c/7284: incorrectly simplifies leftshift followed by signed power-of-2 division

[nathan@gcc.gnu.org]

Synopsis: incorrectly simplifies leftshift followed by signed power-of-2 division

State-Changed-From-To: open->closed
State-Changed-By: nathan
State-Changed-When: Fri Jul 12 07:12:01 2002
State-Changed-Why:
    not a bug. for signed types, if 'n << c' overflows, the
    behaviour is undefined.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=7284