113 lines
2.7 KiB
C
113 lines
2.7 KiB
C
|
/*
|
||
|
|
* ====================================================
|
||
|
|
* 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_ceil.c 5.1 93/09/24
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <sys/cdefs.h>
|
||
|
|
__RCSID("$NetBSD: s_ceill.c,v 1.1 2013/11/11 23:57:34 joerg Exp $");
|
||
|
|
#if 0
|
||
|
|
__FBSDID("$FreeBSD: head/lib/msun/src/s_ceill.c 176280 2008-02-14 15:10:34Z bde $");
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/*
|
||
|
|
* ceill(x)
|
||
|
|
* Return x rounded toward -inf to integral value
|
||
|
|
* Method:
|
||
|
|
* Bit twiddling.
|
||
|
|
* Exception:
|
||
|
|
* Inexact flag raised if x not equal to ceill(x).
|
||
|
|
*/
|
||
|
|
#include "namespace.h"
|
||
|
|
|
||
|
|
#include <float.h>
|
||
|
|
#include <math.h>
|
||
|
|
#include <stdint.h>
|
||
|
|
#include <machine/ieee.h>
|
||
|
|
|
||
|
|
#ifdef __HAVE_LONG_DOUBLE
|
||
|
|
|
||
|
|
#ifdef __weak_alias
|
||
|
|
__weak_alias(ceill, _ceill)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifdef LDBL_IMPLICIT_NBIT
|
||
|
|
#define MANH_SIZE (EXT_FRACHBITS + 1)
|
||
|
|
#define INC_MANH(ux, c) do { \
|
||
|
|
uint64_t oi = ux.extu_frach; \
|
||
|
|
ux.extu_frach += (c); \
|
||
|
|
if (ux.extu_frach < oi) \
|
||
|
|
ux.extu_exp++; \
|
||
|
|
} while (0)
|
||
|
|
#else
|
||
|
|
#define MANH_SIZE EXT_FRACHBITS
|
||
|
|
#define INC_MANH(ux, c) do { \
|
||
|
|
uint64_t oi = ux.extu_frach; \
|
||
|
|
ux.extu_frach += (c); \
|
||
|
|
if (ux.extu_frach < oi) { \
|
||
|
|
ux.extu_exp++; \
|
||
|
|
ux.extu_frach |= 1llu << (EXT_FRACHBITS - 1); \
|
||
|
|
} \
|
||
|
|
} while (0)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
static const long double huge = 1.0e300;
|
||
|
|
|
||
|
|
long double
|
||
|
|
ceill(long double x)
|
||
|
|
{
|
||
|
|
union ieee_ext_u ux = { .extu_ld = x, };
|
||
|
|
int e = ux.extu_exp - LDBL_MAX_EXP + 1;
|
||
|
|
|
||
|
|
if (e < MANH_SIZE - 1) {
|
||
|
|
if (e < 0) { /* raise inexact if x != 0 */
|
||
|
|
if (huge + x > 0.0)
|
||
|
|
if (ux.extu_exp > 0 ||
|
||
|
|
(ux.extu_frach | ux.extu_fracl) != 0)
|
||
|
|
ux.extu_ld = ux.extu_sign ? -0.0 : 1.0;
|
||
|
|
} else {
|
||
|
|
uint64_t m = ((1llu << MANH_SIZE) - 1) >> (e + 1);
|
||
|
|
if (((ux.extu_frach & m) | ux.extu_fracl) == 0)
|
||
|
|
return (x); /* x is integral */
|
||
|
|
if (!ux.extu_sign) {
|
||
|
|
#ifdef LDBL_IMPLICIT_NBIT
|
||
|
|
if (e == 0)
|
||
|
|
ux.extu_exp++;
|
||
|
|
else
|
||
|
|
#endif
|
||
|
|
INC_MANH(ux, 1llu << (MANH_SIZE - e - 1));
|
||
|
|
}
|
||
|
|
if (huge + x > 0.0) { /* raise inexact flag */
|
||
|
|
ux.extu_frach &= ~m;
|
||
|
|
ux.extu_fracl = 0;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
} else if (e < LDBL_MANT_DIG - 1) {
|
||
|
|
uint64_t m = (uint64_t)-1 >> (64 - LDBL_MANT_DIG + e + 1);
|
||
|
|
if ((ux.extu_fracl & m) == 0)
|
||
|
|
return (x); /* x is integral */
|
||
|
|
if (!ux.extu_sign) {
|
||
|
|
if (e == MANH_SIZE - 1)
|
||
|
|
INC_MANH(ux, 1);
|
||
|
|
else {
|
||
|
|
uint64_t o = ux.extu_fracl;
|
||
|
|
ux.extu_fracl += 1llu << (LDBL_MANT_DIG - e - 1);
|
||
|
|
if (ux.extu_fracl < o) /* got a carry */
|
||
|
|
INC_MANH(ux, 1);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if (huge + x > 0.0) /* raise inexact flag */
|
||
|
|
ux.extu_fracl &= ~m;
|
||
|
|
}
|
||
|
|
return (ux.extu_ld);
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif /* __HAVE_LONG_DOUBLE */
|