Coding conversions

Avoid forcing the compiler to convert numbers between integer and floating-point internal representations. Conversions require several instructions, including some double-precision floating-point arithmetic. When you must use mixed-mode arithmetic, code the integral, floating-point, and decimal arithmetic in separate computations wherever possible. Figure 1 shows an example.

Figure 1. Numeric conversions example

/* this example shows how numeric conversions are done */

int main(void)
{
   int i;
   float array[10]={1.0,2.0,3.0,4.0,5.0,6.0,7.0,8.0,9.0,10.0}
   float x = 1.0;
   for (i = 0; i < 10; i++)
      {
       array[i] = array[i]*x;  /* No conversions needed */
       x = x + 1.0;
      }

   for (i = 1; i <= 9; i++)
      array[i] = array[i]*i;  /* Conversions may be needed */

   return(0);
}