Name: LOG2NRM.ASM
         Type: Assembler Macro
      Version: 1.0
 Date Entered: 30-Mar-87
  Last Change: 30-Mar-87

  Description: Normalizing Base 2 Logarithm Macro

 This program calculates the base 2 logarithm of an unnormalized
 24 bit fraction "x" in register A and returns a scaled fraction
 "y" in register A.

 y = log2(x)/32.0       where   2**(-23) =< x < 1.0
                                -23/32 =< y < 0.0

 Note - "x" must be a non-zero, positive fraction.

 Three steps are required.

 1. Normalize "x" so that 0.5 =< A < 1.0.
 2. Calculate the log2(A).
 3. Divide the result by 32.0

 This macro uses a modified version of the log2 library macro.