diff options
Diffstat (limited to 'src/math/__invtrigl.c')
| -rw-r--r-- | src/math/__invtrigl.c | 41 |
1 files changed, 10 insertions, 31 deletions
diff --git a/src/math/__invtrigl.c b/src/math/__invtrigl.c index a51330e2..f2d33d3e 100644 --- a/src/math/__invtrigl.c +++ b/src/math/__invtrigl.c @@ -1,36 +1,8 @@ -/* 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 -/* coefficients used in asinl() and acosl() */ -const long double +static const long double pS0 = 1.66666666666666666631e-01L, pS1 = -4.16313987993683104320e-01L, pS2 = 3.69068046323246813704e-01L, @@ -44,9 +16,16 @@ qS3 = -1.68285799854822427013e+00L, qS4 = 3.90699412641738801874e-01L, qS5 = -3.14365703596053263322e-02L; -const long double pi_hi = 3.1415926535897932384626433832795L; -const long double pi_lo = -5.01655761266833202345e-20L; const long double pio2_hi = 1.57079632679489661926L; const long double pio2_lo = -2.50827880633416601173e-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 |