https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114985
--- Comment #20 from Martin Jambor <jamborm at gcc dot gnu.org> ---
The IL we generate the jump function from is:
<bb 2>
_1 = cclauses_2(D) != 0B;
c_parser_omp_all_clauses (_1);
Which translates to the expected jump function:
callsite void c_parser_omp_teams(int**)/3 -> int*
c_parser_omp_all_clauses(bool)/1 :
param 0: PASS THROUGH: 0, op ne_expr 0B
so IPA looks like it's doing what it should.
(In reply to Aldy Hernandez from comment #6)
> I wonder if something like this would work.
>
> diff --git a/gcc/ipa-cp.cc b/gcc/ipa-cp.cc
> index 5781f50..ea8a685 100644
> --- a/gcc/ipa-cp.cc
> +++ b/gcc/ipa-cp.cc
> @@ -1730,6 +1730,8 @@ ipa_value_range_from_jfunc (vrange &vr,
> }
> else
> {
> + if (TREE_CODE_CLASS (operation) == tcc_comparison)
> + vr_type = boolean_type_node;
> Value_Range op_res (vr_type);
> Value_Range res (vr_type);
> tree op = ipa_get_jf_pass_through_operand (jfunc);
This looks OKish and we also do a similar thing in
ipa_get_jf_arith_result.
Also note that the ipa_value_range_from_jfunc already has a parameter
that tells it what type the result should be. It is called parm_type,
which is boolean_type in the case that ICEs. So we can even bail out
if we really encounter jump function created from bad IL.
I was thinking of using use parm_type from the beginning, to
initialize op_res with it, but there are jump functions representing
an operation followed by a truncation, for example for:
_2 = complain_6(D) & 1;
_3 = (int) std_alignof_7(D);
cxx_sizeof_or_alignof_type (_3, _2);
where _r is in fact bool (has smaller size and precision) and trying
to make ranger do the bit_and_expr directly to bool leads to a failed
assert in fold_range (the test of m_operator->operand_check_p).
So doing the operation in the original type - unless it is a
comparison - and then using ipa_vr_operation_and_type_effects seems to
be the right thing to do.
But I am really curious why propagate_vr_across_jump_function does not
need the same check for tcc_comparison operators and generally why is
it so different (in the non-scc case)? Why is ipa_supports_p (this
predicate has a really really really bad name BTW and I am completely
at loss as to what it does and how or why) used there and not in
ipa_value_range_from_jfunc?
(I also cannot prevent myself from ranting a little that it would
really help if all the ranger (helper) classes and functions were
better documented.)
