Computer Science 281

Fifth Exercise Set

Purpose

• To work with bit manipulation instructions

Due:  Friday, March 5

• Write an assembly language program scanf.s with entry points as follows:

  /*
   Test program to decode a floating point
   number
  */
     
   .global fsgn
   
  fsgn: save %sp, -96, %sp
     
  (some code:  return (in %o0) the sign of the fp number
     
   ret
   restore
   
     
   .global fexp
  fexp: save %sp, -96, %sp
     
  (some code:  return the exponent (an integer)
     
   ret
   restore
   
   .global ffract
  ffract: save %sp, -96, %sp
     
  (some code:  return the unnormalized fraction 
  (an integer, to be printed out in hex)
     
   ret
   restore
   
   .global trunc
   trunc:  save %sp, -96, %sp
   
   (some code:  return the truncated value of
   the fp number (i.e., integer part only))
   
   
   

to be called by the program scanfmain.c in the directory ~matthews/cs281