mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-15 09:30:06 +00:00
119 lines
3.6 KiB
C
119 lines
3.6 KiB
C
/* 68k FPU control word definitions.
|
|
Copyright (C) 1996-2020 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library. If not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#ifndef _FPU_CONTROL_H
|
|
#define _FPU_CONTROL_H
|
|
|
|
/*
|
|
* Motorola floating point control register bits.
|
|
*
|
|
* 31-16 -> reserved (read as 0, ignored on write)
|
|
* 15 -> enable trap for BSUN exception
|
|
* 14 -> enable trap for SNAN exception
|
|
* 13 -> enable trap for OPERR exception
|
|
* 12 -> enable trap for OVFL exception
|
|
* 11 -> enable trap for UNFL exception
|
|
* 10 -> enable trap for DZ exception
|
|
* 9 -> enable trap for INEX2 exception (INEX on Coldfire)
|
|
* 8 -> enable trap for INEX1 exception (IDE on Coldfire)
|
|
* 7-6 -> Precision Control (only bit 6 is used on Coldfire)
|
|
* 5-4 -> Rounding Control
|
|
* 3-0 -> zero (read as 0, write as 0)
|
|
*
|
|
*
|
|
* Precision Control:
|
|
* 00 - round to extended precision
|
|
* 01 - round to single precision
|
|
* 10 - round to double precision
|
|
* 11 - undefined
|
|
*
|
|
* Rounding Control:
|
|
* 00 - rounding to nearest (RN)
|
|
* 01 - rounding toward zero (RZ)
|
|
* 10 - rounding (down)toward minus infinity (RM)
|
|
* 11 - rounding (up) toward plus infinity (RP)
|
|
*
|
|
* The hardware default is 0x0000. I choose 0x5400.
|
|
*/
|
|
|
|
#include <features.h>
|
|
|
|
#if defined (__mcoldfire__) && !defined (__mcffpu__)
|
|
|
|
# define _FPU_RESERVED 0xffffffff
|
|
# define _FPU_DEFAULT 0x00000000
|
|
# define _FPU_GETCW(cw) ((cw) = 0)
|
|
# define _FPU_SETCW(cw) ((void) (cw))
|
|
|
|
#else
|
|
|
|
/* masking of interrupts */
|
|
# define _FPU_MASK_BSUN 0x8000
|
|
# define _FPU_MASK_SNAN 0x4000
|
|
# define _FPU_MASK_OPERR 0x2000
|
|
# define _FPU_MASK_OVFL 0x1000
|
|
# define _FPU_MASK_UNFL 0x0800
|
|
# define _FPU_MASK_DZ 0x0400
|
|
# define _FPU_MASK_INEX1 0x0200
|
|
# define _FPU_MASK_INEX2 0x0100
|
|
|
|
/* precision control */
|
|
# ifdef __mcoldfire__
|
|
# define _FPU_DOUBLE 0x00
|
|
# else
|
|
# define _FPU_EXTENDED 0x00 /* RECOMMENDED */
|
|
# define _FPU_DOUBLE 0x80
|
|
# endif
|
|
# define _FPU_SINGLE 0x40 /* DO NOT USE */
|
|
|
|
/* rounding control */
|
|
# define _FPU_RC_NEAREST 0x00 /* RECOMMENDED */
|
|
# define _FPU_RC_ZERO 0x10
|
|
# define _FPU_RC_DOWN 0x20
|
|
# define _FPU_RC_UP 0x30
|
|
|
|
# ifdef __mcoldfire__
|
|
# define _FPU_RESERVED 0xFFFF800F
|
|
# else
|
|
# define _FPU_RESERVED 0xFFFF000F /* Reserved bits in fpucr */
|
|
# endif
|
|
|
|
|
|
/* Now two recommended fpucr */
|
|
|
|
/* The fdlibm code requires no interrupts for exceptions. Don't
|
|
change the rounding mode, it would break long double I/O! */
|
|
# define _FPU_DEFAULT 0x00000000
|
|
|
|
/* IEEE: same as above, but exceptions. We must make it non-zero so
|
|
that __setfpucw works. This bit will be ignored. */
|
|
# define _FPU_IEEE 0x00000001
|
|
|
|
/* Macros for accessing the hardware control word. */
|
|
# define _FPU_GETCW(cw) __asm__ ("fmove%.l %!, %0" : "=dm" (cw))
|
|
# define _FPU_SETCW(cw) __asm__ volatile ("fmove%.l %0, %!" : : "dm" (cw))
|
|
#endif
|
|
|
|
/* Type of the control word. */
|
|
typedef unsigned int fpu_control_t __attribute__ ((__mode__ (__SI__)));
|
|
|
|
/* Default control word set at startup. */
|
|
extern fpu_control_t __fpu_control;
|
|
|
|
#endif /* _M68K_FPU_CONTROL_H */
|