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authorKacper <kacper@mail.openlinux.dev>2025-12-09 19:20:15 +0100
committerKacper <kacper@mail.openlinux.dev>2025-12-09 19:20:15 +0100
commit885f5974cdf65b59415837ae97f5a14ef1350670 (patch)
tree66ac13de29c7f4932c5fcae11773df574e4e256a /lib/libm/atanl.c
parent8f9e448b2ef6db7cd905540c21f3c5b190e7a1e7 (diff)
feat: add gzip and new headers
Diffstat (limited to 'lib/libm/atanl.c')
-rw-r--r--lib/libm/atanl.c205
1 files changed, 205 insertions, 0 deletions
diff --git a/lib/libm/atanl.c b/lib/libm/atanl.c
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+++ b/lib/libm/atanl.c
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+/* origin: FreeBSD /usr/src/lib/msun/src/s_atanl.c */
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+/*
+ * See comments in atan.c.
+ * Converted to long double by David Schultz <das@FreeBSD.ORG>.
+ */
+
+#include "libm.h"
+
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
+long double atanl(long double x)
+{
+ return atan(x);
+}
+#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
+
+#if LDBL_MANT_DIG == 64
+#define EXPMAN(u) ((u.i.se & 0x7fff) << 8 | (u.i.m >> 55 & 0xff))
+
+static const long double atanhi[] = {
+ 4.63647609000806116202e-01L,
+ 7.85398163397448309628e-01L,
+ 9.82793723247329067960e-01L,
+ 1.57079632679489661926e+00L,
+};
+
+static const long double atanlo[] = {
+ 1.18469937025062860669e-20L,
+ -1.25413940316708300586e-20L,
+ 2.55232234165405176172e-20L,
+ -2.50827880633416601173e-20L,
+};
+
+static const long double aT[] = {
+ 3.33333333333333333017e-01L, -1.99999999999999632011e-01L,
+ 1.42857142857046531280e-01L, -1.11111111100562372733e-01L,
+ 9.09090902935647302252e-02L, -7.69230552476207730353e-02L,
+ 6.66661718042406260546e-02L, -5.88158892835030888692e-02L,
+ 5.25499891539726639379e-02L, -4.70119845393155721494e-02L,
+ 4.03539201366454414072e-02L, -2.91303858419364158725e-02L,
+ 1.24822046299269234080e-02L,
+};
+
+static long double T_even(long double x)
+{
+ return aT[0] +
+ x * (aT[2] +
+ x * (aT[4] + x * (aT[6] + x * (aT[8] + x * (aT[10] +
+ x * aT[12])))));
+}
+
+static long double T_odd(long double x)
+{
+ return aT[1] +
+ x * (aT[3] +
+ x * (aT[5] + x * (aT[7] + x * (aT[9] + x * aT[11]))));
+}
+#elif LDBL_MANT_DIG == 113
+#define EXPMAN(u) ((u.i.se & 0x7fff) << 8 | u.i.top >> 8)
+
+static const long double atanhi[] = {
+ 4.63647609000806116214256231461214397e-01L,
+ 7.85398163397448309615660845819875699e-01L,
+ 9.82793723247329067985710611014666038e-01L,
+ 1.57079632679489661923132169163975140e+00L,
+};
+
+static const long double atanlo[] = {
+ 4.89509642257333492668618435220297706e-36L,
+ 2.16795253253094525619926100651083806e-35L,
+ -2.31288434538183565909319952098066272e-35L,
+ 4.33590506506189051239852201302167613e-35L,
+};
+
+static const long double aT[] = {
+ 3.33333333333333333333333333333333125e-01L,
+ -1.99999999999999999999999999999180430e-01L,
+ 1.42857142857142857142857142125269827e-01L,
+ -1.11111111111111111111110834490810169e-01L,
+ 9.09090909090909090908522355708623681e-02L,
+ -7.69230769230769230696553844935357021e-02L,
+ 6.66666666666666660390096773046256096e-02L,
+ -5.88235294117646671706582985209643694e-02L,
+ 5.26315789473666478515847092020327506e-02L,
+ -4.76190476189855517021024424991436144e-02L,
+ 4.34782608678695085948531993458097026e-02L,
+ -3.99999999632663469330634215991142368e-02L,
+ 3.70370363987423702891250829918659723e-02L,
+ -3.44827496515048090726669907612335954e-02L,
+ 3.22579620681420149871973710852268528e-02L,
+ -3.03020767654269261041647570626778067e-02L,
+ 2.85641979882534783223403715930946138e-02L,
+ -2.69824879726738568189929461383741323e-02L,
+ 2.54194698498808542954187110873675769e-02L,
+ -2.35083879708189059926183138130183215e-02L,
+ 2.04832358998165364349957325067131428e-02L,
+ -1.54489555488544397858507248612362957e-02L,
+ 8.64492360989278761493037861575248038e-03L,
+ -2.58521121597609872727919154569765469e-03L,
+};
+
+static long double T_even(long double x)
+{
+ return (aT[0] +
+ x * (aT[2] +
+ x * (aT[4] +
+ x * (aT[6] +
+ x * (aT[8] +
+ x * (aT[10] +
+ x * (aT[12] +
+ x * (aT[14] +
+ x * (aT[16] +
+ x * (aT[18] +
+ x * (aT[20] +
+ x * aT[22])))))))))));
+}
+
+static long double T_odd(long double x)
+{
+ return (aT[1] +
+ x * (aT[3] +
+ x * (aT[5] +
+ x * (aT[7] +
+ x * (aT[9] +
+ x * (aT[11] +
+ x * (aT[13] +
+ x * (aT[15] +
+ x * (aT[17] +
+ x * (aT[19] +
+ x * (aT[21] +
+ x * aT[23])))))))))));
+}
+#endif
+
+long double atanl(long double x)
+{
+ union ldshape u = { x };
+ long double w, s1, s2, z;
+ int id;
+ unsigned e = u.i.se & 0x7fff;
+ unsigned sign = u.i.se >> 15;
+ unsigned expman;
+
+ if (e >= 0x3fff + LDBL_MANT_DIG + 1) { /* if |x| is large, atan(x)~=pi/2
+ */
+ if (isnan(x))
+ return x;
+ return sign ? -atanhi[3] : atanhi[3];
+ }
+ /* Extract the exponent and the first few bits of the mantissa. */
+ expman = EXPMAN(u);
+ if (expman < ((0x3fff - 2) << 8) + 0xc0) { /* |x| < 0.4375 */
+ if (e < 0x3fff - (LDBL_MANT_DIG + 1) / 2) { /* if |x| is small,
+ atanl(x)~=x */
+ /* raise underflow if subnormal */
+ if (e == 0)
+ FORCE_EVAL((float)x);
+ return x;
+ }
+ id = -1;
+ } else {
+ x = fabsl(x);
+ if (expman < (0x3fff << 8) + 0x30) { /* |x| < 1.1875 */
+ if (expman < ((0x3fff - 1) << 8) + 0x60) { /* 7/16 <=
+ |x| <
+ 11/16 */
+ id = 0;
+ x = (2.0 * x - 1.0) / (2.0 + x);
+ } else { /* 11/16 <= |x| < 19/16 */
+ id = 1;
+ x = (x - 1.0) / (x + 1.0);
+ }
+ } else {
+ if (expman < ((0x3fff + 1) << 8) + 0x38) { /* |x|
+ < 2.4375
+ */
+ id = 2;
+ x = (x - 1.5) / (1.0 + 1.5 * x);
+ } else { /* 2.4375 <= |x| */
+ id = 3;
+ x = -1.0 / x;
+ }
+ }
+ }
+ /* end of argument reduction */
+ z = x * x;
+ w = z * z;
+ /* break sum aT[i]z**(i+1) into odd and even poly */
+ s1 = z * T_even(w);
+ s2 = w * T_odd(w);
+ if (id < 0)
+ return x - x * (s1 + s2);
+ z = atanhi[id] - ((x * (s1 + s2) - atanlo[id]) - x);
+ return sign ? -z : z;
+}
+#endif