vector_algorithms.cpp: further cleanup by AlexGuteniev · Pull Request #5485 · microsoft/STL (original) (raw)

search_n

Generalize the first step for every element size, making the whole approach more readable and use fewer lines of code.

mismatch

Reduce element size variation. We can always compare bytewise, the division by element size would truncate the unneeded remainder length.

The 8 byte element instruction is a bit of odd ball 🎱. The SSE version has a bit higher CPU requirement (SSE4.2, not SSE2), it is a bit longer, and a bit less efficient. Still I don't think it is a performance change: I think the compiler would emit memory-operand version on AVX2 path, which does not differ in performance from the 1-byte equivalent.

minmax_element

Just more tails closer to the function where they are used. Traits are used in all functions here, tails are only for minmax_element

bitset from string

Move AVX2 exit intrinsic inside the implementation function to make the compiler emit a tail call. A perf change, though a very small one.

bitset to string

Ditto. But this time it didn't help emitting tail call. Still done for consistency.