make --noavx512 implicit if host does not have avx512

cmake_targets/build_oai

@@ -613,6 +613,21 @@ function main() {
   cd  $DIR/$BUILD_DIR/build
   if [[ ${#CMAKE_C_FLAGS[@]} > 0 ]]; then CMAKE_CMD="$CMAKE_CMD -DCMAKE_C_FLAGS=\"${CMAKE_C_FLAGS[*]}\""; fi
   if [[ ${#CMAKE_CXX_FLAGS[@]} > 0 ]]; then CMAKE_CMD="$CMAKE_CMD -DCMAKE_CXX_FLAGS=\"${CMAKE_CXX_FLAGS[*]}\""; fi
+
+  # if --noavx512 is not specified the AVX512 equals "True" by default
+  # override AVX512 to "False" if processor does not have avx512
+  # this avoids having to specify --noavx512 systematically
+  if [ -f /proc/cpuinfo ]; then
+      if grep -q avx512 /proc/cpuinfo
+      then
+        echo_info "Processor has avx512 intrinsics"
+      else
+        echo_info "Processor does not have avx512 intrinsics"
+        echo_info "Forcing AVX512 to False"
+	AVX512="False"
+      fi
+  fi
+
   # for historical reasons we build in a subdirectory cmake_targets/XYZ/build,
   # e.g., cmake_targets/ran_build/build, hence the ../../..
   CMAKE_CMD="$CMAKE_CMD -DAVX512=\"${AVX512[*]}\" -DAVX2=\"${AVX2[*]}\" ../../.."