#include "realcnvt.h"

/*  converts TP 6-byte real to IEEE 8-byte real  */

double pasrealtodouble(pasreal OldNum) {

  IEEEdouble NewNum;
  char       Sign;
  int        Exp;
  int        X;

  for(X = 0; X < 2; X++)
    NewNum.byte[X] = 0x00;

  Sign = OldNum[5] & 0x80;
  Exp = OldNum[0] - 0x81 + 0x3FF;
  NewNum.byte[6] = (Exp << 4);
  NewNum.byte[7] = (Exp >> 4) | Sign;

  for(X = 5; X > 1; X--) {
    OldNum[X] <<= 1;
    OldNum[X] |= OldNum[X-1] >> 7;
  }
  OldNum[1] <<= 1;

  for(X = 6; X >= 2; X--) {
    NewNum.byte[X] |= OldNum[X-1] >> 4;
    NewNum.byte[X-1] =  OldNum[X-1] << 4;
  }

  return(NewNum.value);
}