https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105253
--- Comment #12 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #9)
> Ah, I see, expression_expensive_p is called, but
> number_of_iterations_popcount when creating a CALL_EXPR only cares about
> TYPE_PRECISION and happily creates
> __builtin_popcountl with unsigned long long argument because it has the same
> precision. tree_builtin_call_types_compatible_p says it is not valid
> builtin call and so we don't consider it expensive.
Shouldn't it run into
if (!is_inexpensive_builtin (get_callee_fndecl (expr)))
return true;
then? Or does that simply consider all popcount as inexpensive?
Yes it does.
I think we should change the above to
diff --git a/gcc/tree-scalar-evolution.cc b/gcc/tree-scalar-evolution.cc
index 44157265ce8..b53d7aaa71d 100644
--- a/gcc/tree-scalar-evolution.cc
+++ b/gcc/tree-scalar-evolution.cc
@@ -3420,12 +3420,15 @@ expression_expensive_p (tree expr, hash_map<tree,
uint64_t> &cache,
break;
return true;
}
+ break;
+
default:
+ if (cfn == CFN_LAST
+ || !is_inexpensive_builtin (get_callee_fndecl (expr)))
+ return true;
break;
}
- if (!is_inexpensive_builtin (get_callee_fndecl (expr)))
- return true;
FOR_EACH_CALL_EXPR_ARG (arg, iter, expr)
if (expression_expensive_p (arg, cache, op_cost))
return true;
> Either we make number_of_iterations_popcount more accurate on the types, or
> better in tree_builtin_call_types_compatible_p use something like:
> bool in_gimple_form = (cfun && (cfun->curr_properties & PROP_gimple)) != 0;
> and if in_gimple_form, use useless_type_conversion_p instead of the
> TYPE_MAIN_VARIANT / tree_nop_conversion_p checks.
> That is my strong preference...
>
> What do you think?
Hmm, but still tree_nop_conversion_p would work there, no?
