[cairo] [PATCH, pixman] Eliminate fast path flags

[Soeren Sandmann]

Siarhei Siamashka <siarhei.siamashka at gmail.com> writes:

> > Reviews appreciated. I'd also appreciate if people can test that it
> > still compiles and works on ARM as I had to make some changes blindly
> > there.
> 
> It compiles fine, but requires a minor fix for ARM NEON. These two lines need
> a 'PIXMAN_a8' -> 'PIXMAN_solid' change:
> 
> +    { PIXMAN_OP_OVER, PIXMAN_a8r8g8b8, PIXMAN_a8,       PIXMAN_a8r8g8b8, 
> neon_composite_over_8888_n_8888, 0 },
> +    { PIXMAN_OP_OVER, PIXMAN_a8r8g8b8, PIXMAN_a8,       PIXMAN_x8r8g8b8, 
> neon_composite_over_8888_n_8888, 0 },
> 
> This was spotted by just patch review. 

Thanks - I have fixed this and pushed the patch.

> But it's also worth mentioning that
> using 'blitters-test', the problem gets only detected on 3280827th iteration.
> And the test is currently set to run 2000000 iterations by default. Just the
> probability of getting right operation and right formats for source, mask and
> destination all at the same time is a bit too low.

> Tweaking probabilities for more uniform coverage may help a bit. Increasing
> the number of iterations that are run by default may also be useful. But
> still, an overnight run makes sense to spot some of the more rare problems.
 
Yeah, we should probably at have at least two CRC32 values, one for
the 2 million case, and one for a 100 million case that could run
overnight.

It might also be interesting to have many more than two values, and
store them in a table where each row would contain both CRC and seed
for 2 million iterations, for 4 million, for 6 million and so on.

The test could then pick a range to run at random, which would
substantially increase the coverage.


Soren