diff options
Diffstat (limited to 'lib/mlibc/options/ansi/musl-generic-math/sinf.c')
-rw-r--r-- | lib/mlibc/options/ansi/musl-generic-math/sinf.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/lib/mlibc/options/ansi/musl-generic-math/sinf.c b/lib/mlibc/options/ansi/musl-generic-math/sinf.c new file mode 100644 index 0000000..64e39f5 --- /dev/null +++ b/lib/mlibc/options/ansi/musl-generic-math/sinf.c @@ -0,0 +1,76 @@ +/* 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; + uint32_t ix; + int n, sign; + + GET_FLOAT_WORD(ix, x); + sign = ix >> 31; + ix &= 0x7fffffff; + + if (ix <= 0x3f490fda) { /* |x| ~<= pi/4 */ + if (ix < 0x39800000) { /* |x| < 2**-12 */ + /* raise inexact if x!=0 and underflow if subnormal */ + FORCE_EVAL(ix < 0x00800000 ? x/0x1p120f : x+0x1p120f); + return x; + } + return __sindf(x); + } + if (ix <= 0x407b53d1) { /* |x| ~<= 5*pi/4 */ + if (ix <= 0x4016cbe3) { /* |x| ~<= 3pi/4 */ + if (sign) + return -__cosdf(x + s1pio2); + else + return __cosdf(x - s1pio2); + } + return __sindf(sign ? -(x + s2pio2) : -(x - s2pio2)); + } + if (ix <= 0x40e231d5) { /* |x| ~<= 9*pi/4 */ + if (ix <= 0x40afeddf) { /* |x| ~<= 7*pi/4 */ + if (sign) + return __cosdf(x + s3pio2); + else + return -__cosdf(x - s3pio2); + } + return __sindf(sign ? 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); + } +} |