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Code generation for multiple SIMD architectures

I wrote a library where I use CMake to check for headers for MMX, SSE, SSE2, SSE4, AVX, AVX2 and AVX-512. In addition to this, I check for instructions and, if any, I add the necessary compiler flags, -msse2 -mavx -mfma, etc.

All this is very good, but I would like to deploy a single binary file that works on different generations of processors.

Question: Is it possible to tell the compiler (GCC) that whenever it optimizes a function using SIMD, it must generate code for a list of architectures? And, of course, introduce high-level branches.

I think it looks like the compiler generates code for functions where input pointers are either 4 or 8 byte aligned. To prevent this, I use a macro __builtin_assume_aligned.

What is the best practice? Multiple binary files? Naming?

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Until you care about portability, yes.

Recent versions of GCC make this easier than any other compiler I know of using the target_clones function attribute . Just add an attribute with a list of goals for which you want to create versions, and GCC will automatically create various options, as well as a submit function, to automatically select the version at runtime.

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