mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-02 01:40:07 +00:00
41bdb6e20c
2001-07-06 Paul Eggert <eggert@twinsun.com> * manual/argp.texi: Remove ignored LGPL copyright notice; it's not appropriate for documentation anyway. * manual/libc-texinfo.sh: "Library General Public License" -> "Lesser General Public License". 2001-07-06 Andreas Jaeger <aj@suse.de> * All files under GPL/LGPL version 2: Place under LGPL version 2.1.
107 lines
4.3 KiB
C
107 lines
4.3 KiB
C
/* Internal libc stuff for floating point environment routines.
|
|
Copyright (C) 1997 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, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
#ifndef _FENV_LIBC_H
|
|
#define _FENV_LIBC_H 1
|
|
|
|
#include <fenv.h>
|
|
|
|
/* The sticky bits in the FPSCR indicating exceptions have occurred. */
|
|
#define FPSCR_STICKY_BITS ((FE_ALL_EXCEPT | FE_ALL_INVALID) & ~FE_INVALID)
|
|
|
|
/* Equivalent to fegetenv, but returns a fenv_t instead of taking a
|
|
pointer. */
|
|
#define fegetenv_register() \
|
|
({ fenv_t env; asm volatile ("mffs %0" : "=f" (env)); env; })
|
|
|
|
/* Equivalent to fesetenv, but takes a fenv_t instead of a pointer. */
|
|
#define fesetenv_register(env) \
|
|
({ double d = (env); asm volatile ("mtfsf 0xff,%0" : : "f" (d)); })
|
|
|
|
/* This very handy macro:
|
|
- Sets the rounding mode to 'round to nearest';
|
|
- Sets the processor into IEEE mode; and
|
|
- Prevents exceptions from being raised for inexact results.
|
|
These things happen to be exactly what you need for typical elementary
|
|
functions. */
|
|
#define relax_fenv_state() asm ("mtfsfi 7,0")
|
|
|
|
/* Set/clear a particular FPSCR bit (for instance,
|
|
reset_fpscr_bit(FPSCR_VE);
|
|
prevents INVALID exceptions from being raised). */
|
|
#define set_fpscr_bit(x) asm volatile ("mtfsb1 %0" : : "i"(x))
|
|
#define reset_fpscr_bit(x) asm volatile ("mtfsb0 %0" : : "i"(x))
|
|
|
|
typedef union
|
|
{
|
|
fenv_t fenv;
|
|
unsigned int l[2];
|
|
} fenv_union_t;
|
|
|
|
/* Definitions of all the FPSCR bit numbers */
|
|
enum {
|
|
FPSCR_FX = 0, /* exception summary */
|
|
FPSCR_FEX, /* enabled exception summary */
|
|
FPSCR_VX, /* invalid operation summary */
|
|
FPSCR_OX, /* overflow */
|
|
FPSCR_UX, /* underflow */
|
|
FPSCR_ZX, /* zero divide */
|
|
FPSCR_XX, /* inexact */
|
|
FPSCR_VXSNAN, /* invalid operation for SNaN */
|
|
FPSCR_VXISI, /* invalid operation for Inf-Inf */
|
|
FPSCR_VXIDI, /* invalid operation for Inf/Inf */
|
|
FPSCR_VXZDZ, /* invalid operation for 0/0 */
|
|
FPSCR_VXIMZ, /* invalid operation for Inf*0 */
|
|
FPSCR_VXVC, /* invalid operation for invalid compare */
|
|
FPSCR_FR, /* fraction rounded [fraction was incremented by round] */
|
|
FPSCR_FI, /* fraction inexact */
|
|
FPSCR_FPRF_C, /* result class descriptor */
|
|
FPSCR_FPRF_FL, /* result less than (usually, less than 0) */
|
|
FPSCR_FPRF_FG, /* result greater than */
|
|
FPSCR_FPRF_FE, /* result equal to */
|
|
FPSCR_FPRF_FU, /* result unordered */
|
|
FPSCR_20, /* reserved */
|
|
FPSCR_VXSOFT, /* invalid operation set by software */
|
|
FPSCR_VXSQRT, /* invalid operation for square root */
|
|
FPSCR_VXCVI, /* invalid operation for invalid integer convert */
|
|
FPSCR_VE, /* invalid operation exception enable */
|
|
FPSCR_OE, /* overflow exception enable */
|
|
FPSCR_UE, /* underflow exception enable */
|
|
FPSCR_ZE, /* zero divide exception enable */
|
|
FPSCR_XE, /* inexact exception enable */
|
|
FPSCR_NI /* non-IEEE mode (typically, no denormalised numbers) */
|
|
/* the remaining two least-significant bits keep the rounding mode */
|
|
};
|
|
|
|
/* This operation (i) sets the appropriate FPSCR bits for its
|
|
parameter, (ii) converts SNaN to the corresponding NaN, and (iii)
|
|
otherwise passes its parameter through unchanged (in particular, -0
|
|
and +0 stay as they were). The `obvious' way to do this is optimised
|
|
out by gcc. */
|
|
#define f_wash(x) \
|
|
({ double d; asm volatile ("fmul %0,%1,%2" \
|
|
: "=f"(d) \
|
|
: "f" (x), "f"((float)1.0)); d; })
|
|
#define f_washf(x) \
|
|
({ float f; asm volatile ("fmuls %0,%1,%2" \
|
|
: "=f"(f) \
|
|
: "f" (x), "f"((float)1.0)); f; })
|
|
|
|
#endif /* fenv_libc.h */
|