https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110362
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2023-06-22
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.
Also on the GIMPLE level we have
<bb 2> [local count: 1073741824]:
# RANGE [irange] __int128 unsigned [0, 0][4294967296, +INF] NONZERO
0xffffffffffffffffffffffff00000000
_1 = a_2(D) << 32;
__a_4 = _1 | b_3(D);
_5 = (int) __a_4;
the lowpart cast (int) __a_4 can be simplified to (int) b_3(D) based on
the range info of _1. For example via
(simplify
(convert (ior:c with_possible_nonzero_bits@0 @1))
(if ( ... @0 has all zeros in lower TYPE_PRECSION (type) bits ...)
(convert @1)))
I suppose a variant with b & (a << 32) is already optimized (to zero)?
