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From: Roland McGrath <roland@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jakub Jelinek <jakub@redhat.com>,
	linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
	x86@kernel.org
Subject: [PATCH 2/2] x86: BUG(): use UNREACHABLE()
Date: Wed,  9 Sep 2009 19:01:10 -0700 (PDT)	[thread overview]
Message-ID: <20090910020110.DA9838BF6E@magilla.sf.frob.com> (raw)
In-Reply-To: Roland McGrath's message of  Wednesday, 9 September 2009 18:59:23 -0700 <20090910015923.8FB628AE5F@magilla.sf.frob.com>

This uses the new UNREACHABLE() macro in x86's BUG() macro.  In my
test builds, this saved 2022 bytes of text in vmlinux on x86_64,
3051 bytes on i686.  (I didn't bother to calculate the additional
savings in .ko text.)

Signed-off-by: Roland McGrath <roland@redhat.com>
CC: Jakub Jelinek <jakub@redhat.com>
---
 arch/x86/include/asm/bug.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h
index d9cf1cd..a6458a3 100644
--- a/arch/x86/include/asm/bug.h
+++ b/arch/x86/include/asm/bug.h
@@ -22,14 +22,14 @@ do {								\
 		     ".popsection"				\
 		     : : "i" (__FILE__), "i" (__LINE__),	\
 		     "i" (sizeof(struct bug_entry)));		\
-	for (;;) ;						\
+	UNREACHABLE();						\
 } while (0)
 
 #else
 #define BUG()							\
 do {								\
 	asm volatile("ud2");					\
-	for (;;) ;						\
+	UNREACHABLE();						\
 } while (0)
 #endif
 

  parent reply	other threads:[~2009-09-10  2:05 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 ` Roland McGrath [this message]
2009-09-10  4:42 ` [PATCH 0/2] __builtin_unreachable Américo Wang
2009-09-10  6:42   ` H. Peter Anvin
2009-09-10  6:13 ` Jakub Jelinek

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