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Diffstat (limited to 'sysdeps/generic/sincos.c')
| -rw-r--r-- | sysdeps/generic/sincos.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/sysdeps/generic/sincos.c b/sysdeps/generic/sincos.c new file mode 100644 index 0000000..ab88560 --- /dev/null +++ b/sysdeps/generic/sincos.c @@ -0,0 +1,98 @@ +/* + * Copyright (c) 1987, 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. 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. + */ + +#ifndef lint +static char sccsid[] = "@(#)sincos.c 8.1 (Berkeley) 6/4/93"; +#endif /* not lint */ + +#include "trig.h" +double +sin(x) +double x; +{ + double a,c,z; + + if(!finite(x)) /* sin(NaN) and sin(INF) must be NaN */ + return x-x; + x=drem(x,PI2); /* reduce x into [-PI,PI] */ + a=copysign(x,one); + if (a >= PIo4) { + if(a >= PI3o4) /* ... in [3PI/4,PI] */ + x = copysign((a = PI-a),x); + else { /* ... in [PI/4,3PI/4] */ + a = PIo2-a; /* rtn. sign(x)*C(PI/2-|x|) */ + z = a*a; + c = cos__C(z); + z *= half; + a = (z >= thresh ? half-((z-half)-c) : one-(z-c)); + return copysign(a,x); + } + } + + if (a < small) { /* rtn. S(x) */ + big+a; + return x; + } + return x+x*sin__S(x*x); +} + +double +cos(x) +double x; +{ + double a,c,z,s = 1.0; + + if(!finite(x)) /* cos(NaN) and cos(INF) must be NaN */ + return x-x; + x=drem(x,PI2); /* reduce x into [-PI,PI] */ + a=copysign(x,one); + if (a >= PIo4) { + if (a >= PI3o4) { /* ... in [3PI/4,PI] */ + a = PI-a; + s = negone; + } + else { /* ... in [PI/4,3PI/4] */ + a = PIo2-a; + return a+a*sin__S(a*a); /* rtn. S(PI/2-|x|) */ + } + } + if (a < small) { + big+a; + return s; /* rtn. s*C(a) */ + } + z = a*a; + c = cos__C(z); + z *= half; + a = (z >= thresh ? half-((z-half)-c) : one-(z-c)); + return copysign(a,s); +} |