Some more information about my use-case: I use the input buffer as the states of the Mersenne Twister and write the generated numbers in the output buffer. The generation includes the altering of the states because it's a recursive algorithm.
Actually the only confusing part is the fact that the VOLK ctest checks input and output buffer (which is a good feature!) but I haven't seen a hint in the error message which assert failed. Could have been my fault as well! Greetings Stefan On 11/12/2015 04:29 AM, Tom Rondeau wrote: > On Wed, Nov 11, 2015 at 8:32 AM, Stefan Wunsch < > [email protected]> wrote: > >> Aaaah I solved it. Never ever write in a VOLK kernel to your input >> buffer! This throws no errors but it fails during the ctest. So I >> suppose the first test compares the output and the second one the input >> buffers? >> >> Greetings >> Stefan >> > > Ah, interesting. This is something we should take up in the VOLK working > group. We don't claim or not claim that you can use the same memory for the > input and output buffers. Some kernels are known to work with these inplace > operations. Looks like this one doesn't. Perhaps just testing and knowing > which kernels do and do not support this and protect those that do not as > const (which can be easily gotten around) and saying as much in the > kernel's documentation. > > Though for some reason I feel like I'm misunderstanding something. Also, > Nathan will probably have more to say on this issue. > > Tom > > > > >> On 11/11/2015 01:45 PM, Stefan Wunsch wrote: >>> Hi! >>> >>> I have some issues with the (understanding of the) behaviour of the VOLK >>> test-cases (defined in kernel_tests.h). >>> >>> Each test defined in kernel_tests.h runs two times. Now I have the >>> problem that the first one succeeds but the second one fails. >>> >>> I do not understand why the icompare function (the signiture is >>> 32u_foo_32u) in run_volk_tests runs two times. What is the difference >>> between these calls? >>> >>> Btw, I am implementing a SIMD accelerated Mersenne-Twister! >>> >>> Greetings >>> Stefan >>> >>> _______________________________________________ >>> Discuss-gnuradio mailing list >>> [email protected] >>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >>> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> [email protected] >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> > _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
