xref: /freebsd-src/contrib/arm-optimized-routines/math/tools/tan.sollya (revision f3087bef11543b42e0d69b708f367097a4118d24)
1*f3087befSAndrew Turner// polynomial for approximating double precision tan(x)
2*f3087befSAndrew Turner//
3*f3087befSAndrew Turner// Copyright (c) 2023-2024, Arm Limited.
4*f3087befSAndrew Turner// SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
5*f3087befSAndrew Turner
6*f3087befSAndrew Turnerdeg = 8;
7*f3087befSAndrew Turner
8*f3087befSAndrew Turner// interval bounds
9*f3087befSAndrew Turnera = 0x1.0p-126;
10*f3087befSAndrew Turnerb = pi / 8;
11*f3087befSAndrew Turner
12*f3087befSAndrew Turnerdisplay = hexadecimal;
13*f3087befSAndrew Turner
14*f3087befSAndrew Turnerf = (tan(sqrt(x))-sqrt(x))/x^(3/2);
15*f3087befSAndrew Turnerpoly = fpminimax(f, deg, [|double ...|], [a*a;b*b]);
16*f3087befSAndrew Turner
17*f3087befSAndrew Turner//print("rel error:", accurateinfnorm(1-poly(x)/f(x), [a;b], 30));
18*f3087befSAndrew Turnerprint("in [",a,b,"]");
19*f3087befSAndrew Turnerprint("coeffs:");
20*f3087befSAndrew Turnerfor i from 0 to deg do coeff(poly,i);
21