valor absoluto de Intel intrínseco
#include <stdio.h>
#include <stdlib.h>
#include <intrin.h>
void vectorAbs(double *x, double *y, unsigned int N);
int main()
{
double x[] = { -1, -2, -3, -4, -5, -6 };
double y[] = { 2, 2, 2, 2, 2, 2 };
double *pX = x, *pY = y;
vectorAbs(pX, pY, 6);
}
__m128d abs_sample1 (__m128d val)
{
return _mm_castsi128_pd (_mm_srli_epi64 (_mm_slli_epi64 (_mm_castpd_si128 (val), 1), 1));
}
__m128d abs_sample2 (__m128d val)
{
const __m128d mask = _mm_castsi128_pd (_mm_set1_epi64x (0x7FFFFFFFFFFFFFFF));
return _mm_and_pd (mask, val);
}
void vectorAbs(double *x, double *y, unsigned int N)
{
__m128d xVar;
__m128d yVar;
printf("\nSquare of x : \n");
for (int i = 0; i < N; i += 2)
{
xVar = _mm_loadu_pd(&x[i]); // load *x[i] to xVar
yVar = abs_sample1(xVar); // abs of x
_mm_storeu_pd(&y[i], yVar); // store yVar to y[i]
printf("%lf, %lf, ", y[i], y[i + 1]);
}
system("pause");
}
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