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From: "ebotcazou at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/58295] [4.8/4.9 regression] Missed zero-extension elimination in the combiner
Date: Mon, 02 Sep 2013 22:02:00 -0000 [thread overview]
Message-ID: <bug-58295-4-iV1MKI5qt8@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-58295-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58295
Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target| |arm*-*-*
Status|UNCONFIRMED |NEW
Keywords| |missed-optimization
Last reconfirmed| |2013-09-02
CC| |ebotcazou at gcc dot gnu.org
Ever confirmed|0 |1
Summary|The combination pass |[4.8/4.9 regression] Missed
|doesn't eliminate some |zero-extension elimination
|extra zero extensions |in the combiner
Target Milestone|--- |4.8.2
--- Comment #1 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
Confirmed. Seeing that insn 10 is redundant is not immediate but the combiner
was indeed clever enough to do it. The QI subreg is clearly problematic for
the ARM here (and probably most RISC architectures).
next prev parent reply other threads:[~2013-09-02 22:02 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-02 8:39 [Bug rtl-optimization/58295] New: The combination pass doesn't eliminates some extra zero extensions uranus at tinlans dot org
2013-09-02 22:02 ` ebotcazou at gcc dot gnu.org [this message]
2013-09-06 9:54 ` [Bug rtl-optimization/58295] [4.8/4.9 regression] Missed zero-extension elimination in the combiner jasonwucj at gmail dot com
2013-09-06 10:18 ` jakub at gcc dot gnu.org
2013-09-06 12:15 ` uranus at tinlans dot org
2013-09-06 13:18 ` ebotcazou at gcc dot gnu.org
2013-10-16 9:49 ` jakub at gcc dot gnu.org
2013-10-30 13:35 ` rguenth at gcc dot gnu.org
2013-10-30 18:02 ` ebotcazou at gcc dot gnu.org
2013-10-31 3:31 ` npickito at gmail dot com
2013-10-31 6:58 ` ebotcazou at gcc dot gnu.org
2013-10-31 7:14 ` npickito at gmail dot com
2013-10-31 8:02 ` ebotcazou at gcc dot gnu.org
2013-12-10 22:58 ` ebotcazou at gcc dot gnu.org
2013-12-10 22:59 ` ebotcazou at gcc dot gnu.org
2013-12-10 23:01 ` ebotcazou at gcc dot gnu.org
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