glibc/ports/sysdeps/am33/fpu/fpu_control.h

75 lines
2.7 KiB
C

/* FPU control word bits. AM33/2.0 version.
Copyright (C) 1996, 1997, 1998, 1999, 2000, 2004
Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Alexandre Oliva <aoliva@redhat.com>
based on the corresponding file in the mips port.
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
<http://www.gnu.org/licenses/>. */
#ifndef _FPU_CONTROL_H
#define _FPU_CONTROL_H
/* AM33/2.0 FPU floating point control register bits.
*
* 31-22 -> reserved
* 21-18 -> floating-point condition codes (L, G, E, U)
* 17-16 -> rounding modes (00 is to-nearest; other values are reserved
* 15 -> reserved (read as 0, write with 0)
* 14-10 -> Exception Cause (inValid, divZero, Overflow, Underflow, Inexact)
* 9- 5 -> Exception Enable
* 4- 0 -> Exception Flag, cleared when exception cause is set
*/
#include <features.h>
#include <fenv.h>
/* masking of interrupts */
#define _FPU_MASK_V 0x0200 /* Invalid operation */
#define _FPU_MASK_Z 0x0100 /* Division by zero */
#define _FPU_MASK_O 0x0080 /* Overflow */
#define _FPU_MASK_U 0x0040 /* Underflow */
#define _FPU_MASK_I 0x0020 /* Inexact operation */
/* rounding control */
#define _FPU_RC_NEAREST 0x0 /* Only available mode */
#define _FPU_RESERVED 0xffc08000 /* Reserved bits in fpcr */
/* The fdlibm code requires strict IEEE double precision arithmetic,
and no interrupts for exceptions, rounding to nearest. */
#define _FPU_DEFAULT 0x0000001f
/* IEEE: same as above, but exceptions */
#define _FPU_IEEE 0x000003ff
/* Type of the control word. */
typedef unsigned int fpu_control_t;
/* Macros for accessing the hardware control word. _FPU_SETCW is
defined such that it won't modify the EF bits, that are cleared
when assigned bits that are set. Use SETFCW to get them actually
reset. */
#define _FPU_SETFCW(cw) __asm__ ("fmov %0,fpcr" : : "ri" (cw))
#define _FPU_SETCW(cw) _FPU_SETFCW((cw) & ~FE_ALL_EXCEPT)
#define _FPU_GETCW(cw) __asm__ ("fmov fpcr,%0" : "=r" (cw))
/* Default control word set at startup. */
extern fpu_control_t __fpu_control;
#endif /* fpu_control.h */