向量化计算

https://easyperf.net/blog/2017/10/24/Vectorization_part1
https://15721.courses.cs.cmu.edu/spring2018/schedule.html
https://gcc.gnu.org/onlinedocs/gcc/Vector-Extensions.html
https://gcc.gnu.org/projects/tree-ssa/vectorization.html
https://www.codingame.com/playgrounds/283/sse-avx-vectorization/autovectorization
https://spcl.inf.ethz.ch/Teaching/2019-dphpc/lectures/lecture10-simd.pdf

GCC 开启 -fopt-info-vec-optimized -fopt-info-vec-missed 参数可以打出目前已经向量化的代码

vec.h:120:9: optimized: loop vectorized using 16 byte vectors
vec.h:24:17: missed: statement clobbers memory: _100 = operator new [] (8192, &nothrow);