Explain Elimination of common sub expression during code optimization
An optimizing transformation is a regulation for rewriting a segment of a program to enhance its execution competence without influencing its meaning. One of the methods is "Common sub expression elimination"
In given expression as "(a+b)-(a+b)/4", in this "common sub-expression" termed to the duplicated "(a+b)". Compilers implementing such technique realize that "(a+b)" won't modify, and as such, only compute its value once.