https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113576
--- Comment #19 from rguenther at suse dot de <rguenther at suse dot de> --- On Thu, 25 Jan 2024, rsandifo at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113576 > > --- Comment #18 from Richard Sandiford <rsandifo at gcc dot gnu.org> --- > (In reply to Tamar Christina from comment #17) > > Well the mid-end has generated the right precision. The type it generates is > > vector(4) <signed-boolean:1> vexit_reduc_67; > > so it does say it's a single bit boolean. > > > > Isn't this just an expand problem? > That's what I meant. expand is using a QImode comparison to compare things > with 4-bit precision, so I think the masking should happen at that point. > > How about doing the masking in do_compare_and_jump? That sounds sensible. Note that I wonder how to eliminate redundant maskings? I suppose eventually combine tracking nonzero bits where obvious would do that? For example for cmp:V4SI we know the bits will be zero but I wonder if the RTL IL is obvious enough to derive this (or whether there's a target hook for extra nonzero bit discovery, say for unspecs).
