Merge pull request #3125 from SparkiDev/mp_leading_bit

Change mp_leading_bit (integer.c) to not to require a copy
pull/3142/head
toddouska 2020-07-16 11:05:09 -07:00 committed by GitHub
commit 50f228af0a
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1 changed files with 3 additions and 16 deletions

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@ -271,23 +271,10 @@ int mp_count_bits (mp_int * a)
int mp_leading_bit (mp_int * a)
{
int bit = 0;
mp_int t;
int c = mp_count_bits(a);
if (mp_init_copy(&t, a) != MP_OKAY)
return 0;
while (mp_iszero(&t) == MP_NO) {
#ifndef MP_8BIT
bit = (t.dp[0] & 0x80) != 0;
#else
bit = ((t.dp[0] | ((t.dp[1] & 0x01) << 7)) & 0x80) != 0;
#endif
if (mp_div_2d (&t, 8, &t, NULL) != MP_OKAY)
break;
}
mp_clear(&t);
return bit;
if (c == 0) return 0;
return (c % 8) == 0;
}
int mp_to_unsigned_bin_at_pos(int x, mp_int *t, unsigned char *b)