https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98137
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot
gnu.org
Last reconfirmed| |2020-12-04
Status|UNCONFIRMED |ASSIGNED
Ever confirmed|0 |1
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Ah, so the issue is that
/* Split the unconverted operand and try to prove that
wrapping isn't a problem. */
tree tmp_var, tmp_off;
split_constant_offset (op0, &tmp_var, &tmp_off, cache, limit);
/* See whether we have an SSA_NAME whose range is known
to be [A, B]. */
if (TREE_CODE (tmp_var) != SSA_NAME)
return false;
we end up with tmp_var as MULT_EXPR (l_n_189 * 10). We can fix that by
retaining the original code when splitting the constant offset returns zero.
While this makes us match up (_286 + 1) * 8 and (_286 + 2) * 8 it fails
to catch (_286 + 0) * 8 because that now is no longer expanded.
But we can use determine_value_range instead of get_value_range to also handle
expression trees. That fixes the testcase.
