From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([208.118.235.92]:58068)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <aurelien@aurel32.net>) id 1TFVkM-00051n-EA
	for qemu-devel@nongnu.org; Sat, 22 Sep 2012 15:52:15 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <aurelien@aurel32.net>) id 1TFVkL-0002Y5-9j
	for qemu-devel@nongnu.org; Sat, 22 Sep 2012 15:52:14 -0400
Received: from hall.aurel32.net ([88.191.126.93]:41477)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <aurelien@aurel32.net>) id 1TFVkK-0002Xs-SU
	for qemu-devel@nongnu.org; Sat, 22 Sep 2012 15:52:13 -0400
Date: Sat, 22 Sep 2012 21:52:07 +0200
From: Aurelien Jarno <aurelien@aurel32.net>
Message-ID: <20120922195207.GA32463@ohm.aurel32.net>
References: <1348273096-1495-1-git-send-email-rth@twiddle.net>
	<1348273096-1495-7-git-send-email-rth@twiddle.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-15
Content-Disposition: inline
In-Reply-To: <1348273096-1495-7-git-send-email-rth@twiddle.net>
Subject: Re: [Qemu-devel] [PATCH 6/8] tcg: Add tcg_debug_assert
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Richard Henderson <rth@twiddle.net>
Cc: qemu-devel@nongnu.org

On Fri, Sep 21, 2012 at 05:18:14PM -0700, Richard Henderson wrote:
> Like the C assert macro, except only enabled for CONFIG_DEBUG_TCG,
> and without having to set _NDEBUG and disable all other asserts at
> the same time.
> 
> The use of __builtin_unreachable (when available) gives the compiler
> the same information, which may (or may not) help it optimize better.
> 
> Signed-off-by: Richard Henderson <rth@twiddle.net>
> ---
>  tcg/tcg.h | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/tcg/tcg.h b/tcg/tcg.h
> index 48a56f0..4501c15 100644
> --- a/tcg/tcg.h
> +++ b/tcg/tcg.h
> @@ -530,6 +530,15 @@ do {\
>      abort();\
>  } while (0)
>  
> +#ifdef CONFIG_DEBUG_TCG
> +# define tcg_debug_assert(X) do { assert(X); } while (0)
> +#elif QEMU_GNUC_PREREQ(4, 5)
> +# define tcg_debug_assert(X) \
> +    do { if (!(X)) { __builtin_unreachable(); } } while (0)
> +#else
> +# define tcg_debug_assert(X) do { (void)(X); } while (0)
> +#endif
> +
>  void tcg_add_target_add_op_defs(const TCGTargetOpDef *tdefs);
>  
>  #if TCG_TARGET_REG_BITS == 32
> -- 
> 1.7.11.4
> 

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>

-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net