rt_nonfinite.c

simulink real-time workshop for dragon12 development board from

/* Copyright 1994-2002 The MathWorks, Inc.
 *
 * File: rt_nofinite.c     $Revision: 1.7 $
 *
 * Abstract:
 *      Real-Time Workshop function to intialize non-finites,
 *      (Inf, NaN and -Inf).
 */

#include <stdio.h>
#include <stdlib.h>
#include "rt_nonfinite.h"


real_T rtInf;
real_T rtMinusInf;
real_T rtNaN;


/* Function: rt_InitInfAndNaN ==================================================
 * Abstract:
 *	Initialize the rtInf, rtMinusInf, and rtNaN needed by the 
 *	generated code. NaN is initialized as non-signaling. Assumes IEEE.
 */
void rt_InitInfAndNaN(int_T realSize)
{
    short one = 1;
    enum {
        LittleEndian,
        BigEndian
    } machByteOrder = (*((char *) &one) == 1) ? LittleEndian : BigEndian;

    switch (realSize) {  
      case 4:
        switch (machByteOrder) {
          case LittleEndian: {
              typedef struct {
                  uint32_T fraction : 23;
                  uint32_T exponent  : 8;
                  uint32_T sign      : 1;
              } LittleEndianIEEEDouble;
	
              (*(LittleEndianIEEEDouble*)&rtInf).sign      = 0;
              (*(LittleEndianIEEEDouble*)&rtInf).exponent  = 0xFF;
              (*(LittleEndianIEEEDouble*)&rtInf).fraction  = 0;
              rtMinusInf = rtInf;
              rtNaN = rtInf;
              (*(LittleEndianIEEEDouble*)&rtMinusInf).sign = 1;
              (*(LittleEndianIEEEDouble*)&rtNaN).fraction  = 0x7FFFFF;
          }
          break;
          case BigEndian: {
              typedef struct {
                  uint32_T sign      : 1;
                  uint32_T exponent  : 8;
                  uint32_T fraction  : 23;
              } BigEndianIEEEDouble;
	
              (*(BigEndianIEEEDouble*)&rtInf).sign      = 0;
              (*(BigEndianIEEEDouble*)&rtInf).exponent  = 0xFF;
              (*(BigEndianIEEEDouble*)&rtInf).fraction  = 0;
              rtMinusInf = rtInf;
              rtNaN = rtInf;
              (*(BigEndianIEEEDouble*)&rtMinusInf).sign = 1;
              (*(BigEndianIEEEDouble*)&rtNaN).fraction  = 0x7FFFFF;
          }
          break;
        }
        break;    
    
      case 8:
        switch (machByteOrder) {
          case LittleEndian: {
              typedef struct {
                  struct {
                      uint32_T fraction2;
                  } wordH;
                  struct {
                      uint32_T fraction1 : 20;
                      uint32_T exponent  : 11;
                      uint32_T sign      : 1;
                  } wordL;
              } LittleEndianIEEEDouble;
              
              (*(LittleEndianIEEEDouble*)&rtInf).wordL.sign      = 0;
              (*(LittleEndianIEEEDouble*)&rtInf).wordL.exponent  = 0x7FF;
              (*(LittleEndianIEEEDouble*)&rtInf).wordL.fraction1 = 0;
              (*(LittleEndianIEEEDouble*)&rtInf).wordH.fraction2 = 0;
              
              rtMinusInf = rtInf;
              (*(LittleEndianIEEEDouble*)&rtMinusInf).wordL.sign = 1;
              (*(LittleEndianIEEEDouble*)&rtNaN).wordL.sign      = 0;
              (*(LittleEndianIEEEDouble*)&rtNaN).wordL.exponent  = 0x7FF;
              (*(LittleEndianIEEEDouble*)&rtNaN).wordL.fraction1 = 0xFFFFF;
              (*(LittleEndianIEEEDouble*)&rtNaN).wordH.fraction2 = 0xFFFFFFFF;
          }
          break;
          case BigEndian: {
              typedef struct {
                  struct {
                      uint32_T sign      : 1;
                      uint32_T exponent  : 11;
                      uint32_T fraction1 : 20;
                  } wordL;
                  struct {
                      uint32_T fraction2;
                  } wordH;
              } BigEndianIEEEDouble;
              
              (*(BigEndianIEEEDouble*)&rtInf).wordL.sign      = 0;
              (*(BigEndianIEEEDouble*)&rtInf).wordL.exponent  = 0x7FF;
              (*(BigEndianIEEEDouble*)&rtInf).wordL.fraction1 = 0;
              (*(BigEndianIEEEDouble*)&rtInf).wordH.fraction2 = 0;
	
              rtMinusInf = rtInf;
              (*(BigEndianIEEEDouble*)&rtMinusInf).wordL.sign = 1;
              (*(BigEndianIEEEDouble*)&rtNaN).wordL.sign      = 0;
              (*(BigEndianIEEEDouble*)&rtNaN).wordL.exponent  = 0x7FF;
              (*(BigEndianIEEEDouble*)&rtNaN).wordL.fraction1 = 0xFFFFF;
              (*(BigEndianIEEEDouble*)&rtNaN).wordH.fraction2 = 0xFFFFFFFF;
          }
          break;
        }
        break;
      default:
        (void)fprintf(stderr,
                      "Unable to initialize rtInf, rtMinusInf and rtNaN\n");
        exit(1);
        break;
    }

} /* end rt_InitInfAndNaN */