diff options
author | Ian Moffett <ian@osmora.org> | 2024-03-07 17:28:00 -0500 |
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committer | Ian Moffett <ian@osmora.org> | 2024-03-07 17:28:32 -0500 |
commit | bd5969fc876a10b18613302db7087ef3c40f18e1 (patch) | |
tree | 7c2b8619afe902abf99570df2873fbdf40a4d1a1 /lib/mlibc/options/ansi/musl-generic-math/cosf.c | |
parent | a95b38b1b92b172e6cc4e8e56a88a30cc65907b0 (diff) |
lib: Add mlibc
Signed-off-by: Ian Moffett <ian@osmora.org>
Diffstat (limited to 'lib/mlibc/options/ansi/musl-generic-math/cosf.c')
-rw-r--r-- | lib/mlibc/options/ansi/musl-generic-math/cosf.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/lib/mlibc/options/ansi/musl-generic-math/cosf.c b/lib/mlibc/options/ansi/musl-generic-math/cosf.c new file mode 100644 index 0000000..23f3e5b --- /dev/null +++ b/lib/mlibc/options/ansi/musl-generic-math/cosf.c @@ -0,0 +1,78 @@ +/* origin: FreeBSD /usr/src/lib/msun/src/s_cosf.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 +c1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */ +c2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */ +c3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */ +c4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */ + +float cosf(float x) +{ + double y; + uint32_t ix; + unsigned 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 */ + FORCE_EVAL(x + 0x1p120f); + return 1.0f; + } + return __cosdf(x); + } + if (ix <= 0x407b53d1) { /* |x| ~<= 5*pi/4 */ + if (ix > 0x4016cbe3) /* |x| ~> 3*pi/4 */ + return -__cosdf(sign ? x+c2pio2 : x-c2pio2); + else { + if (sign) + return __sindf(x + c1pio2); + else + return __sindf(c1pio2 - x); + } + } + if (ix <= 0x40e231d5) { /* |x| ~<= 9*pi/4 */ + if (ix > 0x40afeddf) /* |x| ~> 7*pi/4 */ + return __cosdf(sign ? x+c4pio2 : x-c4pio2); + else { + if (sign) + return __sindf(-x - c3pio2); + else + return __sindf(x - c3pio2); + } + } + + /* cos(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 __cosdf(y); + case 1: return __sindf(-y); + case 2: return -__cosdf(y); + default: + return __sindf(y); + } +} |