PGI User Forum

[TheMatt]

My question is more of in the vein of "help me to continue to learn CUDA" than a "get this to work". Namely, I was wondering if there was a pgfortran compiler option that one can use to get the compiler to output the CUDA code generated by the accelerator.

Following Dr Wolfe's videos on this site, I constructed the Matrix Multiplication Driver/Kernel pairing that he demonstrates and tested them. On doing so, I used the -Minfo=all,accel -ta=nvidia options, and it does provide quite useful and interesting information about how the accelerator was working. I had just wondered if there was a further compiler option that might write out not just the $!acc do parallel, vector(16) calls, but the CUDA calls themselves, so I could see the shared memory, register, etc. transformations.

[mkcolg]

Hi TheMatt,

At this time we have not made this option available but are considering it. The problem is not so much exposing the generated CUDA code but the follow-up question of "can I then modify the generated CUDA code and have my application use the modified version?" is technically challenging since CUDA does not have a linker.

Thanks,
Mat

[TheMatt]

Mat,

Heh, I hadn't even thought of that. Rather, I was just thinking of learning what certain Accelerator options do, etc, in terms of CUDA. If I wanted to take the next step as you state, it'd be more toward thinking about converting my Fortran code into pure CUDA C to see if I can squeeze more performance out. That way, I'd have a starting point.

And, as I said, learning "better" CUDA through your Accelerator logic which has more expert minds behind them.

Matt

[mkcolg]

Hi Matt,

We've decided that we'll add a flag to the next release (9.0-3) that will allow the user to keep the intermediate CUDA code. It will just be the generated kernel, but will give you at least a starting point.

Thanks,
Mat

[TheMatt]