Dominator-based Value Numbering

Global value numbering replaces fully redundant computations with copies. It detects value equivalence, thus the expressions need not be textually identical. Global value numbering is based on the dominator-based value numbering technique by Preston Briggs, et al.

• Traverses dominance tree instead of basic blocks
• Based on SSA form
• Uses SSA name as the value number
• Alias consistency: uses SSA name as the value number only when its alias is consistent