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Date: Mon, 13 Apr 2015 11:31:50 -0700
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Subject: Re: [PATCH] x86: Align jump targets to 1 byte boundaries
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Ingo Molnar <mingo@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
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On Mon, Apr 13, 2015 at 10:26 AM, Markus Trippelsdorf
<markus@trippelsdorf.de> wrote:
>
> I must have made a measurement mistake above, because the actual code
> size savings are roughly 5%:

Can you check against the -fno-guess-branch-probability output?

Does lto (without pgo) perhaps end up undoing a lot of the random
"branch out and back" noise?

                          Linus