[Bug c++/28553] New: string processing -O3 optimization bug under GCC 4.1.1

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

Note, the following is in reference to this Debian version of GCC:

gcc version 4.1.2 20060729 (prerelease) (Debian 4.1.1-10)

However, it also occurs under a version I have built myself:

Target: i686-pc-linux-gnu
Configured with: ../configure --prefix=/usr/local/gcc-4.1
--enable-languages=c,c++,java
Thread model: posix
gcc version 4.1.1


My C++ knowledge isn't extensive enough to give further details of this other
than it's related to string handling, or guess if it's already been reported,
but the following preprocessed code reproduces the problem under -O3, but not
-O2.  The code performs correctly under GCC 3.4.6 and -O3

Here is the expected output:

op [0]: "A"
op [1]: "B"
op [2]: "C"
op [3]: "D"
op [4]: "E"
op [5]: "F"

Here is a crash caught by GDB:

CfgSchema (this=0xbfd0a400, schema_str=@0xbfd0a40c) at
/usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2/bits/stl_algo.h:260
260               if (__pred(*__first))
(gdb) bt
#0  CfgSchema (this=0xbfd0a400, schema_str=@0xbfd0a40c) at
/usr/lib/gcc/i486-linux-gnu/4.1.2/../../../../include/c++/4.1.2/bits/stl_algo.h:260
#1  0x08048ebe in main () at cfgtblopt.cpp:36


-- 
           Summary: string processing -O3 optimization bug under GCC 4.1.1
           Product: gcc
           Version: 4.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: peter at chocky dot org
  GCC host triplet: i486-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28553