diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 0000000..6e6d04c
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,23 @@
+name: Build
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v3
+
+    - name: Install dependencies
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y libeigen3-dev libpng-dev
+
+    - name: Configure
+      run: cd samples && mkdir build && cd build && cmake ..
+
+    - name: Build
+      run: cd samples/build && make -j
+
diff --git a/lib/gpc/Feature.hpp b/lib/gpc/Feature.hpp
index fac61c5..c461f1a 100644
--- a/lib/gpc/Feature.hpp
+++ b/lib/gpc/Feature.hpp
@@ -41,6 +41,7 @@
 #include <gpc/buffer.hpp>
 #include <iostream>
 #include <iterator>
+#include <gpc/filter.hpp>
 #include <random>
 #include <set>
 #include <string>
diff --git a/samples/CMakeLists.txt b/samples/CMakeLists.txt
index 62b5724..f10bbc0 100644
--- a/samples/CMakeLists.txt
+++ b/samples/CMakeLists.txt
@@ -1,7 +1,7 @@
-cmake_minimum_required(VERSION 3.6)
-
+cmake_minimum_required(VERSION 3.10)
+include(CheckCXXCompilerFlag)
+include(CheckCXXSourceRuns)
 project(openGPC CXX)
-# Use C++11 features.
 set (REQ_CPP11_FEATURES  cxx_strong_enums cxx_auto_type)
 
 set(CMAKE_CXX_STANDARD 11) 
@@ -12,31 +12,42 @@ find_package(Eigen3 REQUIRED)
 include_directories(${EIGEN3_INCLUDE_DIR})
 
 #By default, use SSE intrinsics
-option(SSE "SSE" ON)
+option(SSE "Enable SSE/AVX optimizations if available" ON)
+
+add_compile_options(-O3 -funroll-loops)
 if(SSE)
-  add_definitions(-D_INTRINSICS_SSE)
-  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}  -O3  -mavx2 -march=core-avx2 -lpthread -funroll-loops")
-else()
-  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}  -O3  -lpthread -funroll-loops")
+    message(STATUS "Checking if target CPU supports AVX2 instructions...")
+    check_cxx_source_runs("
+      #include <immintrin.h>
+      int main() {
+        __m256i x = _mm256_set1_epi32(1);
+        return _mm256_extract_epi32(x, 0);
+      }
+    " CPU_HAS_AVX2)
+
+    if(CPU_HAS_AVX2)
+      message(STATUS "AVX2: supported and enabled")
+      add_compile_definitions(_INTRINSICS_SSE)
+      add_compile_options(-mavx2 -march=core-avx2)
+    endif()
 endif()
 
 #find pnglib (used to load and store images for training and during evaluation)
 find_package(PNG REQUIRED)
 include_directories(${PNG_INCLUDE_DIRS})
 
+set(THREADS_PREFER_PTHREAD_FLAG ON)
+find_package(Threads REQUIRED)
 
-#Add gpc header directy
 include_directories("../lib")
 
-#Three examples for GPC library
 add_executable(extract extract.cpp)
-target_link_libraries(extract ${PNG_LIBRARIES})
+target_link_libraries(extract ${PNG_LIBRARIES} Threads::Threads)
 
 add_executable(train train.cpp)
-target_link_libraries(train ${PNG_LIBRARIES})
-
+target_link_libraries(train ${PNG_LIBRARIES} Threads::Threads)
 
 add_executable(sparsematch sparsematch.cpp)
-target_link_libraries(sparsematch ${PNG_LIBRARIES})
+target_link_libraries(sparsematch ${PNG_LIBRARIES} Threads::Threads)