https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102988
--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Alexandre Oliva <aol...@gcc.gnu.org>: https://gcc.gnu.org/g:38e4a361e79a459947540920db645f3d7fa7221a commit r12-5429-g38e4a361e79a459947540920db645f3d7fa7221a Author: Alexandre Oliva <ol...@adacore.com> Date: Sat Nov 20 02:51:27 2021 -0300 harden conds: detach without decls When we create copies of SSA_NAMEs to hold "detached" copies of the values for the hardening tests, we end up with assignments to SSA_NAMEs that refer to the same decls. That would be generally desirable, since it enables the variable to be recognized in dumps, and makes coalescing more likely if the original variable dies at that point. When the decl is a DECL_BY_REFERENCE, the SSA_NAME holds the address of a parm or result, and it's read-only, so we shouldn't create assignments to it. Gimple checkers flag at least the case of results. This patch arranges for us to avoid referencing the same decls, which cures the problem, but retaining the visible association between the SSA_NAMEs, by using the same identifier for the copy. for gcc/ChangeLog PR tree-optimization/102988 * gimple-harden-conditionals.cc (detach_value): Copy SSA_NAME without decl sharing. for gcc/testsuite/ChangeLog PR tree-optimization/102988 * g++.dg/pr102988.C: New.
