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copied!<p>There are several niche verticals where goto is still commonly used as a standard practice, by some very very smart folks and there is no bias against goto in those settings. I used to work at a simulations focused company where all local fortran code had tons of gotos, the team was super smart, and the software worked near flawlessly.</p> <p>So, we can leave the merit of goto aside, and if the question merely is to compare the loops, then we do so by profiling and/or comparing the assembly code. That said however, the question includes statements like printf etc. You can't really have a discussion about loop control logic optimization when doing that. Also, as others have pointed out, the given loops will all generate VERY similar machine codes.</p> <p>All conditional branches are considered "taken" (true) in pipelined processor architectures anyway until decode phase, in addition to small loops being usually expanded to be loopless. So, in line with Harper's point above, it is unrealistic for goto to have any advantage whatsoever in simple loop control (just as for or while don't have an advantage over each other). GOTO makes sense usually in multiple nested loops or multiple nested ifs, when adding the additional condition checked by goto into EACH of the nested loops or nested ifs is suboptimal.</p> <p>When optimizing a search kind of operation in a simple loop, using a sentinal is sometimes more effective than anything else. Essentially, by adding a dummy value at the end of the array, you can avoid checking for two conditions (end of array and value found) to be just one condition (value found), and that saves on cmp operations internally. I am unaware if compilers automatically do that or not.</p>

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