On Mon, Mar 3, 2008 at 6:10 AM, Ronald Oussoren <[EMAIL PROTECTED]> wrote:
> > On Monday, March 03, 2008, at 11:53AM, "Duncan McGregor" < > [EMAIL PROTECTED]> wrote: > > >> I can simply check the calculated size after calling ffi_prep_cif(), > and compare that to sizeof(void*) to see if the return value will fit in a > register. > > > >Is that right? 8 byte structs are returned in EAX and EDX on IA-32, so > >I'd expect to call objc_msgSend. > > The rules are a bit more complex than this (at least on x86). Small > structs are returned in registers (upto 8 bytes), but only if the size of > the struct is a power of 2. That is, a 6-byte struct will not be returned in > registers. I haven't checked recently if the ABI documentation reflects > reality, in 10.4 days it didn't. Thanks for the tip. I shall have to go diving into libffi to see exactly what the rules really are then. I suspect they might be different for PPC & Intel, because the PPC32 docs still say that only r3 is used, for a limit of 4 bytes. sherm-- _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
