------- Comment #24 from rguenther at suse dot de 2009-07-15 13:58 ------- Subject: Re: [4.4/4.5 Regression] internal compiler error: in compute_antic, at tree-ssa-pre.c:2501
On Wed, 15 Jul 2009, dberlin at dberlin dot org wrote: > ------- Comment #23 from dberlin at gcc dot gnu dot org 2009-07-15 13:46 > ------- > Subject: Re: [4.4/4.5 Regression] internal > compiler error: in compute_antic, at tree-ssa-pre.c:2501 > > a_1 shouldn't be in the maximal set. If it is, that's a bug. D.1251_5 = a_1->flag; so it's even in exp_gen. And because a_1 is in the maximal set b_2 has to. Well, as you asy - we'll see if it bootstraps ;) > The history here: > > We didn't use to have a check for domination in avail_out. > As a result, values only died if they were in TMP_GEN. > (This is what is *supposed* to happen. At some point we added a check > for availability to valid_in_sets and i can't remember why). > PHI values are not in TMP_GEN, so they will never disappear from the > set once in it. > > Nowadays, it may be safe to put phi values in there. Where? in TMP_GEN? That doesn't work. > Honestly, the availability check in valid_in_sets worries me, because > it shouldn't be necessary. > Names should be prevented from being ANTIC past the point of their > definition through subtraction of TMP_GEN. Yes, removing the AVAIL_OUT check in clean works. Richard. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40321
