view src/os_cpu/windows_x86/vm/assembler_windows_x86_64.cpp @ 168:7793bd37a336

6705887: Compressed Oops: generate x64 addressing and implicit null checks with narrow oops Summary: Generate addresses and implicit null checks with narrow oops to avoid decoding. Reviewed-by: jrose, never
author kvn
date Thu, 29 May 2008 12:04:14 -0700
parents a61af66fc99e
children d1605aabd0a1
line wrap: on
line source
/*
 * Copyright 2003-2005 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/_assembler_windows_x86_64.cpp.incl"


void MacroAssembler::int3() {
  emit_byte(0xCC);
}

// call (Thread*)TlsGetValue(thread_index());
void MacroAssembler::get_thread(Register thread) {
   if (thread != rax) {
     pushq(rax);
   }
   pushq(rdi);
   pushq(rsi);
   pushq(rdx);
   pushq(rcx);
   pushq(r8);
   pushq(r9);
   pushq(r10);
   // XXX
   movq(r10, rsp);
   andq(rsp, -16);
   pushq(r10);
   pushq(r11);

   movl(c_rarg0, ThreadLocalStorage::thread_index());
   call(RuntimeAddress((address)TlsGetValue));

   popq(r11);
   popq(rsp);
   popq(r10);
   popq(r9);
   popq(r8);
   popq(rcx);
   popq(rdx);
   popq(rsi);
   popq(rdi);
   if (thread != rax) {
       movq(thread, rax);
       popq(rax);
   }
}

bool MacroAssembler::needs_explicit_null_check(intptr_t offset) {
  // Exception handler checks the nmethod's implicit null checks table
  // only when this method returns false.
  if (UseCompressedOops) {
    // The first page after heap_base is unmapped and
    // the 'offset' is equal to [heap_base + offset] for
    // narrow oop implicit null checks.
    uintptr_t heap_base = (uintptr_t)Universe::heap_base();
    if ((uintptr_t)offset >= heap_base) {
      // Normalize offset for the next check.
      offset = (intptr_t)(pointer_delta((void*)offset, (void*)heap_base, 1));
    }
  }
  return offset < 0 || os::vm_page_size() <= offset;
}