Setting FAISS_OPT_LEVEL=avx512_spr drops avx512 build and fails on cmake install

[kyamagu]

The following line assumes libfaiss_avx512 is built when FAISS_OPT_LEVEL=avx512_spr.

faiss/faiss/CMakeLists.txt

Line 421 in 8581b86

install(TARGETS faiss_avx2 faiss_avx512 faiss_avx512_spr

But the following condition on avx512 is not true when FAISS_OPT_LEVEL=avx512_spr and install fails.

faiss/faiss/CMakeLists.txt

Line 262 in 8581b86

add_library(faiss_avx512 ${FAISS_SRC})

When FAISS_OPT_LEVEL=avx512_spr, which behavior is expected?

• Build generic, avx2, and avx512_spr variants and drop avx512
• Build all variants

[mengdilin]

We do have a CI that builds with avx512_spr optimization mode successfully (e.g. https://fburl.com/9xj90b2k) What is your repro instruction to get this behavior? cc @mulugetam

[kyamagu]

The following fails at the install phase, because install target includes both avx512 and avx512_spr variants but does not build avx512

    cmake . \
        -B build \
        -DFAISS_ENABLE_GPU=OFF \
        -DFAISS_ENABLE_PYTHON=OFF \
        -DBUILD_TESTING=OFF \
        -DFAISS_OPT_LEVEL=avx512_spr \
        -DCMAKE_BUILD_TYPE=Release && \
    cmake --build build --config Release -j && \
    cmake --install build

[mengdilin]

@kyamagu if you are looking to install the distributed binary for avx512_spr, that is not supported. To install other optimizations mode, please use conda

[kyamagu]

@mengdilin I am not looking for a pre-built binary but just pointing out the possible bug in the CMakeLists.txt

[mnorris11]

Thanks for reporting this @kyamagu

cc @mulugetam :

The first option of

Build generic, avx2, and avx512_spr variants and drop avx512

makes the most sense to me (and is the approach in @kyamagu 's PR #4170). We'll go ahead and merge that in the next day or two unless you have concerns.

[zsz00]

@kyamagu hope you make a pre-built binary for faiss gpu, I see the faiss-gpu in pypi is version 1.7.2 and not support py3.11