We both want to respect the user's CFLAGS, but also, not all of our arches support
-march or -mtune.
--- a/benchmark/CMakeLists.txt
+++ b/benchmark/CMakeLists.txt
@@ -30,10 +30,6 @@ include(CheckCXXCompilerFlag)
 string(TOUPPER "${CMAKE_BUILD_TYPE}" U_CMAKE_BUILD_TYPE)
 
 if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_CXX_COMPILER_ID MATCHES "GNU" OR CMAKE_CXX_COMPILER_ID MATCHES "Intel")
-    if(NOT CMAKE_CXX_FLAGS MATCHES "-march" AND NOT CMAKE_CXX_FLAGS MATCHES "-arch" AND NOT CMAKE_OSX_ARCHITECTURES)
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=native")
-    endif()
-
     if(NOT MSVC)
         CHECK_CXX_COMPILER_FLAG("-std=c++11" HAS_CPP11_FLAG)
         if (ENABLE_XTL_COMPLEX)
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -26,15 +26,6 @@ else()
     message(STATUS "Tests build type is ${CMAKE_BUILD_TYPE}")
 endif()
 
-if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_CXX_COMPILER_ID MATCHES "GNU" OR CMAKE_CXX_COMPILER_ID MATCHES "Intel")
-    if (NOT CMAKE_CXX_FLAGS MATCHES "-march" AND NOT CMAKE_CXX_FLAGS MATCHES "-arch" AND NOT CMAKE_OSX_ARCHITECTURES)
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=native -mtune=native")
-    endif()
-    if(NOT CMAKE_CXX_COMPILER_ID MATCHES Clang) # We are using clang-cl
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fopenmp")
-    endif()
-endif()
-
 add_executable(mandelbrot mandelbrot.cpp ${XSIMD_HEADERS})
 set_property(TARGET mandelbrot PROPERTY CXX_STANDARD 14)
 if(ENABLE_XTL_COMPLEX)
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -41,10 +41,6 @@ OPTION(XSIMD_ENABLE_WERROR "Turn on -Werror" OFF)
 
 OPTION(CROSS_COMPILE_ARM "cross compile for ARM targets" OFF)
 
-# Note: to compile on ARM (or cross compile), you may need to add the following:
-# -DTARGET_ARCH="armv8-a -mfpu=neon -mfloat-abi=softfp -target arm-linux-gnueabi"
-set(TARGET_ARCH "native" CACHE STRING "Target architecture arguments")
-
 if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_CXX_COMPILER_ID MATCHES "GNU" OR CMAKE_CXX_COMPILER_ID MATCHES "Intel")
     if (NOT WIN32 AND NOT ANDROID)
         set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wunused-parameter -Wextra -Wreorder")
@@ -79,10 +75,6 @@ if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_CXX_COMPILER_ID MATCHES "GNU"
         include_directories(/usr/${ARM_ARCH_DIRECTORY}/include/c++/${ARM_GCC_VER}/${ARM_ARCH_DIRECTORY}/)
         include_directories(/usr/${ARM_ARCH_DIRECTORY}/include/c++/${ARM_GCC_VER}/)
         include_directories(/usr/${ARM_ARCH_DIRECTORY}/include/)
-        if(NOT CMAKE_CXX_FLAGS MATCHES "-march")
-            message(STATUS "SETTING ARCH TO ${TARGET_ARCH}")
-            set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=${TARGET_ARCH}")
-        endif()
         if(ARM_ARCH_DIRECTORY MATCHES "arm-linux-gnueabi")
             set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mfpu=neon -mfloat-abi=softfp -target arm-linux-gnueabi")
         else ()
@@ -91,13 +83,9 @@ if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_CXX_COMPILER_ID MATCHES "GNU"
         message(STATUS "CMAKE_CXX_FLAGS: ${CMAKE_CXX_FLAGS}")
         message(STATUS "CMAKE_CXX_LINK_EXECUTABLE: ${CMAKE_CXX_LINK_EXECUTABLE}")
     elseif(${CMAKE_SYSTEM_PROCESSOR} MATCHES "^ppc64"  OR ${CMAKE_SYSTEM_PROCESSOR} MATCHES "aarch64")
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mcpu=${TARGET_ARCH} -mtune=${TARGET_ARCH}")
     elseif(${CMAKE_SYSTEM_PROCESSOR} MATCHES "riscv64")
         # Nothing specific
     elseif(NOT WIN32 AND NOT EMSCRIPTEN)
-        if(NOT CMAKE_CXX_FLAGS MATCHES "-march" AND NOT CMAKE_CXX_FLAGS MATCHES "-arch" AND NOT CMAKE_OSX_ARCHITECTURES)
-            set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=${TARGET_ARCH}")
-        endif()
     endif()
 endif()