[Bug tree-optimization/102583] [x86] Failure to optimize 32-byte integer vector conversion to 16-byte float vector properly when converting upper part with -mavx2

[crazylht at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102583

--- Comment #2 from Hongtao.liu <crazylht at gmail dot com> ---
Simplify
  _4 = VEC_PERM_EXPR <_1, _1, { 4, 5, 6, 7, 4, 5, 6, 7 }>;
  _5 = BIT_FIELD_REF <_4, 128, 0>;

to

_5 = BIT_FIELD_REF <_1, 128, 128>;

in match.pd?