log1pf.sollya

// polynomial for approximating log(1+x) in single precision
//
// Copyright (c) 2022-2024, Arm Limited.
// SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception

deg = 10;

a = -0.25;
b = 0.5;

f = proc(y) {
  return log(1+y);
};

poly = fpminimax(f(x), deg, [|single ...|], [a;b]);

display = hexadecimal;
print("rel error:", accurateinfnorm(1-poly(x)/f(x), [a;b], 30));
print("in [",a,b,"]");
print("coeffs:");
for i from 2 to deg do round(coeff(poly,i), SG, RN);