https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98211
--- Comment #11 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to rsand...@gcc.gnu.org from comment #8) > (In reply to Richard Biener from comment #7) > > Hmm, OK, so besides the incomplete bool pattern matching the issue seems to > > be that while we reject the problematic conversion in > > vectorizable_conversion it slips through via vectorizable_assignment because > > it does > > > > /* Conversion between boolean types of different sizes is > > a simple assignment in case their vectypes are same > > boolean vectors. */ > > && (!VECTOR_BOOLEAN_TYPE_P (vectype) > > || !VECTOR_BOOLEAN_TYPE_P (vectype_in))) > > > > as opposed to vectorizable_conversions > > > > if (VECTOR_BOOLEAN_TYPE_P (vectype_out) > > && !VECTOR_BOOLEAN_TYPE_P (vectype_in)) > > > > that was added by g:2dab46d5fc9f95de16bd9bf0f219be5e64324d1f without a > > testcase > > or PR reference so it's difficult to tell what it was supposed to allow. > Agree that looks odd… > > > Now, > > for the case in question the conversion would have slipped though anyway > > since > > the only difference in the types is the sign and that one is BOOLEAN_TYPE > > and the other INTEGER_TYPE. So the exception above seems to intent to allow > > conversions with different precisions (note we now have precision 1 for all > > vector bools). > > > > So I'm going to just copy the vectorizable_conversion condition into > > vectorizable_assignment as well. > Shouldn't it instead be: > > VECTOR_BOOLEAN_TYPE_P (vectype) != VECTOR_BOOLEAN_TYPE_P (vectype_in) > > as is used in some other places (sometimes with ^ instead of !=)? > AFAIK using VCE would break in both directions. I think the intent was to allow vector<bool:2> to vector<bool:4>, both SImode to be converted for free (since in the end they have the same representation, _not_ occupying 2 and 4 bits but only one). I've recently "fixed" (changed) the integer mode bool vectors to always be vector<bool:1> to reflect that so I'm going to test simply removing that odd condition.
