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LibCrypto+LibJS: Better bigint bitwise_or binop

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Similar to the bitwise_and change, but we have to be careful to
sign-extend two's complement numbers only up to the highest set bit
in the positive number.
This commit is contained in:
Nico Weber 2022-01-18 08:46:42 -05:00 • committed by Ali Mohammad Pur
parent 1f98639396
commit 013799a4dd
8 changed files with 77 additions and 23 deletions
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16
Userland/Libraries/LibCrypto/BigInt/UnsignedBigInteger.cpp
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@ -5,6 +5,7 @@
*/
#include "UnsignedBigInteger.h"
#include <AK/BuiltinWrappers.h>
#include <AK/CharacterTypes.h>
#include <AK/StringBuilder.h>
#include <AK/StringHash.h>
@ -173,6 +174,17 @@ void UnsignedBigInteger::resize_with_leading_zeros(size_t new_length)
}
}
size_t UnsignedBigInteger::one_based_index_of_highest_set_bit() const
{
size_t number_of_words = trimmed_length();
size_t index = 0;
if (number_of_words > 0) {
index += (number_of_words - 1) * BITS_IN_WORD;
index += BITS_IN_WORD - count_leading_zeroes(m_words[number_of_words - 1]);
}
return index;
}
FLATTEN UnsignedBigInteger UnsignedBigInteger::plus(const UnsignedBigInteger& other) const
{
UnsignedBigInteger result;
@ -218,11 +230,11 @@ FLATTEN UnsignedBigInteger UnsignedBigInteger::bitwise_xor(const UnsignedBigInte
return result;
}
FLATTEN UnsignedBigInteger UnsignedBigInteger::bitwise_not_fill_to_size(size_t size) const
FLATTEN UnsignedBigInteger UnsignedBigInteger::bitwise_not_fill_to_one_based_index(size_t size) const
{
UnsignedBigInteger result;
UnsignedBigIntegerAlgorithms::bitwise_not_fill_to_size_without_allocation(*this, size, result);
UnsignedBigIntegerAlgorithms::bitwise_not_fill_to_one_based_index_without_allocation(*this, size, result);
return result;
}