mul_wide inconsistencies
#4
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tarcieri
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mul_wide inconsistenciesmul_wide inconsistencies
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Fixes the inconsistency between `UInt::mul_wide` and `Limb::mul_wide` by reversing the order of the `UInt` version so it returns `(lo, hi)`. This follows the "little endian" approach used in the rest of this crate for consistency. Closes #4
tarcieri
added a commit
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this issue
Nov 13, 2021
Fixes the inconsistency between `UInt::mul_wide` and `Limb::mul_wide` by reversing the order of the `UInt` version so it returns `(lo, hi)`. This follows the "little endian" approach used in the rest of this crate for consistency. Closes #4
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RustCrypto/utils#563 corrected a bug in
wrapping_mul, however it seems the real issue might've been in the return value ofmul_wideRight now the return values are the following:
UInt::mul_wide->(hi, lo)Limb::mul_wide->(lo, hi)It seems RustCrypto/utils#563 might've been caused by assuming the latter worked like the former. This ordering reflects the little endian internals of this library.
Ideally these would return a
UIntwhich is twice the width using aconst impl Concatto prevent this sort of confusion, but sincemul_wideis aconst fnthat isn't currently possible.Alternatively we could use a
structwithloandhifields to prevent this confusion.At the very least, however, the
UIntandLimbversions should be consistent.The text was updated successfully, but these errors were encountered: