lib/libc/arch/sparc64/gen/fpsetround.c

   1 /*      $NetBSD: fpsetround.c,v 1.7 2013/10/28 01:06:36 mrg 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 1.7 2013/10/28 01:06:36 mrg Exp $");
  11 #endif /* LIBC_SCCS and not lint */
  12
  13 #include "namespace.h"
  14
  15 #include <sys/types.h>
  16 #include <ieeefp.h>
  17
  18 #ifdef __weak_alias
  19 __weak_alias(fpsetround,_fpsetround)
  20 #endif
  21
  22 fp_rnd
  23 fpsetround(fp_rnd rnd_dir)
  24 {
  25         fp_rnd old;
  26         fp_rnd new;
  27 #ifdef SOFTFLOATSPARC64_FOR_GCC
  28         extern fp_rnd _softfloat_float_rounding_mode;
  29 #endif
  30
  31         __asm("st %%fsr,%0" : "=m" (*&old));
  32
  33 #ifdef SOFTFLOATSPARC64_FOR_GCC
  34         _softfloat_float_rounding_mode = rnd_dir;
  35 #endif
  36
  37         new = old;
  38         new &= ~(0x03 << 30);
  39         new |= ((rnd_dir & 0x03) << 30);
  40
  41         __asm("ld %0,%%fsr" : : "m" (*&new));
  42
  43         return ((uint32_t)old >> 30) & 0x03;
  44 }