[Bug target/78246] Incorrect vector variable set but not used warning

[zoltan at hidvegi dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78246

--- Comment #1 from Zoltan Hidvegi <zoltan at hidvegi dot com> ---
Created attachment 39986
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=39986&action=edit
gcc -O2 -S -Wall warning_test.C gives incorrect warning: variable ‘sm’ set but
not used