Comparison operator performance (>, >=, <, <=)

Question

If you were to compare two integers, would the operator have an impact on the time required to perform the comparison? For example, given:

if (x < 60)

and

if (x <= 59)

Which would provide the best performance, or would the performance difference be negligible? Are the performance results language-dependent?

I often find myself mixing the use of these operators within my code. Any thoughts would be appreciated.

Yes, there indeed is a performance difference (at least in JavaScript): on my machine `x < 60` takes 1103,1 picoseconds to execute, and `x <= 59` takes 1103,2 picoseconds to execute, making it a tenth of a picosecond slower. Mind blown `:)` [See for yourself](http://jsperf.com/less-than-vs-greater-than-or-equal) — Šime Vidas, May 02 '11 at 19:10
@Šime Vidas: That's pretty cool. Those results are definitely browser-dependent. — Evan Mulawski, May 02 '11 at 19:15
Yes, in IE9 `<=` is in fact 32% slower (!!) (which is 2.7 nanoseconds on my machine). — Šime Vidas, May 02 '11 at 19:18

score 11 · Accepted Answer · answered May 02 '11 at 19:09

11

Even if there was noticeable difference, I think compilers are smart enough to care for such things. So my advice is to use what makes the code easier to understand, and leave micro-optimizations to the compiler.

answered May 02 '11 at 19:09

Alexey Kukanov

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score 2 · Answer 2 · answered May 02 '11 at 19:08

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In the specific example you gave where one side is constant, I'd expect an optimizer to transform one to the other if it was significantly faster.

answered May 02 '11 at 19:08

AShelly

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score 1 · Answer 3 · edited May 23 '17 at 12:25

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The differences are negligible. Theoretically they could be language dependent.

As another answer mentioned, they are also theoretically platform dependent.

See: Is the inequality operator faster than the equality operator?

edited May 23 '17 at 12:25

Community

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answered May 02 '11 at 19:04

Thomas Langston

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score 0 · Answer 4 · answered May 02 '11 at 19:02

There is almost certainly no difference in performance. For CISC processors, you'll typically have all manner of branch instructions that cope with all the difference < <= > >= etc. On RISC there may be a very small performance difference although I'd seriously doubt it!

Comparison operator performance (>, >=, <, <=)

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