[Discuss-gnuradio] Enabling cpu #1 causes math error on ARM target

[Monahan-Mitchell, Tim]

I wanted to post this observation to the group to see if I get a hit.

I updated Bug #569 today with an additional observation:
http://gnuradio.org/redmine/issues/569 

Basically, on my ARM target, if I enable cpu core #1 (two cores total), the 
qa_mpsk_receiver test fails about 1/3rd of the time, when it compares 0.5 to 
sometimes -.492 or sometimes -.503 (i.e., the sign in the real part of a 
complex result flipped). If I keep cpu #1 disabled, the test passes every time. 
Keeping the CPUs limited to their minimum speed does not help.

I'm compiling with gcc 4.7.3, and -mcpu=cortex-a15 -mfpu=neon 
-mvectorize-with-neon-quad -ffast-math -funsafe-loop-optimizations

I'll be varying the build flags to see if that makes a difference in the 
meantime.

Regards,
Tim