Re: [PATCH] Optimize int_sqrt for small values for faster idle

From: Eric Dumazet
Date: Mon Feb 01 2016 - 19:36:44 EST


On Tue, 2016-02-02 at 00:08 +0100, Rasmus Villemoes wrote:

> Thanks. (Is there a good way to tell gcc that avg*avg is actually a
> 32x32->64 multiplication?)

If avg is 32bit, compiler does that for you.

u32 avg = ...

u64 result = (u64)avg * avg;