Add SSE/AVX flags, regardless of default CXX flags

PCL_ENABLE_SSE and PCL_ENABLE_AVX should be used to choose (by default, both are on)
Previously, the logic made the behaviour quite unclear: if the user has set CMAKE_CXX_FLAGS to a custom value, it was impossible to use SSE_FLAGS/AVX_FLAGS

CMakeLists.txt

@@ -100,13 +100,16 @@ if(CMAKE_TIMING_VERBOSE AND UNIX)
 endif()
 
 # check for SSE flags
+set(SSE_FLAGS "")
+set(SSE_DEFINITIONS "")
 include("${PCL_SOURCE_DIR}/cmake/pcl_find_sse.cmake")
-if(PCL_ENABLE_SSE AND "${CMAKE_CXX_FLAGS}" STREQUAL "${CMAKE_CXX_FLAGS_DEFAULT}")
+if(PCL_ENABLE_SSE)
   PCL_CHECK_FOR_SSE()
 endif()
 
 # check for AVX flags
-if(PCL_ENABLE_AVX AND "${CMAKE_CXX_FLAGS}" STREQUAL "${CMAKE_CXX_FLAGS_DEFAULT}")
+set(AVX_FLAGS "")
+if(PCL_ENABLE_AVX)
   include("${PCL_SOURCE_DIR}/cmake/pcl_find_avx.cmake")
   PCL_CHECK_FOR_AVX()
 endif()
@@ -119,8 +122,9 @@ if(CMAKE_COMPILER_IS_GNUCXX)
     else()
       string(APPEND CMAKE_CXX_FLAGS " -Wabi")
     endif()
-    string(APPEND CMAKE_CXX_FLAGS " -Wall -Wextra -fno-strict-aliasing ${SSE_FLAGS} ${AVX_FLAGS}")
+    string(APPEND CMAKE_CXX_FLAGS " -Wall -Wextra -fno-strict-aliasing")
   endif()
+  string(APPEND CMAKE_CXX_FLAGS " ${SSE_FLAGS} ${AVX_FLAGS}")
 
   if(PCL_WARNINGS_ARE_ERRORS)
     string(APPEND CMAKE_CXX_FLAGS " -Werror -fno-strict-aliasing")
@@ -147,7 +151,7 @@ if(CMAKE_COMPILER_IS_MSVC)
   add_definitions("-DBOOST_ALL_NO_LIB -D_SCL_SECURE_NO_WARNINGS -D_CRT_SECURE_NO_WARNINGS -DNOMINMAX -DPCL_ONLY_CORE_POINT_TYPES ${SSE_DEFINITIONS}")
 
   if("${CMAKE_CXX_FLAGS}" STREQUAL "${CMAKE_CXX_FLAGS_DEFAULT}")
-    string(APPEND CMAKE_CXX_FLAGS " /fp:precise ${SSE_FLAGS} ${AVX_FLAGS}")
+    string(APPEND CMAKE_CXX_FLAGS " /fp:precise")
 
     # Add extra code generation/link optimizations
     if(CMAKE_MSVC_CODE_LINK_OPTIMIZATION AND (NOT BUILD_CUDA) AND (NOT BUILD_GPU))
@@ -203,6 +207,7 @@ if(CMAKE_COMPILER_IS_MSVC)
     endif()
   endif()
   string(APPEND CMAKE_CXX_FLAGS " /bigobj")
+  string(APPEND CMAKE_CXX_FLAGS " ${SSE_FLAGS} ${AVX_FLAGS}")
 
   if(CMAKE_GENERATOR STREQUAL "Ninja")
     string(APPEND CMAKE_C_FLAGS " /FS")
@@ -224,11 +229,12 @@ if(CMAKE_COMPILER_IS_CLANG)
     set(CMAKE_C_FLAGS "-Qunused-arguments")
   endif()
   if("${CMAKE_CXX_FLAGS}" STREQUAL "")
-    set(CMAKE_CXX_FLAGS "-ftemplate-depth=1024 -Qunused-arguments -Wno-invalid-offsetof ${SSE_FLAGS} ${AVX_FLAGS}") # Unfortunately older Clang versions do not have this: -Wno-unnamed-type-template-args
+    set(CMAKE_CXX_FLAGS "-ftemplate-depth=1024 -Qunused-arguments -Wno-invalid-offsetof") # Unfortunately older Clang versions do not have this: -Wno-unnamed-type-template-args
     if(APPLE AND WITH_CUDA AND CUDA_FOUND)
       string(APPEND CMAKE_CXX_FLAGS " -stdlib=libstdc++")
     endif()
   endif()
+  string(APPEND CMAKE_CXX_FLAGS " ${SSE_FLAGS} ${AVX_FLAGS}")
   set(CLANG_LIBRARIES "stdc++")
 endif()