[Pixman] Prototype JIT compiler

[Søren Sandmann]

André Tupinambá <andrelrt at gmail.com> writes:

> Long time no see.

Indeed -- good to see you back.

> I just finished my master degree and was thinking about to return my
> contributions to pixman project, exactly in JIT compiler but with LLVM.
>
> What do you think about? Is it a bad idea to create a dependency with LLVM?
> Or will we get better results developing another infrastructure?

I don't know to be honest -- it may well be that using LLVM is the saner
approach. There are clearly a number of potential advantages: Support
for multiple architectures, and having a big community do the
maintenance are big ones. Also, some of the weak points of my branch,
that I mentioned, for example hoisting constants and register
allocation, would potentially be fixed. The issue of swizzling a8b8g8r8
to a8r8g8b8 probably wouldn't though.

Potential downsides is that it's a huge template based C++ library, and
last time I looked at it (which was a long time ago), the SIMD support
wasn't that convincing. I also suspect that it will be difficult to
generate really top-notch code with LLVM because we won't have direct
control over each machine instruction.


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