/* @(#)s_ceil.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. | |
* ==================================================== | |
*/ | |
#include <LibConfig.h> | |
#include <sys/EfiCdefs.h> | |
#if defined(LIBM_SCCS) && !defined(lint) | |
__RCSID("$NetBSD: s_ceil.c,v 1.11 2002/05/26 22:01:54 wiz Exp $"); | |
#endif | |
/* | |
* ceil(x) | |
* Return x rounded toward -inf to integral value | |
* Method: | |
* Bit twiddling. | |
* Exception: | |
* Inexact flag raised if x not equal to ceil(x). | |
*/ | |
#include "math.h" | |
#include "math_private.h" | |
static const double huge = 1.0e300; | |
double | |
ceil(double x) | |
{ | |
int32_t i0,i1,j0; | |
u_int32_t i,j; | |
EXTRACT_WORDS(i0,i1,x); | |
j0 = ((i0>>20)&0x7ff)-0x3ff; | |
if(j0<20) { | |
if(j0<0) { /* raise inexact if x != 0 */ | |
if(huge+x>0.0) {/* return 0*sign(x) if |x|<1 */ | |
if(i0<0) {i0=0x80000000;i1=0;} | |
else if((i0|i1)!=0) { i0=0x3ff00000;i1=0;} | |
} | |
} else { | |
i = (0x000fffff)>>j0; | |
if(((i0&i)|i1)==0) return x; /* x is integral */ | |
if(huge+x>0.0) { /* raise inexact flag */ | |
if(i0>0) i0 += (0x00100000)>>j0; | |
i0 &= (~i); i1=0; | |
} | |
} | |
} else if (j0>51) { | |
if(j0==0x400) return x+x; /* inf or NaN */ | |
else return x; /* x is integral */ | |
} else { | |
i = ((u_int32_t)(0xffffffff))>>(j0-20); | |
if((i1&i)==0) return x; /* x is integral */ | |
if(huge+x>0.0) { /* raise inexact flag */ | |
if(i0>0) { | |
if(j0==20) i0+=1; | |
else { | |
j = i1 + (1<<(52-j0)); | |
if((int32_t)j<i1) i0+=1; /* got a carry */ | |
i1 = j; | |
} | |
} | |
i1 &= (~i); | |
} | |
} | |
INSERT_WORDS(x,i0,i1); | |
return x; | |
} |