c++ - Vectorize function calls on each element of a vector -

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when call function each element in vector using for_each calls vectorized or not?

in general, no.

std::for_each wrapper around loop.

however, optimizations on, it's quite call std::for_each inlined, , simple functions, function call each element inlined too.

once inlined, it's if loop had been written hand; in such case, question becomes "will compiler vectorize loop doing simple arithmetic"; , that's entirely compiler.

in order happen, compiler needs know target architecture supports simd instructions, , may or may not vectorize depending on optimization level, whether number of iterations constant or not, whether number of iterations known multiple of 4, etc.


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