From: John CarmackDate: Mon, 21 Oct 96 09:00:37 -0500 To: Kamil Ruszkowski Subject: Re: Quake - fast or easy? References: X-PMFLAGS: 34078848 You wrote: > We've had a bit of an argument about QUAKE using floating > math here in Polish USENET. Some say it is faster, some claim > it is easier to > write for FPU and the game would be much faster using just > integer. It is both faster and easier. For a 486, AMD, or cyrix cpu, quake would indeed go faster with just integer ops, but not on a pentium or pentium pro. We do a LOT of multiplies in quake, and we would suffer a great deal if they were blocking integer operations instead of three / one cycle pipelined FP operations. Also, our inner texture mapping loop has an overlapped FP divide running in the background of each group of spans. People that are still resisting FP are living in the past... John Carmack