The test was actually never executed correctly (unsigned -10 is never <= 10), and log2_approx64_ref() was not accurate enough.
Therefore replace it by directly comparing one value above and one value below each rounding boundary.
To skip the test, we use the gtest command line parameter "--gtest_filter" to filter out the unwanted test.
This parameter is described as follows:
--gtest_filter=POSITIVE_PATTERNS[-NEGATIVE_PATTERNS]
Run only the tests whose name matches one of the positive patterns but
none of the negative patterns. '?' matches any single character; '*'
matches any substring; ':' separates two patterns.
This commit introduces google benchmark library and one benchmark for
rotate_cpx_vector. Also extracted common tools used in testcases for
generation and allocation of byte aligned vectors in phy_test_tools.hpp
Matthias Mehlhose