view src/cpu/x86/vm/jniFastGetField_x86_64.cpp @ 453:c96030fff130

6684579: SoftReference processing can be made more efficient Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not. Reviewed-by: jmasa
author ysr
date Thu, 20 Nov 2008 16:56:09 -0800
parents 9ee9cf798b59
children c18cbe5936b8
line wrap: on
line source

/*
 * Copyright 2004-2008 Sun Microsystems, 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */

# include "incls/_precompiled.incl"
# include "incls/_jniFastGetField_x86_64.cpp.incl"

#define __ masm->

#define BUFFER_SIZE 30*wordSize

// Instead of issuing lfence for LoadLoad barrier, we create data dependency
// between loads, which is more efficient than lfence.

// Common register usage:
// rax/xmm0: result
// c_rarg0:    jni env
// c_rarg1:    obj
// c_rarg2:    jfield id

static const Register robj          = r9;
static const Register rcounter      = r10;
static const Register roffset       = r11;
static const Register rcounter_addr = r11;

// Warning: do not use rip relative addressing after the first counter load
// since that may scratch r10!

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;
    default:        ShouldNotReachHere();
  }
  ResourceMark rm;
  BufferBlob* b = BufferBlob::create(name, BUFFER_SIZE);
  address fast_entry = b->instructions_begin();
  CodeBuffer cbuf(fast_entry, b->instructions_size());
  MacroAssembler* masm = new MacroAssembler(&cbuf);

  Label slow;

  ExternalAddress counter(SafepointSynchronize::safepoint_counter_addr());
  __ mov32 (rcounter, counter);
  __ mov   (robj, c_rarg1);
  __ testb (rcounter, 1);
  __ jcc (Assembler::notZero, slow);
  if (os::is_MP()) {
    __ xorptr(robj, rcounter);
    __ xorptr(robj, rcounter);                   // obj, since
                                                // robj ^ rcounter ^ rcounter == robj
                                                // robj is data dependent on rcounter.
  }
  __ movptr(robj, Address(robj, 0));             // *obj
  __ mov   (roffset, c_rarg2);
  __ shrptr(roffset, 2);                         // offset

  assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
  speculative_load_pclist[count] = __ pc();
  switch (type) {
    case T_BOOLEAN: __ movzbl (rax, Address(robj, roffset, Address::times_1)); break;
    case T_BYTE:    __ movsbl (rax, Address(robj, roffset, Address::times_1)); break;
    case T_CHAR:    __ movzwl (rax, Address(robj, roffset, Address::times_1)); break;
    case T_SHORT:   __ movswl (rax, Address(robj, roffset, Address::times_1)); break;
    case T_INT:     __ movl   (rax, Address(robj, roffset, Address::times_1)); break;
    case T_LONG:    __ movq   (rax, Address(robj, roffset, Address::times_1)); break;
    default:        ShouldNotReachHere();
  }

  if (os::is_MP()) {
    __ lea(rcounter_addr, counter);
    // ca is data dependent on rax.
    __ xorptr(rcounter_addr, rax);
    __ xorptr(rcounter_addr, rax);
    __ cmpl (rcounter, Address(rcounter_addr, 0));
  } else {
    __ cmp32 (rcounter, counter);
  }
  __ jcc (Assembler::notEqual, slow);

  __ ret (0);

  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();
  }
  // tail call
  __ jump (ExternalAddress(slow_case_addr));

  __ 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_field0(BasicType type) {
  const char *name;
  switch (type) {
    case T_FLOAT:     name = "jni_fast_GetFloatField";     break;
    case T_DOUBLE:    name = "jni_fast_GetDoubleField";    break;
    default:          ShouldNotReachHere();
  }
  ResourceMark rm;
  BufferBlob* b = BufferBlob::create(name, BUFFER_SIZE);
  address fast_entry = b->instructions_begin();
  CodeBuffer cbuf(fast_entry, b->instructions_size());
  MacroAssembler* masm = new MacroAssembler(&cbuf);

  Label slow;

  ExternalAddress counter(SafepointSynchronize::safepoint_counter_addr());
  __ mov32 (rcounter, counter);
  __ mov   (robj, c_rarg1);
  __ testb (rcounter, 1);
  __ jcc (Assembler::notZero, slow);
  if (os::is_MP()) {
    __ xorptr(robj, rcounter);
    __ xorptr(robj, rcounter);                   // obj, since
                                                // robj ^ rcounter ^ rcounter == robj
                                                // robj is data dependent on rcounter.
  }
  __ movptr(robj, Address(robj, 0));             // *obj
  __ mov   (roffset, c_rarg2);
  __ shrptr(roffset, 2);                         // offset

  assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
  speculative_load_pclist[count] = __ pc();
  switch (type) {
    case T_FLOAT:  __ movflt (xmm0, Address(robj, roffset, Address::times_1)); break;
    case T_DOUBLE: __ movdbl (xmm0, Address(robj, roffset, Address::times_1)); break;
    default:        ShouldNotReachHere();
  }

  if (os::is_MP()) {
    __ lea(rcounter_addr, counter);
    __ movdq (rax, xmm0);
    // counter address is data dependent on xmm0.
    __ xorptr(rcounter_addr, rax);
    __ xorptr(rcounter_addr, rax);
    __ cmpl (rcounter, Address(rcounter_addr, 0));
  } else {
    __ cmp32 (rcounter, counter);
  }
  __ jcc (Assembler::notEqual, slow);

  __ ret (0);

  slowcase_entry_pclist[count++] = __ pc();
  __ bind (slow);
  address slow_case_addr;
  switch (type) {
    case T_FLOAT:     slow_case_addr = jni_GetFloatField_addr();  break;
    case T_DOUBLE:    slow_case_addr = jni_GetDoubleField_addr();
  }
  // tail call
  __ jump (ExternalAddress(slow_case_addr));

  __ flush ();

  return fast_entry;
}

address JNI_FastGetField::generate_fast_get_float_field() {
  return generate_fast_get_float_field0(T_FLOAT);
}

address JNI_FastGetField::generate_fast_get_double_field() {
  return generate_fast_get_float_field0(T_DOUBLE);
}