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C-/C++-Quelltext

#ifndef __VECTOR3_HPP___
#define __VECTOR3_HPP___

#include <xmmintrin.h>

template< typename TypeT >
class vector {
public:
  vector(TypeT x_, TypeT y_, TypeT z_)
    : x(x_)
    , y(y_)
    , z(z_) {}

  TypeT dot(vector< TypeT > other) {
    return x * other.x + y * other.y + z * other.z;
  }

  TypeT dot_sse(vector< TypeT > const& other) {
    TypeT v1_sse_in[3] __attribute__((aligned(16))) = { x, y, z };
    TypeT v2_sse_in[3] __attribute__((aligned(16))) = { other.x, other.y, other.z };
    TypeT v_sse_out[3] __attribute__((aligned(16)));

    __m128 a, b, c;
    a = _mm_load_ps(v1_sse_in);
    b = _mm_load_ps(v2_sse_in);
    c = _mm_mul_ps(a, b);
    _mm_store_ps(v_sse_out, c);

    return v_sse_out[0] + v_sse_out[1] + v_sse_out[2];
  }

  TypeT x;
  TypeT y;
  TypeT z;
};

typedef vector< float > vector3f;
typedef vector< double > vector3d;

#endif // __VECTOR3_HPP___

C-/C++-Quelltext

#include <iostream>
#include <iomanip>

#include "vector3.hpp"

typedef unsigned long long tsc_t;

static inline tsc_t read_tsc() {
  tsc_t tsc;
  __asm__ __volatile__ ("rdtsc": "=A"(tsc));
  return tsc;
}

int main(int argc, char* argv[]) {
  vector3f v1(1.0f, 2.0f, 3.0f);
  vector3f v2(4.0f, 5.0f, 6.0f);
  float dot_product;
  tsc_t start, end;

  start = read_tsc();
  dot_product = v1.dot(v2);
  end = read_tsc();
  std::cout << "ordinary version: " << dot_product
            << ", Time: " << std::setprecision(4)
            << (end - start) << "ns." << std::endl;
  start = read_tsc();
  dot_product = v1.dot_sse(v2);
  end = read_tsc();
  std::cout << "sse version: " << dot_product
            << ", Time: " << std::setprecision(4)
            << (end - start) << "ns." << std::endl;
  return 0;
}

Quellcode

ordinary version: 32, Time: 1386ns.
sse version: 32, Time: 378ns.

Quellcode

ordinary version: 32, Time: 63ns.
sse version: 32, Time: 270ns.