https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111036
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to fail| |16.0
Status|NEW |ASSIGNED
Last reconfirmed|2023-08-20 00:00:00 |2026-1-28
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot
gnu.org
--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
Latest comments still hold. early inlining still introduces
__builtin_unreachable off the else path of
if (__builtin_constant_p(p) && (p & 31) == 0), but does not elide
the checks.
CCP will elide the alignment check (it's given), but not the
__builtin_constant_p one.
Nothing will consider
p_2 = (long unsigned int) &_rl2c_cmd_id_data;
_3 = __builtin_constant_p (p_2);
as constant, but somehow IPA predicate analysis does:
size:2.000000, time:2.000000, executed if:(op0 not constant || op0,((long
unsigned int) #),(# & 31) != 0), nonconst if:(op1 changed) && (op0 not
constant || op0,((long unsigned int) #),(# & 31) != 0)
it somehow elides the nop-conversion, but later folding does not.
A possible solution might be to fold a nop or widening conversion away
for __builtin_constant_p arguments.
