[Bug 83658] Loop unrolling doesn't take into account whether it will decrease or increase performance

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=83658

--- Comment #2 from Eero Tamminen <eero.t.tamminen at intel.com> ---
(In reply to comment #1)
> FWIW there exists code to detect expressions that are constant within a loop
> (during loop analysis), I think this could be used as starting point for
> such optimization.

Loop invariant code handling could also be the root cause making e.g. SynMark2
PSPhong 3x slower than it should be:
- code doesn't get unrolled with all the loop invariant code inside the loop 
- this resulting in cascade effect that causes also other problems. e.g. stuff
which on Windows GL is handled with push & no sampler, changes to (unecessarily
looped) pull and makes thing sampler bound with Mesa instead of it being PS ALU
bound

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/intel-3d-bugs/attachments/20140929/2f0e164b/attachment.html>