diff options
Diffstat (limited to 'src/math/s_expm1f.c')
| -rw-r--r-- | src/math/s_expm1f.c | 122 |
1 files changed, 0 insertions, 122 deletions
diff --git a/src/math/s_expm1f.c b/src/math/s_expm1f.c deleted file mode 100644 index b22cf0f9..00000000 --- a/src/math/s_expm1f.c +++ /dev/null @@ -1,122 +0,0 @@ -/* s_expm1f.c -- float version of s_expm1.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. - * ==================================================== - */ - -#include <math.h> -#include "math_private.h" - -static const float -one = 1.0, -huge = 1.0e+30, -tiny = 1.0e-30, -o_threshold = 8.8721679688e+01,/* 0x42b17180 */ -ln2_hi = 6.9313812256e-01,/* 0x3f317180 */ -ln2_lo = 9.0580006145e-06,/* 0x3717f7d1 */ -invln2 = 1.4426950216e+00,/* 0x3fb8aa3b */ - /* scaled coefficients related to expm1 */ -Q1 = -3.3333335072e-02, /* 0xbd088889 */ -Q2 = 1.5873016091e-03, /* 0x3ad00d01 */ -Q3 = -7.9365076090e-05, /* 0xb8a670cd */ -Q4 = 4.0082177293e-06, /* 0x36867e54 */ -Q5 = -2.0109921195e-07; /* 0xb457edbb */ - -float -expm1f(float x) -{ - float y,hi,lo,c=0.0,t,e,hxs,hfx,r1; - int32_t k,xsb; - uint32_t hx; - - GET_FLOAT_WORD(hx,x); - xsb = hx&0x80000000; /* sign bit of x */ - if(xsb==0) y=x; else y= -x; /* y = |x| */ - hx &= 0x7fffffff; /* high word of |x| */ - - /* filter out huge and non-finite argument */ - if(hx >= 0x4195b844) { /* if |x|>=27*ln2 */ - if(hx >= 0x42b17218) { /* if |x|>=88.721... */ - if(hx>0x7f800000) - return x+x; /* NaN */ - if(hx==0x7f800000) - return (xsb==0)? x:-1.0;/* exp(+-inf)={inf,-1} */ - if(x > o_threshold) return huge*huge; /* overflow */ - } - if(xsb!=0) { /* x < -27*ln2, return -1.0 with inexact */ - if(x+tiny<(float)0.0) /* raise inexact */ - return tiny-one; /* return -1 */ - } - } - - /* argument reduction */ - if(hx > 0x3eb17218) { /* if |x| > 0.5 ln2 */ - if(hx < 0x3F851592) { /* and |x| < 1.5 ln2 */ - if(xsb==0) - {hi = x - ln2_hi; lo = ln2_lo; k = 1;} - else - {hi = x + ln2_hi; lo = -ln2_lo; k = -1;} - } else { - k = invln2*x+((xsb==0)?(float)0.5:(float)-0.5); - t = k; - hi = x - t*ln2_hi; /* t*ln2_hi is exact here */ - lo = t*ln2_lo; - } - x = hi - lo; - c = (hi-x)-lo; - } - else if(hx < 0x33000000) { /* when |x|<2**-25, return x */ - t = huge+x; /* return x with inexact flags when x!=0 */ - return x - (t-(huge+x)); - } - else k = 0; - - /* x is now in primary range */ - hfx = (float)0.5*x; - hxs = x*hfx; - r1 = one+hxs*(Q1+hxs*(Q2+hxs*(Q3+hxs*(Q4+hxs*Q5)))); - t = (float)3.0-r1*hfx; - e = hxs*((r1-t)/((float)6.0 - x*t)); - if(k==0) return x - (x*e-hxs); /* c is 0 */ - else { - e = (x*(e-c)-c); - e -= hxs; - if(k== -1) return (float)0.5*(x-e)-(float)0.5; - if(k==1) { - if(x < (float)-0.25) return -(float)2.0*(e-(x+(float)0.5)); - else return one+(float)2.0*(x-e); - } - if (k <= -2 || k>56) { /* suffice to return exp(x)-1 */ - int32_t i; - y = one-(e-x); - GET_FLOAT_WORD(i,y); - SET_FLOAT_WORD(y,i+(k<<23)); /* add k to y's exponent */ - return y-one; - } - t = one; - if(k<23) { - int32_t i; - SET_FLOAT_WORD(t,0x3f800000 - (0x1000000>>k)); /* t=1-2^-k */ - y = t-(e-x); - GET_FLOAT_WORD(i,y); - SET_FLOAT_WORD(y,i+(k<<23)); /* add k to y's exponent */ - } else { - int32_t i; - SET_FLOAT_WORD(t,((0x7f-k)<<23)); /* 2^-k */ - y = x-(e+t); - y += one; - GET_FLOAT_WORD(i,y); - SET_FLOAT_WORD(y,i+(k<<23)); /* add k to y's exponent */ - } - } - return y; -} |