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author | Ulrich Drepper <drepper@redhat.com> | 1999-07-14 00:54:57 +0000 |
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committer | Ulrich Drepper <drepper@redhat.com> | 1999-07-14 00:54:57 +0000 |
commit | abfbdde177c3a7155070dda1b2cdc8292054cc26 (patch) | |
tree | e021306b596381fbf8311d2b7eb294e918ff17c8 /sysdeps/libm-ieee754/s_log2f.c | |
parent | 86421aa57ecfd70963ae66848bd6a6dd3b8e0fe6 (diff) | |
download | glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.tar.gz glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.tar.xz glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.zip |
Update.
Diffstat (limited to 'sysdeps/libm-ieee754/s_log2f.c')
-rw-r--r-- | sysdeps/libm-ieee754/s_log2f.c | 91 |
1 files changed, 0 insertions, 91 deletions
diff --git a/sysdeps/libm-ieee754/s_log2f.c b/sysdeps/libm-ieee754/s_log2f.c deleted file mode 100644 index 2377acd36a..0000000000 --- a/sysdeps/libm-ieee754/s_log2f.c +++ /dev/null @@ -1,91 +0,0 @@ -/* e_logf.c -- float version of e_log.c. - * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. - * adapted for log2 by Ulrich Drepper <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. - * ==================================================== - */ - - -#include "math.h" -#include "math_private.h" - -#ifdef __STDC__ -static const float -#else -static float -#endif -ln2 = 0.69314718055994530942, -two25 = 3.355443200e+07, /* 0x4c000000 */ -Lg1 = 6.6666668653e-01, /* 3F2AAAAB */ -Lg2 = 4.0000000596e-01, /* 3ECCCCCD */ -Lg3 = 2.8571429849e-01, /* 3E924925 */ -Lg4 = 2.2222198546e-01, /* 3E638E29 */ -Lg5 = 1.8183572590e-01, /* 3E3A3325 */ -Lg6 = 1.5313838422e-01, /* 3E1CD04F */ -Lg7 = 1.4798198640e-01; /* 3E178897 */ - -#ifdef __STDC__ -static const float zero = 0.0; -#else -static float zero = 0.0; -#endif - -#ifdef __STDC__ - float __log2f(float x) -#else - float __log2f(x) - float x; -#endif -{ - float hfsq,f,s,z,R,w,t1,t2,dk; - int32_t k,ix,i,j; - - GET_FLOAT_WORD(ix,x); - - k=0; - if (ix < 0x00800000) { /* x < 2**-126 */ - if ((ix&0x7fffffff)==0) - return -two25/(x-x); /* log(+-0)=-inf */ - if (ix<0) return (x-x)/(x-x); /* log(-#) = NaN */ - k -= 25; x *= two25; /* subnormal number, scale up x */ - GET_FLOAT_WORD(ix,x); - } - if (ix >= 0x7f800000) return x+x; - k += (ix>>23)-127; - ix &= 0x007fffff; - i = (ix+(0x95f64<<3))&0x800000; - SET_FLOAT_WORD(x,ix|(i^0x3f800000)); /* normalize x or x/2 */ - k += (i>>23); - dk = (float)k; - f = x-(float)1.0; - if((0x007fffff&(15+ix))<16) { /* |f| < 2**-20 */ - if(f==zero) return dk; - R = f*f*((float)0.5-(float)0.33333333333333333*f); - return dk-(R-f)/ln2; - } - s = f/((float)2.0+f); - z = s*s; - i = ix-(0x6147a<<3); - w = z*z; - j = (0x6b851<<3)-ix; - t1= w*(Lg2+w*(Lg4+w*Lg6)); - t2= z*(Lg1+w*(Lg3+w*(Lg5+w*Lg7))); - i |= j; - R = t2+t1; - if(i>0) { - hfsq=(float)0.5*f*f; - return dk-((hfsq-(s*(hfsq+R)))-f)/ln2; - } else { - return dk-((s*(f-R))-f)/ln2; - } -} -weak_alias (__log2f, log2f) |