diff options
Diffstat (limited to 'sysdeps/libm-ieee754/e_log10.c')
| -rw-r--r-- | sysdeps/libm-ieee754/e_log10.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/sysdeps/libm-ieee754/e_log10.c b/sysdeps/libm-ieee754/e_log10.c index 5d004ac4e2..e8a3278eaf 100644 --- a/sysdeps/libm-ieee754/e_log10.c +++ b/sysdeps/libm-ieee754/e_log10.c @@ -5,7 +5,7 @@ * * Developed at SunPro, a Sun Microsystems, Inc. business. * Permission to use, copy, modify, and distribute this - * software is freely granted, provided that this notice + * software is freely granted, provided that this notice * is preserved. * ==================================================== */ @@ -16,26 +16,26 @@ static char rcsid[] = "$NetBSD: e_log10.c,v 1.9 1995/05/10 20:45:51 jtc Exp $"; /* __ieee754_log10(x) * Return the base 10 logarithm of x - * + * * Method : * Let log10_2hi = leading 40 bits of log10(2) and * log10_2lo = log10(2) - log10_2hi, * ivln10 = 1/log(10) rounded. * Then - * n = ilogb(x), + * n = ilogb(x), * if(n<0) n = n+1; * x = scalbn(x,-n); * log10(x) := n*log10_2hi + (n*log10_2lo + ivln10*log(x)) * * Note 1: - * To guarantee log10(10**n)=n, where 10**n is normal, the rounding + * To guarantee log10(10**n)=n, where 10**n is normal, the rounding * mode must set to Round-to-Nearest. * Note 2: * [1/log(10)] rounded to 53 bits has error .198 ulps; * log10 is monotonic at all binary break points. * * Special cases: - * log10(x) is NaN with signal if x < 0; + * log10(x) is NaN with signal if x < 0; * log10(+INF) is +INF with no signal; log10(0) is -INF with signal; * log10(NaN) is that NaN with no signal; * log10(10**N) = N for N=0,1,...,22. @@ -80,10 +80,10 @@ static double zero = 0.0; EXTRACT_WORDS(hx,lx,x); k=0; - if (hx < 0x00100000) { /* x < 2**-1022 */ + if (hx < 0x00100000) { /* x < 2**-1022 */ if (((hx&0x7fffffff)|lx)==0) - return -two54/zero; /* log(+-0)=-inf */ - if (hx<0) return (x-x)/zero; /* log(-#) = NaN */ + return -two54/(x-x); /* log(+-0)=-inf */ + if (hx<0) return (x-x)/(x-x); /* log(-#) = NaN */ k -= 54; x *= two54; /* subnormal number, scale up x */ GET_HIGH_WORD(hx,x); } |