[Bug lto/51744] Erroneous warning: memset used with constant zero length parameter

["mark at infocomm dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51744

Mark Pizzolato <mark at infocomm dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |mark at infocomm dot com

--- Comment #3 from Mark Pizzolato <mark at infocomm dot com> 2012-10-23 16:43:01 UTC ---
This may be a bug in gcc OR the linker.  I don't know, BUT I have a more
precise description of the issue and a much simpler minimal test case.

The problem occurs when all of the following conditions are true:
    1) gcc is invoked with -O2 and -flto
    2) memset is called with a non-constant length argument
    3) memset is called with a NON zero fill value argument.

The minimal test case is:

#include <string.h>

void
main (int argc, char **argv)
{
char buf[5000];

memset (buf, 0xFF, argc);
}

To conform to the bug submission guidelines, the preprocessed file for the this
test is attached.