Use-define Chain - Execution

Execution

Consider the sequential execution of the list of statements, s(i), and what can now be observed as the computation at statement, j:

  • A definition at statement s(i) with i < j is alive at j, if it has a use at a statement s(k) with k ≥ j. The set of alive definitions at statement i is denoted as A(i) and the number of alive definitions as |A(i)|. (A(i) is a simple but powerful concept: theoretical and practical results in space complexity theory, access complexity(I/O complexity), register allocation and cache locality exploitation are based on A(i).)
  • A definition at statement s(i) kills all previous definitions (s(k) with k < i) for the same variables.

Read more about this topic:  Use-define Chain

Famous quotes containing the word execution:

    Some hours seem not to be occasion for any deed, but for resolves to draw breath in. We do not directly go about the execution of the purpose that thrills us, but shut our doors behind us and ramble with prepared mind, as if the half were already done. Our resolution is taking root or hold on the earth then, as seeds first send a shoot downward which is fed by their own albumen, ere they send one upward to the light.
    Henry David Thoreau (1817–1862)

    I am gradually drifting to the opinion that this Rebellion can only be crushed finally by either the execution of all the traitors or the abolition of slavery. Crushed, I mean, so as to remove all danger of its breaking out again in the future.
    Rutherford Birchard Hayes (1822–1893)

    My weakness has always been to prefer the large intention of an unskilful artist to the trivial intention of an accomplished one: in other words, I am more interested in the high ideas of a feeble executant than in the high execution of a feeble thinker.
    Thomas Hardy (1840–1928)