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[Bug tree-optimization/39094] New: loop_niter_by_eval should deal with &a[i_1]
- From: "rguenth at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 4 Feb 2009 10:34:31 -0000
- Subject: [Bug tree-optimization/39094] New: loop_niter_by_eval should deal with &a[i_1]
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
Brute force evaluation of niters does not deal with
<bb 5>:
i_10 = i_1 + 1;
<bb 6>:
# i_1 = PHI <0(2), i_10(5)>
# .MEM_11 = PHI <.MEM_17(2), .MEM_11(5)>
if (i_1 <= 4)
goto <bb 3>;
else
goto <bb 7>;
<bb 3>:
D.5476_6 = &a._M_instance[i_1];
D.5457_8 = i_1 * 4;
D.5458_9 = &a._M_instance[0] + D.5457_8;
if (D.5476_6 != D.5458_9)
goto <bb 4>;
else
goto <bb 5>;
where get_val_for cannot handle &a._M_instance[i_1].
--
Summary: loop_niter_by_eval should deal with &a[i_1]
Product: gcc
Version: 4.4.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: rguenth at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39094