------- Comment #7 from bonzini at gnu dot org 2008-11-22 10:15 ------- Subject: Re: "if (i == n) ++i;" or "i += i == n;"?
> The form of the code before CSE is caught in noce_try_addcc. The second form > obviously not (because we don't know that the value of i.20 is "i + 1"). > > So this comes down to a pass ordering problem. I'll just point out that the df merge allowed much better freedom in pass ordering. Ifconv1 could be anticipated before CSE and fwprop. Paolo -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30521
