glibc/sysdeps/unix/sysv/linux/i386/fpu_control.h
Roland McGrath 1177c8babf Tue Mar 12 04:42:01 1996 Roland McGrath <roland@charlie-brown.gnu.ai.mit.edu>
* sysdeps/sparc/jmp_buf.h: Rewritten; use array of ints, not struct.
	* sysdeps/sparc/setjmp.S: Rewritten; store %fp value as well.
	* sysdeps/sparc/__longjmp.S: Rewritten; unwind frames one by one with
	`restore' until the target frame is hit.

Sun Mar 10 20:29:40 1996  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* sysdeps/unix/sysv/linux/sigsuspend.c: New file.
	* sysdeps/unix/sysv/linux/syscalls.list: Remove sigsuspend, add
	s_sigsuspend.

Thu Mar  7 21:30:58 1996  Andreas Schwab  <schwab@issan.informatik.uni-dortmund.de>

	* Makerules (+make-deps, sed-remove-objpfx): Quote periods on the
	left side of sed substitutions.

Sun Mar 10 16:58:10 1996  Ulrich Drepper  <drepper@gnu.ai.mit.edu>

	* stdio-common/printf_fp.c (hack_digit): __mpn_normal_size
	is not available anymore.  Do it ourselves.

	* sysdeps/unix/sysv/linux/i386/fpu_control.h (_FPU_SETCW):
	Correct GCC `asm' syntax.

	* stdio-common/Makefile (tests): Add tst-ungetc.
	* stdio-common/tst-ungetc.c: New test from drepper.
	* stdio-common/tstscanf.c (main): New %[ test case from drepper.

	* sysdeps/libm-ieee754/s_scalbn.c (scalbn): Rename to __scalbn;
	somehow this was missed, though the weak alias is already there.
1996-03-12 09:50:46 +00:00

105 lines
3.1 KiB
C

/* Copyright (C) 1993, 1995, 1996 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. 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
/* Here is the dirty part. Settup 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. I choose 0x1372.
*/
#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
#define _FPU_DOUBLE 0x200 /* fdlibm requires double precision */
#define _FPU_SINGLE 0x0 /* DO NOT USE */
/* 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 0x127f
/* IEEE: same as above, but exceptions */
#define _FPU_IEEE 0x127f
/* 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;
__BEGIN_DECLS
/* Called at startup. It can be used to manipulate fpu control register. */
extern void __setfpucw __P ((fpu_control_t));
__END_DECLS
#endif /* fpu_control.h */