[Libre-soc-isa] [Bug 1077] evaluate removing /vec234 from instructions, move subvl to SVSTATE

[bugzilla-daemon at libre-soc.org]

https://bugs.libre-soc.org/show_bug.cgi?id=1077

--- Comment #4 from Jacob Lifshay <programmerjake at gmail.com> ---
(In reply to Jacob Lifshay from comment #2)
> imho it is not sensible to remove subvl from the prefix because GPU code
> often has subvl different in each instruction, so setvl or similar would
> need to be constantly reran just to change subvl, this would easily be many
> times more setvl ops because otherwise setvl is usually ran once per shader
> or once per function.

as an example, take this not-unusual blur shader from supertuxkart:
https://github.com/supertuxkart/stk-code/blob/fd12829e5b0c2f91fe522df5d8c74e3bb905b0cc/data/shaders/gaussian6h.frag
it would need like 15 setvl ops, and that's without even unrolling that loop!
something like >30 for the loop-unrolled version! If we instead keep the
status-quo with support for subvl in the prefix, the entire function needs just
one setvl op.

-- 
You are receiving this mail because:
You are on the CC list for the bug.