mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-25 20:21:07 +00:00
76da726532
[BZ #6794] Following Joseph comments about bug 6794, here is a proposed fix. It turned out to be a large fix mainly because I had to move some file along to follow libm files/names conventions. Basically I have added wrappers (w_ilogb.c, w_ilogbf.c, w_ilogbl.c) that now calls the symbol '__ieee754_ilogb'. The wrappers checks for '__ieee754_ilogb' output and set the errno and raise exceptions as expected. The '__ieee754_ilogb' is implemented in sysdeps. I have moved the 's_ilogb[f|l]' files to e_ilogb[f|l] and renamed the '__ilogb[f|l]' to '__ieee754_ilogb[f|l]'. I also found out a bug in i386 and x86-64 assembly coded ilogb implementation where it raises a FE_DIVBYZERO when argument is '0.0'. I corrected this issue as well. Finally I added the errno and FE_INVALID tests for 0.0, NaN and +-InF argument. Tested on i386, x86-64, ppc32 and ppc64.
58 lines
1.5 KiB
C
58 lines
1.5 KiB
C
/* s_ilogbl.c -- long double version of s_ilogb.c.
|
|
* Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
|
|
*/
|
|
|
|
/*
|
|
* ====================================================
|
|
* 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
|
|
|
|
/* ilogbl(long double x)
|
|
* return the binary exponent of non-zero x
|
|
* ilogbl(0) = FP_ILOGB0
|
|
* ilogbl(NaN) = FP_ILOGBNAN (no signal is raised)
|
|
* ilogbl(+-Inf) = INT_MAX (no signal is raised)
|
|
*/
|
|
|
|
#include <limits.h>
|
|
#include <math.h>
|
|
#include <math_private.h>
|
|
#include <math_ldbl_opt.h>
|
|
|
|
int __ieee754_ilogbl(long double x)
|
|
{
|
|
int64_t hx,lx;
|
|
int ix;
|
|
|
|
GET_LDOUBLE_WORDS64(hx,lx,x);
|
|
hx &= 0x7fffffffffffffffLL;
|
|
if(hx <= 0x0010000000000000LL) {
|
|
if((hx|(lx&0x7fffffffffffffffLL))==0)
|
|
return FP_ILOGB0; /* ilogbl(0) = FP_ILOGB0 */
|
|
else /* subnormal x */
|
|
if(hx==0) {
|
|
for (ix = -1043; lx>0; lx<<=1) ix -=1;
|
|
} else {
|
|
for (ix = -1022, hx<<=11; hx>0; hx<<=1) ix -=1;
|
|
}
|
|
return ix;
|
|
}
|
|
else if (hx<0x7ff0000000000000LL) return (hx>>52)-0x3ff;
|
|
else if (FP_ILOGBNAN != INT_MAX) {
|
|
/* ISO C99 requires ilogbl(+-Inf) == INT_MAX. */
|
|
if (((hx^0x7ff0000000000000LL)|lx) == 0)
|
|
return INT_MAX;
|
|
}
|
|
return FP_ILOGBNAN;
|
|
}
|