Hello,
Jacob Bachmeyer <jcb62...@gmail.com> wrote:
> Also, if I understand correctly from the previous discussion, "<" is to
> be avoided because compilers can use a branch to implement it.
Than you. Good catch. It is the reason why we have
mpih_ct_limb_less_than.
Using mpih_ct_limb_less_than, it is like:
==========================
/* Do same calculation as _gcry_mpih_add_1 does (under the condition
of RES_PTR == S1_PTR), Least Leak Intended. */
static inline mpi_limb_t
_gcry_mpih_add_1_lli (mpi_ptr_t s1_ptr, mpi_size_t s1_size, mpi_limb_t s2_limb)
{
mpi_limb_t x;
mpi_limb_t cy;
x = *s1_ptr;
s2_limb += x;
*s1_ptr++ = s2_limb;
cy = mpih_ct_limb_less_than (s2_limb, x);
while ( --s1_size )
{
x = *s1_ptr + cy;
*s1_ptr++ = x;
cy = mpih_limb_is_zero (x) & mpih_limb_is_not_zero (cy);
}
return cy;
}
==========================
We will need to arrange header files to allow use of mpih_ct_limb_less_than,
though.
--
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