[Mesa-dev] Mesa llvmpipe for WebGL software rendering

[Jose Fonseca]

----- Original Message -----
> On Die, 2012-02-28 at 09:08 -0800, Benoit Jacob wrote:
> > 
> > At Mozilla we've been wondering if we could get a good software
> > fallback for users who can't get hardware-accelerated WebGL. Mesa
> > llvmpipe seems like the best open source OpenGL renderer, right? At
> > least, it performed superbly in our quick tests.
> 
> [...]
> 
> > 3. On GNU/Linux: why isn't Mesa llvmpipe installed by default by
> > most
> > distros? Is there a real reason or is it just that nobody asked for
> > it, or nobody saw a need for it? Trying to figure if llvmpipe
> > installed by default everywhere (on Linux) is something we can
> > realistically hope for.
> 
> One thing to keep in mind for this is that llvmpipe currently doesn't
> work on PowerPC architectures. I don't know the status for other
> non-x86
> architectures. So 'llvmpipe installed by default everywhere' isn't
> realistic right now, but 'llvmpipe installed by default wherever
> possible' is.

Ah, yes. I had forgot about that.

Indeed llvmpipe currently is only known to work well on x86 (32 or 64bits).

It should be straightforward to support any other little endian architecture that's also supported by LLVM. There are probably a few bugs w/ big endian architectures. 

PowerPC support is currently broken, not only due to big endian issue, but also because it looks that LLVM PowerPC backend has issues/limitations of its own.

Jose