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[Bug tree-optimization/30317] New: VRP cannot extract a range from (unsigned int) i + 0x0ffffffff > 4
- 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: 28 Dec 2006 12:22:36 -0000
- Subject: [Bug tree-optimization/30317] New: VRP cannot extract a range from (unsigned int) i + 0x0ffffffff > 4
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
fold and VRP interact badly if we have a range test like
if (i > 0 && i <=5)
...
as we fold that to
if ((unsigned int) i + 0x0ffffffff > 4)
...
for which VRP fails to extract a range for i. If we write the
range test so that fold doesn't see it, VRP is happy:
if (i > 0)
if (i <= 5)
...
--
Summary: VRP cannot extract a range from (unsigned int) i +
0x0ffffffff > 4
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
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=30317