49 lines
1013 B
C
49 lines
1013 B
C
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#include "libc/math/libm.h"
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#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
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long double tanhl(long double x)
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{
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return tanh(x);
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}
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#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
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long double tanhl(long double x)
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{
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union ldshape u = {x};
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unsigned ex = u.i.se & 0x7fff;
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unsigned sign = u.i.se & 0x8000;
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uint32_t w;
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long double t;
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/* x = |x| */
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u.i.se = ex;
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x = u.f;
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w = u.i.m >> 32;
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if (ex > 0x3ffe || (ex == 0x3ffe && w > 0x8c9f53d5)) {
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/* |x| > log(3)/2 ~= 0.5493 or nan */
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if (ex >= 0x3fff+5) {
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/* |x| >= 32 */
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t = 1 + 0/(x + 0x1p-120f);
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} else {
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t = expm1l(2*x);
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t = 1 - 2/(t+2);
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}
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} else if (ex > 0x3ffd || (ex == 0x3ffd && w > 0x82c577d4)) {
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/* |x| > log(5/3)/2 ~= 0.2554 */
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t = expm1l(2*x);
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t = t/(t+2);
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} else {
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/* |x| is small */
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t = expm1l(-2*x);
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t = -t/(t+2);
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}
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return sign ? -t : t;
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}
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#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
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// TODO: broken implementation to make things compile
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long double tanhl(long double x)
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{
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return tanh(x);
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}
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#endif
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