Displaying 1 result from an estimated 1 matches for "chacha_avx".
2018 Dec 01
2
Restrict global constructors to base ISA
...to the ISA as needed. Then, we guard the higher ISAs at runtime to
avoid SIGILLs. It worked well until we added AVX2.
For AVX2 we see this as expected:
$ CXX=/opt/local/bin/clang++-mp-5.0 make
/opt/local/bin/clang++-mp-5.0 ... -c chacha.cpp
/opt/local/bin/clang++-mp-5.0 ... -mavx2 -c chacha_avx.cpp
/opt/local/bin/clang++-mp-5.0 ... -msse2 -c chacha_simd.cpp
...
At runtime we catch a SIGILL due to chacha_avx.cpp as shown below. It
looks like global constructors are using instructions from AVX
(vxorps), which is beyond what the machine supports.
How do we tell Clang to use the bas...