/* 
 *  Code largement inspire du site 
 *  http://www.codeproject.com/KB/recipes/sseintro.aspx
 * 
 * NB : Le source doit *absolument* etre compile avec l'option -msse
 * sinon on a un message disant qu'on doit autoriser les instructions 
 * SSE et MMX (messages generes parce que __SSE__ et __MMX__ ne sont
 * pas definis).
 */

#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include "size.h"

/* 
 * All SSE instructions and __m128 data type are defined in xmmintrin.h file.
 * Since SSE instructions are compiler intrinsics and not functions, there 
 * are no lib-files. 
*/
#include <xmmintrin.h>

void computeResult(
          float* pArray1,                   // [in] first source array
          float* pArray2,                   // [in] second source array
          float* pResult,                   // [out] result array
          int nSize)                        // [in] size of all arrays

{
  int nLoop = nSize/ 4;
  int i;

  __m128 m1, m2, m3, m4;

  __m128* pSrc1 = (__m128*) pArray1;
  __m128* pSrc2 = (__m128*) pArray2;
  __m128* pDest = (__m128*) pResult;


  __m128 m0_5 = _mm_set_ps1(0.5f);        // m0_5[0, 1, 2, 3] = 0.5


  for ( i = nLoop; i > 0; i-- ) {
    m1 = _mm_mul_ps(*pSrc1, *pSrc1);        // m1 = *pSrc1 * *pSrc1

    m2 = _mm_mul_ps(*pSrc2, *pSrc2);        // m2 = *pSrc2 * *pSrc2
    
    m3 = _mm_add_ps(m1, m2);                // m3 = m1 + m2

    m4 = _mm_sqrt_ps(m3);                   // m4 = sqrt(m3)

    *pDest = _mm_add_ps(m4, m0_5);          // *pDest = m4 + 0.5
        
    pSrc1++;
    pSrc2++;
    pDest++;
  }
}

int main(int argc, char *argv[]) {
  float pArray1[SIZE] __attribute__ ((aligned (16)));
  float pArray2[SIZE] __attribute__ ((aligned (16)));
  float pResult[SIZE] __attribute__ ((aligned (16)));
  int i;

  printf("Debut des calculs...\n");
  printf("\tpArray1 = %p\n\tpArray2 = %p\n\tpResult = %p\n",
	 pArray1, pArray2, pResult);
  for (i=NB_TIMES; i>0; i--) {
    computeResult(pArray1, pArray2, pResult, SIZE);
  }
  printf("...Fin des calculs\n");

  return EXIT_SUCCESS;
}