3 Replies Latest reply on Dec 11, 2009 5:58 AM by genaganna

    2 bugs (?) in SDK beta 4

    davibu
      Internal error + compiler segmentation fault

      Hi,

       

      While writing 2 little tests/demos, I think I have found 2 bugs in SDK beta4 on Linux Ubuntu 9.04 64bit (CPU Q6600 + GPU HD4870).

       

      The first one is about operator "&&" and int4 data type. It looks like the compiler output something wrong and the JIT compiler starts to complains about some error in the intermediate code. It looks very much like an internal error to me. The problem is reproducible with the sources available here: http://davibu.interfree.it/opencl/mandelgpu/mandelGPU.html

      You have only to replace the declaration of variable "notHaveToExit" with "const int4 notHaveToExit = (notEscaped && notMaxIter);"

      As side note, for some unknown reason the "&" operator is not bugged but is very very slow on my hardware (i.e. a lot slower than not vectorized code).

       

      I experienced the second problem in another toy I'm writing: http://davibu.interfree.it/opencl/smallptgpu/smallptGPU.html

      You can download the modified sources with the problem here: http://davibu.interfree.it/tmp/smallptgpu-v1.2.tgz

       

      You have to uncomment the line "#ifndef GPU_KERNEL" and the following "#endif" to reproduce the problem. Everything works fine with CPU device while the compiler throws a segmentation fault inside clBuildProgram() when I try to run on GPU device.

       

      BTW, thanks for the OpenCL SDK, it has proven to be a very interesting tool up to now, I'm looking forward to next releases.

       

        • 2 bugs (?) in SDK beta 4
          genaganna

          davibu,

                    With internal version we are able to run your smallptgpu-v1.2.tgz on Linux OpenSUSE 10.3 64bit with HD 4850. I did not modify any thing in your code.

           

           could you please give us more details to reproduce your problem?

           

            • 2 bugs (?) in SDK beta 4
              davibu

               

              Originally posted by: genaganna davibu,

               

                        With internal version we are able to run your smallptgpu-v1.2.tgz on Linux OpenSUSE 10.3 64bit with HD 4850. I did not modify any thing in your code.

               

               

               

               could you please give us more details to reproduce your problem?

               

              Sorry, my original post was a bit cryptic, you have to comments 2 lines of code in geomfunc.h to replicate the problem. Anyway I updated the file at http://davibu.interfree.it/tmp/smallptgpu-v1.2.tgz

              It should now crash out fo the box, you have only to run smallptGPU executable.

               

              Otherwise, may be the problem has already been fixed (or something specific of 4870 ?).