From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-426404-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 16644 invoked by alias); 20 Jul 2013 09:29:45 -0000
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-bugs.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
Received: (qmail 14411 invoked by uid 48); 20 Jul 2013 09:27:43 -0000
From: "makhaloff at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/57940] New: [PATCH] Rerun df_analyze after delete_unmarked_insns during DCE
Date: Sat, 20 Jul 2013 09:29:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: rtl-optimization
X-Bugzilla-Version: unknown
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: makhaloff at gmail dot com
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter
Message-ID: <bug-57940-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-SW-Source: 2013-07/txt/msg00911.txt.bz2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57940

            Bug ID: 57940
           Summary: [PATCH] Rerun df_analyze after delete_unmarked_insns
                    during DCE
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: makhaloff at gmail dot com

Hello!

If delete_unmarked_insns deletes some insn, DF state might be
out of date, and, regs_ever_live might contain unused registers till the end.
Fixed by forcing regs_ever_live update and rerunning df_analyze () at
fini_dce().
I found this bug on my target (not included into main sources). But I can send
everything you need to reproduce this bug.
Using gcc-4.8.1 

2013-07-20  Alexey Makhalov  <makhaloff@gmail.com>

    * dce.c (fini_dce): Call df_analyze again just in case
delete_unmarked_insns removed anything.

--- dce.c       (revision 361)
+++ dce.c       (working copy)
@@ -745,6 +745,12 @@
       bitmap_obstack_release (&dce_blocks_bitmap_obstack);
       bitmap_obstack_release (&dce_tmp_bitmap_obstack);
     }
+
+  if (!df_in_progress)
+    {
+      df_compute_regs_ever_live (true);
+      df_analyze ();
+    }
 }