Vectorization（矢量化）

Before we understand the vectorization, we can see a common secnario.
We have a array that has 100 float numbers, we want to calculate square of every data. If we use traditional computer, we need to calculate it one by one. For each calculation of data, an instruction needs to be excuted, it is a time-consuming process. As shown in the following figure.

Vectorization is an optimize technique, it uses SIMD（Single Instruction, Multiple Data）instruction set of modern processors to utilize one instruction to judge multiple data at the same time. It reduces the iteration times and overhead of commute instruction. As shown in the following figure.
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矢量化技术依赖于处理器的SIMD指令集，例如Intel的SSE（Streaming SIMD Extensions）和AVX（Advanced Vector Extensions），以及ARM的NEON（Advanced SIMD）。这些指令集提供了特殊的指令和寄存器，可以同时处理多个数据项。

要实现矢量化，编译器需要具备优化器来自动将程序中的循环等代码转换成对应的SIMD指令。同时，编写代码时也需要遵循一些规则，以便编译器能够进行有效的矢量化优化。

总的来说，矢量化是一种通过同时处理多个数据项来提高计算效率的优化技术，可以显著提高程序的性能。它是现代计算机程序优化中的重要手段之一。