This is where the various optimizing switches and their actions are described, grouped per
switch.
     
- 
-On:  
 - with n = 1..4: these switches activate the optimizer. A higher level automatically includes
     all lower levels.
         
         - Level 1 (-O1) activates the peephole optimizer (common instruction sequences are
         replaced by faster equivalents).
         
 
         - Level 2 (-O2) enables the assembler data flow analyzer, which allows the common
         subexpression elimination procedure to remove unnecessary reloads of registers
         with values they already contain.
         
 
         - Level 3 (-O3) equals level 2 optimizations plus some time-intensive optimizations.
         
 
         - Level 4 (-O4) equals level 3 optimizations plus some optimizations which may
         have side effects.
         
 
         - Set alignment of X to Y.
         
 
         - XXX Enable or disable specific optimizations; See section 1.2.58 on 151 for a list
         of possible values for XXX.
         
 
         - Set target cpu for optimizing to XXX; see fpc -i or fpc -ic for possible values.
         
 
         - Generate whole-program optimization feedback for optimization XXX see fpc -i
         or fpc -iw for possible values
         
 
         - Perform whole-program optimization XXX; see fpc -i or fpc -iw for possible values
         
 
         - Optimize for size rather than speed.
 
      
A more complete description of possible optimization switches can be found in section 1.2.58 on
151.