/*

 * 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 "asm/assembler.inline.hpp"

#include "asm/macroAssembler.hpp"

#include "asm/codeBuffer.hpp"

#include "code/codeCache.hpp"

#include "gc/shared/barrierSet.hpp"

#include "gc/shared/barrierSetAssembler.hpp"

#include "oops/accessDecorators.hpp"

#include "runtime/safepointMechanism.hpp"

inline bool MacroAssembler::is_ld_largeoffset(address a) {

  const int inst1 = *(int *)a;

  const int inst2 = *(int *)(a+4);

  return (is_ld(inst1)) ||

         (is_addis(inst1) && is_ld(inst2) && inv_ra_field(inst2) == inv_rt_field(inst1));

}

inline int MacroAssembler::get_ld_largeoffset_offset(address a) {

  assert(MacroAssembler::is_ld_largeoffset(a), "must be ld with large offset");

  const int inst1 = *(int *)a;

  if (is_ld(inst1)) {

    return inv_d1_field(inst1);

  } else {

    const int inst2 = *(int *)(a+4);

    return (inv_d1_field(inst1) << 16) + inv_d1_field(inst2);

  }

}

inline void MacroAssembler::round_to(Register r, int modulus) {

  assert(is_power_of_2_long((jlong)modulus), "must be power of 2");

  addi(r, r, modulus-1);

  clrrdi(r, r, log2_long((jlong)modulus));

}

// Move register if destination register and target register are different.

inline void MacroAssembler::mr_if_needed(Register rd, Register rs) {

  if (rs != rd) mr(rd, rs);

}

inline void MacroAssembler::fmr_if_needed(FloatRegister rd, FloatRegister rs) {

  if (rs != rd) fmr(rd, rs);

}

inline void MacroAssembler::endgroup_if_needed(bool needed) {

  if (needed) {

    endgroup();

  }

}

inline void MacroAssembler::membar(int bits) {

  // Comment: Usage of elemental_membar(bits) is not recommended for Power 8.

  // If elemental_membar(bits) is used, disable optimization of acquire-release

  // (Matcher::post_membar_release where we use PPC64_ONLY(xop == Op_MemBarRelease ||))!

  if (bits & StoreLoad) { sync(); }

  else if (bits) { lwsync(); }

}

inline void MacroAssembler::release() { membar(LoadStore | StoreStore); }

inline void MacroAssembler::acquire() { membar(LoadLoad | LoadStore); }

inline void MacroAssembler::fence()   { membar(LoadLoad | LoadStore | StoreLoad | StoreStore); }

// Address of the global TOC.

inline address MacroAssembler::global_toc() {

  return CodeCache::low_bound();

}

// Offset of given address to the global TOC.

inline int MacroAssembler::offset_to_global_toc(const address addr) {

  intptr_t offset = (intptr_t)addr - (intptr_t)MacroAssembler::global_toc();

  assert(Assembler::is_uimm((long)offset, 31), "must be in range");

  return (int)offset;

}

// Address of current method's TOC.

inline address MacroAssembler::method_toc() {

  return code()->consts()->start();

}

// Offset of given address to current method's TOC.

inline int MacroAssembler::offset_to_method_toc(address addr) {

  intptr_t offset = (intptr_t)addr - (intptr_t)method_toc();

  assert(Assembler::is_uimm((long)offset, 31), "must be in range");

  return (int)offset;

}

inline bool MacroAssembler::is_calculate_address_from_global_toc_at(address a, address bound) {

  const address inst2_addr = a;

  const int inst2 = *(int *) a;

  // The relocation points to the second instruction, the addi.

  if (!is_addi(inst2)) return false;

  // The addi reads and writes the same register dst.

  const int dst = inv_rt_field(inst2);

  if (inv_ra_field(inst2) != dst) return false;

  // Now, find the preceding addis which writes to dst.

  int inst1 = 0;

  address inst1_addr = inst2_addr - BytesPerInstWord;

  while (inst1_addr >= bound) {

    inst1 = *(int *) inst1_addr;

    if (is_addis(inst1) && inv_rt_field(inst1) == dst) {

      // stop, found the addis which writes dst

      break;

    }

    inst1_addr -= BytesPerInstWord;

  }

  if (!(inst1 == 0 || inv_ra_field(inst1) == 29 /* R29 */)) return false;

  return is_addis(inst1);

}

#ifdef _LP64

// Detect narrow oop constants.

inline bool MacroAssembler::is_set_narrow_oop(address a, address bound) {

  const address inst2_addr = a;

  const int inst2 = *(int *)a;

  // The relocation points to the second instruction, the ori.

  if (!is_ori(inst2)) return false;

  // The ori reads and writes the same register dst.

  const int dst = inv_rta_field(inst2);

  if (inv_rs_field(inst2) != dst) return false;

  // Now, find the preceding addis which writes to dst.

  int inst1 = 0;

  address inst1_addr = inst2_addr - BytesPerInstWord;

  while (inst1_addr >= bound) {

    inst1 = *(int *) inst1_addr;

    if (is_lis(inst1) && inv_rs_field(inst1) == dst) return true;

    inst1_addr -= BytesPerInstWord;

  }

  return false;

}

#endif

inline bool MacroAssembler::is_load_const_at(address a) {

  const int* p_inst = (int *) a;

  bool b = is_lis(*p_inst++);

  if (is_ori(*p_inst)) {

    p_inst++;

    b = b && is_rldicr(*p_inst++); // TODO: could be made more precise: `sldi'!

    b = b && is_oris(*p_inst++);

    b = b && is_ori(*p_inst);

  } else if (is_lis(*p_inst)) {

    p_inst++;

    b = b && is_ori(*p_inst++);

    b = b && is_ori(*p_inst);

    // TODO: could enhance reliability by adding is_insrdi

  } else return false;

  return b;

}

inline void MacroAssembler::set_oop_constant(jobject obj, Register d) {

  set_oop(constant_oop_address(obj), d);

}

inline void MacroAssembler::set_oop(AddressLiteral obj_addr, Register d) {

  assert(obj_addr.rspec().type() == relocInfo::oop_type, "must be an oop reloc");

  load_const(d, obj_addr);

}

inline void MacroAssembler::pd_patch_instruction(address branch, address target, const char* file, int line) {

  jint& stub_inst = *(jint*) branch;

  stub_inst = patched_branch(target - branch, stub_inst, 0);

}

// Relocation of conditional far branches.

inline bool MacroAssembler::is_bc_far_variant1_at(address instruction_addr) {

  // Variant 1, the 1st instruction contains the destination address:

  //

  //    bcxx  DEST

  //    nop

  //

  const int instruction_1 = *(int*)(instruction_addr);

  const int instruction_2 = *(int*)(instruction_addr + 4);

  return is_bcxx(instruction_1) &&

         (inv_bd_field(instruction_1, (intptr_t)instruction_addr) != (intptr_t)(instruction_addr + 2*4)) &&

         is_nop(instruction_2);

}

// Relocation of conditional far branches.

inline bool MacroAssembler::is_bc_far_variant2_at(address instruction_addr) {

  // Variant 2, the 2nd instruction contains the destination address:

  //

  //    b!cxx SKIP

  //    bxx   DEST

  //  SKIP:

  //

  const int instruction_1 = *(int*)(instruction_addr);

  const int instruction_2 = *(int*)(instruction_addr + 4);

  return is_bcxx(instruction_1) &&

         (inv_bd_field(instruction_1, (intptr_t)instruction_addr) == (intptr_t)(instruction_addr + 2*4)) &&

         is_bxx(instruction_2);

}

// Relocation for conditional branches

inline bool MacroAssembler::is_bc_far_variant3_at(address instruction_addr) {

  // Variant 3, far cond branch to the next instruction, already patched to nops:

  //

  //    nop

  //    endgroup

  //  SKIP/DEST:

  //

  const int instruction_1 = *(int*)(instruction_addr);

  const int instruction_2 = *(int*)(instruction_addr + 4);

  return is_nop(instruction_1) &&

         is_endgroup(instruction_2);

}

// Convenience bc_far versions

inline void MacroAssembler::blt_far(ConditionRegister crx, Label& L, int optimize) { MacroAssembler::bc_far(bcondCRbiIs1, bi0(crx, less), L, optimize); }

inline void MacroAssembler::bgt_far(ConditionRegister crx, Label& L, int optimize) { MacroAssembler::bc_far(bcondCRbiIs1, bi0(crx, greater), L, optimize); }

inline void MacroAssembler::beq_far(ConditionRegister crx, Label& L, int optimize) { MacroAssembler::bc_far(bcondCRbiIs1, bi0(crx, equal), L, optimize); }

inline void MacroAssembler::bso_far(ConditionRegister crx, Label& L, int optimize) { MacroAssembler::bc_far(bcondCRbiIs1, bi0(crx, summary_overflow), L, optimize); }

inline void MacroAssembler::bge_far(ConditionRegister crx, Label& L, int optimize) { MacroAssembler::bc_far(bcondCRbiIs0, bi0(crx, less), L, optimize); }

inline void MacroAssembler::ble_far(ConditionRegister crx, Label& L, int optimize) { MacroAssembler::bc_far(bcondCRbiIs0, bi0(crx, greater), L, optimize); }

inline void MacroAssembler::bne_far(ConditionRegister crx, Label& L, int optimize) { MacroAssembler::bc_far(bcondCRbiIs0, bi0(crx, equal), L, optimize); }

inline void MacroAssembler::bns_far(ConditionRegister crx, Label& L, int optimize) { MacroAssembler::bc_far(bcondCRbiIs0, bi0(crx, summary_overflow), L, optimize); }

inline address MacroAssembler::call_stub(Register function_entry) {

  mtctr(function_entry);

  bctrl();

  return pc();

}

inline void MacroAssembler::call_stub_and_return_to(Register function_entry, Register return_pc) {

  assert_different_registers(function_entry, return_pc);

  mtlr(return_pc);

  mtctr(function_entry);

  bctr();

}

// Get the pc where the last emitted call will return to.

inline address MacroAssembler::last_calls_return_pc() {

  return _last_calls_return_pc;

}

// Read from the polling page, its address is already in a register.

inline void MacroAssembler::load_from_polling_page(Register polling_page_address, int offset) {

  if (SafepointMechanism::uses_thread_local_poll() && USE_POLL_BIT_ONLY) {

    int encoding = SafepointMechanism::poll_bit();

    tdi(traptoGreaterThanUnsigned | traptoEqual, polling_page_address, encoding);

  } else {

    ld(R0, offset, polling_page_address);

  }

}

// Trap-instruction-based checks.

inline void MacroAssembler::trap_null_check(Register a, trap_to_bits cmp) {

  assert(TrapBasedNullChecks, "sanity");

  tdi(cmp, a/*reg a*/, 0);

}

inline void MacroAssembler::trap_zombie_not_entrant() {

  tdi(traptoUnconditional, 0/*reg 0*/, 1);

}

inline void MacroAssembler::trap_should_not_reach_here() {

  tdi_unchecked(traptoUnconditional, 0/*reg 0*/, 2);

}

inline void MacroAssembler::trap_ic_miss_check(Register a, Register b) {

  td(traptoGreaterThanUnsigned | traptoLessThanUnsigned, a, b);

}

// Do an explicit null check if access to a+offset will not raise a SIGSEGV.

// Either issue a trap instruction that raises SIGTRAP, or do a compare that

// branches to exception_entry.

// No support for compressed oops (base page of heap). Does not distinguish

// loads and stores.

inline void MacroAssembler::null_check_throw(Register a, int offset, Register temp_reg,

                                             address exception_entry) {

  if (!ImplicitNullChecks || needs_explicit_null_check(offset) || !os::zero_page_read_protected()) {

    if (TrapBasedNullChecks) {

      assert(UseSIGTRAP, "sanity");

      trap_null_check(a);

    } else {

      Label ok;

      cmpdi(CCR0, a, 0);

      bne(CCR0, ok);

      load_const_optimized(temp_reg, exception_entry);

      mtctr(temp_reg);

      bctr();

      bind(ok);

    }

  }

}

inline void MacroAssembler::null_check(Register a, int offset, Label *Lis_null) {

  if (!ImplicitNullChecks || needs_explicit_null_check(offset) || !os::zero_page_read_protected()) {

    if (TrapBasedNullChecks) {

      assert(UseSIGTRAP, "sanity");

      trap_null_check(a);

    } else if (Lis_null){

      Label ok;

      cmpdi(CCR0, a, 0);

      beq(CCR0, *Lis_null);

    }

  }

}

inline void MacroAssembler::access_store_at(BasicType type, DecoratorSet decorators,

                                            Register base, RegisterOrConstant ind_or_offs, Register val,

                                            Register tmp1, Register tmp2, Register tmp3, bool needs_frame) {

  assert((decorators & ~(AS_RAW | IN_HEAP | IN_NATIVE | IS_ARRAY | IS_NOT_NULL |

                         ON_UNKNOWN_OOP_REF)) == 0, "unsupported decorator");

  BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();

  bool as_raw = (decorators & AS_RAW) != 0;

  decorators = AccessInternal::decorator_fixup(decorators);

  if (as_raw) {

    bs->BarrierSetAssembler::store_at(this, decorators, type,

                                      base, ind_or_offs, val,

                                      tmp1, tmp2, tmp3, needs_frame);

  } else {

    bs->store_at(this, decorators, type,

                 base, ind_or_offs, val,

                 tmp1, tmp2, tmp3, needs_frame);

  }

}

inline void MacroAssembler::access_load_at(BasicType type, DecoratorSet decorators,

                                           Register base, RegisterOrConstant ind_or_offs, Register dst,

                                           Register tmp1, Register tmp2, bool needs_frame, Label *L_handle_null) {

  assert((decorators & ~(AS_RAW | IN_HEAP | IN_NATIVE | IS_ARRAY | IS_NOT_NULL |

                         ON_PHANTOM_OOP_REF | ON_WEAK_OOP_REF)) == 0, "unsupported decorator");

  BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();

  decorators = AccessInternal::decorator_fixup(decorators);

  bool as_raw = (decorators & AS_RAW) != 0;

  if (as_raw) {

    bs->BarrierSetAssembler::load_at(this, decorators, type,

                                     base, ind_or_offs, dst,

                                     tmp1, tmp2, needs_frame, L_handle_null);

  } else {

    bs->load_at(this, decorators, type,

                base, ind_or_offs, dst,

                tmp1, tmp2, needs_frame, L_handle_null);

  }

}

inline void MacroAssembler::load_heap_oop(Register d, RegisterOrConstant offs, Register s1,

                                          Register tmp1, Register tmp2,

                                          bool needs_frame, DecoratorSet decorators, Label *L_handle_null) {

  access_load_at(T_OBJECT, IN_HEAP | decorators, s1, offs, d, tmp1, tmp2, needs_frame, L_handle_null);

}

inline void MacroAssembler::store_heap_oop(Register d, RegisterOrConstant offs, Register s1,

                                           Register tmp1, Register tmp2, Register tmp3,

                                           bool needs_frame, DecoratorSet decorators) {

  access_store_at(T_OBJECT, IN_HEAP | decorators, s1, offs, d, tmp1, tmp2, tmp3, needs_frame);

}

inline Register MacroAssembler::encode_heap_oop_not_null(Register d, Register src) {

  Register current = (src != noreg) ? src : d; // Oop to be compressed is in d if no src provided.

  if (Universe::narrow_oop_base_overlaps()) {

    sub_const_optimized(d, current, Universe::narrow_oop_base(), R0);

    current = d;

  }

  if (Universe::narrow_oop_shift() != 0) {

    rldicl(d, current, 64-Universe::narrow_oop_shift(), 32);  // Clears the upper bits.

    current = d;

  }

  return current; // Encoded oop is in this register.

}

inline Register MacroAssembler::encode_heap_oop(Register d, Register src) {

  if (Universe::narrow_oop_base() != NULL) {

    if (VM_Version::has_isel()) {

      cmpdi(CCR0, src, 0);

      Register co = encode_heap_oop_not_null(d, src);

      assert(co == d, "sanity");

      isel_0(d, CCR0, Assembler::equal);

    } else {

      Label isNull;

      or_(d, src, src); // move and compare 0

      beq(CCR0, isNull);

      encode_heap_oop_not_null(d, src);

      bind(isNull);

    }

    return d;

  } else {

    return encode_heap_oop_not_null(d, src);

  }

}

inline Register MacroAssembler::decode_heap_oop_not_null(Register d, Register src) {

  if (Universe::narrow_oop_base_disjoint() && src != noreg && src != d &&

      Universe::narrow_oop_shift() != 0) {

    load_const_optimized(d, Universe::narrow_oop_base(), R0);

    rldimi(d, src, Universe::narrow_oop_shift(), 32-Universe::narrow_oop_shift());

    return d;

  }

  Register current = (src != noreg) ? src : d; // Compressed oop is in d if no src provided.

  if (Universe::narrow_oop_shift() != 0) {

    sldi(d, current, Universe::narrow_oop_shift());

    current = d;

  }

  if (Universe::narrow_oop_base() != NULL) {

    add_const_optimized(d, current, Universe::narrow_oop_base(), R0);

    current = d;

  }

  return current; // Decoded oop is in this register.

}

inline void MacroAssembler::decode_heap_oop(Register d) {

  Label isNull;

  bool use_isel = false;

  if (Universe::narrow_oop_base() != NULL) {

    cmpwi(CCR0, d, 0);

    if (VM_Version::has_isel()) {

      use_isel = true;

    } else {

      beq(CCR0, isNull);

    }

  }

  decode_heap_oop_not_null(d);

  if (use_isel) {

    isel_0(d, CCR0, Assembler::equal);

  }

  bind(isNull);

}

// SIGTRAP-based range checks for arrays.

inline void MacroAssembler::trap_range_check_l(Register a, Register b) {

  tw (traptoLessThanUnsigned,                  a/*reg a*/, b/*reg b*/);

}

inline void MacroAssembler::trap_range_check_l(Register a, int si16) {

  twi(traptoLessThanUnsigned,                  a/*reg a*/, si16);

}

inline void MacroAssembler::trap_range_check_le(Register a, int si16) {

  twi(traptoEqual | traptoLessThanUnsigned,    a/*reg a*/, si16);

}

inline void MacroAssembler::trap_range_check_g(Register a, int si16) {

  twi(traptoGreaterThanUnsigned,               a/*reg a*/, si16);

}

inline void MacroAssembler::trap_range_check_ge(Register a, Register b) {

  tw (traptoEqual | traptoGreaterThanUnsigned, a/*reg a*/, b/*reg b*/);

}

inline void MacroAssembler::trap_range_check_ge(Register a, int si16) {

  twi(traptoEqual | traptoGreaterThanUnsigned, a/*reg a*/, si16);

}

// unsigned integer multiplication 64*64 -> 128 bits

inline void MacroAssembler::multiply64(Register dest_hi, Register dest_lo,

                                       Register x, Register y) {

  mulld(dest_lo, x, y);

  mulhdu(dest_hi, x, y);

}

#if defined(ABI_ELFv2)

inline address MacroAssembler::function_entry() { return pc(); }

#else

inline address MacroAssembler::function_entry() { return emit_fd(); }

#endif