refactor NEO_DISABLE_MITIGATIONS option

Related-To: NEO-7227
Signed-off-by: Artur Harasimiuk <[email protected]>

Author: ArturHarasimiuk

CMakeLists.txt

@@ -617,18 +617,18 @@ if(MSVC)
 endif()
 
 # spectre mitigation
-if(MSVC)
-  check_cxx_compiler_flag(/Qspectre COMPILER_SUPPORTS_QSPECTRE)
-  check_cxx_compiler_flag(/d2guardspecload COMPILER_SUPPORTS_D2GUARDSPECLOAD)
-  if(COMPILER_SUPPORTS_QSPECTRE)
-    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /Qspectre")
-  elseif(COMPILER_SUPPORTS_D2GUARDSPECLOAD)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /d2guardspecload")
+if(NOT NEO_DISABLE_MITIGATIONS)
+  if(MSVC)
+    check_cxx_compiler_flag(/Qspectre COMPILER_SUPPORTS_QSPECTRE)
+    check_cxx_compiler_flag(/d2guardspecload COMPILER_SUPPORTS_D2GUARDSPECLOAD)
+    if(COMPILER_SUPPORTS_QSPECTRE)
+      SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /Qspectre")
+    elseif(COMPILER_SUPPORTS_D2GUARDSPECLOAD)
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /d2guardspecload")
+    else()
+      message(WARNING "Spectre mitigation is not supported by the compiler")
+    endif()
   else()
-    message(WARNING "Spectre mitigation is not supported by the compiler")
-  endif()
-else()
-  if(NOT NEO_DISABLE_MITIGATIONS)
     if(${CMAKE_CXX_COMPILER_ID} STREQUAL "Clang")
       check_cxx_compiler_flag(-mretpoline COMPILER_SUPPORTS_RETPOLINE)
       if(COMPILER_SUPPORTS_RETPOLINE)
@@ -656,9 +656,12 @@ else()
         message(WARNING "Spectre mitigation -mindirect-branch-register flag is not supported by the compiler")
       endif()
     endif()
-  else()
-    message(WARNING "Spectre mitigation DISABLED")
   endif()
+else()
+  message(WARNING "Spectre mitigation DISABLED")
+endif()
+
+if(NOT MSVC)
   check_cxx_compiler_flag(-msse4.2 COMPILER_SUPPORTS_SSE42)
   check_cxx_compiler_flag(-mavx2 COMPILER_SUPPORTS_AVX2)
   check_cxx_compiler_flag(-march=armv8-a+simd COMPILER_SUPPORTS_NEON)