On Sat, Aug 20, 2016 at 4:52 AM, james <gar...@verizon.net> wrote: <snip>
>> Back to my own glass house.. It will take a few years, but I am trying >> to make it easier (internally) to expose in some clear way all the >> pieces which compose a fine tuning per-processor. If this was "just" >> scheduling models it would be really easy, but it's not.. Those >> latencies and other magic bits decide things like.. "should I unroll >> this loop or do something else" and then you venture into the land of >> accelerators where a custom regalloc may be what you really need and >> *nothing* off the shelf fits to meet your goals.. (projects like that >> can take 9 months and in the end only give a general 1-5% median >> performance gain..) > > > If this is your mantra, I resend the generous comments. Cray use to work > that way, milking the Petroleum Industry for tons of money, but, things have > changed and the change is accelerating, rapidly. Perhaps too much off those > Cray patents that your company owns are leaking toxins into the brain-trust > where you park? > > Vendor walk-back is sad, imho. ymmv. > > Best of luck to your company's 5-year plan.... I have no idea what on earth you were trying to say in most of your reply. I am speaking only from a compiler perspective. Nothing more and nothing less.. it may be my difficultly to describe the target level and processor specific optimization choices a compiler *must* make. Beyond not understanding your email, I found it insulting. So please keep rude comments to yourself. So again to try to explain the technical side of this - We can't and have no desire to optimize for every class of processor on the planet. We have a narrow band of focus on mostly HPC centric code patterns and processors which are are typically used in HPC workloads. I'd love to expand past this, but we're a small company and that's our niche. There's no walking back or trying to claim to be something we're not.. this is pure honest transparency. (imagine it like - do one thing and do it well) The only special note I'd add on to this - the CPU isn't where we spend most of our time tuning, it's by far more on the accelerator support.
