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Diffstat (limited to 'sysdeps/ieee754/hypot.c')
| -rw-r--r-- | sysdeps/ieee754/hypot.c | 197 |
1 files changed, 0 insertions, 197 deletions
diff --git a/sysdeps/ieee754/hypot.c b/sysdeps/ieee754/hypot.c deleted file mode 100644 index cdc2ed02b9..0000000000 --- a/sysdeps/ieee754/hypot.c +++ /dev/null @@ -1,197 +0,0 @@ -/* - * Copyright (c) 1985 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. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 4. 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. - */ - -/* HYPOT(X,Y) - * RETURN THE SQUARE ROOT OF X^2 + Y^2 WHERE Z=X+iY - * DOUBLE PRECISION (VAX D format 56 bits, IEEE DOUBLE 53 BITS) - * CODED IN C BY K.C. NG, 11/28/84; - * REVISED BY K.C. NG, 7/12/85. - * - * Required system supported functions : - * copysign(x,y) - * finite(x) - * scalb(x,N) - * sqrt(x) - * - * Method : - * 1. replace x by |x| and y by |y|, and swap x and - * y if y > x (hence x is never smaller than y). - * 2. Hypot(x,y) is computed by: - * Case I, x/y > 2 - * - * y - * hypot = x + ----------------------------- - * 2 - * sqrt ( 1 + [x/y] ) + x/y - * - * Case II, x/y <= 2 - * y - * hypot = x + -------------------------------------------------- - * 2 - * [x/y] - 2 - * (sqrt(2)+1) + (x-y)/y + ----------------------------- - * 2 - * sqrt ( 1 + [x/y] ) + sqrt(2) - * - * - * - * Special cases: - * hypot(x,y) is INF if x or y is +INF or -INF; else - * hypot(x,y) is NAN if x or y is NAN. - * - * Accuracy: - * hypot(x,y) returns the sqrt(x^2+y^2) with error less than 1 ulps (units - * in the last place). See Kahan's "Interval Arithmetic Options in the - * Proposed IEEE Floating Point Arithmetic Standard", Interval Mathematics - * 1980, Edited by Karl L.E. Nickel, pp 99-128. (A faster but less accurate - * code follows in comments.) In a test run with 500,000 random arguments - * on a VAX, the maximum observed error was .959 ulps. - * - * 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 "mathimpl.h" - -vc(r2p1hi, 2.4142135623730950345E0 ,8279,411a,ef32,99fc, 2, .9A827999FCEF32) -vc(r2p1lo, 1.4349369327986523769E-17 ,597d,2484,754b,89b3, -55, .84597D89B3754B) -vc(sqrt2, 1.4142135623730950622E0 ,04f3,40b5,de65,33f9, 1, .B504F333F9DE65) - -ic(r2p1hi, 2.4142135623730949234E0 , 1, 1.3504F333F9DE6) -ic(r2p1lo, 1.2537167179050217666E-16 , -53, 1.21165F626CDD5) -ic(sqrt2, 1.4142135623730951455E0 , 0, 1.6A09E667F3BCD) - -#ifdef vccast -#define r2p1hi vccast(r2p1hi) -#define r2p1lo vccast(r2p1lo) -#define sqrt2 vccast(sqrt2) -#endif - -double -hypot(x,y) -double x, y; -{ - static const double zero=0, one=1, - small=1.0E-18; /* fl(1+small)==1 */ - static const ibig=30; /* fl(1+2**(2*ibig))==1 */ - double t,r; - int exp; - - if(finite(x)) - if(finite(y)) - { - x=copysign(x,one); - y=copysign(y,one); - if(y > x) - { t=x; x=y; y=t; } - if(x == zero) return(zero); - if(y == zero) return(x); - exp= logb(x); - if(exp-(int)logb(y) > ibig ) - /* raise inexact flag and return |x| */ - { one+small; return(x); } - - /* start computing sqrt(x^2 + y^2) */ - r=x-y; - if(r>y) { /* x/y > 2 */ - r=x/y; - r=r+sqrt(one+r*r); } - else { /* 1 <= x/y <= 2 */ - r/=y; t=r*(r+2.0); - r+=t/(sqrt2+sqrt(2.0+t)); - r+=r2p1lo; r+=r2p1hi; } - - r=y/r; - return(x+r); - - } - - else if(y==y) /* y is +-INF */ - return(copysign(y,one)); - else - return(y); /* y is NaN and x is finite */ - - else if(x==x) /* x is +-INF */ - return (copysign(x,one)); - else if(finite(y)) - return(x); /* x is NaN, y is finite */ -#if !defined(vax)&&!defined(tahoe) - else if(y!=y) return(y); /* x and y is NaN */ -#endif /* !defined(vax)&&!defined(tahoe) */ - else return(copysign(y,one)); /* y is INF */ -} - -/* A faster but less accurate version of cabs(x,y) */ -#if 0 -double hypot(x,y) -double x, y; -{ - static const double zero=0, one=1; - small=1.0E-18; /* fl(1+small)==1 */ - static const ibig=30; /* fl(1+2**(2*ibig))==1 */ - double temp; - int exp; - - if(finite(x)) - if(finite(y)) - { - x=copysign(x,one); - y=copysign(y,one); - if(y > x) - { temp=x; x=y; y=temp; } - if(x == zero) return(zero); - if(y == zero) return(x); - exp= logb(x); - x=scalb(x,-exp); - if(exp-(int)logb(y) > ibig ) - /* raise inexact flag and return |x| */ - { one+small; return(scalb(x,exp)); } - else y=scalb(y,-exp); - return(scalb(sqrt(x*x+y*y),exp)); - } - - else if(y==y) /* y is +-INF */ - return(copysign(y,one)); - else - return(y); /* y is NaN and x is finite */ - - else if(x==x) /* x is +-INF */ - return (copysign(x,one)); - else if(finite(y)) - return(x); /* x is NaN, y is finite */ - else if(y!=y) return(y); /* x and y is NaN */ - else return(copysign(y,one)); /* y is INF */ -} -#endif |