Fix detection of MMX capabilities on ix86 archs

Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>
(cherry picked from commit 1a7322da1c)

CMakeLists.txt

@@ -20,13 +20,10 @@ project( k3b )
 ##### include essential cmake modules ###########
 
 include( FindPkgConfig )
+include( CheckCSourceCompiles )
 include( CheckIncludeFile )
 include( CheckLibraryExists )
 include( CheckSymbolExists )
-# EXAMPLE:
-# include( CheckTypeSize )
-# include( CheckCSourceCompiles )
-# include( CheckCXXSourceCompiles )
 
 
 ##### include our cmake modules #################

ConfigureChecks.cmake

@@ -243,3 +243,38 @@ if( WITH_LAME )
     tde_message_fatal( "lame is requested, but was not found on your system" )
   endif( )
 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" )
+
+  # 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
+  )
+
+endif( )

config.h.cmake

@@ -35,3 +35,6 @@
 // #cmakedefine HAVE_RESMGR
 
 #cmakedefine HAVE_TAGLIB
+
+// Defined if you have MMX support
+#cmakedefine HAVE_X86_MMX 1

src/fastscale/CMakeLists.txt

@@ -21,15 +21,22 @@ link_directories(
   ${TQT_LIBRARY_DIRS}
 )
 
-# Force to use C compiler for asm_scale.S instead of ASM
-# because contains mixed code - ASM with C definitions
-set_source_files_properties( asm_scale.S PROPERTIES LANGUAGE C )
-
-# TODO add assembler flags here (2016-01-14, Fat-Zer)
 
 ##### 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 scale.cpp asm_scale.S
+  SOURCES ${fastscale_SRCS}
   LINK tdecore-shared
 )