https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108979
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Assignee|rguenth at gcc dot gnu.org |unassigned at gcc dot
gnu.org
CC| |rsandifo at gcc dot gnu.org
Status|ASSIGNED |NEW
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Error: definition in block 4 does not dominate use in block 6
for SSA_NAME: loop_mask_16 in statement:
vect__33.10_19 = .COND_MUL (loop_mask_16, _1, _4, _1);
that stmt ended up in the preheader. That happens when scheduling
t.f90:4:26: note: node 0x3c6a870 (max_nunits=4, refcnt=1) vector([4,4])
real(kind=4)
t.f90:4:26: note: op template: _33 = tmp_17(D) * p_bd_18(D);
t.f90:4:26: note: stmt 0 _33 = tmp_17(D) * p_bd_18(D);
t.f90:4:26: note: stmt 1 _33 = tmp_17(D) * p_bd_18(D);
t.f90:4:26: note: children 0x3c6a900 0x3c6a990
because as can be seen, the operands are all loop invariant and we are
appearantly not honoring the implicit dependence on a mask (those are not
added as implicit operand to the SLP graph - something we eventually
would want to do).
Now - it's also completely unnecessary to mask this statement, and _that's_
possibly the easier way out here.
Instead of -fnon-call-exceptions one can also use -fno-tree-loop-im to keep
the invariant computation inside the loop and trigger the same ICE.
Richard - you are more familiar with loop masking - where do we decide
whether a stmt needs masking and couldn't we easily decide it doesn't
need if all operand dt are external or invariant?
