diff options
Diffstat (limited to 'lib/msun/src')
| -rw-r--r-- | lib/msun/src/math.h | 2 | ||||
| -rw-r--r-- | lib/msun/src/s_truncl.c | 62 |
2 files changed, 63 insertions, 1 deletions
diff --git a/lib/msun/src/math.h b/lib/msun/src/math.h index 5ac6e56..ba918a3 100644 --- a/lib/msun/src/math.h +++ b/lib/msun/src/math.h @@ -464,8 +464,8 @@ long double sqrtl(long double); long double tanhl(long double); long double tanl(long double); long double tgammal(long double); -long double truncl(long double); #endif +long double truncl(long double); #endif /* __ISO_C_VISIBLE >= 1999 */ __END_DECLS diff --git a/lib/msun/src/s_truncl.c b/lib/msun/src/s_truncl.c new file mode 100644 index 0000000..d535e9c --- /dev/null +++ b/lib/msun/src/s_truncl.c @@ -0,0 +1,62 @@ +/* + * ==================================================== + * 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. + * ==================================================== + * + * From: @(#)s_floor.c 5.1 93/09/24 + */ + +#ifndef lint +static char rcsid[] = "$FreeBSD$"; +#endif + +/* + * truncl(x) + * Return x rounded toward 0 to integral value + * Method: + * Bit twiddling. + * Exception: + * Inexact flag raised if x not equal to truncl(x). + */ + +#include <float.h> +#include <math.h> +#include <stdint.h> + +#include "fpmath.h" + +#ifdef LDBL_IMPLICIT_NBIT +#define MANH_SIZE (LDBL_MANH_SIZE + 1) +#else +#define MANH_SIZE LDBL_MANH_SIZE +#endif + +long double +truncl(long double x) +{ + union IEEEl2bits u = { .e = x }; + int e = u.bits.exp - LDBL_MAX_EXP + 1; + + if (e < MANH_SIZE - 1) { + if (e < 0) { /* raise inexact if x != 0 */ + u.e = 0.0; + } else { + uint64_t m = ((1llu << MANH_SIZE) - 1) >> (e + 1); + if (((u.bits.manh & m) | u.bits.manl) == 0) + return (x); /* x is integral */ + u.bits.manh &= ~m; + u.bits.manl = 0; + } + } else if (e < LDBL_MANT_DIG - 1) { + uint64_t m = (uint64_t)-1 >> (64 - LDBL_MANT_DIG + e + 1); + if ((u.bits.manl & m) == 0) + return (x); /* x is integral */ + u.bits.manl &= ~m; + } + return (u.e); +} |
