[Bug debug/89463] debug information for iteractor of an empty loop is gone (at -O3)

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89463

--- Comment #11 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Wed Mar 27 09:31:53 2019
New Revision: 269961

URL: https://gcc.gnu.org/viewcvs?rev=269961&root=gcc&view=rev
Log:
2019-03-27  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/89463
        * tree-ssa-dce.c (remove_dead_stmt): Take output vector to
        queue edges to remove.
        (eliminate_unnecessary_stmts): Remove dead PHIs alongside
        dead stmts.  Delay edge removal until PHIs are removed to
        make debug-stmt creation not confused by seemingly degenerate
        PHIs.

        * gcc.dg/guality/pr89463.c: New testcase.

Added:
    trunk/gcc/testsuite/gcc.dg/guality/pr89463.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-dce.c