特别推荐： https://www.codeproject.com/Articles/874396/Crunching-Numbers-with-AVX-and-AVX
1. 查看自己cpu支持指令集：
直接去官网查：
https://ark.intel.com/content/www/cn/zh/ark.html#@Processors
比如这颗
https://ark.intel.com/content/www/cn/zh/ark/products/75131/intel-core-i7-4900mq-processor-8m-cache-up-to-3-80-ghz.html
2. 测试例子：
#include#include int main(int argc, char* argv[]) { __m256i first = _mm256_set_epi64x(10, 20, 30, 40); __m256i second = _mm256_set_epi64x(5, 5, 5, 5); __m256i result = _mm256_add_epi64(first, second); long int* values = (long int*) &result; printf("==%ld \n", sizeof(long int)); for (int i = 0;i < 4; i++) { printf("%ld ", values[i]); } return 0; }
_mm256_set_epi64x() _mm256_add_epi64() 等内建函数的含义和用法：
https://software.intel.com/sites/landingpage/IntrinsicsGuide
注意：左边栏勾选后，右栏结果不一定准确。比如SSE的addss指令在有AVX机器中中变为vaddvss，但是勾选AVX512中才能搜到。
编译命令：
gcc -mavx2 -S -fverbose-asm fun.c #看详细的汇编语言结果 gcc -mavx2 fun.c
补充个例子：
#include#include float aa[] = {10, 20, 30, 40, 50, 60, 70, 80}; float bb[] = {0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5}; float cc[] = {0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5}; int main(int argc, char* argv[]) { __m256 first = _mm256_loadu_ps (aa); __m256 second = _mm256_loadu_ps (bb); __m256 result = _mm256_add_ps (first, second); _mm256_storeu_ps (cc, result); printf("==%ld \n", sizeof(float)); for (int i = 0;i < 8; i++) { printf("%f\n", cc[i]); } return 0; }
查错手册：
AVX vector return without AVX enabled changes the ABI ——————————没有 -mavx2
inlining failed in call to always_inline 'xxx': target specific option mismatch —————— 架构不匹配，看看cpu是否支持 avx2
参考资料：
https://software.intel.com/content/www/cn/zh/develop/articles/introduction-to-intel-advanced-vector-extensions.html
https://zhuanlan.zhihu.com/p/94649418
https://www.codeproject.com/Articles/874396/Crunching-Numbers-with-AVX-and-AVX
https://software.intel.com/sites/landingpage/IntrinsicsGuid