https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90313
--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-9 branch has been updated by Richard Sandiford <rsand...@gcc.gnu.org>: https://gcc.gnu.org/g:52db14c1f700e14e5b1b6c7fc702c0a08cc3781c commit r9-8252-g52db14c1f700e14e5b1b6c7fc702c0a08cc3781c Author: Richard Sandiford <richard.sandif...@arm.com> Date: Fri Aug 9 09:37:55 2019 +0000 Reject tail calls that read from an escaped RESULT_DECL [PR90313] In this PR we have two return paths from a function "map". The common code sets <result> to the value returned by one path, while the other path does: <retval> = map (&<retval>, ...); We treated this call as tail recursion, losing the copy semantics on the value returned by the recursive call. We'd correctly reject the same thing for variables: local = map (&local, ...); The problem is that RESULT_DECLs didn't get the same treatment. 2020-02-18 Richard Sandiford <richard.sandif...@arm.com> gcc/ Backport from mainline 2019-08-09 Richard Sandiford <richard.sandif...@arm.com> PR middle-end/90313 * tree-tailcall.c (find_tail_calls): Reject calls that might read from an escaped RESULT_DECL. gcc/testsuite/ PR middle-end/90313 * g++.dg/torture/pr90313.cc: New test.
