From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-288770-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 23303 invoked by alias); 14 Jul 2009 19:21:20 -0000
Received: (qmail 23247 invoked by uid 48); 14 Jul 2009 19:21:09 -0000
Date: Tue, 14 Jul 2009 19:21:00 -0000
Message-ID: <20090714192109.23246.qmail@sourceware.org>
X-Bugzilla-Reason: CC
References: <bug-40752-15110@http.gcc.gnu.org/bugzilla/>
Subject: [Bug c++/40752] -Wconversion generates false warnings
In-Reply-To: <bug-40752-15110@http.gcc.gnu.org/bugzilla/>
Reply-To: gcc-bugzilla@gcc.gnu.org
To: gcc-bugs@gcc.gnu.org
From: "pinskia at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-bugs.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
X-SW-Source: 2009-07/txt/msg01151.txt.bz2



------- Comment #1 from pinskia at gcc dot gnu dot org  2009-07-14 19:21 -------
Theses are not false warnings:
        c >>= 1;

is really c = (int)c >> 1;

        c += (char) 1;

c =  (int)c + (int)(char)1;

        c += c2;

c = (int)c + (int) c2;


        c = ~c2;

c = ~(int)c2;

Only the last one might be a false warning depending on if c2 is negative or
unsigned or not.  The rest are correct because of the way C/C++ define
arithmetic operations and automatic promotions.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40752