[Patch, fortran] PR24518 and PR24520 - Improvements to MOD and

[Paul Thomas]

Tim,

>
> The code generated by a simple sum(a*b) for Itanium does not pipeline. 
> It consists of purely serial operations with the same 3 registers 
> repeated by the loop unrolling.  So, it will be limited to one 
> addition per 4 clock cycles, at best, only 13% of peak floating point 
> performance.  I don't think this should influence your decisions about 
> implementation of sum() and dot_product().  It's one of the basic 
> deficiencies of gnu compilers for this CPU.
>
Does the library dot product pipeline or do we have to do pairs of 
multiply/add, within the loop?

Paul