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Beautiful branchless binary search

(probablydance.com)
386 points ingve | 1 comments | 28 Apr 23 05:46 UTC | HN request time: 0.447s | source
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SleepyMyroslav ◴[28 Apr 23 07:34 UTC] No.35738552[source]▶
If being branchless is important property of the algorithm then it is better to enforce it. Or at least test for it. If his GCC version will get an update and it will stop producing assembly that he wants no-one will ever know.

Which brings us back to regular discussion: C ( and C++ ) does not match hardware anymore. There is no real control over important properties of generated code. Programmers need tools to control what they write. Plug and pray compilation is not a solid engineering approach.

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1. gsliepen ◴[28 Apr 23 07:46 UTC] No.35738629[source]▶
What you gain is hardware independence. There is a lot of variation in CPUs, even if you stick with one vendor they will have in-order efficiency cores and out-of-order performance cores, and an algorithm optimized for one might not work as great on the other. I think it's better if time is spent by compiler engineers to produce good assembly on all CPUs, instead of giving tools to programmers to optimize their code for one particular CPU.