xref: /aosp_15_r20/external/arm-optimized-routines/pl/math/tools/asin.sollya (revision 412f47f9e737e10ed5cc46ec6a8d7fa2264f8a14)
1*412f47f9SXin Li// polynomial for approximating asin(x)
2*412f47f9SXin Li//
3*412f47f9SXin Li// Copyright (c) 2023, Arm Limited.
4*412f47f9SXin Li// SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
5*412f47f9SXin Li
6*412f47f9SXin Lif = asin(x);
7*412f47f9SXin Lidtype = double;
8*412f47f9SXin Li
9*412f47f9SXin Liprec=256;
10*412f47f9SXin Li
11*412f47f9SXin Lia = 0x1p-106;
12*412f47f9SXin Lib = 0.25;
13*412f47f9SXin Li
14*412f47f9SXin Lideg = 11;
15*412f47f9SXin Li
16*412f47f9SXin Libackward = proc(poly, d) {
17*412f47f9SXin Li  return d + d ^ 3 * poly(d * d);
18*412f47f9SXin Li};
19*412f47f9SXin Li
20*412f47f9SXin Liforward = proc(f, d) {
21*412f47f9SXin Li  return (f(sqrt(d))-sqrt(d))/(d*sqrt(d));
22*412f47f9SXin Li};
23*412f47f9SXin Li
24*412f47f9SXin Lipoly = fpminimax(forward(f, x), [|0,...,deg|], [|dtype ...|], [a;b], relative, floating);
25*412f47f9SXin Li
26*412f47f9SXin Lidisplay = hexadecimal!;
27*412f47f9SXin Liprint("rel error:", dirtyinfnorm(1-backward(poly, x)/f(x), [a;b]));
28*412f47f9SXin Liprint("in [", a, b, "]");
29*412f47f9SXin Lifor i from 0 to deg do print(coeff(poly, i));
30