Removing unused variables is harmless. (GCC would do this automaticelly.)
So this change seems fine.
-Karthik
> On 23 Jul 2020, at 12:05, Jason A. Donenfeld <jason@xxxxxxxxx> wrote:
>
> Hi Herbert,
>
> On Thu, Jul 23, 2020 at 9:51 AM Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote:
>>
>> The carry variables are assigned but never used, which upsets
>> the compiler. This patch removes them.
>>
>> Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
>>
>> diff --git a/arch/x86/crypto/curve25519-x86_64.c b/arch/x86/crypto/curve25519-x86_64.c
>> index 8a17621f7d3a..8acbb6584a37 100644
>> --- a/arch/x86/crypto/curve25519-x86_64.c
>> +++ b/arch/x86/crypto/curve25519-x86_64.c
>> @@ -948,10 +948,8 @@ static void store_felem(u64 *b, u64 *f)
>> {
>> u64 f30 = f[3U];
>> u64 top_bit0 = f30 >> (u32)63U;
>> - u64 carry0;
>> u64 f31;
>> u64 top_bit;
>> - u64 carry;
>> u64 f0;
>> u64 f1;
>> u64 f2;
>> @@ -970,11 +968,11 @@ static void store_felem(u64 *b, u64 *f)
>> u64 o2;
>> u64 o3;
>> f[3U] = f30 & (u64)0x7fffffffffffffffU;
>> - carry0 = add_scalar(f, f, (u64)19U * top_bit0);
>> + add_scalar(f, f, (u64)19U * top_bit0);
>> f31 = f[3U];
>> top_bit = f31 >> (u32)63U;
>> f[3U] = f31 & (u64)0x7fffffffffffffffU;
>> - carry = add_scalar(f, f, (u64)19U * top_bit);
>> + add_scalar(f, f, (u64)19U * top_bit);
>> f0 = f[0U];
>> f1 = f[1U];
>> f2 = f[2U];
>> --
>
> That seems obvious and reasonable, and so I'm inclined to ack this,
> but I first wanted to give Karthik (CC'd) a chance to chime in here,
> as it's his HACL* project that's responsible, and he might have some
> curious insight.
>
> Jason
