diff options
author | Andreas Grois <andi@grois.info> | 2022-10-24 09:04:41 +0200 |
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committer | Andreas Grois <andi@grois.info> | 2022-10-24 09:04:41 +0200 |
commit | 6b36d6396915181d38598928e35a20cf2308c5aa (patch) | |
tree | 614ad6917f07cd92c7aa5477ab123d786a1b84ed | |
parent | cb219708923df26e0efc0ce172e1be7414287fe2 (diff) |
Improve long division performance.
In PasswordMaker, the numbers that are fed into long division can only
decrease. Therefore, skipping leading zeros is a rather reasonable
improvement.
-rw-r--r-- | src/passwordmaker/base_conversion/remainders_impl.rs | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/passwordmaker/base_conversion/remainders_impl.rs b/src/passwordmaker/base_conversion/remainders_impl.rs index 7bc6c0e..8f0a7f9 100644 --- a/src/passwordmaker/base_conversion/remainders_impl.rs +++ b/src/passwordmaker/base_conversion/remainders_impl.rs @@ -13,7 +13,7 @@ impl<const N : usize> Division<usize> for [u32;N] { //uses mutation, because why not? self is owned after all :D let divisor : UsizeAndFour = *divisor as UsizeAndFour; - let remainder = self.iter_mut().fold(0 as UsizeAndFour,|carry, current| { + let remainder = self.iter_mut().skip_while(|x| **x == 0).fold(0 as UsizeAndFour,|carry, current| { debug_assert_eq!(carry, carry & (usize::MAX as UsizeAndFour)); //carry has to be lower than divisor, and divisor is usize. let carry_shifted = carry << 32; let dividend = (carry_shifted) + (*current as UsizeAndFour); |