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[Bug optimization/14758] New: [tree-ssa] another missed forward propagation opportunity
- From: "kazu at cs dot umass dot edu" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 28 Mar 2004 01:54:10 -0000
- Subject: [Bug optimization/14758] New: [tree-ssa] another missed forward propagation opportunity
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
void bar (void);
void
foo (int a)
{
a = !a;
a = !a;
a = !a;
a = !a;
a = !a;
if (a)
bar ();
}
Here is the last tree in SSA form:
foo (a)
{
<bb 0>:
a_2 = a_1 == 0;
a_3 = a_2 == 0;
if (a_3 == 0) goto <L0>; else goto <L1>;
<L0>:;
bar () [tail call];
<L1>:;
return;
}
Note that a_2 and a_3 still remain.
--
Summary: [tree-ssa] another missed forward propagation
opportunity
Product: gcc
Version: tree-ssa
Status: UNCONFIRMED
Keywords: pessimizes-code
Severity: enhancement
Priority: P2
Component: optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: kazu at cs dot umass dot edu
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14758