Do floating point math by using AVX feature in x86 CPU

avx.c

/*
	Copyright (c) CureComp Technology Trading & Services
	
	Generic vs AVX
	--------------
	
	Show how fast and how accurate CPU processing,
	3 GHz Generic vs 1.8 GHz AVX
*/

#include <immintrin.h>
#include <stdio.h>

#include <time.h>

int main()
{
	void multiply_and_add(const float* a, const float* b, const float* c, float* d);
	__m256 multiply_and_add(__m256 a, __m256 b, __m256 c);

	clock_t start, end, _start, _end;
	double cpu_time, _cpu_time;

	float a[8] = { 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8 };
	float b[8] = { 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7 };
	float c[8] = { 1, 2, 3, 4, 5, 6, 7, 8 };
	float d[8];

	start = clock();
	multiply_and_add(a,b,c,d);
	end = clock();

	__m256 _a = _mm256_set_ps(1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8);
	__m256 _b = _mm256_set_ps(2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7);
	__m256 _c = _mm256_set_ps(1, 2, 3, 4, 5, 6, 7, 8);

	_start = clock();
	__m256 result = multiply_and_add(_a,_b,_c);
	_end = clock();

	float* f = (float*)&result;

	cpu_time = ((double)(end - start)) / CLOCKS_PER_SEC;
	_cpu_time = ((double)(_end - _start)) / CLOCKS_PER_SEC;

	printf("Compare Non-AVX CPU (Core i3 1st Gen) vs AVX CPU (Core i3 2nd Gen)\n");
	printf("\nResults (No AVX):\n");
	for (int i = 0; i < 8; i++) {
		printf("%f ", d[i]);
	}

	printf("\nResults (AVX):\n");
	for (int i = 7; 0 <= i; i--) {
		printf("%f ", f[i]);
	}

	printf("\n\n");
	return 0;
}

void multiply_and_add(const float* a, const float* b, const float* c, float* d) {

	for (int i = 0; i < 8; i++) {
		d[i] = a[i] * b[i];
		d[i] = d[i] + c[i];
	}
}

__m256 multiply_and_add(__m256 a, __m256 b, __m256 c) {

	return _mm256_fmadd_ps(a, b, c);
}