-/* origin: FreeBSD /usr/src/lib/msun/src/ld80/invtrig.c */
-/*-
- * Copyright (c) 2008 David Schultz <das@FreeBSD.ORG>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
#include "__invtrigl.h"
#if LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
-/*
- * asinl() and acosl()
- */
-const long double
+
+static const long double
pS0 = 1.66666666666666666631e-01L,
pS1 = -4.16313987993683104320e-01L,
pS2 = 3.69068046323246813704e-01L,
qS4 = 3.90699412641738801874e-01L,
qS5 = -3.14365703596053263322e-02L;
-/*
- * atanl()
- */
-const long double atanhi[] = {
- 4.63647609000806116202e-01L,
- 7.85398163397448309628e-01L,
- 9.82793723247329067960e-01L,
- 1.57079632679489661926e+00L,
-};
-
-const long double atanlo[] = {
- 1.18469937025062860669e-20L,
- -1.25413940316708300586e-20L,
- 2.55232234165405176172e-20L,
- -2.50827880633416601173e-20L,
-};
-
-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,
-};
+const long double pio2_hi = 1.57079632679489661926L;
+const long double pio2_lo = -2.50827880633416601173e-20L;
-const long double pi_lo = -5.01655761266833202345e-20L;
+/* used in asinl() and acosl() */
+/* R(x^2) is a rational approximation of (asin(x)-x)/x^3 with Remez algorithm */
+long double __invtrigl_R(long double z)
+{
+ long double p, q;
+ p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*(pS5+z*pS6))))));
+ q = 1.0+z*(qS1+z*(qS2+z*(qS3+z*(qS4+z*qS5))));
+ return p/q;
+}
#endif