lib/libc/arch/ia64/gen/fpsetround.c

   1 /*
   2  * Copyright (c) 2003 Marcel Moolenaar
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/lib/libc/ia64/gen/fpsetround.c,v 1.1 2003/01/11 07:24:54 marcel Exp $
  27  */
  28
  29 #include <sys/types.h>
  30 #include <ieeefp.h>
  31
  32 fp_rnd
  33 fpsetround(fp_rnd rnd)
  34 {
  35         uint64_t fpsr;
  36         fp_rnd prev;
  37
  38         __asm __volatile("mov %0=ar.fpsr" : "=r"(fpsr));
  39         prev = (fp_rnd)((fpsr >> 10) & 3);
  40         fpsr = (fpsr & ~0xC00ULL) | ((unsigned int)rnd << 10);
  41         __asm __volatile("mov ar.fpsr=%0" :: "r"(fpsr));
  42         return (prev);
  43 }