- /*
- * div_spoiler contains a multiple of md_size that is used to cause the
- * modulo operation to be constant time. Without this, the time varies
- * based on the amount of padding when running on Intel chips at least.
- * The aim of right-shifting md_size is so that the compiler doesn't
- * figure out that it can remove div_spoiler as that would require it to
- * prove that md_size is always even, which I hope is beyond it.
- */
- div_spoiler = md_size >> 1;
- div_spoiler <<= (sizeof(div_spoiler) - 1) * 8;
- rotate_offset = (div_spoiler + mac_start - scan_start) % md_size;