From mboxrd@z Thu Jan  1 00:00:00 1970
From: ralph@inputplus.co.uk (Ralph Corderoy)
Date: Thu, 09 Nov 2017 01:22:07 +0000
Subject: [TUHS] C question for the historians
In-Reply-To: <dcc53445-a7b1-2a12-cc17-739dacb3b06f@case.edu>
References: <bd0bd6ba-ef3d-768f-6ae1-89240dff165c@kilonet.net>
 <20171108181420.517711F949@orac.inputplus.co.uk>
 <20171108190540.GA7241@mcvoy.com>
 <CAP6exYKVyTAmOTT944md+0Lmg-yN=2=qwrDm+n3p_6+QvQ2JFg@mail.gmail.com>
 <dcc53445-a7b1-2a12-cc17-739dacb3b06f@case.edu>
Message-ID: <20171109012207.BA4111F942@orac.inputplus.co.uk>

Hi Chet,

> > But this w & MASK discussion is one of the weirder ones.
>
> gcc warns about it in its default mode

I'm having trouble triggering that, though often these things crop up
when you don't want them, not when you do.

    $ cat t.c
    #define M 0xa5

    int foo(int i, int j)
    {
	if (i & M && j & ~M)
	    return 42;
	return -314;
    }
    $ gcc -Wall -pedantic`: swine` -O3 -c t.c
    $

When it does moan, is it one of those things where just extra
parenthesis suffice as a signal that you meant it?

-- 
Cheers, Ralph.
https://plus.google.com/+RalphCorderoy