Converting a C++ project to x64 with __m64 references

Question

So when I started the conversion and set the target to \'x64\', I get 7 unresolved externals. Two examples:

error LNK2001: unresolved external symbol _m_empt         


        

Answer 1

From the __m64 type documentation:

The __m64 data type is not supported on x64 processors. Applications that use __m64 as part of MMX intrinsics must be rewritten to use equivalent SSE and SSE2 intrinsics.

http://msdn.microsoft.com/en-us/library/08x3t697(v=vs.110).aspx

So it looks like you have three options: stick with 32 bits, port the MMX intrinsics to SSE, or fall back to a non-SIMD implementation (if you have one - if not then consider re-implementing in scalar code).