Modified implementation of maximum & minimum with improved efficiency. #5256
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With this modified implementation, we don't have to check (v != v) within inner loops. Rationales: (1) NaN only exist for floating points -- so only have to deal with them in versions specialized to floating point. (2) Once a non-NaN value is found, we can then follow the normal routine. Because x > v (or x < v) is never true when x is NaN, and therefore, v won't become NaN again.
base/abstractarray.jl
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I will change that. Thanks for pointing out.
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Excellent. This is a great change. Thanks for taking the time and effort to apply these kinds of optimizations in Base. |
StefanKarpinski
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Dec 29, 2013
Modified implementation of maximum & minimum with improved efficiency.
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Yes, this is good. But I wonder if the FloatingPoint version should just be used for all types --- LLVM might be able to figure out that |
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With this modified implementation, we don't have to check
(v != v)within inner loops.Rationales:
x > v(orx < v) is never true whenxisNaN, and therefore,vwon't becomeNaNagain.Note: I also added several test cases to ensure the correctness.