Editing Dead-code elimination (section)

{{Short description|Compiler optimization to remove code which does not affect the program results}}
{{Use dmy dates|date=April 2019|cs1-dates=y}}
{{Use list-defined references|date=December 2021}}
In [[compiler theory]], '''dead-code elimination''' ('''DCE''', '''dead-code removal''', '''dead-code stripping''', or '''dead-code strip''') is a [[compiler optimization]] to remove [[dead code]] (code that does not affect the program results). Removing such code has several benefits: it shrinks [[executable|program]] size, an important consideration in some contexts, it reduces resource usage such as the number of bytes to be transferred<ref>Malavolta, Ivano et al. “JavaScript Dead Code Identification, Elimination, and Empirical Assessment.” IEEE transactions on software engineering 49.7 (2023): 3692–3714. Web.</ref> and it allows the running program to avoid executing irrelevant [[CPU instruction|operations]], which reduces its [[execution (computing)|running time]]. It can also enable further optimizations by simplifying program structure. Dead code includes code that can never be executed ([[unreachable code]]), and code that only affects [[dead variable]]s (written to, but never read again), that is, irrelevant to the program.