ports/sysdeps/am33/fpu/fpu_control.h

   1 /* FPU control word bits.  AM33/2.0 version.
   2    Copyright (C) 1996-2014 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Alexandre Oliva <aoliva@redhat.com>
   5    based on the corresponding file in the mips port.
   6
   7    The GNU C Library is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Lesser General Public
   9    License as published by the Free Software Foundation; either
  10    version 2.1 of the License, or (at your option) any later version.
  11
  12    The GNU C Library is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    Lesser General Public License for more details.
  16
  17    You should have received a copy of the GNU Lesser General Public
  18    License along with the GNU C Library.  If not, see
  19    <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef _FPU_CONTROL_H
  22 #define _FPU_CONTROL_H
  23
  24 /* AM33/2.0 FPU floating point control register bits.
  25  *
  26  * 31-22  -> reserved
  27  * 21-18  -> floating-point condition codes (L, G, E, U)
  28  * 17-16  -> rounding modes (00 is to-nearest; other values are reserved
  29  * 15     -> reserved (read as 0, write with 0)
  30  * 14-10  -> Exception Cause (inValid, divZero, Overflow, Underflow, Inexact)
  31  *  9- 5  -> Exception Enable
  32  *  4- 0  -> Exception Flag, cleared when exception cause is set
  33  */
  34
  35 #include <features.h>
  36 #include <fenv.h>
  37
  38 /* masking of interrupts */
  39 #define _FPU_MASK_V     0x0200  /* Invalid operation */
  40 #define _FPU_MASK_Z     0x0100  /* Division by zero  */
  41 #define _FPU_MASK_O     0x0080  /* Overflow          */
  42 #define _FPU_MASK_U     0x0040  /* Underflow         */
  43 #define _FPU_MASK_I     0x0020  /* Inexact operation */
  44
  45 /* rounding control */
  46 #define _FPU_RC_NEAREST 0x0     /* Only available mode */
  47
  48 #define _FPU_RESERVED 0xffc08000  /* Reserved bits in fpcr */
  49
  50
  51 /* The fdlibm code requires strict IEEE double precision arithmetic,
  52    and no interrupts for exceptions, rounding to nearest.  */
  53
  54 #define _FPU_DEFAULT  0x0000001f
  55
  56 /* IEEE:  same as above, but exceptions */
  57 #define _FPU_IEEE     0x000003ff
  58
  59 /* Type of the control word.  */
  60 typedef unsigned int fpu_control_t;
  61
  62 /* Macros for accessing the hardware control word.  _FPU_SETCW is
  63    defined such that it won't modify the EF bits, that are cleared
  64    when assigned bits that are set.  Use SETFCW to get them actually
  65    reset.  */
  66 #define _FPU_SETFCW(cw) __asm__ ("fmov %0,fpcr" : : "ri" (cw))
  67 #define _FPU_SETCW(cw) _FPU_SETFCW((cw) & ~FE_ALL_EXCEPT)
  68 #define _FPU_GETCW(cw) __asm__ ("fmov fpcr,%0" : "=r" (cw))
  69
  70 /* Default control word set at startup.  */
  71 extern fpu_control_t __fpu_control;
  72
  73 #endif  /* fpu_control.h */