If you think you may have found a bug in GNU CC, please
read the Bugs section of the GCC manual for advice on

(1) how to tell when to report a bug, 
(2) where to send your bug report, and
(2) how to write a useful bug report and what information
it needs to have.

There are three ways to read the Bugs section.

(1) In a printed copy of the GCC manual.  You can order one from the
Free Software Foundation; see the file ORDERS.  But if you don't have
a copy on hand and you think you have found a bug, you shouldn't wait
to get a printed manual; you should read the section right away as
described below.

(2) With Info.  Start Emacs, do C-h i to enter Info,
then m gcc RET to get to the GCC manual, then m Bugs RET
to get to the section on bugs.  Or use standalone Info in
a like manner.  (Standalone Info is part of the Texinfo distribution.)

(3) By hand. Search for the chapter "Reporting Bugs" in gcc.texi, or
    cat /usr/local/info/gcc* | more "+/^File: emacs,  Node: Bugs,"