linux-kernel - Re: [RFC] gcc feature request: Moving blocks into sections

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Message-ID: <CA+55aFwrxRr4+kN8t8HCRnnVQyur5EGzQ_bRdYK3T-KW9Zp0aw@mail.gmail.com>
Date:	Mon, 5 Aug 2013 12:57:46 -0700
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>
Cc:	"H. Peter Anvin" <hpa@...ux.intel.com>,
	Steven Rostedt <rostedt@...dmis.org>,
	LKML <linux-kernel@...r.kernel.org>, gcc <gcc@....gnu.org>,
	Ingo Molnar <mingo@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	David Daney <ddaney.cavm@...il.com>,
	Behan Webster <behanw@...verseincode.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Herbert Xu <herbert@...dor.apana.org.au>
Subject: Re: [RFC] gcc feature request: Moving blocks into sections

On Mon, Aug 5, 2013 at 12:54 PM, Mathieu Desnoyers
<mathieu.desnoyers@...icios.com> wrote:
>
> I remember that choosing between 2 and 5 bytes nop in the asm goto was
> tricky: it had something to do with the fact that gcc doesn't know the
> exact size of each instructions until further down within compilation

Oh, you can't do it in the coompiler, no. But you don't need to. The
assembler will pick the right version if you just do "jmp target".

             Linus
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