/* ##C_FILE#
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
FILE :          MTH_fopt.c
MODULE :        MTH     (Common Mathematic Library) 
 
DESCRIPTION :   Optimization for PC and float
 
VERSION :       MTH V5.0.13 / Alexandre LANGER [ALX] Ubi R&D / Add Comments
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
 
 
/* NOT for U64 */
#ifndef U64 
 
/* ##INCLUDE#----------------------------------------------------------------------------
                          Includes Files
---------------------------------------------------------------------------------------*/
 
#include <math.h>
 
 
 
#include "cpa_expt.h" 
 
 
/* ##GLOBVAR#----------------------------------------------------------------------------
                          Globale variable declaration
---------------------------------------------------------------------------------------*/
 
double  MTH_gs_dDecal; /* = 3.0F*pow(2, 51); */
 
/* sqrt : */
CPA_EXPORT unsigned long MTH_g_a2048_fSquareRootTable[1024*2];
/* div : */
CPA_EXPORT unsigned long MTH_g_a1024_fInverse[1024];
/* inv sqrt : */
CPA_EXPORT unsigned long MTH_g_a2048_fInvSquareRootTable[1024*2];
 
 
 
 
/* ##FUNCDEF#----------------------------------------------------------------------------
                          Functions definition
---------------------------------------------------------------------------------------*/
 
 
/* ##-########################### 
   ## SQRT
   ############################## */
 
/* ##F===================================================================================
NAME :          MTH_fn_vInitSqrtRootOpt
DESCRIPTION :   Initialize Square root table
INPUT :         void
OUTPUT :        void
=======================================================================================*/
void MTH_fn_vInitSqrtRootOpt( void )
{
  long i;
  float ft;
  unsigned long m;
 
  for ( i=0; i<1024; i++)
    {
      ft = (float) sqrt((double) 1.0+((float)i/1024) );
      m = *(long *)&ft;
      m&= 0x7FFFFF;
      MTH_g_a2048_fSquareRootTable[i+1024] = m;
 
      ft = (float) ( sqrt(2.0)*sqrt((double) 1.0+((float)i/1024) ) );
      m = *(long *)&ft;
      m&= 0x7FFFFF;
      MTH_g_a2048_fSquareRootTable[i] = m;
    }
}
 
 
 
/* ##-########################### 
   ## DIV
   ############################## */
 
/* ##F===================================================================================
NAME :          MTH_fn_vInitInverseOpt
DESCRIPTION :   Initialize Inverse table
INPUT :         void
OUTPUT :        void
=======================================================================================*/
void MTH_fn_vInitInverseOpt( void )
{
  long i;
  float ft;
 
  for ( i=0; i<1024; i++ )
    {
      ft = 1.0F / ( 1.0F + ((float)i/1024) );
      MTH_g_a1024_fInverse[i]  = (*(long *)&ft) & 0x7FFFFF;
    }
  MTH_g_a1024_fInverse[0]=(1<<23); /* Because of problems with 2^n */
}
 
 
 
 
 
/* ##-########################### 
   ## INV SQRT
   ############################## */
 
/* ##F===================================================================================
NAME :          MTH_fn_vInitInvSqrtRootOpt
DESCRIPTION :   Initialize Inverse Square root table
INPUT :         void
OUTPUT :        void
=======================================================================================*/
void MTH_fn_vInitInvSqrtRootOpt(void)
{
  long i;               /* index on the table   */
  unsigned long m;      /* mantis               */
  float ft;             /* float value          */
    
  for ( i=0; i<1024; i++ )
    {        
      ft = (float) ( 2.0/sqrt((double)( 1.0+((float)i/1024) )) );
      m = *(long *)&ft;
      m &= 0x7FFFFF;
      MTH_g_a2048_fInvSquareRootTable[i+1024] = m;
      ft = (float) ( sqrt(2.0)/sqrt((double)( 1.0+((float)i/1024) )) ); 
      m = *(long *)&ft;
      m &= 0x7FFFFF;
      m+=0x800000;
      MTH_g_a2048_fInvSquareRootTable[i] = m;
    }  
  MTH_g_a2048_fInvSquareRootTable[1024]=(1<<23);
}
 
 
 
/* ##-########################### 
   ## INIT 
   ############################## */
 
/* ##F===================================================================================
NAME :          MTH_fn_vInit
DESCRIPTION :   Initialize all table if it not yet done
INPUT :         void
OUTPUT :        void
=======================================================================================*/
void MTH_fn_vInit( void )
{
  static unsigned char InitDone=0;
 
  MTH_gs_dDecal= 3.0F*pow(2, 51);
 
  if(InitDone==0)
    {
      MTH_fn_vInitSqrtRootOpt();
      MTH_fn_vInitInverseOpt();
      MTH_fn_vInitInvSqrtRootOpt();
      InitDone=1;
    }
}
 
 
 
#endif /* NOT U64 */