1 /* origin: FreeBSD /usr/src/lib/msun/src/k_sinf.c */ 2 /* 3 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 4 * Optimized by Bruce D. Evans. 5 */ 6 /* 7 * ==================================================== 8 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 9 * 10 * Developed at SunPro, a Sun Microsystems, Inc. business. 11 * Permission to use, copy, modify, and distribute this 12 * software is freely granted, provided that this notice 13 * is preserved. 14 * ==================================================== 15 */ 16 17 #include "libm.h" 18 19 /* |sin(x)/x - s(x)| < 2**-37.5 (~[-4.89e-12, 4.824e-12]). */ 20 static const double 21 S1 = -0x15555554cbac77.0p-55, /* -0.166666666416265235595 */ 22 S2 = 0x111110896efbb2.0p-59, /* 0.0083333293858894631756 */ 23 S3 = -0x1a00f9e2cae774.0p-65, /* -0.000198393348360966317347 */ 24 S4 = 0x16cd878c3b46a7.0p-71; /* 0.0000027183114939898219064 */ 25 26 float __sindf(double x) 27 { 28 double_t r, s, w, z; 29 30 /* Try to optimize for parallel evaluation as in __tandf.c. */ 31 z = x*x; 32 w = z*z; 33 r = S3 + z*S4; 34 s = z*x; 35 return (x + s*(S1 + z*S2)) + s*w*r; 36 } 37