Use sse4.2 CRC32 instructions to hash when available.

cmake/CMakeLists.txt

 # Boilerplate.
 cmake_minimum_required (VERSION 3.1)   # First version with CMAKE_CXX_STANDARD.
 project (skimake)
 set (CMAKE_CXX_STANDARD 11)
 
 # Default to Release mode.  We're mainly targeting Skia users, not Skia developers.
 if (NOT CMAKE_BUILD_TYPE)
     set (CMAKE_BUILD_TYPE Release)
 endif ()
 
@@ skipping 112 matching lines @@
 if (WIN32)
     if(SKIA_GDI)
         remove_srcs(../src/ports/SkFontMgr_win_dw_factory.cpp)
     else()
         remove_srcs(../src/ports/SkFontMgr_win_gdi_factory.cpp)
     endif()
 endif()
 
 # Certain files must be compiled with support for SSSE3, SSE4.1, AVX, or AVX2 intrinsics.
 file (GLOB_RECURSE ssse3_srcs ../src/*ssse3*.cpp ../src/*SSSE3*.cpp)
-file (GLOB_RECURSE sse41_srcs ../src/*sse4*.cpp ../src/*SSE4*.cpp)
+file (GLOB_RECURSE sse41_srcs ../src/*sse41*.cpp ../src/*SSE41*.cpp)
+file (GLOB_RECURSE sse42_srcs ../src/*sse42*.cpp ../src/*SSE42*.cpp)
 file (GLOB_RECURSE avx_srcs   ../src/*_avx.cpp)
 file (GLOB_RECURSE avx2_srcs  ../src/*_avx2.cpp)
 if (NOT WIN32)
     set_source_files_properties(${ssse3_srcs} PROPERTIES COMPILE_FLAGS -mssse3)
     set_source_files_properties(${sse41_srcs} PROPERTIES COMPILE_FLAGS -msse4.1)
+    set_source_files_properties(${sse42_srcs} PROPERTIES COMPILE_FLAGS -msse4.2)
     set_source_files_properties(${avx_srcs}   PROPERTIES COMPILE_FLAGS -mavx)
     set_source_files_properties(${avx2_srcs}  PROPERTIES COMPILE_FLAGS -mavx2)
 endif()
 
 # Detect our optional dependencies.
 # If we can't find them, don't build the parts of Skia that use them.
 find_package (EXPAT)
 find_package (Lua)
 find_package (ZLIB)
 # No find_package for libwebp as far as I can tell, so simulate it here.
@@ skipping 200 matching lines @@
         file (APPEND ${skia_h_path} "#include \"${filename_component}\"\n")
       endif ()
     endforeach()
   endif()
 endforeach()
 file(APPEND ${skia_h_path} "\n#endif  // skia_DEFINED\n")
 
 # Now build a simple example app that uses Skia via libskia.so.
 add_executable(example example.cpp)
 target_link_libraries(example skia ${OPENGL_LIBRARIES})