Path: csiph.com!eternal-september.org!feeder.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: gcc failure (optimised/non-optimised)
Date: Sun, 30 Apr 2017 11:24:47 -0700
Organization: None to speak of
Lines: 23
Message-ID: <lnshkpkb2o.fsf@kst-u.example.com>
References: <odf2pf$dd0$1@dont-email.me> <58fb2265.5246218@news.xs4all.nl> <EEFKA.484957$fL.133530@fx24.am4> <lnzif8pi97.fsf@kst-u.example.com> <QlLKA.442109$Iy2.238516@fx28.am4> <oe4tco$g5p$1@dont-email.me>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Injection-Info: mx02.eternal-september.org; posting-host="518c2254bac820b1cb24a1d9d6a93e31"; logging-data="23057"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX19+DF4QEEYV+1F1pQdCQDPL"
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux)
Cancel-Lock: sha1:g0CtcW8XQVYeeoXQNv4W+WdnL/Y= sha1:WW5vfit1Hg+crH9bVfqM5Dqibc8=
Xref: csiph.com comp.lang.c:108788

Noob <root@127.0.0.1> writes:
[...]
> Let's consider a slightly different situation.
>
> int foo(int n) {
>   return n * 2 / 2;
> }
>
> Does anyone disagree that an optimizing compiler would
> determine that this is the identity function, and would
> drop the calls altogether, by replacing foo(x) with x.

I agree that an optimizing compiler (actually any compiler) *could*
do that, given that x is of type int.  But there is no requirement
to do so.

[...]

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"