Question about vec_extract

[Paolo Bonzini]

Andrew Pinski wrote:
> I have been trying to figure out when the pattern vec_extract is
> invoked.  I understand it is invoked from extract_bit_field but I
> don't see how it can be invoked.  For both SSE and altivec I have
> tried the following code (which I thought would cause vec_extract
> pattern to be called) but on both, it is not.
> Does anyone know to get vec_extract working, or is it broken in 4.0.0 
> and above?

I think it could never be generated -- even on 3.x.

Maybe if SRA could optimize such unions to VIEW_CONVERT_EXPR, you would 
get both: a vec_extract pattern being generated, and no need to go from 
V4SFmode to SFmode via TImode.

Paolo