Subject: Re: [boost] [Block Pointer] benchmark
From: Phil Bouchard (philippe_at_[hidden])
Date: 2011-05-25 18:40:10
On 5/25/2011 3:27 PM, Nevin Liber wrote:
>
> You have yet to explain why your make_auto is so much slower than new
> directly. It just isn't that expensive to copy one pointer and zero out
> another. I can't imagine what else your code can possibly be doing. I
> can't imagine how that can be more, let alone significantly more expensive
> than a heap allocation. Enlighten me.
Well if you have a direct assignment coming from operator new then the
pointer can be transferred directly into a register. If you have
temporary r-values to copy it into then the transfer will be done from
one memory location to another, but it won't be a fast as a
register-to-register transfer.
-Phil