[Bug tree-optimization/102794] [12 Regression] missing vrp in evrp dealing with casts and ands
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102794 Andrew Pinski changed: What|Removed |Added Resolution|--- |FIXED Status|UNCONFIRMED |RESOLVED --- Comment #4 from Andrew Pinski --- Fixed most likely by r12-4526.
[Bug tree-optimization/102794] [12 Regression] missing vrp in evrp dealing with casts and ands
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102794 --- Comment #3 from Andrew Pinski --- (In reply to Aldy Hernandez from comment #2) > I haven't looked at this, but there's a pending patch with more > restrictions for loop threading in the presence of loops. Does this help? > > https://gcc.gnu.org/pipermail/gcc-patches/2021-October/581637.html > > We really shouldn't be destroying loop info. Yes I think it does, though I have not tried it. There was a jump threading here: : if (d_10 != 0) goto ; [INV] else goto ; [INV] : foo (); : a_12 = a_3 + 1; : ;;; loop header # a_3 = PHI <-100(2), a_12(6)> if (a_3 != 0) goto ; [INV] else goto ; [INV] where d_10 is defined as: d_10 = (short unsigned int) a_3; So yes blocking jumping through the loop header would help. It is very similar to your f3 in ssa-thread-invalid.c testcase.
[Bug tree-optimization/102794] [12 Regression] missing vrp in evrp dealing with casts and ands
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102794 --- Comment #2 from Aldy Hernandez --- I haven't looked at this, but there's a pending patch with more restrictions for loop threading in the presence of loops. Does this help? https://gcc.gnu.org/pipermail/gcc-patches/2021-October/581637.html We really shouldn't be destroying loop info. On Sat, Oct 16, 2021, 07:01 pinskia at gcc dot gnu.org < gcc-bugzi...@gcc.gnu.org> wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102794 > > Andrew Pinski changed: > >What|Removed |Added > > > CC||aldyh at gcc dot gnu.org > > --- Comment #1 from Andrew Pinski --- > Jump threading really messes up the loop here ... > about to thread: path: 4 -> 6, 6 -> 7, 7 -> 3, > just threaded: path: 4 -> 9, 6 -> 7, 7 -> 3, > > I don't know what else to say. Maybe move ethread after evpr? > > Note with -fno-thread-jumps, evpr is able to figure out the induction > variable > goes from [-100, -1] . It does look like jump threading is full on > messing up > how induction variable detection works; we get two a = a +1; statement > after > the jump threading improvements. > Maybe there is another bug about that case already. > > -- > You are receiving this mail because: > You are on the CC list for the bug. > >
[Bug tree-optimization/102794] [12 Regression] missing vrp in evrp dealing with casts and ands
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102794 Andrew Pinski changed: What|Removed |Added CC||aldyh at gcc dot gnu.org --- Comment #1 from Andrew Pinski --- Jump threading really messes up the loop here ... about to thread: path: 4 -> 6, 6 -> 7, 7 -> 3, just threaded: path: 4 -> 9, 6 -> 7, 7 -> 3, I don't know what else to say. Maybe move ethread after evpr? Note with -fno-thread-jumps, evpr is able to figure out the induction variable goes from [-100, -1] . It does look like jump threading is full on messing up how induction variable detection works; we get two a = a +1; statement after the jump threading improvements. Maybe there is another bug about that case already.
[Bug tree-optimization/102794] [12 Regression] missing vrp in evrp dealing with casts and ands
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102794 Andrew Pinski changed: What|Removed |Added Target Milestone|--- |12.0
