PSL Optimizer

The PSL Optimizer includes the following:

• PSL Optimizer architecture
  • Three levels
  • Mutli-pass
  • Intermediate code optimizer
• PSL Optimizer functions
• Specifying options
  • Command line
  • Pragma PSL statement

Levels of Optimization

The PSL Optimizer supports the following levels:

• 0 - no optimization
• Level 1 (peephole) optimization
• Level 2 (local) optimization
• Level 3 (global) optimization

Level 1 Optimization

The following figures provide example code that illustrate Level 1 optimization. 

Level 1 - Remove Useless Jumps 



Level 1 - Reduce Jump Chains 



Level 1 - Remove Redundant Quad 



Level 1 - Pack Parameters 

Level 2 Optimization

The following figures provide example code that illustrate Level 2 optimization. 

Level 2 - String joining 



Level 2 - Fold and propagate 



Level 2 - Remove Multiple and unused Definitions 



Level 2 - Reorder Parameters 

Level 3 Optimization

The following figures provide example code that illustrate Level 3 optimization. 

Level 3 - Remove Unreachable Code 



Level 3 - Reduce Block Chains 

The Optimizer and Menu Commands

• Menu commands are compiled for every execution (if in PSL source)
• Optimization is by default 3 (version 3.2 and later)
  • Every time cost of optimization (which is expensive): pragma "O0" (O-zero)
  • Libraries: No cost