This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug tree-optimization/35609] [4.3/4.4 Regression] "is used uninitialized in this function" should be may warning
- 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: 16 Mar 2008 21:32:33 -0000
- Subject: [Bug tree-optimization/35609] [4.3/4.4 Regression] "is used uninitialized in this function" should be may warning
- References: <bug-35609-9876@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #2 from rguenth at gcc dot gnu dot org 2008-03-16 21:32 -------
The warning works as designed, the PHI node in question that causes the
warning only has a single incoming edge:
testfunc ()
{
int alt_reloc;
int foo.0;
<bb 2>:
foo.0_1 = foo;
if (foo.0_1 > 19)
goto <bb 5>;
else
goto <bb 3>;
<bb 3>:
if (foo.0_1 > 9)
goto <bb 6>;
else
goto <bb 4>;
<bb 4>:
if (alt_reloc_4(D) != 0)
goto <bb 5>;
else
goto <bb 6>;
<bb 5>:
bar = 42;
<bb 6>:
return;
}
we don't check whether the uninitialized use post-dominates the function
entry. I don't know if we should.
This is just a case of 4.3 optimizing better than 4.2 which makes the
warning less precise.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2008-03-16 21:32:33
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35609