From 7ce331c01ce6eb7b3f5c715a38a24359da9c6ee2 Mon Sep 17 00:00:00 2001 From: Eric Andersen Date: Thu, 22 Nov 2001 14:04:29 +0000 Subject: Totally rework the math library, this time based on the MacOs X math library (which is itself based on the math lib from FreeBSD). -Erik --- libm/float/sqrtf.c | 140 ----------------------------------------------------- 1 file changed, 140 deletions(-) delete mode 100644 libm/float/sqrtf.c (limited to 'libm/float/sqrtf.c') diff --git a/libm/float/sqrtf.c b/libm/float/sqrtf.c deleted file mode 100644 index bc75a907b..000000000 --- a/libm/float/sqrtf.c +++ /dev/null @@ -1,140 +0,0 @@ -/* sqrtf.c - * - * Square root - * - * - * - * SYNOPSIS: - * - * float x, y, sqrtf(); - * - * y = sqrtf( x ); - * - * - * - * DESCRIPTION: - * - * Returns the square root of x. - * - * Range reduction involves isolating the power of two of the - * argument and using a polynomial approximation to obtain - * a rough value for the square root. Then Heron's iteration - * is used three times to converge to an accurate value. - * - * - * - * ACCURACY: - * - * - * Relative error: - * arithmetic domain # trials peak rms - * IEEE 0,1.e38 100000 8.7e-8 2.9e-8 - * - * - * ERROR MESSAGES: - * - * message condition value returned - * sqrtf domain x < 0 0.0 - * - */ - -/* -Cephes Math Library Release 2.2: June, 1992 -Copyright 1984, 1987, 1988, 1992 by Stephen L. Moshier -Direct inquiries to 30 Frost Street, Cambridge, MA 02140 -*/ - -/* Single precision square root - * test interval: [sqrt(2)/2, sqrt(2)] - * trials: 30000 - * peak relative error: 8.8e-8 - * rms relative error: 3.3e-8 - * - * test interval: [0.01, 100.0] - * trials: 50000 - * peak relative error: 8.7e-8 - * rms relative error: 3.3e-8 - * - * Copyright (C) 1989 by Stephen L. Moshier. All rights reserved. - */ -#include - -#ifdef ANSIC -float frexpf( float, int * ); -float ldexpf( float, int ); - -float sqrtf( float xx ) -#else -float frexpf(), ldexpf(); - -float sqrtf(xx) -float xx; -#endif -{ -float f, x, y; -int e; - -f = xx; -if( f <= 0.0 ) - { - if( f < 0.0 ) - mtherr( "sqrtf", DOMAIN ); - return( 0.0 ); - } - -x = frexpf( f, &e ); /* f = x * 2**e, 0.5 <= x < 1.0 */ -/* If power of 2 is odd, double x and decrement the power of 2. */ -if( e & 1 ) - { - x = x + x; - e -= 1; - } - -e >>= 1; /* The power of 2 of the square root. */ - -if( x > 1.41421356237 ) - { -/* x is between sqrt(2) and 2. */ - x = x - 2.0; - y = - ((((( -9.8843065718E-4 * x - + 7.9479950957E-4) * x - - 3.5890535377E-3) * x - + 1.1028809744E-2) * x - - 4.4195203560E-2) * x - + 3.5355338194E-1) * x - + 1.41421356237E0; - goto sqdon; - } - -if( x > 0.707106781187 ) - { -/* x is between sqrt(2)/2 and sqrt(2). */ - x = x - 1.0; - y = - ((((( 1.35199291026E-2 * x - - 2.26657767832E-2) * x - + 2.78720776889E-2) * x - - 3.89582788321E-2) * x - + 6.24811144548E-2) * x - - 1.25001503933E-1) * x * x - + 0.5 * x - + 1.0; - goto sqdon; - } - -/* x is between 0.5 and sqrt(2)/2. */ -x = x - 0.5; -y = -((((( -3.9495006054E-1 * x - + 5.1743034569E-1) * x - - 4.3214437330E-1) * x - + 3.5310730460E-1) * x - - 3.5354581892E-1) * x - + 7.0710676017E-1) * x - + 7.07106781187E-1; - -sqdon: -y = ldexpf( y, e ); /* y = y * 2**e */ -return( y); -} -- cgit v1.2.3