Code Optimization in MIPS
- 1. Code Optimization Code optimization is a technique in which code of a program is transformed in such a way that it uses fewer resources (instructions, memory) or it works efficiently. Example: The following function return the sum of two numbers in C++. int sum(int num1, int num2){ int sum; sum = num1 +num2; return sum; } The above code can be optimized in such a way that it can only takes one instruction and it does not reserve memory for sum variable. int sum(int num1, int num2){ return num1 + num2; } Code OptimizationTechniques Branch optimization It transforms the code to optimize the branching statements. Example: The code for finding greatest number between three numbers. if(num1>num2){ if(num1>num3){ greatNum = num1; } else{ greatNum = num3; } else{ if(num2>num3){ greatNum = num2; }
- 2. else{ greatNum = num3; } } The above code can be optimized in such a way that it takes less branching statements. if(num1>num2 && num1>num3) greatNum = num1; else if (num2>num1 && num2>num3) greatNum = num2; else greatNum = num3; In-lining function Convert the regular function into In-lining function if needed. Example: The function that return the sum of two numbers. int sum(int a, int b){ return a+b; } The above code can be optimized by converting it into In-lining. #define sum(a, b)((a+b)) Recursive function Convert the regular function into In-lining function if possible. Example: The function that return the factorial of number. int factorial(int n){ int fact=1; for(int i=1; i<=n; i++) fact=fact*i; return fact; } The above code can be optimized by converting it into recursive function. int factorial(int n){ if(n==1) return 1; else return n*factorial(n-1); }