libm/metag/fesetenv.c

   1 /* Install given floating-point environment.
   2    Copyright (C) 2013 Imagination Technologies Ltd.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If
  17    not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include <fenv.h>
  20 #include <assert.h>
  21
  22 #include "internal.h"
  23
  24 libm_hidden_proto(fesetenv)
  25
  26 int
  27 fesetenv (const fenv_t *envp)
  28 {
  29   unsigned int exc;
  30   unsigned int txmode;
  31
  32   __asm__ ("MOV %0,TXMODE" : "=r" (txmode));
  33
  34   /* Clear rounding mode bits (round to nearest).  */
  35   txmode &= ~(0x3 << 16);
  36
  37   if (envp == FE_DFL_ENV)
  38     {
  39       exc = 0;
  40     }
  41   else if (envp == FE_NOMASK_ENV)
  42     {
  43       exc = 0x1f;
  44     }
  45   else
  46     {
  47       exc = envp->txdefr & (FE_ALL_EXCEPT | (FE_ALL_EXCEPT << 16));
  48       /* Write rounding mode and guard bit.  */
  49       txmode |= (0x1 << 18 ) | (envp->txmode & (0x3 << 16));
  50     }
  51
  52   __asm__ ("MOV TXMODE,%0" : : "r" (txmode));
  53
  54   metag_set_fpu_flags(exc);
  55
  56   /* Success.  */
  57   return 0;
  58 }
  59 libm_hidden_def(fesetenv)