Re: [Patch, fortran] Inline DOT_PRODUCT

[Paolo Bonzini <paolo dot bonzini at lu dot unisi dot ch>]

> Whilst I have regtested and all is well, the main purpose of this patch 
> is to speed up execution of dot_product for small arrays.  To this end, 
> I attach a test program that is not part of the patch but produces the 
> results below, on a quiet Athlon1700.  It may be seen that, with -O3, 
> the patch removes the function call overhead of ~25-30ns, which is 
> highly significant for arrays of sizes below approximately 32.  The 
> error on the timing is a few ns and there is a residual overhead, which 
> must(?) be the dot_product loop overhead, which is about 15ns.  The 
> performance, with the patch, is identical to that of ifort.

Have you tested -ftree-vectorize?

Paolo