sysdeps/am33/fpu/fpu_control.h

   1 /* FPU control word bits.  AM33/2.0 version.
   2    Copyright (C) 1996, 1997, 1998, 1999, 2000, 2004
   3    Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5    Contributed by Alexandre Oliva <aoliva@redhat.com>
   6    based on the corresponding file in the mips port.
   7
   8    The GNU C Library is free software; you can redistribute it and/or
   9    modify it under the terms of the GNU Lesser General Public
  10    License as published by the Free Software Foundation; either
  11    version 2.1 of the License, or (at your option) any later version.
  12
  13    The GNU C Library is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16    Lesser General Public License for more details.
  17
  18    You should have received a copy of the GNU Lesser General Public
  19    License along with the GNU C Library.  If not, see
  20    <http://www.gnu.org/licenses/>.  */
  21
  22 #ifndef _FPU_CONTROL_H
  23 #define _FPU_CONTROL_H
  24
  25 /* AM33/2.0 FPU floating point control register bits.
  26  *
  27  * 31-22  -> reserved
  28  * 21-18  -> floating-point condition codes (L, G, E, U)
  29  * 17-16  -> rounding modes (00 is to-nearest; other values are reserved
  30  * 15     -> reserved (read as 0, write with 0)
  31  * 14-10  -> Exception Cause (inValid, divZero, Overflow, Underflow, Inexact)
  32  *  9- 5  -> Exception Enable
  33  *  4- 0  -> Exception Flag, cleared when exception cause is set
  34  */
  35
  36 #include <features.h>
  37 #include <fenv.h>
  38
  39 /* masking of interrupts */
  40 #define _FPU_MASK_V     0x0200  /* Invalid operation */
  41 #define _FPU_MASK_Z     0x0100  /* Division by zero  */
  42 #define _FPU_MASK_O     0x0080  /* Overflow          */
  43 #define _FPU_MASK_U     0x0040  /* Underflow         */
  44 #define _FPU_MASK_I     0x0020  /* Inexact operation */
  45
  46 /* rounding control */
  47 #define _FPU_RC_NEAREST 0x0     /* Only available mode */
  48
  49 #define _FPU_RESERVED 0xffc08000  /* Reserved bits in fpcr */
  50
  51
  52 /* The fdlibm code requires strict IEEE double precision arithmetic,
  53    and no interrupts for exceptions, rounding to nearest.  */
  54
  55 #define _FPU_DEFAULT  0x0000001f
  56
  57 /* IEEE:  same as above, but exceptions */
  58 #define _FPU_IEEE     0x000003ff
  59
  60 /* Type of the control word.  */
  61 typedef unsigned int fpu_control_t;
  62
  63 /* Macros for accessing the hardware control word.  _FPU_SETCW is
  64    defined such that it won't modify the EF bits, that are cleared
  65    when assigned bits that are set.  Use SETFCW to get them actually
  66    reset.  */
  67 #define _FPU_SETFCW(cw) __asm__ ("fmov %0,fpcr" : : "ri" (cw))
  68 #define _FPU_SETCW(cw) _FPU_SETFCW((cw) & ~FE_ALL_EXCEPT)
  69 #define _FPU_GETCW(cw) __asm__ ("fmov fpcr,%0" : "=r" (cw))
  70
  71 /* Default control word set at startup.  */
  72 extern fpu_control_t __fpu_control;
  73
  74 #endif  /* fpu_control.h */