On 05 July 2006 19:11, Rene Rebe wrote: > Hi, > > On Wednesday 05 July 2006 19:57, Mike Stump wrote: >> On Jul 4, 2006, at 7:43 PM, [EMAIL PROTECTED] wrote: >>> The codec is at http://www.sourceforge.net/projects/openavs/. >>> Currently, it requires a 3Ghz or better CPU to get a resonable >>> framerate. I would like the codec to be useful even on 586 ( 1Ghz or >>> so ). Any ideas? >> >> Recode slower parts in assembler or punt to video card. > > Aside the general com.lang.c boilderplate (...) usually it is > already a gain to rewrite inefficent algorithms with something > more clever and to use gcc SIMD vector extensions.
I believe Lionel's real problem is likely to be that he was hoping that turning on the "-mmx -sse -sse2 -3dnow" options would auto-vectorise his code for him. Lionel, (IIUIC) those options just /enable/ the use of the various SIMD features; they don't adjust your code to use those features if it doesn't do so already, so apart from a fairly small speed-up on some floating point operations that can be done more efficiently in the mmx unit, you shouldn't have been expecting to see much difference in the first place. cheers, DaveK -- Can't think of a witty .sigline today....