Improve code for detection of architecture and MMX support

Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>
(cherry picked from commit 1c5de88934)

CMakeLists.txt

@@ -29,6 +29,7 @@ include( CheckCSourceCompiles )
 include( CheckIncludeFile )
 include( CheckLibraryExists )
 include( CheckSymbolExists )
+enable_language( ASM )
 
 
 ##### include our cmake modules #################

ConfigureChecks.cmake

@@ -245,36 +245,16 @@ if( WITH_LAME )
 endif( )
 
 
-##### check architecture
-
-if( NOT CMAKE_ARCHITECTURE )
-  execute_process(
-    COMMAND ${CMAKE_C_COMPILER} -dumpmachine
-    OUTPUT_VARIABLE CMAKE_ARCHITECTURE
-    ERROR_VARIABLE CMAKE_ARCHITECTURE
-    OUTPUT_STRIP_TRAILING_WHITESPACE
-    ERROR_STRIP_TRAILING_WHITESPACE )
-  set( CMAKE_ARCHITECTURE "${CMAKE_ARCHITECTURE}" CACHE INTERNAL "" FORCE )
-  message( STATUS "Detected ${CMAKE_ARCHITECTURE} target architecture" )
-endif( )
-
-
 ##### check specific architecture dependant support
 
-if( ${CMAKE_ARCHITECTURE} MATCHES "i.86" )
+if( CMAKE_SYSTEM_PROCESSOR MATCHES "i.86" )
 
   # MMX support
   message( STATUS "Performing MMX support test" )
-  check_c_source_compiles( "
-    int main() {
-      #if defined(__GNUC__)
-      __asm__(\"pxor %mm0, %mm0\");
-      #else
-      #error Not gcc on x86/x86_64
-      #endif
-      return 0;
-    }"
-    HAVE_X86_MMX
-  )
+  cmake_host_system_information( RESULT HAVE_X86_MMX QUERY HAS_MMX )
+  if( HAVE_X86_MMX )
+    message( STATUS "Performing MMX support test - Success" )
+    set( CMAKE_ASM_FLAGS "${CMAKE_ASM_FLAGS} -DHAVE_X86_MMX" )
+  endif( )
 
 endif( )

src/fastscale/CMakeLists.txt

@@ -24,19 +24,7 @@ link_directories(
 
 ##### fastscale (static) ########################
 
-set( fastscale_SRCS scale.cpp )
-
-if( HAVE_X86_MMX )
-  list( APPEND fastscale_SRCS asm_scale.S )
-
-  # Force to use C compiler for asm_scale.S instead of ASM
-  # because it contains mixed code - ASM with C definitions
-  set_source_files_properties( asm_scale.S PROPERTIES LANGUAGE C )
-
-  add_compile_options( -DHAVE_X86_MMX )
-endif( )
-
 tde_add_library( fastscale STATIC_PIC AUTOMOC
-  SOURCES ${fastscale_SRCS}
+  SOURCES scale.cpp asm_scale.S
   LINK tdecore-shared
 )