From 4f9f0f26c05b8b88efd3e8804dd8e47f0894929b Mon Sep 17 00:00:00 2001
From: christopher <christopher.weyand@student.hpi.de>
Date: Tue, 20 Feb 2018 13:48:18 +0100
Subject: [PATCH 1/4] simd detection script

---
 cmake/CheckSimd.cmake | 81 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 cmake/CheckSimd.cmake

diff --git a/cmake/CheckSimd.cmake b/cmake/CheckSimd.cmake
new file mode 100644
index 0000000..f1ac159
--- /dev/null
+++ b/cmake/CheckSimd.cmake
@@ -0,0 +1,81 @@
+
+include(CheckCXXSourceRuns)
+
+
+# set flags
+set(AVX_FLAGS)
+set(AVX2_FLAGS)
+set(AVX512_FLAGS)
+if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "MSVC")
+  set(AVX_FLAGS "/arch:AVX")
+  set(AVX2_FLAGS "/arch:AVX2")
+  # set(AVX512_FLAGS "/arch:AVX512") found no option for msvc
+endif()
+if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU" OR "${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
+  set(AVX_FLAGS "-mavx")
+  set(AVX2_FLAGS "-mavx2")
+  set(AVX512_FLAGS "-mavx512f" "-mavx512cd") # xeon processors have more flags
+endif()
+
+
+# check for AVX
+set(CMAKE_REQUIRED_FLAGS ${AVX_FLAGS})
+CHECK_CXX_SOURCE_RUNS("
+    #include <immintrin.h>
+    int main(){
+      const float src[8] = { 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f };
+      float dst[8];
+      __m256 a = _mm256_loadu_ps( src );
+      __m256 b = _mm256_add_ps( a, a );
+      _mm256_storeu_ps( dst, b );
+      for( int i = 0; i < 8; i++ )
+        if( ( src[i] + src[i] ) != dst[i] ) return -1;
+      return 0;
+    }"
+    AVX_ENABLED)
+# remove flags if cpu does not support AVX
+if(NOT AVX_ENABLED)
+  set(AVX_FLAGS "")
+endif()
+
+
+# check for AVX2
+set(CMAKE_REQUIRED_FLAGS ${AVX2_FLAGS})
+CHECK_CXX_SOURCE_RUNS("
+    #include <immintrin.h>
+    int main(){
+      const int src[8] = { 1, 2, 3, 4, 5, 6, 7, 8 };
+      int dst[8];
+      __m256i a =  _mm256_loadu_si256( (__m256i*)src );
+      __m256i b = _mm256_add_epi32( a, a );
+      _mm256_storeu_si256( (__m256i*)dst, b );
+      for( int i = 0; i < 8; i++ )
+        if( ( src[i] + src[i] ) != dst[i] ) return -1;
+      return 0;
+    }"
+    AVX2_ENABLED)
+# remove flags if cpu does not support AVX
+if(NOT AVX2_ENABLED)
+  set(AVX2_FLAGS "")
+endif()
+
+
+# check for AVX512
+set(CMAKE_REQUIRED_FLAGS ${AVX512_FLAGS})
+CHECK_CXX_SOURCE_RUNS("
+    #include <zmmintrin.h>
+    int main(){
+      const int src[16] = { 1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8 };
+      int dst[16];
+      __m512i a =  _mm512_loadu_si512( (__m512i*)src );
+      __m512i b = _mm512_add_epi32( a, a );
+      _mm512_storeu_si512( (__m512i*)dst, b );
+      for( int i = 0; i < 16; i++ )
+        if( ( src[i] + src[i] ) != dst[i] ) return -1;
+      return 0;
+    }"
+    AVX512_ENABLED)
+# remove flags if cpu does not support AVX
+if(NOT AVX512_ENABLED)
+  set(AVX512_FLAGS "")
+endif()

From 25fc466dd9a74c18500f9648059275af33cb7206 Mon Sep 17 00:00:00 2001
From: christopher <christopher.weyand@student.hpi.de>
Date: Tue, 20 Feb 2018 14:23:33 +0100
Subject: [PATCH 2/4] empty CMAKE_REQUIRED_FLAGS

---
 cmake/CheckSimd.cmake | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/cmake/CheckSimd.cmake b/cmake/CheckSimd.cmake
index f1ac159..4bb1826 100644
--- a/cmake/CheckSimd.cmake
+++ b/cmake/CheckSimd.cmake
@@ -79,3 +79,7 @@ CHECK_CXX_SOURCE_RUNS("
 if(NOT AVX512_ENABLED)
   set(AVX512_FLAGS "")
 endif()
+
+
+# cleanup cmake var
+set(CMAKE_REQUIRED_FLAGS "")

From d84338ba296e0d2653c9fbee60478bd579710ba7 Mon Sep 17 00:00:00 2001
From: christopher <christopher.weyand@student.hpi.de>
Date: Tue, 20 Feb 2018 14:30:36 +0100
Subject: [PATCH 3/4] consider previous cmake state

---
 cmake/CheckSimd.cmake | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/cmake/CheckSimd.cmake b/cmake/CheckSimd.cmake
index 4bb1826..8e16024 100644
--- a/cmake/CheckSimd.cmake
+++ b/cmake/CheckSimd.cmake
@@ -1,6 +1,8 @@
 
 include(CheckCXXSourceRuns)
 
+# save old configuration
+set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
 
 # set flags
 set(AVX_FLAGS)
@@ -19,7 +21,7 @@ endif()
 
 
 # check for AVX
-set(CMAKE_REQUIRED_FLAGS ${AVX_FLAGS})
+set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS} ${AVX_FLAGS})
 CHECK_CXX_SOURCE_RUNS("
     #include <immintrin.h>
     int main(){
@@ -40,7 +42,7 @@ endif()
 
 
 # check for AVX2
-set(CMAKE_REQUIRED_FLAGS ${AVX2_FLAGS})
+set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS} ${AVX2_FLAGS})
 CHECK_CXX_SOURCE_RUNS("
     #include <immintrin.h>
     int main(){
@@ -61,7 +63,7 @@ endif()
 
 
 # check for AVX512
-set(CMAKE_REQUIRED_FLAGS ${AVX512_FLAGS})
+set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS} ${AVX512_FLAGS})
 CHECK_CXX_SOURCE_RUNS("
     #include <zmmintrin.h>
     int main(){
@@ -81,5 +83,5 @@ if(NOT AVX512_ENABLED)
 endif()
 
 
-# cleanup cmake var
-set(CMAKE_REQUIRED_FLAGS "")
+# restore previous state of cmake variable
+set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})

From a9ce225769b05bb9ffd0282a8163899666a0a10a Mon Sep 17 00:00:00 2001
From: christopher <christopher.weyand@student.hpi.de>
Date: Tue, 20 Feb 2018 14:32:16 +0100
Subject: [PATCH 4/4] remove space and tab at line end

---
 CMakeLists.txt | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f2d0df8..5e14b99 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,7 +1,7 @@
 
-# 
+#
 # CMake options
-# 
+#
 
 # CMake version
 cmake_minimum_required(VERSION 3.0 FATAL_ERROR)
@@ -37,9 +37,9 @@ include(cmake/HealthCheck.cmake)
 include(cmake/GenerateTemplateExportHeader.cmake)
 
 
-# 
+#
 # Project description and (meta) information
-# 
+#
 
 # Get git revision
 get_git_head_revision(GIT_REFSPEC GIT_SHA1)
@@ -66,9 +66,9 @@ string(MAKE_C_IDENTIFIER ${META_PROJECT_NAME} META_PROJECT_ID)
 string(TOUPPER ${META_PROJECT_ID} META_PROJECT_ID)
 
 
-# 
+#
 # Project configuration options
-# 
+#
 
 # Project options
 option(BUILD_SHARED_LIBS     "Build shared instead of static libraries."              ON)
@@ -78,9 +78,9 @@ option(OPTION_BUILD_DOCS     "Build documentation."
 option(OPTION_BUILD_EXAMPLES "Build examples."                                        OFF)
 
 
-# 
+#
 # Declare project
-# 
+#
 
 # Generate folders for IDE targets (e.g., VisualStudio solutions)
 set_property(GLOBAL PROPERTY USE_FOLDERS ON)
@@ -98,9 +98,9 @@ set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR})
 file(WRITE "${PROJECT_BINARY_DIR}/VERSION" "${META_NAME_VERSION}")
 
 
-# 
+#
 # Compiler settings and options
-# 
+#
 
 include(cmake/CompileOptions.cmake)
 
@@ -117,9 +117,9 @@ enable_cppcheck(On)
 enable_clang_tidy(On)
 
 
-# 
+#
 # Deployment/installation setup
-# 
+#
 
 # Get project name
 set(project ${META_PROJECT_NAME})
@@ -171,23 +171,23 @@ if(NOT SYSTEM_DIR_INSTALL)
     if(APPLE)
         set(CMAKE_INSTALL_RPATH "@loader_path/../../../${INSTALL_LIB}")
     else()
-        set(CMAKE_INSTALL_RPATH "$ORIGIN/${INSTALL_LIB}")       
+        set(CMAKE_INSTALL_RPATH "$ORIGIN/${INSTALL_LIB}")
     endif()
 endif()
 
 
-# 
+#
 # Project modules
-# 
+#
 
 add_subdirectory(source)
 add_subdirectory(docs)
 add_subdirectory(deploy)
 
 
-# 
+#
 # Deployment (global project files)
-# 
+#
 
 # Install version file
 install(FILES "${PROJECT_BINARY_DIR}/VERSION" DESTINATION ${INSTALL_ROOT} COMPONENT runtime)