diff options
Diffstat (limited to 'libm/src/s_log1pf.c')
-rw-r--r-- | libm/src/s_log1pf.c | 107 |
1 files changed, 0 insertions, 107 deletions
diff --git a/libm/src/s_log1pf.c b/libm/src/s_log1pf.c deleted file mode 100644 index 8364da0..0000000 --- a/libm/src/s_log1pf.c +++ /dev/null @@ -1,107 +0,0 @@ -/* s_log1pf.c -- float version of s_log1p.c. - * Conversion to float 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. - * ==================================================== - */ - -#ifndef lint -static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_log1pf.c,v 1.9 2005/12/04 12:30:44 bde Exp $"; -#endif - -#include "math.h" -#include "math_private.h" - -static const float -ln2_hi = 6.9313812256e-01, /* 0x3f317180 */ -ln2_lo = 9.0580006145e-06, /* 0x3717f7d1 */ -two25 = 3.355443200e+07, /* 0x4c000000 */ -Lp1 = 6.6666668653e-01, /* 3F2AAAAB */ -Lp2 = 4.0000000596e-01, /* 3ECCCCCD */ -Lp3 = 2.8571429849e-01, /* 3E924925 */ -Lp4 = 2.2222198546e-01, /* 3E638E29 */ -Lp5 = 1.8183572590e-01, /* 3E3A3325 */ -Lp6 = 1.5313838422e-01, /* 3E1CD04F */ -Lp7 = 1.4798198640e-01; /* 3E178897 */ - -static const float zero = 0.0; - -float -log1pf(float x) -{ - float hfsq,f,c,s,z,R,u; - int32_t k,hx,hu,ax; - - GET_FLOAT_WORD(hx,x); - ax = hx&0x7fffffff; - - k = 1; - if (hx < 0x3ed413d0) { /* 1+x < sqrt(2)+ */ - if(ax>=0x3f800000) { /* x <= -1.0 */ - if(x==(float)-1.0) return -two25/zero; /* log1p(-1)=+inf */ - else return (x-x)/(x-x); /* log1p(x<-1)=NaN */ - } - if(ax<0x31000000) { /* |x| < 2**-29 */ - if(two25+x>zero /* raise inexact */ - &&ax<0x24800000) /* |x| < 2**-54 */ - return x; - else - return x - x*x*(float)0.5; - } - if(hx>0||hx<=((int32_t)0xbe95f619)) { - k=0;f=x;hu=1;} /* sqrt(2)/2- <= 1+x < sqrt(2)+ */ - } - if (hx >= 0x7f800000) return x+x; - if(k!=0) { - if(hx<0x5a000000) { - *(volatile float *)&u = (float)1.0+x; - GET_FLOAT_WORD(hu,u); - k = (hu>>23)-127; - /* correction term */ - c = (k>0)? (float)1.0-(u-x):x-(u-(float)1.0); - c /= u; - } else { - u = x; - GET_FLOAT_WORD(hu,u); - k = (hu>>23)-127; - c = 0; - } - hu &= 0x007fffff; - /* - * The approximation to sqrt(2) used in thresholds is not - * critical. However, the ones used above must give less - * strict bounds than the one here so that the k==0 case is - * never reached from here, since here we have committed to - * using the correction term but don't use it if k==0. - */ - if(hu<0x3504f4) { /* u < sqrt(2) */ - SET_FLOAT_WORD(u,hu|0x3f800000);/* normalize u */ - } else { - k += 1; - SET_FLOAT_WORD(u,hu|0x3f000000); /* normalize u/2 */ - hu = (0x00800000-hu)>>2; - } - f = u-(float)1.0; - } - hfsq=(float)0.5*f*f; - if(hu==0) { /* |f| < 2**-20 */ - if(f==zero) if(k==0) return zero; - else {c += k*ln2_lo; return k*ln2_hi+c;} - R = hfsq*((float)1.0-(float)0.66666666666666666*f); - if(k==0) return f-R; else - return k*ln2_hi-((R-(k*ln2_lo+c))-f); - } - s = f/((float)2.0+f); - z = s*s; - R = z*(Lp1+z*(Lp2+z*(Lp3+z*(Lp4+z*(Lp5+z*(Lp6+z*Lp7)))))); - if(k==0) return f-(hfsq-s*(hfsq+R)); else - return k*ln2_hi-((hfsq-(s*(hfsq+R)+(k*ln2_lo+c)))-f); -} |