src/hotspot/cpu/aarch64/foreignGlobals_aarch64.cpp

/*
 * Copyright (c) 2020, 2025, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2019, 2022, Arm Limited. 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
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 * questions.
 */

#include "code/vmreg.inline.hpp"
#include "runtime/jniHandles.hpp"
#include "runtime/jniHandles.inline.hpp"
#include "oops/typeArrayOop.inline.hpp"
#include "oops/oopCast.inline.hpp"
#include "prims/foreignGlobals.hpp"
#include "prims/foreignGlobals.inline.hpp"
#include "prims/vmstorage.hpp"
#include "utilities/formatBuffer.hpp"

bool ForeignGlobals::is_foreign_linker_supported() {
  return true;
}

bool ABIDescriptor::is_volatile_reg(Register reg) const {
  return _integer_argument_registers.contains(reg)
    || _integer_additional_volatile_registers.contains(reg);
}

bool ABIDescriptor::is_volatile_reg(FloatRegister reg) const {
    return _vector_argument_registers.contains(reg)
        || _vector_additional_volatile_registers.contains(reg);
}

const ABIDescriptor ForeignGlobals::parse_abi_descriptor(jobject jabi) {
  oop abi_oop = JNIHandles::resolve_non_null(jabi);
  ABIDescriptor abi;

  objArrayOop inputStorage = jdk_internal_foreign_abi_ABIDescriptor::inputStorage(abi_oop);
  parse_register_array(inputStorage, StorageType::INTEGER, abi._integer_argument_registers, as_Register);
  parse_register_array(inputStorage, StorageType::VECTOR, abi._vector_argument_registers, as_FloatRegister);

  objArrayOop outputStorage = jdk_internal_foreign_abi_ABIDescriptor::outputStorage(abi_oop);
  parse_register_array(outputStorage, StorageType::INTEGER, abi._integer_return_registers, as_Register);
  parse_register_array(outputStorage, StorageType::VECTOR, abi._vector_return_registers, as_FloatRegister);

  objArrayOop volatileStorage = jdk_internal_foreign_abi_ABIDescriptor::volatileStorage(abi_oop);
  parse_register_array(volatileStorage, StorageType::INTEGER, abi._integer_additional_volatile_registers, as_Register);
  parse_register_array(volatileStorage, StorageType::VECTOR, abi._vector_additional_volatile_registers, as_FloatRegister);

  abi._stack_alignment_bytes = jdk_internal_foreign_abi_ABIDescriptor::stackAlignment(abi_oop);
  abi._shadow_space_bytes = jdk_internal_foreign_abi_ABIDescriptor::shadowSpace(abi_oop);

  abi._scratch1 = parse_vmstorage(jdk_internal_foreign_abi_ABIDescriptor::scratch1(abi_oop));
  abi._scratch2 = parse_vmstorage(jdk_internal_foreign_abi_ABIDescriptor::scratch2(abi_oop));

  return abi;
}

int RegSpiller::pd_reg_size(VMStorage reg) {
  if (reg.type() == StorageType::INTEGER) {
    return 8;
  } else if (reg.type() == StorageType::VECTOR) {
    return 16;   // Always spill/unspill Q registers
  }
  return 0; // stack and BAD
}

void RegSpiller::pd_store_reg(MacroAssembler* masm, int offset, VMStorage reg) {
  if (reg.type() == StorageType::INTEGER) {
    masm->spill(as_Register(reg), true, offset);
  } else if (reg.type() == StorageType::VECTOR) {
    masm->spill(as_FloatRegister(reg), masm->Q, offset);
  } else {
    // stack and BAD
  }
}

void RegSpiller::pd_load_reg(MacroAssembler* masm, int offset, VMStorage reg) {
  if (reg.type() == StorageType::INTEGER) {
    masm->unspill(as_Register(reg), true, offset);
  } else if (reg.type() == StorageType::VECTOR) {
    masm->unspill(as_FloatRegister(reg), masm->Q, offset);
  } else {
    // stack and BAD
  }
}

static constexpr int RFP_BIAS = 16; // skip old rfp and lr

static void move_reg64(MacroAssembler* masm, int out_stk_bias,
                       Register from_reg, VMStorage to_reg) {
  int out_bias = 0;
  switch (to_reg.type()) {
    case StorageType::INTEGER:
      assert(to_reg.segment_mask() == REG64_MASK, "only moves to 64-bit registers supported");
      masm->mov(as_Register(to_reg), from_reg);
      break;
    case StorageType::STACK:
      out_bias = out_stk_bias;
    case StorageType::FRAME_DATA: {
      Address dest(sp, to_reg.offset() + out_bias);
      switch (to_reg.stack_size()) {
        case 8: masm->str (from_reg, dest); break;
        case 4: masm->strw(from_reg, dest); break;
        case 2: masm->strh(from_reg, dest); break;
        case 1: masm->strb(from_reg, dest); break;
        default: ShouldNotReachHere();
      }
    } break;
    default: ShouldNotReachHere();
  }
}

static void move_stack(MacroAssembler* masm, Register tmp_reg, int in_stk_bias, int out_stk_bias,
                       VMStorage from_reg, VMStorage to_reg) {
  Address from_addr(rfp, RFP_BIAS + from_reg.offset() + in_stk_bias);
  int out_bias = 0;
  switch (to_reg.type()) {
    case StorageType::INTEGER:
      assert(to_reg.segment_mask() == REG64_MASK, "only moves to 64-bit registers supported");
      switch (from_reg.stack_size()) {
        case 8: masm->ldr (as_Register(to_reg), from_addr); break;
        case 4: masm->ldrw(as_Register(to_reg), from_addr); break;
        case 2: masm->ldrh(as_Register(to_reg), from_addr); break;
        case 1: masm->ldrb(as_Register(to_reg), from_addr); break;
        default: ShouldNotReachHere();
      }
      break;
    case StorageType::VECTOR:
      assert(to_reg.segment_mask() == V128_MASK, "only moves to v128 registers supported");
      switch (from_reg.stack_size()) {
        case 8:
          masm->ldrd(as_FloatRegister(to_reg), from_addr);
        break;
        case 4:
          masm->ldrs(as_FloatRegister(to_reg), from_addr);
        break;
        default: ShouldNotReachHere();
      }
      break;
    case StorageType::STACK:
      out_bias = out_stk_bias;
    case StorageType::FRAME_DATA: {
      switch (from_reg.stack_size()) {
        case 8: masm->ldr (tmp_reg, from_addr); break;
        case 4: masm->ldrw(tmp_reg, from_addr); break;
        case 2: masm->ldrh(tmp_reg, from_addr); break;
        case 1: masm->ldrb(tmp_reg, from_addr); break;
        default: ShouldNotReachHere();
      }
      Address dest(sp, to_reg.offset() + out_bias);
      switch (to_reg.stack_size()) {
        case 8: masm->str (tmp_reg, dest); break;
        case 4: masm->strw(tmp_reg, dest); break;
        case 2: masm->strh(tmp_reg, dest); break;
        case 1: masm->strb(tmp_reg, dest); break;
        default: ShouldNotReachHere();
      }
    } break;
    default: ShouldNotReachHere();
  }
}

static void move_v128(MacroAssembler* masm, int out_stk_bias,
                      FloatRegister from_reg, VMStorage to_reg) {
  switch (to_reg.type()) {
    case StorageType::INTEGER:
      assert(to_reg.segment_mask() == REG64_MASK, "only moves to 64-bit registers supported");
      masm->fmovd(as_Register(to_reg), from_reg);
      break;
    case StorageType::VECTOR:
      assert(to_reg.segment_mask() == V128_MASK, "only moves to v128 registers supported");
      masm->fmovd(as_FloatRegister(to_reg), from_reg);
      break;
    case StorageType::STACK: {
      Address dest(sp, to_reg.offset() + out_stk_bias);
      switch (to_reg.stack_size()) {
        case 8: masm->strd(from_reg, dest); break;
        case 4: masm->strs(from_reg, dest); break;
        default: ShouldNotReachHere();
      }
    } break;
    default: ShouldNotReachHere();
  }
}

void ArgumentShuffle::pd_generate(MacroAssembler* masm, VMStorage tmp, int in_stk_bias, int out_stk_bias) const {
  Register tmp_reg = as_Register(tmp);
  for (int i = 0; i < _moves.length(); i++) {
    Move move = _moves.at(i);
    VMStorage from_reg = move.from;
    VMStorage to_reg   = move.to;

    switch (from_reg.type()) {
      case StorageType::INTEGER:
        assert(from_reg.segment_mask() == REG64_MASK, "only 64-bit register supported");
        move_reg64(masm, out_stk_bias, as_Register(from_reg), to_reg);
        break;
      case StorageType::VECTOR:
        assert(from_reg.segment_mask() == V128_MASK, "only v128 register supported");
        move_v128(masm, out_stk_bias, as_FloatRegister(from_reg), to_reg);
        break;
      case StorageType::STACK:
        move_stack(masm, tmp_reg, in_stk_bias, out_stk_bias, from_reg, to_reg);
        break;
      default: ShouldNotReachHere();
    }
  }
}