On Sun, Nov 1, 2009 at 9:34 AM, Pierre Ossman <pierre-l...@ossman.eu> wrote: > I'm looking at r600/r700 compiler with the ambition of filling in the > missing pieces. I've just read through the documentation and the basic > structure of the compiler, and I'm having a hard time understanding the > design choices of the code. Hopefully someone can fill me in on what > the plan is here. > > The basic problem is that the compiler is a somewhat poor fit for the > hardware. The compiler is designed around vectors, whilst the hardware > works more in terms of individual elements (albeit with a whole bunch > of restrictions). This disparity means that the compiler in its current > form can be very inefficient. Worst case scenario is using 25% of the > hardware. > > As an example, I've been looking at implementing the EXP op. A simple > implementation would use 4 instruction groups with the current > compiler, but the hardware should be capable of doing it with 2. An > optimised implementation would range in efficiency between 100% and 33% > of hardware capability. The common case would probably still be 50%. > > So what's the plan here? This kind of inefficiency must be a temporary > solution and not the final goal?
At this point the compiler is pretty much unoptimized; it was written to make sure everything worked. In most cases it just provides the basic functionality, so optimizations are welcome. I've cc'ed Richard as he has written most of the shader code at this point. Alex ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Mesa3d-dev mailing list Mesa3d-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mesa3d-dev
