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author | Raghuram Subramani <raghus2247@gmail.com> | 2022-06-19 19:47:51 +0530 |
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committer | Raghuram Subramani <raghus2247@gmail.com> | 2022-06-19 19:47:51 +0530 |
commit | 4fd287655a72b9aea14cdac715ad5b90ed082ed2 (patch) | |
tree | 65d393bc0e699dd12d05b29ba568e04cea666207 /circuitpython/lib/libm/asinfacosf.c | |
parent | 0150f70ce9c39e9e6dd878766c0620c85e47bed0 (diff) |
add circuitpython code
Diffstat (limited to 'circuitpython/lib/libm/asinfacosf.c')
-rw-r--r-- | circuitpython/lib/libm/asinfacosf.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/circuitpython/lib/libm/asinfacosf.c b/circuitpython/lib/libm/asinfacosf.c new file mode 100644 index 0000000..22dbb3d --- /dev/null +++ b/circuitpython/lib/libm/asinfacosf.c @@ -0,0 +1,130 @@ +/*****************************************************************************/ +/*****************************************************************************/ +// asinf from musl-0.9.15 +/*****************************************************************************/ +/*****************************************************************************/ + +/* origin: FreeBSD /usr/src/lib/msun/src/e_asinf.c */ +/* + * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. + */ +/* + * ==================================================== + * 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" + +// dpgeorge: pio2 was double in original implementation of asinf +static const float +pio2_hi = 1.5707962513e+00f, /* 0x3fc90fda */ +pio2_lo = 7.5497894159e-08f; /* 0x33a22168 */ + +static const float +/* coefficients for R(x^2) */ +pS0 = 1.6666586697e-01f, +pS1 = -4.2743422091e-02f, +pS2 = -8.6563630030e-03f, +qS1 = -7.0662963390e-01f; + +static float R(float z) +{ + float_t p, q; + p = z*(pS0+z*(pS1+z*pS2)); + q = 1.0f+z*qS1; + return p/q; +} + +float asinf(float x) +{ + // dpgeorge: s was double in original implementation + float s,z; + uint32_t hx,ix; + + GET_FLOAT_WORD(hx, x); + ix = hx & 0x7fffffff; + if (ix >= 0x3f800000) { /* |x| >= 1 */ + if (ix == 0x3f800000) /* |x| == 1 */ + return x*pio2_hi + 0x1p-120f; /* asin(+-1) = +-pi/2 with inexact */ + return 0/(x-x); /* asin(|x|>1) is NaN */ + } + if (ix < 0x3f000000) { /* |x| < 0.5 */ + /* if 0x1p-126 <= |x| < 0x1p-12, avoid raising underflow */ + if (ix < 0x39800000 && ix >= 0x00800000) + return x; + return x + x*R(x*x); + } + /* 1 > |x| >= 0.5 */ + z = (1 - fabsf(x))*0.5f; + s = sqrtf(z); + x = pio2_hi - (2*(s+s*R(z)) - pio2_lo); // dpgeorge: use pio2_hi and pio2_lo + if (hx >> 31) + return -x; + return x; +} + +/*****************************************************************************/ +/*****************************************************************************/ +// acosf from musl-0.9.15 +/*****************************************************************************/ +/*****************************************************************************/ + +/* origin: FreeBSD /usr/src/lib/msun/src/e_acosf.c */ +/* + * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. + */ +/* + * ==================================================== + * 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. + * ==================================================== + */ + +float acosf(float x) +{ + float z,w,s,c,df; + uint32_t hx,ix; + + GET_FLOAT_WORD(hx, x); + ix = hx & 0x7fffffff; + /* |x| >= 1 or nan */ + if (ix >= 0x3f800000) { + if (ix == 0x3f800000) { + if (hx >> 31) + return 2*pio2_hi + 0x1p-120f; + return 0; + } + return 0/(x-x); + } + /* |x| < 0.5 */ + if (ix < 0x3f000000) { + if (ix <= 0x32800000) /* |x| < 2**-26 */ + return pio2_hi + 0x1p-120f; + return pio2_hi - (x - (pio2_lo-x*R(x*x))); + } + /* x < -0.5 */ + if (hx >> 31) { + z = (1+x)*0.5f; + s = sqrtf(z); + w = R(z)*s-pio2_lo; + return 2*(pio2_hi - (s+w)); + } + /* x > 0.5 */ + z = (1-x)*0.5f; + s = sqrtf(z); + GET_FLOAT_WORD(hx,s); + SET_FLOAT_WORD(df,hx&0xfffff000); + c = (z-df*df)/(s+df); + w = R(z)*s+c; + return 2*(df+w); +} |