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[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.
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* Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
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*/
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#if defined(LIBM_SCCS) && !defined(lint)
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static char rcsid[] = "$NetBSD: $";
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#endif
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/* ilogbl(long double x)
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* return the binary exponent of non-zero x
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* ilogbl(0) = FP_ILOGB0
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* ilogbl(NaN) = FP_ILOGBNAN (no signal is raised)
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* ilogbl(+-Inf) = INT_MAX (no signal is raised)
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*/
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#include <limits.h>
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#include <math.h>
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#include <math_private.h>
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#include <math_ldbl_opt.h>
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int __ieee754_ilogbl(long double x)
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{
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int64_t hx,lx;
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int ix;
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GET_LDOUBLE_WORDS64(hx,lx,x);
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hx &= 0x7fffffffffffffffLL;
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if(hx <= 0x0010000000000000LL) {
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if((hx|(lx&0x7fffffffffffffffLL))==0)
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return FP_ILOGB0; /* ilogbl(0) = FP_ILOGB0 */
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else /* subnormal x */
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if(hx==0) {
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for (ix = -1043; lx>0; lx<<=1) ix -=1;
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} else {
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for (ix = -1022, hx<<=11; hx>0; hx<<=1) ix -=1;
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}
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return ix;
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}
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else if (hx<0x7ff0000000000000LL) return (hx>>52)-0x3ff;
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else if (FP_ILOGBNAN != INT_MAX) {
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/* ISO C99 requires ilogbl(+-Inf) == INT_MAX. */
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if (((hx^0x7ff0000000000000LL)|lx) == 0)
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return INT_MAX;
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}
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return FP_ILOGBNAN;
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}
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