libgcc/config/mips/crtfastmath.c

   1 /* Copyright (C) 2010-2015 Free Software Foundation, Inc.
   2
   3    This file is part of GCC.
   4
   5    GCC is free software; you can redistribute it and/or modify it
   6    under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3, or (at your option)
   8    any later version.
   9
  10    GCC is distributed in the hope that it will be useful, but WITHOUT
  11    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  13    License for more details.
  14
  15    Under Section 7 of GPL version 3, you are granted additional
  16    permissions described in the GCC Runtime Library Exception, version
  17    3.1, as published by the Free Software Foundation.
  18
  19    You should have received a copy of the GNU General Public License
  20    and a copy of the GCC Runtime Library Exception along with this
  21    program; see the files COPYING3 and COPYING.RUNTIME respectively.
  22    If not, see <http://www.gnu.org/licenses/>.  */
  23
  24 #ifdef __mips_hard_float
  25
  26 /* Flush denormalized numbers to zero.  */
  27 #define _FPU_FLUSH_TZ   0x1000000
  28
  29 /* Rounding control.  */
  30 #define _FPU_RC_NEAREST 0x0     /* RECOMMENDED */
  31 #define _FPU_RC_ZERO    0x1
  32 #define _FPU_RC_UP      0x2
  33 #define _FPU_RC_DOWN    0x3
  34
  35 /* Enable interrupts for IEEE exceptions.  */
  36 #define _FPU_IEEE     0x00000F80
  37
  38 /* Macros for accessing the hardware control word.  */
  39 #define _FPU_GETCW(cw) __asm__ ("cfc1 %0,$31" : "=r" (cw))
  40 #define _FPU_SETCW(cw) __asm__ ("ctc1 %0,$31" : : "r" (cw))
  41
  42 static void __attribute__((constructor,nomips16))
  43 set_fast_math (void)
  44 {
  45   unsigned int fcr;
  46
  47   /* Flush to zero, round to nearest, IEEE exceptions disabled.  */
  48   fcr = _FPU_FLUSH_TZ | _FPU_RC_NEAREST;
  49
  50   _FPU_SETCW(fcr);
  51 }
  52
  53 #endif /* __mips_hard_float */