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Diffstat (limited to 'lib/libm/noieee_src/n_expm1.c')
| -rw-r--r-- | lib/libm/noieee_src/n_expm1.c | 149 |
1 files changed, 0 insertions, 149 deletions
diff --git a/lib/libm/noieee_src/n_expm1.c b/lib/libm/noieee_src/n_expm1.c deleted file mode 100644 index 9494c41f3e4..00000000000 --- a/lib/libm/noieee_src/n_expm1.c +++ /dev/null @@ -1,149 +0,0 @@ -/* $OpenBSD: n_expm1.c,v 1.13 2016/09/12 04:39:47 guenther Exp $ */ -/* $NetBSD: n_expm1.c,v 1.1 1995/10/10 23:36:46 ragge Exp $ */ -/* - * Copyright (c) 1985, 1993 - * The Regents of the University of California. All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. - */ - -/* EXPM1(X) - * RETURN THE EXPONENTIAL OF X MINUS ONE - * DOUBLE PRECISION (IEEE 53 BITS, VAX D FORMAT 56 BITS) - * CODED IN C BY K.C. NG, 1/19/85; - * REVISED BY K.C. NG on 2/6/85, 3/7/85, 3/21/85, 4/16/85. - * - * Required system supported functions: - * scalbn(x,n) - * copysign(x,y) - * isfinite(x) - * - * Kernel function: - * exp__E(x,c) - * - * Method: - * 1. Argument Reduction: given the input x, find r and integer k such - * that - * x = k*ln2 + r, |r| <= 0.5*ln2 . - * r will be represented as r := z+c for better accuracy. - * - * 2. Compute EXPM1(r)=exp(r)-1 by - * - * EXPM1(r=z+c) := z + exp__E(z,c) - * - * 3. EXPM1(x) = 2^k * ( EXPM1(r) + 1-2^-k ). - * - * Remarks: - * 1. When k=1 and z < -0.25, we use the following formula for - * better accuracy: - * EXPM1(x) = 2 * ( (z+0.5) + exp__E(z,c) ) - * 2. To avoid rounding error in 1-2^-k where k is large, we use - * EXPM1(x) = 2^k * { [z+(exp__E(z,c)-2^-k )] + 1 } - * when k>56. - * - * Special cases: - * EXPM1(INF) is INF, EXPM1(NaN) is NaN; - * EXPM1(-INF)= -1; - * for finite argument, only EXPM1(0)=0 is exact. - * - * Accuracy: - * EXPM1(x) returns the exact (exp(x)-1) nearly rounded. In a test run with - * 1,166,000 random arguments on a VAX, the maximum observed error was - * .872 ulps (units of the last place). - * - * Constants: - * The hexadecimal values are the intended ones for the following constants. - * The decimal values may be used, provided that the compiler will convert - * from decimal to binary accurately enough to produce the hexadecimal values - * shown. - */ - -#include "math.h" -#include "mathimpl.h" - -static const double ln2hi = 6.9314718055829871446E-1; -static const double ln2lo = 1.6465949582897081279E-12; -static const double lnhuge = 9.4961163736712506989E1; -static const double invln2 = 1.4426950408889634148E0; - -double -expm1(double x) -{ - static const double one=1.0, half=1.0/2.0, tiny=1e-300; - double z,hi,lo,c; - int k; -#if defined(__vax__) - static prec=56; -#else /* defined(__vax__) */ - static prec=53; -#endif /* defined(__vax__) */ - - if (isnan(x)) - return (x); - - if( x <= lnhuge ) { - if( x >= -40.0 ) { - - /* argument reduction : x - k*ln2 */ - k= invln2 *x+copysign(0.5,x); /* k=NINT(x/ln2) */ - hi=x-k*ln2hi ; - z=hi-(lo=k*ln2lo); - c=(hi-z)-lo; - - if(k==0) return(z+__exp__E(z,c)); - if(k==1) - if(z< -0.25) - {x=z+half;x +=__exp__E(z,c); return(x+x);} - else - {z+=__exp__E(z,c); x=half+z; return(x+x);} - /* end of k=1 */ - - else { - if(k<=prec) - { x=one-scalbn(one,-k); z += __exp__E(z,c);} - else if(k<100) - { x = __exp__E(z,c)-scalbn(one,-k); x+=z; z=one;} - else - { x = __exp__E(z,c)+z; z=one;} - - return (scalbn(x+z,k)); - } - } - /* end of x > lnunfl */ - - else - /* expm1(-big#) rounded to -1 (inexact) */ - if(isfinite(x)) - return(tiny-one); - - /* expm1(-INF) is -1 */ - else return(-one); - } - /* end of x < lnhuge */ - - else - /* expm1(INF) is INF, expm1(+big#) overflows to INF */ - return( isfinite(x) ? scalbn(one,5000) : x); -} |