From patchwork Wed Aug 10 10:13:42 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: tip-bot for Dave Martin X-Patchwork-Id: 1052552 Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p7AAFMjp029791 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 10 Aug 2011 10:15:43 GMT Received: from canuck.infradead.org ([2001:4978:20e::1]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Qr5oc-0006yf-4a; Wed, 10 Aug 2011 10:15:10 +0000 Received: from localhost ([127.0.0.1] helo=canuck.infradead.org) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1Qr5oa-0002Jj-VN; Wed, 10 Aug 2011 10:15:08 +0000 Received: from mail-wy0-f177.google.com ([74.125.82.177]) by canuck.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Qr5nT-00021g-Ny for linux-arm-kernel@lists.infradead.org; Wed, 10 Aug 2011 10:14:01 +0000 Received: by mail-wy0-f177.google.com with SMTP id 11so726674wyh.36 for ; Wed, 10 Aug 2011 03:13:59 -0700 (PDT) Received: by 10.227.12.18 with SMTP id v18mr6700256wbv.72.1312971239370; Wed, 10 Aug 2011 03:13:59 -0700 (PDT) Received: from e200948.peterhouse.linaro.org (fw-lnat.cambridge.arm.com [217.140.96.63]) by mx.google.com with ESMTPS id fr7sm627419wbb.22.2011.08.10.03.13.57 (version=SSLv3 cipher=OTHER); Wed, 10 Aug 2011 03:13:58 -0700 (PDT) From: Dave Martin To: linux-arm-kernel@lists.infradead.org Subject: [RFC PATCH 4/5] ARM: entry: Remove unnecessary masking when decoding Thumb-2 instructions Date: Wed, 10 Aug 2011 11:13:42 +0100 Message-Id: <1312971223-28165-5-git-send-email-dave.martin@linaro.org> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1312971223-28165-1-git-send-email-dave.martin@linaro.org> References: <1312971223-28165-1-git-send-email-dave.martin@linaro.org> X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110810_061359_968227_FC6B6869 X-CRM114-Status: GOOD ( 12.53 ) X-Spam-Score: -0.7 (/) X-Spam-Report: SpamAssassin version 3.3.1 on canuck.infradead.org summary: Content analysis details: (-0.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [74.125.82.177 listed in list.dnswl.org] Cc: Nicolas Pitre , Kukjin Kim , Jon Medhurst , Ben Dooks , patches@linaro.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Wed, 10 Aug 2011 10:15:43 +0000 (UTC) When testing whether a Thumb-2 instruction is 32 bits long or not, the masking done in order to test bits 11-15 of the first instruction halfword won't affect the result of the comparison, so remove it. Signed-off-by: Dave Martin --- arch/arm/kernel/entry-armv.S | 6 ++---- 1 files changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index a87cbf8..b7236d4 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -262,8 +262,7 @@ __und_svc: ldr r0, [r4, #-4] #else ldrh r0, [r4, #-2] @ Thumb instruction at LR - 2 - and r9, r0, #0xf800 - cmp r9, #0xe800 @ 32-bit instruction if xx >= 0 + cmp r0, #0xe800 @ 32-bit instruction if xx >= 0 ldrhhs r9, [r4] @ bottom 16 bits orrhs r0, r9, r0, lsl #16 #endif @@ -445,8 +444,7 @@ __und_usr: ARM( ldrht r5, [r4], #2 ) THUMB( ldrht r5, [r4] ) THUMB( add r4, r4, #2 ) - and r0, r5, #0xf800 @ mask bits 111x x... .... .... - cmp r0, #0xe800 @ 32bit instruction if xx != 0 + cmp r5, #0xe800 @ 32bit instruction if xx != 0 blo __und_usr_unknown 3: ldrht r0, [r4] add r2, r2, #2 @ r2 is PC + 2, make it PC + 4