site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com On 04 Nov 2006, at 11:01, Uli Kusterer wrote: Indeed. Jonas _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.appl... Am 03.11.2006 um 23:43 schrieb Jonas Maebe: All PPC ABI's used by Apple have always required a 16 byte aligned stack afaik, there's nothing G4-specific about that. Well, I just remember that RealBASIC or somesuch compiler had a problem with menu text colors all going wonky because they didn't align the stack properly, and apparently that didn't show on G3s, but showed on G4s when Apple used more AltiVec-optimized code. I guess that also fits your explanation below. So, my app will be launched with a mis-aligned stack? Aha! That also explains the (seemingly pointless) subl $8, %esp at the start of even empty functions. So, whenever I enter a function, the stack will be at 4 because the return address has been pushed? Yes. The requirement in the ABI is that the stack is aligned at a multiple of 16 bytes /before/ every function call. This email sent to site_archiver@lists.apple.com