On Tue, Nov 3, 2015 at 8:23 PM, Timothy Arceri <timothy.arc...@collabora.com> wrote: > On Wed, 2015-11-04 at 12:12 +1100, Timothy Arceri wrote: >> On Tue, 2015-11-03 at 19:39 -0500, Ilia Mirkin wrote: >> > On Tue, Nov 3, 2015 at 7:31 PM, Timothy Arceri <t_arc...@yahoo.com.au> >> > wrote: >> > > On Tue, 2015-11-03 at 19:21 -0500, Ilia Mirkin wrote: >> > > > I'm still unclear what problem you're trying to solve here? What's >> > > > wrong with having b[1] = b[1]? >> > > >> > > There is nothing wrong with it, but nir seems to expect this type of >> > > assignment to be optimised out and hits an assert if its not. Its >> > > removed >> > > for >> > > non arrays in opt_copy_propagation.cpp see add_copy() >> > >> > Sounds like a bugfix for nir might be in order then? What if you have, >> > say, b[1] = b[1] + 0 and then NIR optimizes away the + 0? Or + >> > some_var which happens to become 0 as a result of optimizations? >> >> Assuming the GLSL IR doesn't get to it first your right, however this is >> tripping up nir_lower_vars_to_ssa() which is the first optimisation call for >> nir drivers, so we still need to add this to the GLSL IR optimisations >> unless >> there is an argument to move the lower pass until after the other >> optimisation >> passes but I assume it was added to the beginning for a reason. >> >> I moved the lower call to the end of the optimisation list to see what >> happens >> and it does indeed still fail. I can have a go at adding the optimisation to >> nir when I get some time > > I can also note this in the bug report and leave it open until it is resolved. > >> but I don't think this should be a blocker to the >> GLSL IR fix.
Perhaps you should wait for someone with a better understanding of what's going on than me to review. It just seems odd to have this super-special-cased thing in a GLSL IR opt just because of some generic-looking NIR deficiency. It sounds like the sort of thing that'd be very easy to fix there, instead of adding seemingly unnecessary extra work in the GLSL IR. -ilia _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
