[Mesa-dev] [Bug 94957] dEQP failures on llvmpipe

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=94957

--- Comment #8 from Roland Scheidegger <sroland at vmware.com> ---
(In reply to Ilia Mirkin from comment #7)
> > Also, I'm wondering if the test is overly picky about pow. The spec says
> > right there the error is derived as pow(x,y) = exp2(log2(y) * x) (note there
> > is a spec bug, x and y are swapped), which is exactly as we implement it.
> > Therefore, if our results are good enough for passing exp2 and log2, we
> > should pass pow as well.
> 
> pow() fails for inf ^ x == inf. I glanced at the gallivm code, and this
> appears to be on purpose (i.e. you generate faster code that doesn't handle
> inf).
>

Ahh right forgot about that - we hook up the safe log2 version for LG2 tgsi
opcode, but use the unsafe version for pow.
I think we did the lg2 safe version for d3d10 initially, since in gl it
traditionally didn't really matter. And pow doesn't exist in d3d10.
I suppose we could switch that if it's really worth it (too bad the special
values require 3 comparisons, 3 selects).

-- 
You are receiving this mail because:
You are the assignee for the bug.
You are the QA Contact for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/mesa-dev/attachments/20160419/018ad61c/attachment.html>