------- Additional Comments From dberlin at gcc dot gnu dot org 2005-08-29 15:15 ------- Subject: Re: Missed pre opportunity
On Mon, 2005-08-29 at 12:46 +0000, rakdver at gcc dot gnu dot org wrote: > ------- Additional Comments From rakdver at gcc dot gnu dot org 2005-08-29 > 12:46 ------- > Is it really a duplicate? I think that in 23286, VUSE at ii may be the > problem; > but in this testcase, there is nothing that can prevent p+q from being moved > out > of loop. Also, in the expression p + q is partially redundant over the back > edge of the loop, so PRE should work for it. > Disabling reassoc, it knows that p + q is antic over the backedge. Which means it knows it *could* insert it. Why it's deciding not to do an insert is what i'm analyzing now. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23619
