add sse2 intrinsic version of Overlay Blend mode
remove leftover debugging code (sorry)
change MMerge_SSE to use por instead of pxor
remove auto type as it's only support in newer version of msvc
add sse2 intrinsic version of Overlay lighten/darken mode
change unsigned char type to BYTE
rename blend_asm.cpp/h to blend_common.cpp/h
fix compile error cause by file moving
restructuring masked_blend function
call _mm_empty only once all mmx instruction ended
make blend_c_core accept int instead of BYTE to support opacity
fix error when calling on non-mod16/8 width
restructuring blend_opacity function
finish blend mode asm optimization
- add missing _mm_empty()
- add missing header
- change BYTE& to BYTE (using reference here is silly)
restructuring darken/lighten mode function
make all common overlay function static
fix #ifdef wrong function
fix compile error on x64 (#ifdef all mmx function)
make calling C routines for non mod8/16 pixels more efficient