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-rw-r--r--libc-top-half/musl/src/math/asinl.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/libc-top-half/musl/src/math/asinl.c b/libc-top-half/musl/src/math/asinl.c
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+/* origin: FreeBSD /usr/src/lib/msun/src/e_asinl.c */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunSoft, 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 asin.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 asinl(long double x)
+{
+ return asin(x);
+}
+#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
+#include "__invtrigl.h"
+#if LDBL_MANT_DIG == 64
+#define CLOSETO1(u) (u.i.m>>56 >= 0xf7)
+#define CLEARBOTTOM(u) (u.i.m &= -1ULL << 32)
+#elif LDBL_MANT_DIG == 113
+#define CLOSETO1(u) (u.i.top >= 0xee00)
+#define CLEARBOTTOM(u) (u.i.lo = 0)
+#endif
+
+long double asinl(long double x)
+{
+ union ldshape u = {x};
+ long double z, r, s;
+ uint16_t e = u.i.se & 0x7fff;
+ int sign = u.i.se >> 15;
+
+ if (e >= 0x3fff) { /* |x| >= 1 or nan */
+ /* asin(+-1)=+-pi/2 with inexact */
+ if (x == 1 || x == -1)
+ return x*pio2_hi + 0x1p-120f;
+ return 0/(x-x);
+ }
+ if (e < 0x3fff - 1) { /* |x| < 0.5 */
+ if (e < 0x3fff - (LDBL_MANT_DIG+1)/2) {
+ /* return x with inexact if x!=0 */
+ FORCE_EVAL(x + 0x1p120f);
+ return x;
+ }
+ return x + x*__invtrigl_R(x*x);
+ }
+ /* 1 > |x| >= 0.5 */
+ z = (1.0 - fabsl(x))*0.5;
+ s = sqrtl(z);
+ r = __invtrigl_R(z);
+ if (CLOSETO1(u)) {
+ x = pio2_hi - (2*(s+s*r)-pio2_lo);
+ } else {
+ long double f, c;
+ u.f = s;
+ CLEARBOTTOM(u);
+ f = u.f;
+ c = (z - f*f)/(s + f);
+ x = 0.5*pio2_hi-(2*s*r - (pio2_lo-2*c) - (0.5*pio2_hi-2*f));
+ }
+ return sign ? -x : x;
+}
+#endif