Comment # 1
on bug 95438
from Bas Nieuwenhuizen
Last I looked at the elemental demo, we have multiple issues: - The shared array (1024 elements) get wrongly promoted to a private array. There is a fix for that at https://lists.freedesktop.org/archives/mesa-dev/2016-April/113832.html - in radeonsi we compile arrays to vectors with insert/extract element. This pretty much results in the array being SSA version, which results in a very large program. - a 1024 element vector does not fit in 256 VGPR's so LLVM tries to load and spill around every operation and therefore every versioned array element takes scratch space. - As a result I needed 7 MiB of scratch space per wave, or 6,7 GiB in total. This overflows the 32-bit buffer size and we only allocate a smaller buffer. - This resulted in hangs (or maybe long long shader execution times, not really sure...). So not sure how long a long long time is, last I tried (which admittedly is some weeks ago) I certainly could get past the compilation stage. If you did get past that and did not get hangs, I'm not sure why. Fixing the first problem also circumvents problems 2 & 3, although it would be nice to get those fixed as well.
You are receiving this mail because:
- You are the assignee for the bug.
_______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
