https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111668
--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:7ab01269396203d5200fff8579768da54dcfde5d commit r14-4391-g7ab01269396203d5200fff8579768da54dcfde5d Author: Jakub Jelinek <ja...@redhat.com> Date: Wed Oct 4 09:27:40 2023 +0200 match.pd: Fix up a ? cst1 : cst2 regression on signed bool [PR111668] My relatively recent changes to these simplifiers to avoid doing build_nonstandard_integer_type (primarily for BITINT_TYPE) broke PR111668, a recurrence of the PR110487 bug. I thought the build_nonstandard_integer_type isn't ever needed there, but there is one special case where it is. For the a ? -1 : 0 and a ? 0 : -1 simplifications there are actually 3 different cases. One is for signed 1-bit precision types (signed kind of implied from integer_all_onesp, because otherwise it would match integer_onep earlier), where the simplifier wierdly was matching them using the a ? powerof2cst : 0 -> a << (log2(powerof2cst)) simplification and then another simplifier optimizing away the left shift when log2(powerof2cst) was 0. Another one is signed BOOLEAN_TYPE with precision > 1, where indeed we shouldn't be doing the negation in type, because it isn't well defined in that type, the type only has 2 valid values, 0 and -1. As an alternative, we could also e.g. cast to signed 1-bit precision BOOLEAN_TYPE and then extend to type. And the last case is what we were doing for types which have both 1 and -1 (all all ones) as valid values (i.e. all signed/unsigned ENUMERAL_TYPEs, INTEGRAL_TYPEs and BITINT_TYPEs with precision > 1). The following patch avoids the hops through << 0 for 1-bit precision and uses build_nonstandard_integer_type solely for the BOOLEAN_TYPE types (where we have a guarantee the precision is reasonably small, nothing ought to be created 129+ bit precision BOOLEAN_TYPEs). 2023-10-04 Jakub Jelinek <ja...@redhat.com> PR tree-optimization/111668 * match.pd (a ? CST1 : CST2): Handle the a ? -1 : 0 and a ? 0 : -1 cases before the powerof2cst cases and differentiate between 1-bit precision types, larger precision boolean types and other integral types. Fix comment pastos and formatting.
