https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90313
--- Comment #4 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> --- Author: rsandifo Date: Fri Aug 9 09:37:55 2019 New Revision: 274234 URL: https://gcc.gnu.org/viewcvs?rev=274234&root=gcc&view=rev Log: 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. 2019-08-09 Richard Sandiford <richard.sandif...@arm.com> gcc/ 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. Added: trunk/gcc/testsuite/g++.dg/torture/pr90313.cc Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-tailcall.c
