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From: "pchang9 at cs dot wisc.edu" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/57812] New: Waste work in computed_jump_p()
Date: Wed, 03 Jul 2013 19:13:00 -0000
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X-Bugzilla-Type: new
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X-Bugzilla-Product: gcc
X-Bugzilla-Component: rtl-optimization
X-Bugzilla-Version: 4.9.0
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X-Bugzilla-Severity: normal
X-Bugzilla-Who: pchang9 at cs dot wisc.edu
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57812

            Bug ID: 57812
           Summary: Waste work in computed_jump_p()
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pchang9 at cs dot wisc.edu
                CC: nistor1 at illinois dot edu

The problem appears in revision 200588 in version 4.9.

In method "computed_jump_p()" in gcc/rtlanal.c, the loop on line 2801 should
break immediately after "has_use_labelref" is set to "1". All the iterations
after "has_use_labelref" set to "1" do not perform any useful work, at best
they just set "has_use_labelref" again to "1".