“Pack it in, mathematicians, someone owes LLVM a million bucks”

Re:“Pack it in, mathematicians, someone owes LLVM a million ... by ludocode on Thursday August 19, 2021 @11:13AM (#28234880)

This doesn't exactly follow the Collatz conjecture because multiplication by 3 will be truncated to a 128-bit unsigned int. It is possible that this truncation causes a loop. Even though the Collatz conjecture has been tested for all numbers in this range, it has probably not been tested with this overflow effect.

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Re:“Pack it in, mathematicians, someone owes LLVM a million ... by plasticchris on Thursday August 19, 2021 @11:33AM (#28235153)

Edit: removing my comment, I misunderstood.

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Re:“Pack it in, mathematicians, someone owes LLVM a million ... by WJW on Thursday August 19, 2021 @11:40AM (#28235247)

Not so, since the fact that it is in the range does not mean it will steadily go downwards. It might have numbers much bigger than the maximum value for a uint128 somewhere in its Collatz sequence and it is possible (though unlikely) that one of those numbers modulo the maximum value for a uint128 is the original number again. (That is, the modulo operation might introduce loops that are not present in the normal Collatz sequence because mathematical integers don't overflow)

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