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From: Simon Wright <simon@pushface.org>
Newsgroups: comp.lang.ada
Subject: Re: GNAT for AVR - Mathematical Functions
Date: Mon, 17 Sep 2018 13:22:05 +0100
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Date: 2018-09-17T13:22:05+01:00
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ada.newcomer@gmail.com writes:

> I'm programming an ATmega328P with the GNAT compiler for AVR.
>
> I need to use the Sqrt, Arctan and Atan2 functions. But maybe in the
> future I will need to use some more.
>
> I don't have access to the regular Ada.Numerics package.
>
> By now, I wrote the Sqrt using the Newton's method and Arctan using
> Taylor series.
>
> I would like to know if there is a better way to use/implement
> mathematical functions (maybe import them from C?).
>
> I really appreciate any help.

For what it's worth, the FSF GCC arm-eabi compiler/runtime that I built
imports the basic maths functions from the C library. This may be
because I built the C library (newlib) first?

The GNAT CE arm-eabi compiler goes to basics with very deep-looking
code; possibly because it's "the Ada Cert Math specific version" (from
s-libsin.ads), i.e. one with which AdaCore will support customers with
certification requirements.