On Thu, 2007-05-17 at 20:30 +0000, Matthieu CASTET wrote: > On Thu, 17 May 2007 10:29:31 -0700, Andrew Morton wrote: > > > On Thu, 17 May 2007 18:09:50 +0300 Artem Bityutskiy > > <[EMAIL PROTECTED]> wrote: > > > > umm.. I'd say what you've done in there is an improvement to the > > exiting stuff: getting gcc to check it is better than having to use > > sparse. > > > > I'd have expected gcc to generate poorer code with your approach but I'm > > showing zero text size changes from Christoph's patch (gcc-4.1 and > > gcc-3.4.5). > > > > > On which arch did you try ? > X86 where unaligned access are ok ? > > On arch that don't support aligned access, packed struct access will be > done byte per byte (but it could be the expected behavior if there > unaligned access).
When I tested this on ARM, the output for je32_to_cpu et al was fine. For _other_ structures where I'd used __attribute__((packed)) to be safe, gcc would emit code to handle unaligned loads. But not in the simple case where the struct has only one member. Are you suggesting that this has changed since I did my testing? -- dwmw2 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/