https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108068
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jsm28 at gcc dot gnu.org,
| |rguenth at gcc dot gnu.org
Priority|P3 |P2
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Optimizing statement if (_5 != 0)
Visiting conditional with predicate: if (_5 != 0)
With known ranges
_5: [unsupported_range] UNDEFINED
Predicate evaluates to: DON'T KNOW
LKUP STMT _5 ne_expr 0
0>>> COPY _5 = 0
<<<< COPY _5 = 0
the issue is we do
bool can_infer_simple_equiv
= !(HONOR_SIGNED_ZEROS (op1)
&& (TREE_CODE (op1) == SSA_NAME || real_zerop (op1)));
but real_zerop is false for Decimal zero. That's because "Trailing zeroes
matter for decimal float constants, so don't return 1 for them.". We'd
need a real_maybe_zerop () for this usage. We have other !real_zerop
checks in match.pd and elsewhere, those are susceptible as well.
Joseph, do you think adding DECIMAL_FLOAT_MODE_P checks in users is what
we want to do or do you think a real_nonzerop would be more appropriate
here? I guess DOM want's to ask whether op1 may compare equal to zero.
