[Bug optimization/13301] New: [tree-ssa] deficiency in jump threading

["rth at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

$ ./cc1 -quiet -Wall -O z.c
z.c: In function `test':
z.c:22: warning: 'idx' might be used uninitialized in this function

The test case is representative of (reportedly many) similar warnings
generated from the Linux source code.  The warning is suppressed at -O2
by rtl's jump bypassing pass.  IMO this case should be handled by the
tree-level jump threading routines.

-- 
           Summary: [tree-ssa] deficiency in jump threading
           Product: gcc
           Version: tree-ssa
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P2
         Component: optimization
        AssignedTo: law at gcc dot gnu dot org
        ReportedBy: rth at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: i686-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13301