https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91460
H.J. Lu <hjl.tools at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target| |i386
Status|UNCONFIRMED |NEW
Last reconfirmed| |2019-08-15
Ever confirmed|0 |1
--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> ---
When loop trip count is known, vectorizer won't select 256-bit vector when
266-bit vector can't be used. When loop trip count is unknown, 256-bit
vector can be slower than 128-bit vector, depending on workloads. In
case of SPEC CPU 2017, 128-bit vector is much faster than 256-bit vector
for a couple benchmarks. For most of benchmarks, there are no performance
differences between 128-bit vector and 256-bit vector.
