From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NnfOs-0005Sc-9r for qemu-devel@nongnu.org; Fri, 05 Mar 2010 16:49:38 -0500 Received: from [199.232.76.173] (port=52749 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NnfOr-0005SN-Vf for qemu-devel@nongnu.org; Fri, 05 Mar 2010 16:49:38 -0500 Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim 4.60) (envelope-from ) id 1NnfOq-00078U-SK for qemu-devel@nongnu.org; Fri, 05 Mar 2010 16:49:37 -0500 Received: from hall.aurel32.net ([88.191.82.174]:49758) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1NnfOq-00078C-Cs for qemu-devel@nongnu.org; Fri, 05 Mar 2010 16:49:36 -0500 From: Aurelien Jarno Date: Fri, 5 Mar 2010 22:49:23 +0100 Message-Id: <1267825763-7372-1-git-send-email-aurelien@aurel32.net> Subject: [Qemu-devel] [PATCH] tcg: update README with const and pure helpers List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Aurelien Jarno Signed-off-by: Aurelien Jarno --- tcg/README | 11 +++++++---- 1 files changed, 7 insertions(+), 4 deletions(-) diff --git a/tcg/README b/tcg/README index f0e21a1..281c114 100644 --- a/tcg/README +++ b/tcg/README @@ -75,10 +75,13 @@ destroyed, but local temporaries and globals are preserved. * Helpers: Using the tcg_gen_helper_x_y it is possible to call any function -taking i32, i64 or pointer types. Before calling an helper, all -globals are stored at their canonical location and it is assumed that -the function can modify them. In the future, function modifiers will -be allowed to tell that the helper does not read or write some globals. +taking i32, i64 or pointer types. By default, before calling an helper, +all globals are stored at their canonical location and it is assumed +that the function can modify them. This can be overriden by the +TCG_CALL_CONST function modifier. By default, the helper is allowed to +modify the CPU state or raise an exception. This can be overriden by +the TCG_CALL_PURE function modifier, in which case the call to the +function is removed if the return value is not used. On some TCG targets (e.g. x86), several calling conventions are supported. -- 1.7.0