site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com On Nov 4, 2006, at 5:49 AM, Jonas Maebe wrote: On 04 Nov 2006, at 11:51, Uli Kusterer wrote: -Eric _______________________________________________ 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... What is meant by the STx registers being empty on entry/exit to function calls. Does that mean they contain zero? Or is there some status flag to indicate one as unused? The x86' fpu, the x87, uses a stack-based register file (with 8 slots) rather than a flat register file like pretty much every other cpu/fpu out there. The statement means that the register stack of the x87 must be empty on entry/exit. Yep. We rarely use the x87 FPU on Mac OS X. It's mostly only used for long longs. We default to using SSE for floating point math, so most functions don't end up having to care about the state of the x87 FP stack. This email sent to site_archiver@lists.apple.com