From patchwork Thu Aug 18 17:01:53 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: 1076802 Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by demeter1.kernel.org (8.14.4/8.14.4) with ESMTP id p7IH3M5D029780 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Thu, 18 Aug 2011 17:03:43 GMT Received: from canuck.infradead.org ([134.117.69.58]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Qu5zT-0004ly-G7; Thu, 18 Aug 2011 17:02:48 +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 1Qu5zS-000870-Nu; Thu, 18 Aug 2011 17:02:46 +0000 Received: from mail-ww0-f49.google.com ([74.125.82.49]) by canuck.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Qu5yp-000808-UR for linux-arm-kernel@lists.infradead.org; Thu, 18 Aug 2011 17:02:10 +0000 Received: by wwf10 with SMTP id 10so1676214wwf.18 for ; Thu, 18 Aug 2011 10:02:06 -0700 (PDT) Received: by 10.227.19.194 with SMTP id c2mr835700wbb.65.1313686926825; Thu, 18 Aug 2011 10:02:06 -0700 (PDT) Received: from e200948.peterhouse.linaro.org (fw-lnat.cambridge.arm.com [217.140.96.63]) by mx.google.com with ESMTPS id 8sm1907629wbx.51.2011.08.18.10.02.05 (version=SSLv3 cipher=OTHER); Thu, 18 Aug 2011 10:02:06 -0700 (PDT) From: Dave Martin To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 2/3] ARM: entry: Remove unnecessary masking when decoding Thumb-2 instructions Date: Thu, 18 Aug 2011 18:01:53 +0100 Message-Id: <1313686914-29481-3-git-send-email-dave.martin@linaro.org> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1313686914-29481-1-git-send-email-dave.martin@linaro.org> References: <1313686914-29481-1-git-send-email-dave.martin@linaro.org> X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110818_130208_132924_1A9590BE X-CRM114-Status: GOOD ( 11.32 ) 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 [74.125.82.49 listed in list.dnswl.org] Cc: Nicolas Pitre , Jon Medhurst , 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 (demeter1.kernel.org [140.211.167.41]); Thu, 18 Aug 2011 17:03:43 +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 Reviewed-by: Jon Medhurst Acked-by: Nicolas Pitre --- 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