tmp, (int)(short)xa);

    Assembler::lis(d, (int)(short)xc);

    Assembler::ori(tmp, tmp, (unsigned int)xb);

    Assembler::ori(d, d, (unsigned int)xd);

    Assembler::insrdi(d, tmp, 32, 0);

  }

}

// Load a 64 bit constant, optimized, not identifyable.

// Tmp can be used to increase ILP. Set return_simm16_rest=true to get a

// 16 bit immediate offset.

int Assembler::load_const_optimized(Register d, long x, Register tmp, bool return_simm16_rest) {

  // Avoid accidentally trying to use R0 for indexed addressing.

  assert_different_registers(d, tmp);

  short xa, xb, xc, xd; // Four 16-bit chunks of const.

  long rem = x;         // Remaining part of const.

  xd = rem & 0xFFFF;    // Lowest 16-bit chunk.

  rem = (rem >> 16) + ((unsigned short)xd >> 15); // Compensation for sign extend.

  if (rem == 0) { // opt 1: simm16

    li(d, xd);

    return 0;

  }

  int retval = 0;

  if (return_simm16_rest) {

    retval = xd;

    x = rem << 16;

    xd = 0;

  }

  if (d == R0) { // Can't use addi.

    if (is_simm(x, 32)) { // opt 2: simm32

      lis(d, x >> 16);

      if (xd) ori(d, d, (unsigned short)xd);

    } else {

      // 64-bit value: x = xa xb xc xd

      xa = (x >> 48) & 0xffff;

      xb = (x >> 32) & 0xffff;

      xc = (x >> 16) & 0xffff;

      bool xa_loaded = (xb & 0x8000) ? (xa != -1) : (xa != 0);

      if (tmp == noreg || (xc == 0 && xd == 0)) {

        if (xa_loaded) {

          lis(d, xa);

          if (xb) { ori(d, d, (unsigned short)xb); }

        } else {

          li(d, xb);

        }

        sldi(d, d, 32);

        if (xc) { oris(d, d, (unsigned short)xc); }

        if (xd) { ori( d, d, (unsigned short)xd); }

      } else {

        // Exploit instruction level parallelism if we have a tmp register.

        bool xc_loaded = (xd & 0x8000) ? (xc != -1) : (xc != 0);

        if (xa_loaded) {

          lis(tmp, xa);

        }

        if (xc_loaded) {

          lis(d, xc);

        }

        if (xa_loaded) {

          if (xb) { ori(tmp, tmp, (unsigned short)xb); }

        } else {

          li(tmp, xb);

        }

        if (xc_loaded) {

          if (xd) { ori(d, d, (unsigned short)xd); }

        } else {

          li(d, xd);

        }

        insrdi(d, tmp, 32, 0);

      }

    }

    return retval;

  }

  xc = rem & 0xFFFF; // Next 16-bit chunk.

  rem = (rem >> 16) + ((unsigned short)xc >> 15); // Compensation for sign extend.

  if (rem == 0) { // opt 2: simm32

    lis(d, xc);

  } else { // High 32 bits needed.

    if (tmp != noreg  && (int)x != 0) { // opt 3: We have a temp reg.

      // No carry propagation between xc and higher chunks here (use logical instructions).

      xa = (x >> 48) & 0xffff;

      xb = (x >> 32) & 0xffff; // No sign compensation, we use lis+ori or li to allow usage of R0.

      bool xa_loaded = (xb & 0x8000) ? (xa != -1) : (xa != 0);

      bool return_xd = false;

      if (xa_loaded) { lis(tmp, xa); }

      if (xc) { lis(d, xc); }

      if (xa_loaded) {

        if (xb) { ori(tmp, tmp, (unsigned short)xb); } // No addi, we support tmp == R0.

      } else {

        li(tmp, xb);

      }

      if (xc) {

        if (xd) { addi(d, d, xd); }

      } else {

        li(d, xd);

      }

      insrdi(d, tmp, 32, 0);

      return retval;

    }

    xb = rem & 0xFFFF; // Next 16-bit chunk.

    rem = (rem >> 16) + ((unsigned short)xb >> 15); // Compensation for sign extend.

    xa = rem & 0xFFFF; // Highest 16-bit chunk.

    // opt 4: avoid adding 0

    if (xa) { // Highest 16-bit needed?

      lis(d, xa);

      if (xb) { addi(d, d, xb); }

    } else {

      li(d, xb);

    }

    sldi(d, d, 32);

    if (xc) { addis(d, d, xc); }

  }

  if (xd) { addi(d, d, xd); }

  return retval;

}

// We emit only one addition to s to optimize latency.

int Assembler::add_const_optimized(Register d, Register s, long x, Register tmp, bool return_simm16_rest) {

  assert(s != R0 && s != tmp, "unsupported");

  long rem = x;

  // Case 1: Can use mr or addi.

  short xd = rem & 0xFFFF; // Lowest 16-bit chunk.

  rem = (rem >> 16) + ((unsigned short)xd >> 15);

  if (rem == 0) {

    if (xd == 0) {

      if (d != s) { mr(d, s); }

      return 0;

    }

    if (return_simm16_rest && (d == s)) {

      return xd;

    }

    addi(d, s, xd);

    return 0;

  }

  // Case 2: Can use addis.

  if (xd == 0) {

    short xc = rem & 0xFFFF; // 2nd 16-bit chunk.

    if (rem == 0) {

      addis(d, s, xc);

      return 0;

    }

  }

  // Other cases: load & add.

  Register tmp1 = tmp,

           tmp2 = noreg;

  if ((d != tmp) && (d != s)) {

    // Can use d.

    tmp1 = d;

    tmp2 = tmp;

  }

  int simm16_rest = load_const_optimized(tmp1, x, tmp2, return_simm16_rest);

  add(d, tmp1, s);

  return simm16_rest;

}

#ifndef PRODUCT

// Test of ppc assembler.

void Assembler::test_asm() {

  // PPC 1, section 3.3.8, Fixed-Point Arithmetic Instructions

  addi(   R0,  R1,  10);

  addis(  R5,  R2,  11);

  addic_( R3,  R31, 42);

  subfic( R21, R12, 2112);

  add(    R3,  R2,  R1);

  add_(   R11, R22, R30);