Pass -march=x86-64 to build JNI library

.github/workflows/CD.yml

@@ -35,6 +35,8 @@ jobs:
           CXX: ${{ matrix.compiler }}
         run: |
             cd jni
+            git submodule update --init -- jni/external/nmslib
+            sed -i 's/-march=native/-march=x86-64/g' external/nmslib/similarity_search/CMakeLists.txt
             cmake .
             make package
 

README.md

@@ -32,6 +32,9 @@ make
 
 The library will be placed in the `jni/release` directory.
 
+## JNI Library Artifacts
+We build and distribute binary library artifacts with Opendistro for Elasticsearch. We build the library binary, RPM and DEB in [this GitHub action](https://github.com/opendistro-for-elasticsearch/k-NN/blob/master/.github/workflows/CD.yml). We use Ubuntu 16.04 with g++ 5.4.0 to build the library. Additionally, in order to provide as much general compatibility as possible, we compile the library without optimized instruction sets enabled. For users that want to get the most out of the library, they should follow [this section](##Build JNI Library RPM/DEB) and build the library from source in their production environment, so that if their environment has optimized instruction sets, they take advantage of them.
+
 ## Build JNI Library RPM/DEB
 
 To build an RPM or DEB of the JNI library, follow these steps:
@@ -44,7 +47,7 @@ make package
 
 The artifacts will be placed in the `jni/packages` directory.
 
-Additionally, we build the RPM and DEB in [this GitHub action](https://github.com/opendistro-for-elasticsearch/k-NN/blob/master/.github/workflows/CD.yml). We use Ubuntu 16.04 with g++ 5.4.0.
+
 
 ## Running Multi-node Cluster Locally