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

   1 /*      $NetBSD: fpsetround.c,v 1.6 2012/03/21 00:38:35 christos Exp $  */
   2
   3 /*
   4  * Written by J.T. Conklin, Apr 10, 1995
   5  * Public domain.
   6  */
   7
   8 #include <sys/cdefs.h>
   9 #if defined(LIBC_SCCS) && !defined(lint)
  10 __RCSID("$NetBSD: fpsetround.c,v 1.6 2012/03/21 00:38:35 christos Exp $");
  11 #endif /* LIBC_SCCS and not lint */
  12
  13 #include "namespace.h"
  14
  15 #include <ieeefp.h>
  16
  17 #ifdef __weak_alias
  18 __weak_alias(fpsetround,_fpsetround)
  19 #endif
  20
  21 fp_rnd
  22 fpsetround(fp_rnd rnd_dir)
  23 {
  24         fp_rnd old;
  25         fp_rnd new;
  26
  27         __asm("st %%fsr,%0" : "=m" (*&old));
  28
  29         new = old;
  30         new &= ~(0x03 << 30);
  31         new |= ((rnd_dir & 0x03) << 30);
  32
  33         __asm("ld %0,%%fsr" : : "m" (*&new));
  34
  35         return ((unsigned int)old >> 30) & 0x03;
  36 }