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Diffstat (limited to 'sysdeps/x86_64/fpu_control.h')
| -rw-r--r-- | sysdeps/x86_64/fpu_control.h | 109 |
1 files changed, 0 insertions, 109 deletions
diff --git a/sysdeps/x86_64/fpu_control.h b/sysdeps/x86_64/fpu_control.h deleted file mode 100644 index 605302c09b..0000000000 --- a/sysdeps/x86_64/fpu_control.h +++ /dev/null @@ -1,109 +0,0 @@ -/* FPU control word bits. x86 version. - Copyright (C) 1993-2012 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, see - <http://www.gnu.org/licenses/>. */ - -#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. "*&" is used to - work around a bug in older versions of GCC. __volatile__ is used - to support combination of writing the control register and reading - it back. Without __volatile__, the old value may be used for reading - back under compiler optimization. - - Note that the use of these macros is not sufficient anymore with - recent hardware nor on x86-64. Some floating point operations are - executed in the SSE/SSE2 engines which have their own control and - status register. */ -#define _FPU_GETCW(cw) __asm__ __volatile__ ("fnstcw %0" : "=m" (*&cw)) -#define _FPU_SETCW(cw) __asm__ __volatile__ ("fldcw %0" : : "m" (*&cw)) - -/* Default control word set at startup. */ -extern fpu_control_t __fpu_control; - -#endif /* fpu_control.h */ |