glibc/sysdeps/ieee754/ldbl-96/s_floorl.c
Ulrich Drepper abfbdde177 Update.
1999-07-14 00:54:57 +00:00

91 lines
2.1 KiB
C

/* s_floorl.c -- long double version of s_floor.c.
* Conversion to long double by Ulrich Drepper,
* Cygnus Support, 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: $";
#endif
/*
* floorl(x)
* Return x rounded toward -inf to integral value
* Method:
* Bit twiddling.
* Exception:
* Inexact flag raised if x not equal to floor(x).
*/
#include "math.h"
#include "math_private.h"
#ifdef __STDC__
static const long double huge = 1.0e4930;
#else
static long double huge = 1.0e4930;
#endif
#ifdef __STDC__
long double __floorl(long double x)
#else
long double __floorl(x)
long double x;
#endif
{
int32_t i1,j0;
u_int32_t i,j,se,i0,sx;
GET_LDOUBLE_WORDS(se,i0,i1,x);
sx = (se>>15)&1;
j0 = (se&0x7fff)-0x3fff;
if(j0<31) {
if(j0<0) { /* raise inexact if x != 0 */
if(huge+x>0.0) {/* return 0*sign(x) if |x|<1 */
if(sx==0) {se=0;i0=i1=0;}
else if(((se&0x7fff)|i0|i1)!=0)
{ se=0xbfff;i0=i1=0;}
}
} else {
i = (0x7fffffff)>>j0;
if(((i0&i)|i1)==0) return x; /* x is integral */
if(huge+x>0.0) { /* raise inexact flag */
if(sx) {
if (j0>0) i0 += (0x80000000)>>j0;
else ++se;
}
i0 &= (~i); i1=0;
}
}
} else if (j0>62) {
if(j0==0x4000) return x+x; /* inf or NaN */
else return x; /* x is integral */
} else {
i = ((u_int32_t)(0xffffffff))>>(j0-31);
if((i1&i)==0) return x; /* x is integral */
if(huge+x>0.0) { /* raise inexact flag */
if(sx) {
if(j0==31) i0+=1;
else {
j = i1+(1<<(63-j0));
if(j<i1) i0 +=1 ; /* got a carry */
i1=j;
}
}
i1 &= (~i);
}
}
SET_LDOUBLE_WORDS(x,se,i0,i1);
return x;
}
weak_alias (__floorl, floorl)