https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99456
--- Comment #14 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:82bb66730bc42b8694fdebef607ea6e49e8496bf commit r11-7740-g82bb66730bc42b8694fdebef607ea6e49e8496bf Author: Jakub Jelinek <ja...@redhat.com> Date: Fri Mar 19 18:36:56 2021 +0100 c++: Only reject reinterpret casts from pointers to integers for manifestly_const_eval evaluation [PR99456] My PR82304/PR95307 fix moved reinterpret cast from pointer to integer diagnostics from cxx_eval_outermost_constant_expr where it caught invalid code only at the outermost level down into cxx_eval_constant_expression. Unfortunately, it regressed following testcase, we emit worse code including dynamic initialization of some vars. While the initializers are not constant expressions due to the reinterpret_cast in there, there is no reason not to fold them as an optimization. I've tried to make this dependent on !ctx->quiet, but that regressed two further tests, and on ctx->strict, which regressed other tests, so this patch bases that on manifestly_const_eval. The new testcase is now optimized as much as it used to be in GCC 10 and the only regression it causes is an extra -Wnarrowing warning on vla22.C test on invalid code (which the patch adjusts). 2021-03-19 Jakub Jelinek <ja...@redhat.com> PR c++/99456 * constexpr.c (cxx_eval_constant_expression): For CONVERT_EXPR from INDIRECT_TYPE_P to ARITHMETIC_TYPE_P, when !ctx->manifestly_const_eval don't diagnose it, set *non_constant_p nor return t. * g++.dg/opt/pr99456.C: New test. * g++.dg/ext/vla22.C: Expect a -Wnarrowing warning for c++11 and later.
