[i386] scalar ops that preserve the high part of a vector

[Richard Henderson]

On 2012-12-07 09:12, Marc Glisse wrote:
> but change ix86_expand_vector_set and others to generate vec_merge
> and have only the vec_merge define_insn in sse.md? I guess it would
> buy a large part of it. That's a pretty invasive change, I'll have to
> try...

Is it really that invasive?  Anyway, it's something worth trying for 4.9...


r~