task8

ex3/seq/skalar/mylib.cpp

@@ -0,0 +1,56 @@
+#include "mylib.h"
+#include <cassert>                  // assert()
+#include <cmath>
+#include <cstdlib>                  // alignof()
+//#include <iostream>
+#include <numeric>
+#include <vector>
+using namespace std;
+
+
+double scalar(unsigned int const N, double const x[], double const y[])
+{
+    double sum = 0.0;
+    for (unsigned int i = 0; i < N; ++i)
+    {
+        sum += x[i] * y[i];
+//     sum += exp(x[i])*log(y[i]);
+    }
+    return sum;
+}
+
+double scalar_unroll(unsigned int const N, double const x[], double const y[])
+{
+    constexpr unsigned int Stride{8};
+    alignas(32) double sk[Stride] = {0.0};
+    assert(alignof(sk)==32);
+    assert(alignof(x)==8);
+    assert(alignof(y)==8);
+    for (unsigned int i = 0; i < (N/Stride)*Stride; i+=Stride)
+    {
+        for (unsigned int k=0; k<Stride; ++k)
+        {
+            sk[k] += x[i+k] * y[i+k];
+        }
+    }
+    double sum = std::accumulate(sk, sk+Stride,0.0);
+    for (unsigned int i = (N/Stride)*Stride; i < N; ++i)
+    {
+        sum += x[i]*y[i];
+    }
+    
+    return sum;
+}
+
+
+
+double norm(unsigned int const N, double const x[])
+{
+    double sum = 0.0;
+    for (unsigned int i = 0; i < N; ++i)
+    {
+        sum += x[i] * x[i];
+    }
+    return std::sqrt(sum);
+}
+