/* FPU control word bits.  x86-64 version.   Copyright (C) 1993,1995,1996,1997,1998,2000,2001,2002 Free Software Foundation, Inc.   This file is part of the GNU C Library.   Contributed by Olaf Flebbe.   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, write to the Free   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA   02111-1307 USA.  */#ifndef _FPU_CONTROL_H#define _FPU_CONTROL_H	1/* Note that this file sets on x86-64 only the x87 FPU, it does not   touch the SSE unit.  *//* Here is the dirty part. Set up your 387 through the control word * (cw) register. * *     15-13    12  11-10  9-8     7-6     5    4    3    2    1    0 * | reserved | IC | RC  | PC | reserved | PM | UM | OM | ZM | DM | IM * * IM: Invalid operation mask * DM: Denormalized operand mask * ZM: Zero-divide mask * OM: Overflow mask * UM: Underflow mask * PM: Precision (inexact result) mask * * Mask bit is 1 means no interrupt. * * PC: Precision control * 11 - round to extended precision * 10 - round to double precision * 00 - round to single precision * * RC: Rounding control * 00 - rounding to nearest * 01 - rounding down (toward - infinity) * 10 - rounding up (toward + infinity) * 11 - rounding toward zero * * IC: Infinity control * That is for 8087 and 80287 only. * * The hardware default is 0x037f which we use. */#include <features.h>/* masking of interrupts */#define _FPU_MASK_IM  0x01#define _FPU_MASK_DM  0x02#define _FPU_MASK_ZM  0x04#define _FPU_MASK_OM  0x08#define _FPU_MASK_UM  0x10#define _FPU_MASK_PM  0x20/* precision control */#define _FPU_EXTENDED 0x300	/* libm requires double extended precision.  */#define _FPU_DOUBLE   0x200#define _FPU_SINGLE   0x0/* rounding control */#define _FPU_RC_NEAREST 0x0    /* RECOMMENDED */#define _FPU_RC_DOWN    0x400#define _FPU_RC_UP      0x800#define _FPU_RC_ZERO    0xC00#define _FPU_RESERVED 0xF0C0  /* Reserved bits in cw *//* The fdlibm code requires strict IEEE double precision arithmetic,   and no interrupts for exceptions, rounding to nearest.  */#define _FPU_DEFAULT  0x037f/* IEEE:  same as above.  */#define _FPU_IEEE     0x037f/* Type of the control word.  */typedef unsigned int fpu_control_t __attribute__ ((__mode__ (__HI__)));/* Macros for accessing the hardware control word.  */#define _FPU_GETCW(cw) __asm__ ("fnstcw %0" : "=m" (*&cw))#define _FPU_SETCW(cw) __asm__ ("fldcw %0" : : "m" (*&cw))/* Default control word set at startup.  */extern fpu_control_t __fpu_control;#endif	/* fpu_control.h */