Richard Sandiford <richard.sandif...@arm.com> writes: > Richard Biener <rguent...@suse.de> writes: >> When change_vec_perm_layout runs into a permute combining two >> nodes where one is invariant and one internal the partition of >> one input can be -1 but the other might not be. The following >> supports this case by simply ignoring inputs with input partiton -1. >> >> I'm not sure this is correct but it avoids ICEing when accessing >> that partitions layout for gcc.target/i386/pr98928.c with the >> change to avoid splitting store dataref groups during SLP discovery. >> >> Bootstrap and regtest running on x86_64-unknown-linux-gnu (ontop of >> the SLP series). The change can't break anything that's already >> broken but I'm not sure this does the right thing - the testcase >> has an uniform constant. I'll try to come up with a better runtime >> testcase tomorrow. Hints as to where to correctly fix such case >> appreciated. > > Famous last words, but yeah, it looks correct to me. I think the > routine in principle should have a free choice of which layout to > choose for invariants (as long as it's consistent for all queries > about the same node). So it should just be a question of whether > keeping the original layout is more likely to give a valid > permutation, or whether going with out_layout_i would be better. > I don't have a strong intuition either way.
BTW, I should have said that using a different layout from 0 would require compensating code in the materialize function. So this is definitely the simplest and most direct fix. Thanks, Richard
