diff options
Diffstat (limited to 'REORG.TODO/sysdeps/ieee754/dbl-64/s_nearbyint.c')
| -rw-r--r-- | REORG.TODO/sysdeps/ieee754/dbl-64/s_nearbyint.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/ieee754/dbl-64/s_nearbyint.c b/REORG.TODO/sysdeps/ieee754/dbl-64/s_nearbyint.c new file mode 100644 index 0000000000..dec0c5d6ee --- /dev/null +++ b/REORG.TODO/sysdeps/ieee754/dbl-64/s_nearbyint.c @@ -0,0 +1,78 @@ +/* Adapted for use as nearbyint by Ulrich Drepper <drepper@cygnus.com>. */ +/* + * ==================================================== + * 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. + * ==================================================== + */ + +#if defined(LIBM_SCCS) && !defined(lint) +static char rcsid[] = "$NetBSD: s_rint.c,v 1.8 1995/05/10 20:48:04 jtc Exp $"; +#endif + +/* + * rint(x) + * Return x rounded to integral value according to the prevailing + * rounding mode. + * Method: + * Using floating addition. + * Exception: + * Inexact flag raised if x not equal to rint(x). + */ + +#include <fenv.h> +#include <math.h> +#include <math_private.h> + +static const double + TWO52[2] = { + 4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */ + -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */ +}; + +double +__nearbyint (double x) +{ + fenv_t env; + int32_t i0, j0, sx; + double w, t; + GET_HIGH_WORD (i0, x); + sx = (i0 >> 31) & 1; + j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; + if (j0 < 52) + { + if (j0 < 0) + { + libc_feholdexcept (&env); + w = TWO52[sx] + x; + t = w - TWO52[sx]; + math_force_eval (t); + libc_fesetenv (&env); + GET_HIGH_WORD (i0, t); + SET_HIGH_WORD (t, (i0 & 0x7fffffff) | (sx << 31)); + return t; + } + } + else + { + if (j0 == 0x400) + return x + x; /* inf or NaN */ + else + return x; /* x is integral */ + } + libc_feholdexcept (&env); + w = TWO52[sx] + x; + t = w - TWO52[sx]; + math_force_eval (t); + libc_fesetenv (&env); + return t; +} +weak_alias (__nearbyint, nearbyint) +#ifdef NO_LONG_DOUBLE +strong_alias (__nearbyint, __nearbyintl) +weak_alias (__nearbyint, nearbyintl) +#endif |