Search results
Results from the WOW.Com Content Network
In computer science, control flow (or flow of control) is the order in which individual statements, instructions or function calls of an imperative program are executed or evaluated. The emphasis on explicit control flow distinguishes an imperative programming language from a declarative programming language.
Loop unrolling, also known as loop unwinding, is a loop transformation technique that attempts to optimize a program's execution speed at the expense of its binary size, which is an approach known as space–time tradeoff. The transformation can be undertaken manually by the programmer or by an optimizing compiler.
first checks whether x is less than 5, which it is, so then the {loop body} is entered, where the printf function is run and x is incremented by 1. After completing all the statements in the loop body, the condition, (x < 5), is checked again, and the loop is executed again, this process repeating until the variable x has the value 5.
Control dependencies must also be considered when analyzing dependencies between different statements in a loop. Control dependencies are dependencies introduced by the code or the programming algorithm itself. They control the order in which instructions occur within the execution of code. [4]
In the C programming language, Duff's device is a way of manually implementing loop unrolling by interleaving two syntactic constructs of C: the do-while loop and a switch statement. Its discovery is credited to Tom Duff in November 1983, when Duff was working for Lucasfilm and used it to speed up a real-time animation program.
A few arithmetic instructions (like 'CleaR', 'INCrement', 'DECrement', 'CoPY', ...) operate on the registers. The only control flow instruction is 'LOOP x DO... END'. It causes the instructions within its scope to be repeated x times. (Changes of the content of register x during the execution of the loop do not affect the number of passes.)
In computer science, software pipelining is a technique used to optimize loops, in a manner that parallels hardware pipelining.Software pipelining is a type of out-of-order execution, except that the reordering is done by a compiler (or in the case of hand written assembly code, by the programmer) instead of the processor.
In computer programming, a loop counter is a control variable that controls the iterations of a loop (a computer programming language construct). It is so named because most uses of this construct result in the variable taking on a range of integer values in some orderly sequences (for example., starting at 0 and ending at 10 in increments of 1)