optimization/3507: appalling optimisation with sub/cmp on i386

[rth@gcc.gnu.org]

Synopsis: appalling optimisation with sub/cmp on i386

State-Changed-From-To: open->analyzed
State-Changed-By: rth
State-Changed-When: Tue Apr  2 02:36:06 2002
State-Changed-Why:
       (set (reg/v:SI 61)
            (minus:SI (reg/v:SI 59) (reg/v:SI 60)))
    
    and
    
       (set (reg:CC 17 flags)
            (compare:CC (reg/v:SI 59) (reg/v:SI 60))) 
    
    are not LOG_LINK related, because they share no common
    destination, so combine doesn't merge them.  But after
    reload, they don't have the same arguments, so we can't
    peephole them there either.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=3507