GATE CS 2023 Q27 — Data Flow Analyses: Constant Propagation, Liveness, CSE

Consider the following code segment. x = u - t; y = x * v; x = y + w; y = t - z; y = x * y; The minimum number of total variables required to convert the above code segment to static single assignment form is __________.

A variable $x$ is said to be live at a statement $s_{i}$ in a program if the following three conditions hold simultaneously: There exists a statement $S_{j}$ that uses $x$ There is a path from $S_{i}$ to $S_{j}$ in the flow graph corresponding to the program The path has no intervening assignment to $x$ including at $S_{i}$ and $S_{j}$ The …