Faster remainders when the divisor is a constant: beating compilers & libdivide

Re:Faster remainders when the divisor is a constant: beating... by thijsvandien on Friday February 08, 2019 @09:37PM (#19120342)

For a range that small you could even build a lookup table. Or is this a case where cheap computation beats memory access?

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Re:Faster remainders when the divisor is a constant: beating... by Const-me on Saturday February 09, 2019 @02:06AM (#19121157)

On modern hardware, computation beats RAM access almost always.

Here's a repo with 2 tests, counting bits, and calculating sine/cosine: https://github.com/Const-me/LookupTables

Neither code is particularly cheap but still faster than RAM.

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Re:Faster remainders when the divisor is a constant: beating... by mark-r on Friday February 08, 2019 @11:33PM (#19120746)

For modern processors you can assume that a couple of instructions will be much faster than a memory lookup. Even if the lookup is cached it will most likely push something else important out of cache.

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