From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47365) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WQoAz-00060b-GM for qemu-devel@nongnu.org; Thu, 20 Mar 2014 21:23:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WQoAt-0004r2-Gd for qemu-devel@nongnu.org; Thu, 20 Mar 2014 21:23:13 -0400 Received: from mout.gmx.net ([212.227.15.18]:60548) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WQoAt-0004qi-7X for qemu-devel@nongnu.org; Thu, 20 Mar 2014 21:23:07 -0400 Message-ID: <532B94FF.4090809@caramail.com> Date: Fri, 21 Mar 2014 02:25:19 +0100 From: Olivier Danet MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] [PATCH v3] sparc : 32bits integer division overflow List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel , Richard Henderson , Mark Cave-Ayland , Blue Swirl The signed integer division -0x8000_0000_0000_0000 / -1 must be handled separately to avoid an overflow on the QEMU host. Negative overflow must be a negative number for correct sign extension in Sparc64 mode. Use constants. Signed-off-by: Olivier Danet --- target-sparc/helper.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/target-sparc/helper.c b/target-sparc/helper.c index f3c7fbf..ae7740b 100644 --- a/target-sparc/helper.c +++ b/target-sparc/helper.c @@ -85,8 +85,8 @@ static target_ulong helper_udiv_common(CPUSPARCState *env, target_ulong a, } x0 = x0 / x1; - if (x0 > 0xffffffff) { - x0 = 0xffffffff; + if (x0 > UINT32_MAX) { + x0 = UINT32_MAX; overflow = 1; } @@ -122,12 +122,15 @@ static target_ulong helper_sdiv_common(CPUSPARCState *env, target_ulong a, if (x1 == 0) { cpu_restore_state(CPU(cpu), GETPC()); helper_raise_exception(env, TT_DIV_ZERO); - } - - x0 = x0 / x1; - if ((int32_t) x0 != x0) { - x0 = x0 < 0 ? 0x80000000 : 0x7fffffff; + } else if (x1 == -1 && x0 == INT64_MIN) { + x0 = INT32_MAX; overflow = 1; + } else { + x0 = x0 / x1; + if ((int32_t) x0 != x0) { + x0 = x0 < 0 ? INT32_MIN : INT32_MAX; + overflow = 1; + } } if (cc) { -- 1.8.1.5