#include <xmmintrin.h>
int main(int argc, char *argv[]) {
int n = ...;
float *x, *y;
x = new float[n+1];
y = new float[n+1];
... // fill x, y
// do computation
float ve[4] = {0, 0, 0, 0};
float e = 0;
for (int i=1; i<n; i+=4) {
float half =.5;
_mm_store_ps(&x[i],
_mm_mul_ps(_mm_load1_ps(&half),
_mm_add_ps(_mm_loadu_ps(&y[i+1]),
_mm_loadu_ps(&y[i-1]))));
_mm_store_ps(&ve[0],
_mm_add_ps(_mm_load_ps(&ve[0]),
_mm_mul_ps(_mm_load_ps(&y[i]),
_mm_load_ps(&y[i]))));
}
e += ve[0] + ve[1] + ve[2] + ve[3];
... // output x, e
delete[] x, y;
return 0;
}
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