MoTheG (better@not.tell) on 11/9/09 wrote:
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>a reader (a@b.c) on 11/9/09 wrote:
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>>stop blabbering.
>>
>>do you have access to GPU nda docs or not?
>
>I do not.
>Does one have to?

Yes of course,

Give me for Nvidia cpu's a listing of which hardware instructions the hardware supports and what latency which instruction has please.

Rather trivial to get for cpu's. Real important for gpu's of course. You're not coding for a gpu to get generic code to work without performance incentives.

AMD seems to have released the instructions the gpu hardware supports. This is good and makes AMD more attractive to me to program for. Note i was amazed by the many conditional move equivalent type instructions the hardware supported.

>The data on the old parts is disclosed.
>
>We had to learn about CPUs too.

You can download from cpu's about everything. Just tiny small things are difficult like that documentation doesn't show some hidden thigns like which units get blocked when and for how long depending upon what instruction you execute. Sometimes there is also nasty surprises in that specific instructions are not 2 cycles but 7+ cycles (example: shifting right at P4).

>As DK wrote there is optimised CPU code and not so optimised code as well. Just
>slapping something together in a high level language without architectual concerns
>doesn't work for a CPU as well (and if it does, it is not the credit of the programmer,
>but the compiler and the CPU guys).
>The average programmer will not get in contact with problems that would gain from GPGPU anyhow.

the average programmer is not writing code to get executed fast. Only a few on this planet do that. I'm one of them.

>This is why I think arguing that one needs to be able to programm a GPU just like
>we used to programm single core CPUs is to much asked.

Lucky just 1 guy has to solve the problem for each number crunching product. A single programmer can have a huge impact on an entire field there. There is LOTS of people who help you out then theoretically, as i figured out.