/*

 * Copyright (c) 2004, 2017, Oracle and/or its affiliates. All rights reserved.

 * Copyright (c) 2014, Red Hat Inc. 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.hpp"

#include "memory/resourceArea.hpp"

#include "prims/jniFastGetField.hpp"

#include "prims/jvm_misc.hpp"

#include "runtime/safepoint.hpp"

#define __ masm->

#define BUFFER_SIZE 30*wordSize

// Instead of issuing a LoadLoad barrier we create an address

// dependency between loads; this might be more efficient.

// Common register usage:

// r0/v0:      result

// c_rarg0:    jni env

// c_rarg1:    obj

// c_rarg2:    jfield id

static const Register robj          = r3;

static const Register rcounter      = r4;

static const Register roffset       = r5;

static const Register rcounter_addr = r6;

static const Register result        = r7;

address JNI_FastGetField::generate_fast_get_int_field0(BasicType type) {

  const char *name;

  switch (type) {

    case T_BOOLEAN: name = "jni_fast_GetBooleanField"; break;

    case T_BYTE:    name = "jni_fast_GetByteField";    break;

    case T_CHAR:    name = "jni_fast_GetCharField";    break;

    case T_SHORT:   name = "jni_fast_GetShortField";   break;

    case T_INT:     name = "jni_fast_GetIntField";     break;

    case T_LONG:    name = "jni_fast_GetLongField";    break;

    case T_FLOAT:   name = "jni_fast_GetFloatField";   break;

    case T_DOUBLE:  name = "jni_fast_GetDoubleField";  break;

    default:        ShouldNotReachHere();

      name = NULL;  // unreachable

  }

  ResourceMark rm;

  BufferBlob* blob = BufferBlob::create(name, BUFFER_SIZE);

  CodeBuffer cbuf(blob);

  MacroAssembler* masm = new MacroAssembler(&cbuf);

  address fast_entry = __ pc();

  Label slow;

  unsigned long offset;

  __ adrp(rcounter_addr,

          SafepointSynchronize::safepoint_counter_addr(), offset);

  Address safepoint_counter_addr(rcounter_addr, offset);

  __ ldrw(rcounter, safepoint_counter_addr);

  __ tbnz(rcounter, 0, slow);

  __ eor(robj, c_rarg1, rcounter);

  __ eor(robj, robj, rcounter);               // obj, since

                                              // robj ^ rcounter ^ rcounter == robj

                                              // robj is address dependent on rcounter.

  // If mask changes we need to ensure that the inverse is still encodable as an immediate

  STATIC_ASSERT(JNIHandles::weak_tag_mask == 1);

  __ andr(robj, robj, ~JNIHandles::weak_tag_mask);

  __ ldr(robj, Address(robj, 0));             // *obj

  __ lsr(roffset, c_rarg2, 2);                // offset

  assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");

  speculative_load_pclist[count] = __ pc();   // Used by the segfault handler

  switch (type) {

    case T_BOOLEAN: __ ldrb    (result, Address(robj, roffset)); break;

    case T_BYTE:    __ ldrsb   (result, Address(robj, roffset)); break;

    case T_CHAR:    __ ldrh    (result, Address(robj, roffset)); break;

    case T_SHORT:   __ ldrsh   (result, Address(robj, roffset)); break;

    case T_FLOAT:   __ ldrw    (result, Address(robj, roffset)); break;

    case T_INT:     __ ldrsw   (result, Address(robj, roffset)); break;

    case T_DOUBLE:

    case T_LONG:    __ ldr     (result, Address(robj, roffset)); break;

    default:        ShouldNotReachHere();

  }

  // counter_addr is address dependent on result.

  __ eor(rcounter_addr, rcounter_addr, result);

  __ eor(rcounter_addr, rcounter_addr, result);

  __ ldrw(rscratch1, safepoint_counter_addr);

  __ cmpw(rcounter, rscratch1);

  __ br (Assembler::NE, slow);

  switch (type) {

    case T_FLOAT:   __ fmovs(v0, result); break;

    case T_DOUBLE:  __ fmovd(v0, result); break;

    default:        __ mov(r0, result);   break;

  }

  __ ret(lr);

  slowcase_entry_pclist[count++] = __ pc();

  __ bind(slow);

  address slow_case_addr;

  switch (type) {

    case T_BOOLEAN: slow_case_addr = jni_GetBooleanField_addr(); break;

    case T_BYTE:    slow_case_addr = jni_GetByteField_addr();    break;

    case T_CHAR:    slow_case_addr = jni_GetCharField_addr();    break;

    case T_SHORT:   slow_case_addr = jni_GetShortField_addr();   break;

    case T_INT:     slow_case_addr = jni_GetIntField_addr();     break;

    case T_LONG:    slow_case_addr = jni_GetLongField_addr();    break;

    case T_FLOAT:   slow_case_addr = jni_GetFloatField_addr();   break;

    case T_DOUBLE:  slow_case_addr = jni_GetDoubleField_addr();  break;

    default:        ShouldNotReachHere();

      slow_case_addr = NULL;  // unreachable

  }

  {

    __ enter();

    __ lea(rscratch1, ExternalAddress(slow_case_addr));

    __ blr(rscratch1);

    __ maybe_isb();

    __ leave();

    __ ret(lr);

  }

  __ flush ();

  return fast_entry;

}

address JNI_FastGetField::generate_fast_get_boolean_field() {

  return generate_fast_get_int_field0(T_BOOLEAN);

}

address JNI_FastGetField::generate_fast_get_byte_field() {

  return generate_fast_get_int_field0(T_BYTE);

}

address JNI_FastGetField::generate_fast_get_char_field() {

  return generate_fast_get_int_field0(T_CHAR);

}

address JNI_FastGetField::generate_fast_get_short_field() {

  return generate_fast_get_int_field0(T_SHORT);

}

address JNI_FastGetField::generate_fast_get_int_field() {

  return generate_fast_get_int_field0(T_INT);

}

address JNI_FastGetField::generate_fast_get_long_field() {

  return generate_fast_get_int_field0(T_LONG);

}

address JNI_FastGetField::generate_fast_get_float_field() {

  return generate_fast_get_int_field0(T_FLOAT);

}

address JNI_FastGetField::generate_fast_get_double_field() {

  return generate_fast_get_int_field0(T_DOUBLE);

}