lib/i386/math/fesetround.c

   1 #include <errno.h>
   2 #include <fenv.h>
   3
   4 #include "fpu_cw.h"
   5
   6 int fesetround(int round)
   7 {
   8         u16_t cw;
   9
  10         /* read and update FPUCW */
  11         cw = fpu_cw_get() & ~FPUCW_ROUNDING_CONTROL;
  12         switch (round)
  13         {
  14                 case FE_TONEAREST: cw |= FPUCW_ROUNDING_CONTROL_NEAREST; break;
  15                 case FE_DOWNWARD: cw |= FPUCW_ROUNDING_CONTROL_DOWN; break;
  16                 case FE_UPWARD: cw |= FPUCW_ROUNDING_CONTROL_UP; break;
  17                 case FE_TOWARDZERO: cw |= FPUCW_ROUNDING_CONTROL_TRUNC; break;
  18
  19                 default:
  20                         errno = EINVAL;
  21                         return -1;
  22         }
  23
  24         /* set FPUCW to the updated value */
  25         fpu_cw_set(cw);
  26         return 0;
  27 }