avx512readme.md

gcc -O2 -mavx512f vector.c -fopt-info-vec-all -S -o vector.s
gcc -O2 -mavx512f vector.c -fopt-info-vec-all -c  -o vector
gcc -O0 -mavx512f test3.c -fopt-info-vec-all -o test3 vector

test3.c

#include<stdio.h>
#include<x86intrin.h>
#include "vector.h"



int main(void)
{
	float a[] = {1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f};
	float b[] = {1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f, 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f};
	printf("%f\n", sumProduct(a, b, 16));
	return 0;
}

vector.c

#include "vector.h"
#include <immintrin.h>

float sumProduct(float* vec1, float* vec2, int num)
{
	__m512 avx_sum = _mm512_setzero_ps();
	for (int i = 0;i < num;i += 16) {
		const __m512 a512 = _mm512_loadu_ps((double*)&vec1[i]);
		const __m512 b512 = _mm512_loadu_ps((double*)&vec2[i]);
		avx_sum = _mm512_fmadd_ps(a512, b512, avx_sum);
	}

  	float __attribute__((aligned(32))) out[16] = {};
    _mm512_storeu_ps(out, avx_sum);
	float sum = 0;
	for (int i = 0;i < 16;i++) {
		sum += out[i];
	}
	return sum;
}

vector.h

float sumProduct(float* vec1, float* vec2, int num);