[Bug tree-optimization/103393] [12 Regression] Generating 256bit register usage with -mprefer-avx128 -mprefer-vector-width=128

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103393

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |12.0
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
                 CC|                            |hjl.tools at gmail dot com
            Summary|[ 12 Regression ] Auto      |[12 Regression] Generating
                   |vectorizer generating       |256bit register usage with
                   |256bit register usage with  |-mprefer-avx128
                   |-mprefer-avx128             |-mprefer-vector-width=128
                   |-mprefer-vector-width=128   |
             Target|                            |x86_64-*-* i?86-*-*
   Last reconfirmed|                            |2021-11-24

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
It isn't the vectorizer but memmove inline expansion.  I'm not sure it's really
a bug, but there isn't a way to disable %ymm use besides disabling AVX
entirely.
HJ?