We have a system in which an x86 master controls an army of ppc slaves. Communication is via network message described as structs. Some messages contain 64 bit integers. Standard ABIs for these respective architectures differ wrt the notion of maximum alignment (x86 saturates at 4 bytes, ppc at 8). Our original implementation compiled the master with gcc 2.96 and the slaves with the commercial Diab compiler. The Diab compiler, perhaps because it targeted embedded environments, provided a means of overriding the standard maximum alignment. In this way our network message ended up laid out identically on both platforms and life was good :-) We are currently attempting to replace the Diab compiler with a 3.4.3 or later (possibly even 4.1) ppc gcc. At this point the incompatible ABIs issue has reappeared. Is there ANY way that we can convince gcc to hold its nose, to ignore the dictates of the ABI, and to use a lesser maximum alignment value? /john -- John S. Yates, Jr. 508 665-6897 (voice) Netezza Inc 508 665-6811 (fax) 200 Crossing Blvd. Framingham, MA 01701
