Add AVX checks (#20)

Co-authored-by: mancini <mancini@astron.nl>

CMakeLists.txt

@@ -12,6 +12,7 @@ option(TRIGDX_BUILD_TESTS "Build tests" ON)
 option(TRIGDX_BUILD_BENCHMARKS "Build tests" ON)
 option(TRIGDX_BUILD_PYTHON "Build Python interface" ON)
 
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake")
 configure_file(
   ${CMAKE_CURRENT_SOURCE_DIR}/cmake/trigdx_config.hpp.in
   ${CMAKE_CURRENT_BINARY_DIR}/include/trigdx/trigdx_config.hpp @ONLY)

benchmarks/CMakeLists.txt

@@ -13,8 +13,11 @@ target_link_libraries(benchmark_reference PRIVATE trigdx benchmark::benchmark)
 add_executable(benchmark_lookup benchmark_lookup.cpp)
 target_link_libraries(benchmark_lookup PRIVATE trigdx benchmark::benchmark)
 
-add_executable(benchmark_lookup_avx benchmark_lookup_avx.cpp)
-target_link_libraries(benchmark_lookup_avx PRIVATE trigdx benchmark::benchmark)
+if(HAVE_AVX)
+  add_executable(benchmark_lookup_avx benchmark_lookup_avx.cpp)
+  target_link_libraries(benchmark_lookup_avx PRIVATE trigdx
+                                                     benchmark::benchmark)
+endif()
 
 if(TRIGDX_USE_MKL)
   add_executable(benchmark_mkl benchmark_mkl.cpp)

cmake/FindAVX.cmake

@@ -0,0 +1,42 @@
+include(CheckCXXSourceRuns)
+
+set(SUPPORTED_COMPILERS Clang;GNU;Intel;IntelLLVM)
+
+if(CMAKE_CXX_COMPILER_ID IN_LIST SUPPORTED_COMPILERS)
+  if(CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
+    set(CMAKE_REQUIRED_FLAGS "-xHost") # ICC
+  elseif(CMAKE_CXX_COMPILER_ID STREQUAL "IntelLLVM")
+    set(CMAKE_REQUIRED_FLAGS "-march=native") # ICX
+  else()
+    set(CMAKE_REQUIRED_FLAGS "-march=native") # GCC/Clang
+  endif()
+else()
+  message(FATAL_ERROR "Unsupported compiler: ${CMAKE_CXX_COMPILER_ID}.")
+endif()
+
+# AVX check
+check_cxx_source_runs(
+  "
+#include <immintrin.h>
+int main() {
+    __m256 a = _mm256_setzero_ps(); // AVX
+    (void) a;
+    return 0;
+}
+"
+  HAVE_AVX)
+
+if(HAVE_AVX)
+  # AVX2 check
+  check_cxx_source_runs(
+    "
+#include <immintrin.h>
+int main() {
+    __m256i a = _mm256_set1_epi32(-1);
+    __m256i b = _mm256_abs_epi32(a); // AVX2
+    (void) b;
+    return 0;
+}
+"
+    HAVE_AVX2)
+endif()

src/CMakeLists.txt

@@ -1,10 +1,12 @@
 include(FetchContent)
-
-add_library(trigdx reference.cpp lookup.cpp lookup_avx.cpp)
+include(FindAVX)
+add_library(trigdx reference.cpp lookup.cpp)
 
 target_include_directories(trigdx PUBLIC ${PROJECT_SOURCE_DIR}/include)
 
-target_compile_options(trigdx PRIVATE -O3 -march=native)
+if(HAVE_AVX)
+  target_sources(trigdx PRIVATE lookup_avx.cpp)
+endif()
 
 if(TRIGDX_USE_MKL)
   find_package(MKL REQUIRED)
@@ -22,7 +24,8 @@ if(TRIGDX_USE_GPU)
 endif()
 
 if(TRIGDX_USE_XSIMD)
-  find_package(xsimd QUIET)
+  # Requires XSIMD > 13 for architecture independent dispatching
+  find_package(xsimd 13 QUIET)
   if(NOT TARGET xsimd)
     FetchContent_Declare(
       xsimd

src/lookup_avx.cpp

@@ -160,7 +160,6 @@ template <std::size_t NR_SAMPLES> struct LookupAVXBackend<NR_SAMPLES>::Impl {
     for (std::size_t i = 0; i < n; ++i) {
       std::size_t idx = static_cast<std::size_t>(x[i] * SCALE) & MASK;
       std::size_t idx_cos = (idx + NR_SAMPLES / 4) & MASK;
-      s[i] = lookup[idx];
       c[i] = lookup[idx_cos];
     }
 #endif

tests/CMakeLists.txt

@@ -10,9 +10,11 @@ target_link_libraries(test_lookup PRIVATE trigdx Catch2::Catch2WithMain)
 add_test(NAME test_lookup COMMAND test_lookup)
 
 # LookupAVX backend test
-add_executable(test_lookup_avx test_lookup_avx.cpp)
-target_link_libraries(test_lookup_avx PRIVATE trigdx Catch2::Catch2WithMain)
-add_test(NAME test_lookup_avx COMMAND test_lookup_avx)
+if(HAVE_AVX)
+  add_executable(test_lookup_avx test_lookup_avx.cpp)
+  target_link_libraries(test_lookup_avx PRIVATE trigdx Catch2::Catch2WithMain)
+  add_test(NAME test_lookup_avx COMMAND test_lookup_avx)
+endif()
 
 # MKL backend test
 if(TRIGDX_USE_MKL)