From: Michael Haggerty Date: Fri, 05 Jun 2015 20:03:27 GMT Subject: Re: Pack files, standards compliance, and efficiency Message-ID: <5572008F.6030203@alum.mit.edu> In-Reply-To: <20150605194200.GB356121@vauxhall.crustytoothpaste.net> On 06/05/2015 09:42 PM, brian m. carlson wrote: > On Fri, Jun 05, 2015 at 05:22:08PM +0200, Michael Haggerty wrote: >> I don't know that there would necessarily be problems, but I >> would worry about code involving structure assignment. For >> example, suppose the following snippet: >> >> void f(struct object_id *oid) { struct object_id oid_copy = >> *oid; /* ... */ } >> >> The compiler is allowed to implement the copy using instructions >> that rely on proper alignment. Such code would fail if oid is not >> properly aligned. > > We use oidcpy which doesn't use object assignment. I brought that > up previously, and Junio was opposed to doing *dest = *src. So I > don't think this ends up being an issue. Sorry for overlooking (or forgetting :-( ) that discussion. Indeed, that would allay my worry. Michael -- Michael Haggerty mhagger@alum.mit.edu