Only use -march=native if it's available

Not all architecture support this flag, e.g. gcc on ppc64le doesn't support this flag.
glemercier · Oct 7, 2020 · cf84096 · cf84096
1 parent 5df857c
commit cf84096
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Showing 5 changed files with 13 additions and 6 deletions.
diff --git a/benchmark/CMakeLists.txt b/benchmark/CMakeLists.txt
@@ -23,7 +23,8 @@ 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")
+    CHECK_CXX_COMPILER_FLAG(-march=native arch_native_supported)
+    if(arch_native_supported AND NOT CMAKE_CXX_FLAGS MATCHES "-march")
         set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=native")
     endif()
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O3 -g -Wunused-parameter -Wextra -Wreorder")

diff --git a/docs/source/build-options.rst b/docs/source/build-options.rst
@@ -103,7 +103,8 @@ anything, the system will do its best to enable the most recent supported instru
 Linux/OSX
 ~~~~~~~~~
 
-Whether you enabled ``XTENSOR_USE_XSIMD`` or not, it is highly recommended to build with ``-march=native`` option:
+Whether you enabled ``XTENSOR_USE_XSIMD`` or not, it is highly recommended to build with ``-march=native`` option,
+if your compiler supports it:
 
 .. code:: cmake
 

diff --git a/docs/source/getting_started.rst b/docs/source/getting_started.rst
@@ -99,7 +99,7 @@ The following minimal ``CMakeLists.txt`` is enough to build the first example:
 
         target_link_libraries(... xtensor::optimize)
 
-    set the following compiler flags:
+    set the following compiler flags, if supported by the target compiler:
 
     *   Unix: ``-march=native``;
     *   Windows: ``/EHsc /MP /bigobj``.

diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
@@ -63,7 +63,8 @@ if(NOT _cxx_std_flag)
 endif()
 
 if(CMAKE_CXX_COMPILER_ID MATCHES "GNU" OR (CMAKE_CXX_COMPILER_ID MATCHES "Intel" AND NOT WIN32))
-  if(NOT CMAKE_CXX_FLAGS MATCHES "-march")
+  CHECK_CXX_COMPILER_FLAG(-march=native arch_native_supported)
+  if(arch_native_supported AND NOT CMAKE_CXX_FLAGS MATCHES "-march")
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=native")
   endif()
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${_cxx_std_flag} -Wunused-parameter -Wextra -Wreorder -Wconversion -Wsign-conversion")
@@ -83,7 +84,8 @@ elseif(CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
   endif()
 elseif(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   if(NOT WIN32)
-    if(NOT CMAKE_CXX_FLAGS MATCHES "-march")
+    CHECK_CXX_COMPILER_FLAG(-march=native arch_native_supported)
+    if(arch_native_supported AND NOT CMAKE_CXX_FLAGS MATCHES "-march")
       set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=native")
     endif()
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${_cxx_std_flag} -Wunused-parameter -Wextra -Wreorder -Wconversion -Wsign-conversion")

diff --git a/xtensorConfig.cmake.in b/xtensorConfig.cmake.in
@@ -43,7 +43,10 @@ if (${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION} VERSION_GREATER_EQUAL 3.11)
             target_compile_options(xtensor::optimize INTERFACE /EHsc /MP /bigobj)
         # gcc, clang, ...
         else()
-            target_compile_options(xtensor::optimize INTERFACE -march=native)
+            CHECK_CXX_COMPILER_FLAG(-march=native arch_native_supported)
+            if(arch_native_supported)
+              target_compile_options(xtensor::optimize INTERFACE -march=native)
+          endif()
         endif()
     endif()