Value numbering

Welcome back to compiler land. Today we’re going to talk about value numbering, which is like SSA, but more. Static single assignment (SSA) gives names to values: every expression has a name, and each name corresponds to exactly one expression. It transforms programs like this: x = 0 x = x + 1 x = x + 1 where the variable x is assigned more than once in the program text, into programs like this: v0 = 0 v1 = v0 + 1 v2 = v1 + 1 where each assignment to x has been replaced with an assignm...