5 Replies Latest reply on Oct 11, 2008 8:13 AM by zimoch

    printf() function inside kernel

    bjang

      CUDA allows printf() function inside kernel in emulation mode. But it doesn't seem to be the case for Brook. I think debugging is very hard without this.

      I am wondering how you debug Brook other than printing before and after streamRead() and streamWrite().

        • printf() function inside kernel
          jski

          I've been wondering the same.  Some print routine would seem to be essential for debugging!

          ---jski

          • printf() function inside kernel
            josopait

            You can simply use printf (or cout) in the generated cpp file. It will be overwritten the next time you run brcc, but that's not a big problem if you want the output only for debugging purposes. It would be nice though if one could somehow pass c++ commands directly into the cpp file, bypassing brcc.

            Ingo

              • printf() function inside kernel
                michael.chu
                I'll ask the Brook+ team to look into adding printf() support for CPU backend debugging.

                Michael.
                • printf() function inside kernel
                  zimoch

                   

                  Originally posted by: josopait You can simply use printf (or cout) in the generated cpp file. Ingo


                   

                  Could  You tell me how to do that? I compile brook file then add

                  std::cout << si.swizzle1(maskX) << " " << si.swizzle1(maskY) << " " << si.swizzle1(maskZ) <<'\n' ;

                  in void __SAD3D_cpu_inner function.

                  I put break point on cout line and it seems that this function isn't run because program doesn't stop on it.

                  My steps:

                  1) Compilation br file.

                  2) Adding line in generated cpp

                  3) Compilation cpp

                  4) Linking project

                  I use Brook 1.01 Driver 8.8 WinXp 32bit.

                  I realize that other sample programs  doesn't debug either so it may be not problem of my code insertion at all.

                   

                  I found that there is an enviroment variable need to be set  BRT_RUNTIME = cpu , but I don't know where to do it so?

                   

                  I use VS 2005 - Where can I set the variable?

                  I also found it

                  It has to be set in Windows enviroment variables