1. CStar Optimizing a C Compiler
Group Hellim

2. GROUP MEMBERS - Halit Emre Sayılır - Anıl Koyuncu - Kutay Yıldırıcı
- Tayfun Çakıcıer

3. OUTLINE Problem Definition Framework Information Modules
1 Optimizations
2 Optimization Manager
3 Test Case Generator
Screenshots

4. PROBLEM DEFINITION Why Performance and Efficiency
- Reduce Execution Time
- Decrease Space of Code
- Reduce Memory Space
Must be Reliable

5. FRAMEWORK INFO Object Oriented Software Library
Own intermediate representation
Design by Contract
Modular

6. OPTIMIZATIONS Dead Code Elemination if(0) a=1;
else will be replaced by a=2; a=2;
Evaluation of if statement in run time avoided
Space of code reduced

7. OPTIMIZATIONS(cont.)
Constant Folding
return 100*40
return 4000

8. OPTIMIZATIONS(cont.) Local Copy Propagation a=b; c=a+d; c = b + d ;
also after dead code elimination

9. OPTIMIZATIONS (%35) Constant Folding (+) Basic Block Ordering
Dead Code Elimination
Local/Global Forward Substitution
Local/Global Copy Propagation(+)
Strength Reduction (+)
Local/Global Common SubExpression Elimination (+)
If Simplifications
Algebraic Simplifications (+)

10. OPTIMIZATIONS(cont.) Dead Object Elimination Jump Optimizations
Tail Merging
Tail Recursion
Procedure Cloning and Specilization
Partial Redundancy Elimination
Unreachable Code Elimination (+)

11. OPTIMIZATION MANAGER (%40)
A tool for managing the optimizations which will be used during compilation
An assistant for advanced users

12. OPTIMIZATION MANAGER Two modes: 1- File mode:
There is an external file. The optimizations which will be used ,are configured in the file
When the file is read , rules will be managed
and then chosen optimizations will be executed

13. Optimization Manager Configuration File

14. OPTIMIZATION MANAGER 2- Interactive mode:
It is a mode which interacts with user.
The user will enter input via keyboard.
Optimizations will be done in an interactive manner.

15. TEST CASE GENERATOR (%30)
Aim:
Automating the process of test case generation
* Reduce and prevent human errors
* Flexibility for generation of different test cases

16. TEST CASE GENERATOR
How
Option File
Inspection

17. OPTION FILE

18. TEST CASE GENERATOR How Parse Option File Generate Options Option File
Inspection
IR Dump
IR Code
Generation
Generated
Test File

19. Screenshots
Some result screenshots of the optimizations

20. Constant Folding

21. Algebraic Simplifications

22. Local Common Subexpression Elimination

23. QUESTIONS
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