code review 7763050: runtime: Use aligned loads for AES key schedule.

runtime: Use aligned loads for AES key schedule.

[khr, 2013-03-20 21:08:53]

Hello rsc@golang.org (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://code.google.com/p/go/

[rsc, 2013-03-20 21:11:24]

LGTM

[minux1, 2013-03-20 21:12:04]

any benchmark data?

in writing AES-NI support for crypto/aes, i benchmarked aligned and
unaligned form
of load instructions, and found out (surprisingly) that with aligned
data, the difference
is negligible.

[khr1, 2013-03-20 21:15:27]

No, I suspect it is in the noise of any measurement.  It saves 2
instructions for hash32 and hash64.


On Wed, Mar 20, 2013 at 2:11 PM, minux <minux.ma@gmail.com> wrote:

> any benchmark data?
>
> in writing AES-NI support for crypto/aes, i benchmarked aligned and
> unaligned form
> of load instructions, and found out (surprisingly) that with aligned
> data, the difference
> is negligible.
>

[minux1, 2013-03-20 21:17:14]

On Thu, Mar 21, 2013 at 5:15 AM, Keith Randall <khr@google.com> wrote:
> No, I suspect it is in the noise of any measurement.  It saves 2
> instructions for hash32 and hash64.
ok, thanks for confirmation.

[khr, 2013-03-20 21:34:29]

*** Submitted as https://code.google.com/p/go/source/detail?r=77d9e6e1900c ***

runtime: Use aligned loads for AES key schedule.

R=rsc, minux.ma, khr
CC=golang-dev
https://codereview.appspot.com/7763050