From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Khapyorsky Subject: Re: [OPENSM] cast to remove warnings about signed vs. unsigned comparisons Date: Thu, 1 Oct 2009 19:02:12 +0200 Message-ID: <20091001170212.GR17846@me> References: <839303D0FDC14F77AE516FDC9CF8B6A7@amr.corp.intel.com> <20091001155613.GN17846@me> <3F6F638B8D880340AB536D29CD4C1E1912C86E862B@orsmsx501.amr.corp.intel.com> <20091001162715.GC22310@obsidianresearch.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20091001162715.GC22310-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jason Gunthorpe Cc: "Smith, Stan" , "ofw-ZwoEplunGu1OwGhvXhtEPSCwEArCW2h5@public.gmane.org" , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-rdma@vger.kernel.org On 10:27 Thu 01 Oct , Jason Gunthorpe wrote: > > I've always felt the warning on implicit cast from larger to smaller > type to be somewhat useless - that is an unavoidable operation when > working with networking. Adding casts does nothing to actually improve > the code, and trying to change to smaller types results in worse code > gen and no improvement in function. In general I would agree, but in case of OpenSM we are not in so excellent state where fixed size int types are always used for a reason. For instance a code like: int32_t i; for (i = 0; i < SOME_CONST; i++) do_something(array[i]); is not so uncommon. I would prefer to use generic int types where is possible and fixed sized where is needed. And then yes - to ignore "int casting" warning seems fine for me. This could be true, but not always in our case - OpenSM code base has a lot of fixed sized types unmotivated case where > Maybe OFW would be better off just turning that warning off? :) To minimize a porting efforts it could be an option. > > > In general to simplify a detection of such cases we can consider to > > > use -Wsign-compare gcc flag in linux environment. > > And -Wsign-conversion Yes. Sasha -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html