[Bug tree-optimization/77438] Vector lowering should also consider larger vector sizes (MMX -> SSE)

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77438

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Profitability also depends on the ABI in this case as well as the ability to
do the required extensions/extractions (and resource availability).  For
bit operations that directly map to the integer representation it will likely
be a loss unless you consider ABI.

As said in another PR vector lowering should be re-written to sth
tree-complex.c
like, with a lattice that allows to optimize insertion of extensions/extracts
(and also could track cost of parameter / return value transform).