X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fmath%2Fsinf.c;fp=src%2Fmath%2Fsinf.c;h=dcca67af1b29428b3441d962c6551707b4b1c03e;hb=b69f695acedd4ce2798ef9ea28d834ceccc789bd;hp=0000000000000000000000000000000000000000;hpb=d46cf2e14cc4df7cc75e77d7009fcb6df1f48a33;p=musl diff --git a/src/math/sinf.c b/src/math/sinf.c new file mode 100644 index 00000000..dcca67af --- /dev/null +++ b/src/math/sinf.c @@ -0,0 +1,73 @@ +/* origin: FreeBSD /usr/src/lib/msun/src/s_sinf.c */ +/* + * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. + * Optimized by Bruce D. Evans. + */ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunPro, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +#include "libm.h" + +/* Small multiples of pi/2 rounded to double precision. */ +static const double +s1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */ +s2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */ +s3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */ +s4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */ + +float sinf(float x) +{ + double y; + int32_t n, hx, ix; + + GET_FLOAT_WORD(hx, x); + ix = hx & 0x7fffffff; + + if (ix <= 0x3f490fda) { /* |x| ~<= pi/4 */ + if (ix < 0x39800000) /* |x| < 2**-12 */ + /* raise inexact if x != 0 */ + if((int)x == 0) + return x; + return __sindf(x); + } + if (ix <= 0x407b53d1) { /* |x| ~<= 5*pi/4 */ + if (ix <= 0x4016cbe3) { /* |x| ~<= 3pi/4 */ + if (hx > 0) + return __cosdf(x - s1pio2); + else + return -__cosdf(x + s1pio2); + } + return __sindf(hx > 0 ? s2pio2 - x : -s2pio2 - x); + } + if (ix <= 0x40e231d5) { /* |x| ~<= 9*pi/4 */ + if (ix <= 0x40afeddf) { /* |x| ~<= 7*pi/4 */ + if (hx > 0) + return -__cosdf(x - s3pio2); + else + return __cosdf(x + s3pio2); + } + return __sindf(hx > 0 ? x - s4pio2 : x + s4pio2); + } + + /* sin(Inf or NaN) is NaN */ + if (ix >= 0x7f800000) + return x - x; + + /* general argument reduction needed */ + n = __rem_pio2f(x, &y); + switch (n&3) { + case 0: return __sindf(y); + case 1: return __cosdf(y); + case 2: return __sindf(-y); + default: + return -__cosdf(y); + } +}