From: "H. Peter Anvin" <hpa@kernel.org>
To: "Américo Wang" <xiyou.wangcong@gmail.com>
Cc: Roland McGrath <roland@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Jakub Jelinek <jakub@redhat.com>,
linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
x86@kernel.org
Subject: Re: [PATCH 0/2] __builtin_unreachable
Date: Wed, 09 Sep 2009 23:42:34 -0700 [thread overview]
Message-ID: <4AA89FDA.3090105@kernel.org> (raw)
In-Reply-To: <2375c9f90909092142i58595fedod6780a7c41190f5f@mail.gmail.com>
On 09/09/2009 09:42 PM, Américo Wang wrote:
>
> Just curious, what different asm code will gcc generate for this? Comparing it
> to for(;;) ? I am sorry that I don't have gcc 4.5 on hand.
>
It generates nothing. It is you as the programmer guaranteeing that we
will never get there, and as such gcc will generate no code at all.
-hpa
next prev parent reply other threads:[~2009-09-10 6:44 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-10 1:59 [PATCH 0/2] __builtin_unreachable Roland McGrath
2009-09-10 2:00 ` [PATCH 1/2] UNREACHABLE() macro Roland McGrath
2009-09-11 20:45 ` Andrew Morton
2009-09-11 20:59 ` Kyle McMartin
2009-09-11 21:55 ` Roland McGrath
2009-09-12 3:49 ` Arjan van de Ven
2009-09-12 4:43 ` H. Peter Anvin
2009-09-12 5:30 ` Arjan van de Ven
2009-09-12 5:52 ` Andrew Morton
2009-09-12 6:38 ` Jakub Jelinek
2009-09-13 20:10 ` H. Peter Anvin
2009-09-10 2:01 ` [PATCH 2/2] x86: BUG(): use UNREACHABLE() Roland McGrath
2009-09-10 4:42 ` [PATCH 0/2] __builtin_unreachable Américo Wang
2009-09-10 6:42 ` H. Peter Anvin [this message]
2009-09-10 6:13 ` Jakub Jelinek
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