Volatile (computer programming): Difference between revisions

Revision as of 17:26, 26 March 2023

Revision as of 23:15, 30 April 2023

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===Optimization comparison in C===

The following C programs, and accompanying assembliesassembler language excerpts, demonstrate how the <code>volatile</code> keyword affects the compiler's output. The compiler in this case was [[GNU Compiler Collection|GCC]].

While observing the assembly code, it is clearly visible that the code generated with <code>volatile</code> objects is more verbose, making it longer so the nature of <code>volatile</code> objects can be fulfilled. The <code>volatile</code> keyword prevents the compiler from performing optimization on code involving volatile objects, thus ensuring that each volatile variable assignment and read has a corresponding memory access. Without the <code>volatile</code> keyword, the compiler knows a variable does not need to be reread from memory at each use, because there should not be any writes to its memory ___location from any other thread or process.