Using volk in Mac: test report

GNU Radio
21

On Thu, Feb 23, 2012 at 6:08 PM, Nowlan, Sean
[email protected]wrote:

correspond to the failed cases. Do you know what is causing these? Printf

Best arch: orc

Best guess is timer resolution problems. The profiler should give saner
results, although it’ll take a while.

–n

22

On Thu, Feb 23, 2012 at 9:08 PM, Nowlan, Sean
[email protected]wrote:

correspond to the failed cases. Do you know what is causing these? Printf
formatting issue? Hitting bounds of float type and wrapping around?
Relevant output:

So these test results are really interesting. The time results are one
thing, but it might be that the numerical results you pointed out are
hopefully easy to fix. In the volk_32fc_s32f_magnitude_16i_a block, it
could be an issue with rounding. At first, I was thinking it was the
direction of the rounding operation, but the documents from ARM say that
the only mode is to round to nearest neighbor and that other modes are
disabled (which is what we’ve set the SSE to, as well). Perhaps instead
of
truncation when converting to 16-bit shorts it rounds first.

The 32fc_x2_multiply_32fc_a kernel looks like all of the numbers are
correct. This is probably just a precision thing and we’re asking for
the
numbers to be exact for way too many decimal places.

Hopefully I’ll get access to an E100 soon to look into this more.

Tom

23

On Mon, Feb 27, 2012 at 11:01 AM, Tom R. [email protected] wrote:

could be an issue with rounding. At first, I was thinking it was the

Tom

Well, I can’t seem to make anything out of those errors. They just don’t
make sense. Especially the volk_32fc_x2_mutliply_32fc_a, which gives
what
look like are the exact same results, but the tests fail. This even
happens
when I turn the tolerance way up.

When I run volk_profile, the same tests fail in the same way. Also, the
timing numbers still don’t make sense, even when running much longer
tests.

Now, the good news is that after running volk_profile, those failed
tests
are never selected for use. So when using Volk, these errors will never
effect the system at runtime. It’s too bad, since we won’t benefit from
the
speedup of Orc, but I don’t think the current blocks in GNU Radio make
use
of these particular blocks, anyways.

I was also getting an new error running make test in gr-core-test-all.
Is
anyone else seeing this?

Tom

24

On Thu, Mar 1, 2012 at 5:52 PM, Tom R. [email protected] wrote:

expected.****
thing, but it might be that the numerical results you pointed out are

When I run volk_profile, the same tests fail in the same way. Also, the

Tom

I just recompiled the gr-core-test-all and the error went away. I’m not
entirely happy about that, but until I can recreate it, I think it’s
time
to declare success and walk away…

Tom