Re: AIX atomicity.h support

[David Edelsohn <dje at watson dot ibm dot com>]

	Appended are the current version of my v3/acinclude.m4 patch and
atomicity.h.  If cpu_include_dir is blank, then the Makefiles point to
invalid directory hierarchies or hierarchies with two slashes, so I am not
sure what value to use on AIX. 

	Also, as I mentioned before, I implemented all of the atomicity
functions from powerpc/bits/atomicity.h, but generic/bits/atomicity.h
defines fewer functions which more easily match the primitives provided by
AIX.  It would be better to remove the extra functions if they are
unused. 

David

Index: acinclude.m4
===================================================================
RCS file: /cvs/gcc/egcs/libstdc++-v3/acinclude.m4,v
retrieving revision 1.59
diff -c -p -r1.59 acinclude.m4
*** acinclude.m4	2000/09/12 01:06:02	1.59
--- acinclude.m4	2000/09/26 18:08:30
*************** AC_DEFUN(GLIBCPP_CHECK_CPU, [
*** 714,721 ****
  	cpu_include_dir="config/cpu/i486"
          ;;
        powerpc | rs6000)
! 	cpu_include_dir="config/cpu/powerpc"
!     	CPU_FLAGS='-mcpu=powerpc'
          ;;
        sparc64 | ultrasparc)
  	cpu_include_dir="config/cpu/sparc/sparc64"
--- 714,730 ----
  	cpu_include_dir="config/cpu/i486"
          ;;
        powerpc | rs6000)
! 	case "${target_os}" in
! 	  aix3*)
! 	    cpu_include_dir="config/cpu/generic"
! 	    ;;
! 	  aix[[456789]]*)
! 	    cpu_include_dir=""
! 	    ;;
! 	  *)
! 	    cpu_include_dir="config/cpu/powerpc"
! 	    ;;
! 	esac
          ;;
        sparc64 | ultrasparc)
  	cpu_include_dir="config/cpu/sparc/sparc64"
*************** AC_DEFUN(GLIBCPP_ENABLE_THREADS, [
*** 1312,1318 ****
  		target_thread_file=''
  		;;
  	xdecosf1 | xirix | xmach | xos2 | xposix | xpthreads | xsingle | \
! 	xsolaris | xwin32 | xdce | xvxworks)
  		target_thread_file=$enable_threads_flag
  		;;
  	*)
--- 1321,1327 ----
  		target_thread_file=''
  		;;
  	xdecosf1 | xirix | xmach | xos2 | xposix | xpthreads | xsingle | \
! 	xsolaris | xwin32 | xdce | xvxworks | xaix)
  		target_thread_file=$enable_threads_flag
  		;;
  	*)
*************** AC_DEFUN(GLIBCPP_ENABLE_THREADS, [
*** 1326,1332 ****
      no | none | single)
        THREADS=none
        ;;
!     posix | pthreads)
        THREADS=posix
        case "$target" in
          *-*-linux*)
--- 1335,1341 ----
      no | none | single)
        THREADS=none
        ;;
!     posix | pthreads | aix)
        THREADS=posix
        case "$target" in
          *-*-linux*)
*************** AC_DEFUN(GLIBCPP_ENABLE_THREADS, [
*** 1355,1361 ****
        THREADSPEC=-lpthread
        dnl Not presently used
        dnl THREADOBJS=threads-posix.lo
!       THREADH=threads-posix.h
        ;;
      none)
        dnl Not presently used
--- 1364,1377 ----
        THREADSPEC=-lpthread
        dnl Not presently used
        dnl THREADOBJS=threads-posix.lo
!       case "${target_os}" in
! 	aix[[456789]]*)
! 	  THREADH=threads-aix.h
! 	  ;;
! 	*)
! 	  THREADH=threads-posix.h
! 	  ;;
!       esac
        ;;
      none)
        dnl Not presently used


----- config/aix/bits/atomicity.h -----
/* Low-level functions for atomic operations.  AIX version.
   Copyright (C) 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#ifndef _BITS_ATOMICITY_H
#define _BITS_ATOMICITY_H	1

#include <sys/atomic_op.h>

static inline int
__attribute__ ((unused))
__exchange_and_add (atomic_p __mem, int __val)
{
  return fetch_and_add (__mem, __val);
}

static inline void
__attribute__ ((unused))
__atomic_add (atomic_p __mem, int __val)
{
  (void) fetch_and_add (__mem, __val);
}

static inline int
__attribute__ ((unused))
__compare_and_swap (atomic_l __p, long int __oldval, long int __newval)
{
  return compare_and_swaplp (__p, &__oldval, __newval);
}

static inline long
__attribute__ ((unused))
__always_swap (atomic_l __p, long int __newval)
{
  volatile long __val = *__p;

  while (! compare_and_swaplp (__p, &__val, __newval))
    /* EMPTY */;

  return __val;
}

static inline int
__attribute__ ((unused))
__test_and_set (atomic_l __p, long int __newval)
{
  long __val = 0;

  (void) compare_and_swaplp (__p, &__val, __newval);

  return __val;
}

#endif /* atomicity.h */
===============================================================================
David Edelsohn                                      T.J. Watson Research Center
dje@watson.ibm.com                                  P.O. Box 218
+1 914 945 4364 (TL 862)                            Yorktown Heights, NY 10598