glibc/sysdeps/ieee754/dbl-64/s_isnan.c
Adhemerval Zanella 197dbda1a1 math: Use wordsize-64 version for isnan
- math.h will use compiler builtin for gcc 4.4 when built without
    -fsignaling-nans and the builtin is expanded inline for all
    support architectures.  As an example, there is no intra isnan
    call on libm for the architecture I checked, x86, arm, aarch64,
    and powerpc.

  - The resulting binary difference on 32 bits architecture is minimum
    for the non hotspot symbol.

  - It helps wordsize-64 architectures that use ldbl-opt.

  - It add some code simplification with reduction of duplicated
    implementations.

Checked on powerpc-linux-gnu (built without --with-cpu, with
--with-cpu=power4 and with --with-cpu=power5+ and --disable-multi-arch),
powerpc64-linux-gnu (built without --with-cp and with --with-cpu=power5+
and --disable-multi-arch).

	* sysdeps/ieee754/dbl-64/wordsize-64/s_isnan.c: Move to ...
	* sysdeps/ieee754/dbl-64/s_isnan.c: ... here and format code.

Reviewed-by: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>
2019-06-12 14:32:18 -03:00

41 lines
1.0 KiB
C

/* @(#)s_isnan.c 5.1 93/09/24 */
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
/*
* isnan(x) returns 1 is x is nan, else 0;
* no branching!
*/
#include <math.h>
#include <math_private.h>
#include <ldbl-classify-compat.h>
#include <shlib-compat.h>
#include <stdint.h>
int
__isnan (double x)
{
int64_t hx;
EXTRACT_WORDS64 (hx, x);
hx &= UINT64_C (0x7fffffffffffffff);
hx = UINT64_C (0x7ff0000000000000) - hx;
return (int)(((uint64_t)hx)>>63);
}
hidden_def (__isnan)
weak_alias (__isnan, isnan)
#ifdef NO_LONG_DOUBLE
# if LDBL_CLASSIFY_COMPAT && SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23)
compat_symbol (libc, __isnan, __isnanl, GLIBC_2_0);
# endif
weak_alias (__isnan, isnanl)
#endif