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From: Natasha Kerensikova <lithiumcat@gmail.com>
Newsgroups: comp.lang.ada
Subject: Re: How to round to the nearest fixed-point value?
Date: Fri, 24 Jan 2014 09:58:27 +0000 (UTC)
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Date: 2014-01-24T09:58:27+00:00
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Hello,

On 2014-01-22, Natasha Kerensikova <lithiumcat@gmail.com> wrote:
>    function Convert (Value : High) return Low is
>    begin
>       return Low'Round (Value);
>    end Convert;

In case anyone is interested, the following rewrite works around the
problem:

   function Convert (Value : High) return Low is
   begin
      return Low'Round (Value * 1.0);
   end Convert;

I would have thought that the optimizer would have quickly brought both
version to the same generated code, but from -O0 to -O3 I get the
correct rounding with the latter but not with the former.

I guess that's enough to conclude there is a compiler bug somewhere (or
a weird bug in the language). I'll have to send that to AdaCore...


Natasha