diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3cb9c3bc..9d5fa774 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -17,210 +17,7 @@ if(NOT CMAKE_BUILD_TYPE)
   )
 endif()
 
-################################################################################
-# Generate the config.h to compile with specific intrinsics / libs.
-
-## Check for compiler options.
-include(CheckCSourceCompiles)
-check_c_source_compiles("
-    int main(void) {
-      (void)__builtin_bswap16(0);
-      return 0;
-    }
-  "
-  HAVE_BUILTIN_BSWAP16
-)
-check_c_source_compiles("
-    int main(void) {
-      (void)__builtin_bswap32(0);
-      return 0;
-    }
-  "
-  HAVE_BUILTIN_BSWAP32
-)
-check_c_source_compiles("
-    int main(void) {
-      (void)__builtin_bswap64(0);
-      return 0;
-    }
-  "
-  HAVE_BUILTIN_BSWAP64
-)
-
-## Check for libraries.
-find_package(Threads)
-if(Threads_FOUND)
-  if(CMAKE_USE_PTHREADS_INIT)
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pthread")
-  endif()
-  foreach(PTHREAD_TEST HAVE_PTHREAD_PRIO_INHERIT PTHREAD_CREATE_UNDETACHED)
-    check_c_source_compiles("
-        #include <pthread.h>
-        int main (void) {
-          int attr = ${PTHREAD_TEST};
-          return attr;
-        }
-      " ${PTHREAD_TEST}
-    )
-  endforeach()
-  list(APPEND WEBP_DEP_LIBRARIES ${CMAKE_THREAD_LIBS_INIT})
-endif()
-set(WEBP_USE_THREAD ${Threads_FOUND})
-
-# TODO: this seems unused, check with autotools.
-set(LT_OBJDIR ".libs/")
-
-# Only useful for vwebp, so useless for now.
-# find_package(OpenGL)
-# set(WEBP_HAVE_GL ${OPENGL_FOUND})
-# set(WEBP_DEP_INCLUDE_DIRS ${WEBP_DEP_INCLUDE_DIRS} ${OPENGL_INCLUDE_DIRS})
-# set(WEBP_DEP_LIBRARIES ${WEBP_DEP_LIBRARIES} ${OPENGL_LIBRARIES})
-
-# Find the standard C math library.
-find_library(MATH_LIBRARY NAMES m)
-if(MATH_LIBRARY)
-  list(APPEND WEBP_DEP_LIBRARIES ${MATH_LIBRARY})
-endif()
-
-# Find the standard image libraries.
-set(WEBP_DEP_IMG_LIBRARIES)
-set(WEBP_DEP_IMG_INCLUDE_DIRS)
-foreach(I_LIB PNG JPEG TIFF GIF)
-  find_package(${I_LIB})
-  set(WEBP_HAVE_${I_LIB} ${${I_LIB}_FOUND})
-  if(${I_LIB}_FOUND)
-    list(APPEND WEBP_DEP_IMG_LIBRARIES ${${I_LIB}_LIBRARIES})
-    list(APPEND WEBP_DEP_IMG_INCLUDE_DIRS ${${I_LIB}_INCLUDE_DIRS})
-  endif()
-endforeach()
-
-## Check for specific headers.
-include(CheckIncludeFiles)
-check_include_files("stdlib.h;stdarg.h;string.h;float.h" STDC_HEADERS)
-check_include_files(dlfcn.h HAVE_DLFCN_H)
-check_include_files(GLUT/glut.h HAVE_GLUT_GLUT_H)
-check_include_files(GL/glut.h HAVE_GL_GLUT_H)
-check_include_files(inttypes.h HAVE_INTTYPES_H)
-check_include_files(memory.h HAVE_MEMORY_H)
-check_include_files(OpenGL/glut.h HAVE_OPENGL_GLUT_H)
-check_include_files(shlwapi.h HAVE_SHLWAPI_H)
-check_include_files(stdint.h HAVE_STDINT_H)
-check_include_files(stdlib.h HAVE_STDLIB_H)
-check_include_files(strings.h HAVE_STRINGS_H)
-check_include_files(string.h HAVE_STRING_H)
-check_include_files(sys/stat.h HAVE_SYS_STAT_H)
-check_include_files(sys/types.h HAVE_SYS_TYPES_H)
-check_include_files(unistd.h HAVE_UNISTD_H)
-check_include_files(wincodec.h HAVE_WINCODEC_H)
-check_include_files(windows.h HAVE_WINDOWS_H)
-
-# Windows specifics
-if(HAVE_WINCODEC_H)
-  list(APPEND WEBP_DEP_LIBRARIES shlwapi ole32 windowscodecs)
-endif()
-
-## Check for SIMD extensions.
-set(WEBP_SIMD_FLAGS "SSE2;SSE41;AVX2")
-set(WEBP_SIMD_FILE_EXTENSIONS "_sse2.c;_sse41.c;_avx2.c")
-if(MSVC)
-  # MSVC does not have a SSE4 flag but AVX2 support implies
-  # SSE4 support.
-  set(SIMD_ENABLE_FLAGS "/arch:SSE2;/arch:AVX2;/arch:AVX2")
-  set(SIMD_DISABLE_FLAGS)
-else()
-  set(SIMD_ENABLE_FLAGS "-msse2;-msse4.1;-mavx2")
-  set(SIMD_DISABLE_FLAGS "-mno-sse2;-mno-sse4.1;-mno-avx2")
-endif()
-
-set(WEBP_SIMD_FILES_TO_NOT_INCLUDE)
-set(WEBP_SIMD_FILES_TO_INCLUDE)
-set(WEBP_SIMD_FLAGS_TO_INCLUDE)
-
-list(LENGTH WEBP_SIMD_FLAGS WEBP_SIMD_FLAGS_LENGTH)
-math(EXPR WEBP_SIMD_FLAGS_RANGE "${WEBP_SIMD_FLAGS_LENGTH} - 1")
-
-foreach(I_SIMD RANGE ${WEBP_SIMD_FLAGS_RANGE})
-  list(GET WEBP_SIMD_FLAGS ${I_SIMD} WEBP_SIMD_FLAG)
-  list(GET SIMD_ENABLE_FLAGS ${I_SIMD} SIMD_COMPILE_FLAG)
-  set(CMAKE_REQUIRED_FLAGS ${SIMD_COMPILE_FLAG})
-  check_c_source_compiles("
-      #include \"${CMAKE_CURRENT_LIST_DIR}/src/dsp/dsp.h\"
-      int main(void) {
-        #if !defined(WEBP_USE_${WEBP_SIMD_FLAG})
-        this is not valid code
-        #endif
-        return 0;
-      }
-    "
-    WEBP_HAVE_${WEBP_SIMD_FLAG}
-  )
-
-  # Check which files we should include or not.
-  list(GET WEBP_SIMD_FILE_EXTENSIONS ${I_SIMD} WEBP_SIMD_FILE_EXTENSION)
-  file(GLOB SIMD_FILES RELATIVE ${CMAKE_CURRENT_LIST_DIR}
-    "${CMAKE_CURRENT_SOURCE_DIR}/src/dsp/*${WEBP_SIMD_FILE_EXTENSION}"
-  )
-  if(WEBP_HAVE_${WEBP_SIMD_FLAG})
-    # Memorize the file and flags.
-    foreach(FILE ${SIMD_FILES})
-      list(APPEND WEBP_SIMD_FILES_TO_INCLUDE ${FILE})
-      list(APPEND WEBP_SIMD_FLAGS_TO_INCLUDE ${SIMD_COMPILE_FLAG})
-    endforeach()
-  else()
-    # Remove the file from the list.
-    foreach(FILE ${SIMD_FILES})
-      list(APPEND WEBP_SIMD_FILES_NOT_TO_INCLUDE ${FILE})
-    endforeach()
-    # Explicitly disable SIMD.
-    if(SIMD_DISABLE_FLAGS)
-      list(GET SIMD_DISABLE_FLAGS ${I_SIMD} SIMD_COMPILE_FLAG)
-      include(CheckCCompilerFlag)
-      check_c_compiler_flag(${SIMD_COMPILE_FLAG} HAS_COMPILE_FLAG)
-      if(HAS_COMPILE_FLAG)
-        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${SIMD_COMPILE_FLAG}")
-      endif()
-    endif()
-  endif()
-endforeach()
-
-## Define extra info.
-set(PACKAGE ${PROJECT_NAME})
-set(PACKAGE_NAME ${PROJECT_NAME})
-
-# Read from configure.ac.
-file(READ ${CMAKE_CURRENT_SOURCE_DIR}/configure.ac CONFIGURE_AC)
-string(REGEX MATCHALL "\\[([0-9a-z\\.:/]*)\\]"
-  CONFIGURE_AC_PACKAGE_INFO ${CONFIGURE_AC}
-)
-function(strip_bracket VAR)
-  string(LENGTH ${${VAR}} TMP_LEN)
-  math(EXPR TMP_LEN ${TMP_LEN}-2)
-  string(SUBSTRING ${${VAR}} 1 ${TMP_LEN} TMP_SUB)
-  set(${VAR} ${TMP_SUB} PARENT_SCOPE)
-endfunction()
-
-list(GET CONFIGURE_AC_PACKAGE_INFO 1 PACKAGE_VERSION)
-strip_bracket(PACKAGE_VERSION)
-list(GET CONFIGURE_AC_PACKAGE_INFO 2 PACKAGE_BUGREPORT)
-strip_bracket(PACKAGE_BUGREPORT)
-list(GET CONFIGURE_AC_PACKAGE_INFO 3 PACKAGE_URL)
-strip_bracket(PACKAGE_URL)
-
-# Build more info.
-set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
-set(PACKAGE_TARNAME ${PACKAGE_NAME})
-set(VERSION ${PACKAGE_VERSION})
-
-## Generate the config.h header.
-configure_file(${CMAKE_CURRENT_LIST_DIR}/cmake/config.h.in
-  ${CMAKE_CURRENT_BINARY_DIR}/include/webp/config.h)
-add_definitions(-DHAVE_CONFIG_H)
-# The webp folder is included as we reference config.h as
-# ../webp/config.h or webp/config.h
-include_directories(${CMAKE_CURRENT_BINARY_DIR}/include
-  ${CMAKE_CURRENT_BINARY_DIR}/include/webp
-)
-
+include(cmake/config.h.cmake)
 
 ################################################################################
 # WebP source files.
diff --git a/cmake/config.h.cmake b/cmake/config.h.cmake
new file mode 100644
index 00000000..0aade0c0
--- /dev/null
+++ b/cmake/config.h.cmake
@@ -0,0 +1,141 @@
+# Generate the config.h to compile with specific intrinsics / libs.
+
+## Check for compiler options.
+include(CheckCSourceCompiles)
+check_c_source_compiles("
+    int main(void) {
+      (void)__builtin_bswap16(0);
+      return 0;
+    }
+  "
+  HAVE_BUILTIN_BSWAP16
+)
+check_c_source_compiles("
+    int main(void) {
+      (void)__builtin_bswap32(0);
+      return 0;
+    }
+  "
+  HAVE_BUILTIN_BSWAP32
+)
+check_c_source_compiles("
+    int main(void) {
+      (void)__builtin_bswap64(0);
+      return 0;
+    }
+  "
+  HAVE_BUILTIN_BSWAP64
+)
+
+## Check for libraries.
+find_package(Threads)
+if(Threads_FOUND)
+  if(CMAKE_USE_PTHREADS_INIT)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pthread")
+  endif()
+  foreach(PTHREAD_TEST HAVE_PTHREAD_PRIO_INHERIT PTHREAD_CREATE_UNDETACHED)
+    check_c_source_compiles("
+        #include <pthread.h>
+        int main (void) {
+          int attr = ${PTHREAD_TEST};
+          return attr;
+        }
+      " ${PTHREAD_TEST}
+    )
+  endforeach()
+  list(APPEND WEBP_DEP_LIBRARIES ${CMAKE_THREAD_LIBS_INIT})
+endif()
+set(WEBP_USE_THREAD ${Threads_FOUND})
+
+# TODO: this seems unused, check with autotools.
+set(LT_OBJDIR ".libs/")
+
+# Only useful for vwebp, so useless for now.
+# find_package(OpenGL)
+# set(WEBP_HAVE_GL ${OPENGL_FOUND})
+# set(WEBP_DEP_INCLUDE_DIRS ${WEBP_DEP_INCLUDE_DIRS} ${OPENGL_INCLUDE_DIRS})
+# set(WEBP_DEP_LIBRARIES ${WEBP_DEP_LIBRARIES} ${OPENGL_LIBRARIES})
+
+# Find the standard C math library.
+find_library(MATH_LIBRARY NAMES m)
+if(MATH_LIBRARY)
+  list(APPEND WEBP_DEP_LIBRARIES ${MATH_LIBRARY})
+endif()
+
+# Find the standard image libraries.
+set(WEBP_DEP_IMG_LIBRARIES)
+set(WEBP_DEP_IMG_INCLUDE_DIRS)
+foreach(I_LIB PNG JPEG TIFF GIF)
+  find_package(${I_LIB})
+  set(WEBP_HAVE_${I_LIB} ${${I_LIB}_FOUND})
+  if(${I_LIB}_FOUND)
+    list(APPEND WEBP_DEP_IMG_LIBRARIES ${${I_LIB}_LIBRARIES})
+    list(APPEND WEBP_DEP_IMG_INCLUDE_DIRS ${${I_LIB}_INCLUDE_DIRS})
+  endif()
+endforeach()
+
+## Check for specific headers.
+include(CheckIncludeFiles)
+check_include_files("stdlib.h;stdarg.h;string.h;float.h" STDC_HEADERS)
+check_include_files(dlfcn.h HAVE_DLFCN_H)
+check_include_files(GLUT/glut.h HAVE_GLUT_GLUT_H)
+check_include_files(GL/glut.h HAVE_GL_GLUT_H)
+check_include_files(inttypes.h HAVE_INTTYPES_H)
+check_include_files(memory.h HAVE_MEMORY_H)
+check_include_files(OpenGL/glut.h HAVE_OPENGL_GLUT_H)
+check_include_files(shlwapi.h HAVE_SHLWAPI_H)
+check_include_files(stdint.h HAVE_STDINT_H)
+check_include_files(stdlib.h HAVE_STDLIB_H)
+check_include_files(strings.h HAVE_STRINGS_H)
+check_include_files(string.h HAVE_STRING_H)
+check_include_files(sys/stat.h HAVE_SYS_STAT_H)
+check_include_files(sys/types.h HAVE_SYS_TYPES_H)
+check_include_files(unistd.h HAVE_UNISTD_H)
+check_include_files(wincodec.h HAVE_WINCODEC_H)
+check_include_files(windows.h HAVE_WINDOWS_H)
+
+# Windows specifics
+if(HAVE_WINCODEC_H)
+  list(APPEND WEBP_DEP_LIBRARIES shlwapi ole32 windowscodecs)
+endif()
+
+## Check for SIMD extensions.
+include(${CMAKE_CURRENT_LIST_DIR}/cpu.cmake)
+
+## Define extra info.
+set(PACKAGE ${PROJECT_NAME})
+set(PACKAGE_NAME ${PROJECT_NAME})
+
+# Read from configure.ac.
+file(READ ${CMAKE_CURRENT_SOURCE_DIR}/configure.ac CONFIGURE_AC)
+string(REGEX MATCHALL "\\[([0-9a-z\\.:/]*)\\]"
+  CONFIGURE_AC_PACKAGE_INFO ${CONFIGURE_AC}
+)
+function(strip_bracket VAR)
+  string(LENGTH ${${VAR}} TMP_LEN)
+  math(EXPR TMP_LEN ${TMP_LEN}-2)
+  string(SUBSTRING ${${VAR}} 1 ${TMP_LEN} TMP_SUB)
+  set(${VAR} ${TMP_SUB} PARENT_SCOPE)
+endfunction()
+
+list(GET CONFIGURE_AC_PACKAGE_INFO 1 PACKAGE_VERSION)
+strip_bracket(PACKAGE_VERSION)
+list(GET CONFIGURE_AC_PACKAGE_INFO 2 PACKAGE_BUGREPORT)
+strip_bracket(PACKAGE_BUGREPORT)
+list(GET CONFIGURE_AC_PACKAGE_INFO 3 PACKAGE_URL)
+strip_bracket(PACKAGE_URL)
+
+# Build more info.
+set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+set(PACKAGE_TARNAME ${PACKAGE_NAME})
+set(VERSION ${PACKAGE_VERSION})
+
+## Generate the config.h header.
+configure_file(${CMAKE_CURRENT_LIST_DIR}/config.h.in
+  ${CMAKE_CURRENT_BINARY_DIR}/include/webp/config.h)
+add_definitions(-DHAVE_CONFIG_H)
+# The webp folder is included as we reference config.h as
+# ../webp/config.h or webp/config.h
+include_directories(${CMAKE_CURRENT_BINARY_DIR}/include
+  ${CMAKE_CURRENT_BINARY_DIR}/include/webp
+)
diff --git a/cmake/cpu.cmake b/cmake/cpu.cmake
new file mode 100644
index 00000000..85fb89df
--- /dev/null
+++ b/cmake/cpu.cmake
@@ -0,0 +1,63 @@
+## Check for SIMD extensions.
+set(WEBP_SIMD_FLAGS "SSE2;SSE41;AVX2")
+set(WEBP_SIMD_FILE_EXTENSIONS "_sse2.c;_sse41.c;_avx2.c")
+if(MSVC)
+  # MSVC does not have a SSE4 flag but AVX2 support implies
+  # SSE4 support.
+  set(SIMD_ENABLE_FLAGS "/arch:SSE2;/arch:AVX2;/arch:AVX2")
+  set(SIMD_DISABLE_FLAGS)
+else()
+  set(SIMD_ENABLE_FLAGS "-msse2;-msse4.1;-mavx2")
+  set(SIMD_DISABLE_FLAGS "-mno-sse2;-mno-sse4.1;-mno-avx2")
+endif()
+
+set(WEBP_SIMD_FILES_TO_NOT_INCLUDE)
+set(WEBP_SIMD_FILES_TO_INCLUDE)
+set(WEBP_SIMD_FLAGS_TO_INCLUDE)
+
+list(LENGTH WEBP_SIMD_FLAGS WEBP_SIMD_FLAGS_LENGTH)
+math(EXPR WEBP_SIMD_FLAGS_RANGE "${WEBP_SIMD_FLAGS_LENGTH} - 1")
+
+foreach(I_SIMD RANGE ${WEBP_SIMD_FLAGS_RANGE})
+  list(GET WEBP_SIMD_FLAGS ${I_SIMD} WEBP_SIMD_FLAG)
+  list(GET SIMD_ENABLE_FLAGS ${I_SIMD} SIMD_COMPILE_FLAG)
+  set(CMAKE_REQUIRED_FLAGS ${SIMD_COMPILE_FLAG})
+  check_c_source_compiles("
+      #include \"${CMAKE_CURRENT_LIST_DIR}/../src/dsp/dsp.h\"
+      int main(void) {
+        #if !defined(WEBP_USE_${WEBP_SIMD_FLAG})
+        this is not valid code
+        #endif
+        return 0;
+      }
+    "
+    WEBP_HAVE_${WEBP_SIMD_FLAG}
+  )
+
+  # Check which files we should include or not.
+  list(GET WEBP_SIMD_FILE_EXTENSIONS ${I_SIMD} WEBP_SIMD_FILE_EXTENSION)
+  file(GLOB SIMD_FILES "${CMAKE_CURRENT_LIST_DIR}/../"
+    "src/dsp/*${WEBP_SIMD_FILE_EXTENSION}"
+  )
+  if(WEBP_HAVE_${WEBP_SIMD_FLAG})
+    # Memorize the file and flags.
+    foreach(FILE ${SIMD_FILES})
+      list(APPEND WEBP_SIMD_FILES_TO_INCLUDE ${FILE})
+      list(APPEND WEBP_SIMD_FLAGS_TO_INCLUDE ${SIMD_COMPILE_FLAG})
+    endforeach()
+  else()
+    # Remove the file from the list.
+    foreach(FILE ${SIMD_FILES})
+      list(APPEND WEBP_SIMD_FILES_NOT_TO_INCLUDE ${FILE})
+    endforeach()
+    # Explicitly disable SIMD.
+    if(SIMD_DISABLE_FLAGS)
+      list(GET SIMD_DISABLE_FLAGS ${I_SIMD} SIMD_COMPILE_FLAG)
+      include(CheckCCompilerFlag)
+      check_c_compiler_flag(${SIMD_COMPILE_FLAG} HAS_COMPILE_FLAG)
+      if(HAS_COMPILE_FLAG)
+        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${SIMD_COMPILE_FLAG}")
+      endif()
+    endif()
+  endif()
+endforeach()