On Wed, Sep 23, 2015 at 3:41 PM, Ilya Enkovich <enkovich....@gmail.com> wrote: > 2015-09-18 16:40 GMT+03:00 Ilya Enkovich <enkovich....@gmail.com>: >> 2015-09-18 15:22 GMT+03:00 Richard Biener <richard.guent...@gmail.com>: >>> >>> I was thinking about targets not supporting generating vec<bool> >>> (of whatever mode) from a comparison directly but only via >>> a COND_EXPR. >> >> Where may these direct comparisons come from? Vectorizer never >> generates unsupported statements. It means we get them from >> gimplifier? So touch optabs in gimplifier to avoid direct comparisons? >> Actually vect lowering checks if we are able to make comparison and >> expand also uses vec_cond to expand vector comparison, so probably we >> may live with them. >> >>> >>> Not sure if we are always talking about the same thing for >>> "bool patterns". I'd remove bool patterns completely, IMHO >>> they are not necessary at all. >> >> I refer to transformations made by vect_recog_bool_pattern. Don't see >> how to remove them completely for targets not supporting comparison >> vectorization. >> >>> >>> I think we do allow this, just the vectorizer doesn't expect it. In the >>> long >>> run I want to get rid of the GENERIC exprs in both COND_EXPR and >>> VEC_COND_EXPR. Just didn't have the time to do this... >> >> That would be nice. As a first step I'd like to support optabs for >> VEC_COND_EXPR directly using vec<bool>. >> >> Thanks, >> Ilya >> >>> >>> Richard. > > Hi Richard, > > Do you think we have enough confidence approach is working and we may > start integrating it into trunk? What would be integration plan then?
I'm still worried about the vec<bool> vector size vs. element size issue (well, somewhat). Otherwise the integration plan would be 1) put in the vector<bool> GIMPLE type support and change the vector comparison type IL requirement to be vector<bool>, fixing all fallout 2) get support for directly expanding vector comparisons to vector<bool> and make use of that from the x86 backend 3) make the vectorizer generate the above if supported I think independent improvements are 1) remove (most) of the bool patterns from the vectorizer 2) make VEC_COND_EXPR not have a GENERIC comparison embedded (same for COND_EXPR?) Richard. > Thanks, > Ilya
