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/* See the import.pl script for potential modifications */
/* e_log10f.c -- Simple version of e_log10.c.
* Conversion to Simple by Ian Lance Taylor, Cygnus Support, ian@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: e_log10f.c,v 1.5f 1995/05/10 20:45:53 jtc Exp $";
#endif
#include "SMath.h"
#include "math_private.h"
namespace streflop_libm {
#ifdef __STDC__
static const Simple
#else
static Simple
#endif
two25 = 3.3554432000e+07f, /* 0x4c000000 */
ivln10 = 4.3429449201e-01f, /* 0x3ede5bd9 */
log10_2hi = 3.0102920532e-01f, /* 0x3e9a2080 */
log10_2lo = 7.9034151668e-07f; /* 0x355427db */
#ifdef __STDC__
static const Simple zero = 0.0f;
#else
static Simple zero = 0.0f;
#endif
#ifdef __STDC__
Simple __ieee754_log10f(Simple x)
#else
Simple __ieee754_log10f(x)
Simple x;
#endif
{
Simple y,z;
int32_t i,k,hx;
GET_FLOAT_WORD(hx,x);
k=0;
if (hx < 0x00800000) { /* x < 2**-126 */
if ((hx&0x7fffffff)==0)
return -two25/(x-x); /* log(+-0)=-inf */
if (hx<0) return (x-x)/(x-x); /* log(-#) = NaN */
k -= 25; x *= two25; /* subnormal number, scale up x */
GET_FLOAT_WORD(hx,x);
}
if (hx >= 0x7f800000) return x+x;
k += (hx>>23)-127;
i = ((u_int32_t)k&0x80000000)>>31;
hx = (hx&0x007fffff)|((0x7f-i)<<23);
y = (Simple)(k+i);
SET_FLOAT_WORD(x,hx);
z = y*log10_2lo + ivln10*__ieee754_logf(x);
return z+y*log10_2hi;
}
}
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