1 /*
   2  * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "asm/macroAssembler.hpp"
  27 #include "asm/macroAssembler.inline.hpp"
  28 #include "runtime/os.hpp"
  29 #include "runtime/threadLocalStorage.hpp"
  30 
  31 
  32 // get_thread can be called anywhere inside generated code so we need
  33 // to save whatever non-callee save context might get clobbered by the
  34 // call to the C thread_local lookup call or, indeed, the call setup
  35 // code. x86 appears to save C arg registers.
  36 
  37 void MacroAssembler::get_thread(Register dst) {
  38   // call pthread_getspecific
  39   // void * pthread_getspecific(pthread_key_t key);
  40 
  41   // Save all call-clobbered regs except dst, plus r19 and r20.
  42   RegSet saved_regs = RegSet::range(r0, r20) + lr - dst;
  43   push(saved_regs, sp);
  44   mov(c_rarg0, ThreadLocalStorage::thread_index());
  45   mov(r19, CAST_FROM_FN_PTR(address, pthread_getspecific));
  46   blr(r19);
  47   if (dst != c_rarg0) {
  48     mov(dst, c_rarg0);
  49   }
  50   // restore pushed registers
  51   pop(saved_regs, sp);
  52 }
  53