[fix][make] add linker flags to tests/demo_ivfpq_indexing target

[blandinw]

before:

/usr/local/opt/llvm/bin/clang++ -o tests/demo_ivfpq_indexing -fPIC -m64 -Wall -g -O3 -msse4 -mpopcnt -fopenmp -Wno-sign-compare -Dnullptr=NULL -I/usr/local/opt/llvm/include -Doverride= -g -O3 tests/demo_i
vfpq_indexing.cpp libfaiss.a  -framework Accelerate
ld: library not found for -lomp
clang-3.9: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [tests/demo_ivfpq_indexing] Error 1

after:

λ make
/usr/local/opt/llvm/bin/clang++ -o tests/demo_ivfpq_indexing -fPIC -m64 -Wall -g -O3 -msse4 -mpopcnt -fopenmp -Wno-sign-compare -Dnullptr=NULL -I/usr/local/opt/llvm/include -Doverride= -g -O3 tests/demo_i
vfpq_indexing.cpp libfaiss.a -g -fPIC -fopenmp -L/usr/local/opt/llvm/lib -framework Accelerate
# success

[mdouze]

Let me investigate a bit more. The flags are not needed for g++. Could you confirm that in your case they are needed for tests/demo_ivfpq_indexing but not tests/demo_sift1M?

[blandinw]

I'm using clang 3.9 (from brew install llvm).
Maybe that's why? Will try again when I get to my computer

[mdouze]

Ok I'll add to both tests/demo_ivfpq_indexing and tests/demo_sift1M