[Bug tree-optimization/95481] Failure to optimize infinite recursion for empty struct types

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95481

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Andrew Pinski <pinskia@gcc.gnu.org>:

https://gcc.gnu.org/g:ea418485c700494c3efdc282854c5f5a08702416

commit r12-1151-gea418485c700494c3efdc282854c5f5a08702416
Author: Andrew Pinski <apinski@marvell.com>
Date:   Mon May 31 00:17:22 2021 +0000

    Fix PR 95481: tail call fails with empty struct types

    The problem here is we don't have an assignment type any more
    for empty structs as they were removed during gimplifcation.
    This adds a special case where the assignment var does not exist
    and the return decl is empty typed.

    OK? Tested on aarch64-linux-gnu with no regressions.

    Thanks,
    Andrew Pinski

    changes since v1:
    v2: Use is_empty_type instead of zero-sized type.

    gcc/ChangeLog:
            PR tree-optimization/95481
            * tree-tailcall.c (find_tail_calls): Handle empty typed
            return decls.

    gcc/testsuite/ChangeLog:

            PR tree-optimization/95481
            * gcc.dg/tree-ssa/tailcall-10.c: New test.
            * gcc.dg/tree-ssa/tailcall-11.c: New test.
            * gcc.dg/tree-ssa/tailcall-12.c: New test.
            * gcc.dg/tree-ssa/tailcall-13.c: New test.
            * gcc.dg/tree-ssa/tailrecursion-8.c: New test.