On Wed, Sep 19, 2018 at 3:39 AM Jason A. Donenfeld [off-list ref] wrote:

quoted

quoted

+     const size_t num = ctx->num % POLY1305_BLOCK_SIZE;

0 <= ctx->num < POLY1305_BLOCK_SIZE, so no need to mod by POLY1305_BLOCK_SIZE.

quoted

+     size_t num = ctx->num % POLY1305_BLOCK_SIZE;

Same here.

I know, but I was having a hard time convincing gcc-8 of that
invariant, and it was warning me. Perhaps this is something they
fixed, though, between 8.1 and 8.2 though. I'll check back and adjust
accordingly.

This was changed here:
https://git.zx2c4.com/WireGuard/commit/?id=37f114a73ba37219b00a66f0a51219a696599745

I can't reproduce with 8.2 anymore, so perhaps I should remove it now.
Unless you'd like to avoid a warning on old compilers. Since there's
no difference in speed, probably we should avoid the 8.1 warning and
leave it be?