[Bug c++/62080] Suboptimal code generation with eigen library

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62080

--- Comment #5 from Marc Glisse <glisse at gcc dot gnu.org> ---
With the intrinsics patch, I notice that we don't simplify in gimple either:

  _40 = VIEW_CONVERT_EXPR<__m128i>(_39);
  MEM[(__m128i * {ref-all})vec_4(D)] = _40;
  _60 = MEM[(const double *)vec_4(D)];
  _61 = MEM[(const double *)vec_4(D) + 8B];
  _62 = {_60, _61};
  _63 = VIEW_CONVERT_EXPR<__v4si>(_62);

(_39 and _63 have the same type)