https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95448
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|middle-end |tree-optimization
Last reconfirmed| |2020-06-02
CC| |jakub at gcc dot gnu.org
Status|UNCONFIRMED |NEW
Ever confirmed|0 |1
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed. The pass with the strongest bit tracking (CCP) does not handle
the special assume-like CFGs at all and EVRP which would does not handle
the indirect assumption of bit test vs. constant:
_1 = v.v;
_2 = _1 & 7;
if (_2 != 1)
goto <bb 3>; [INV]
else
goto <bb 4>; [INV]
<bb 3> :
__builtin_unreachable ();
<bb 4> :
_12 = _1 & 18446744073709551608;
so while we see that _2 = [1, 1] at the start of bb 4 the value-range
for _1 is determined from
Adding assert for _1 from _1 + 18446744073709551615 <= 18446744073709551608
Adding assert for _1 from _1 != 0
to
pushing new range for _1: long unsigned int [1, 18446744073709551609]
EQUIVALENCES: { _1 } (1 elements)
sth is amiss there. It looks like is_masked_range_test is the closest
candidate but there
if ((inv_mask & (inv_mask + 1)) != 0
|| (val & mask) != val)
return false;
trips. Guess we're looking for a different kind of logic here.
