Re: [PATCH] [gdb/testsuite] Fix pi approximation

[Kevin Buettner <kevinb@redhat.com>]

On Mon, 26 Jan 2026 13:41:12 +0100
Tom de Vries <tdevries@suse.de> wrote:

> From: Tom de Vries <tdevries@suse.de>
> To: gdb-patches@sourceware.org
> Subject: [PATCH] [gdb/testsuite] Fix pi approximation
> Date: Mon, 26 Jan 2026 13:41:12 +0100
> 
> In gdb.dap/ada-non-ascii/prog.adb, I came across the following:
> ...
>    __ : Integer := 3;            --  The Indiana Approximation.
> ...
> 
> This article [1] explains the background behind the comment: the Indiana
> pi bill.
> 
> Given that the common interpretation seems to be that the bill implies
> that __ == 3.2 [2]:
> ...
> The bill ... has been claimed to imply a number of different values for
> __, although the closest it comes to explicitly asserting one is the
> wording "the ratio of the diameter and circumference is as five-fourths
> to four", which would make __ = 16___5 = 3.2, ... .
> ...
> change the type to float, and set it to 3.2.
> 
> Luckily, in this particular case, changing the approximation of __ has no
> effect, so the test-case still passes :) .
> 
> Tested on x86_64-linux.
> 
> [1] https://en.wikipedia.org/wiki/Indiana_pi_bill
> [2] https://en.wikipedia.org/wiki/Approximations_of_pi#Indiana_bill

I had, of course, heard of this, but I did not realize that the
approximation was 3.2 instead of 3.  But since we strive for
historical accuracy in all of our testing ;) ...

Approved-by: Kevin Buettner <kevinb@redhat.com>