Because of spam, account creation through this form is restricted. If creating an account fails, contact gcc-bugzilla-account-request@gcc.gnu.org to request a GCC Bugzilla account. You should receive a response within 24 hours.
If you already have an account and want to change your email address, you can change it from the Preferences page after logging in.
A user account is required to report new bugs or to comment into existing ones, as you may be contacted for more information if needed. This also lets other users clearly identify who is the author of comments or changes made into bugs.