Richard Biener <richard.guent...@gmail.com> writes: > On October 19, 2019 5:06:40 PM GMT+02:00, Richard Sandiford > <richard.sandif...@arm.com> wrote: >>After the previous patch, it seems more natural to apply the >>PARAM_SLP_MAX_INSNS_IN_BB threshold as soon as we know what >>the region is, rather than delaying it to vect_slp_analyze_bb_1. >>(But rather than carve out the biggest region possible and then >>reject it, wouldn't it be better to stop when the region gets >>too big, so we at least have a chance of vectorising something?) >> >>It also seems more natural for vect_slp_bb_region to create the >>bb_vec_info itself rather than (a) having to pass bits of data down >>for the initialisation and (b) forcing vect_slp_analyze_bb_1 to free >>on every failure return. >> >>Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install? > > Ok. But I wonder what the reason was for this limit? Dependency analysis was > greatly simplified, being no longer quadratic here. Can you check where the > limit originally came from? But indeed splitting the region makes more sense > then, but at dataref group boundaries I'd say.
Yeah, looks it was the complexity of dependence analysis: https://gcc.gnu.org/ml/gcc-patches/2009-05/msg01303.html > Is there any limit on the size of the BB you consider for > vectorization? I see we do compute_all_dependences on it - that > might be quite costly. I added slp-max-insns-in-bb parameter with initial value 1000. Thanks, Richard
