From patchwork Fri Sep 7 13:16:28 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Aurelien Jarno X-Patchwork-Id: 182377 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id C3D872C008B for ; Fri, 7 Sep 2012 23:51:29 +1000 (EST) Received: from localhost ([::1]:50131 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T9yRX-0005lY-9m for incoming@patchwork.ozlabs.org; Fri, 07 Sep 2012 09:17:55 -0400 Received: from eggs.gnu.org ([208.118.235.92]:57171) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T9yQT-0003Eo-7V for qemu-devel@nongnu.org; Fri, 07 Sep 2012 09:16:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T9yQH-0000rt-Uo for qemu-devel@nongnu.org; Fri, 07 Sep 2012 09:16:49 -0400 Received: from hall.aurel32.net ([88.191.126.93]:37139) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T9yQH-0000rS-On for qemu-devel@nongnu.org; Fri, 07 Sep 2012 09:16:37 -0400 Received: from [46.27.142.81] (helo=ohm.aurel32.net) by hall.aurel32.net with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.72) (envelope-from ) id 1T9yQG-00040l-UI; Fri, 07 Sep 2012 15:16:37 +0200 Received: from aurel32 by ohm.aurel32.net with local (Exim 4.80) (envelope-from ) id 1T9yQE-0006P1-6L; Fri, 07 Sep 2012 15:16:34 +0200 From: Aurelien Jarno To: qemu-devel@nongnu.org Date: Fri, 7 Sep 2012 15:16:28 +0200 Message-Id: <1347023792-24045-6-git-send-email-aurelien@aurel32.net> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1347023792-24045-1-git-send-email-aurelien@aurel32.net> References: <1347023792-24045-1-git-send-email-aurelien@aurel32.net> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 88.191.126.93 Cc: Aurelien Jarno Subject: [Qemu-devel] [PATCH v2 5/9] tcg/optimize: simplify shift/rot r, 0, a => movi r, 0 cases X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org shift/rot r, 0, a is equivalent to movi r, 0. Reviewed-by: Richard Henderson Signed-off-by: Aurelien Jarno --- tcg/optimize.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/tcg/optimize.c b/tcg/optimize.c index c12cb2b..1698ba3 100644 --- a/tcg/optimize.c +++ b/tcg/optimize.c @@ -322,6 +322,26 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, break; } + /* Simplify expressions for "shift/rot r, 0, a => movi r, 0" */ + switch (op) { + CASE_OP_32_64(shl): + CASE_OP_32_64(shr): + CASE_OP_32_64(sar): + CASE_OP_32_64(rotl): + CASE_OP_32_64(rotr): + if (temps[args[1]].state == TCG_TEMP_CONST + && temps[args[1]].val == 0) { + gen_opc_buf[op_index] = op_to_movi(op); + tcg_opt_gen_movi(gen_args, args[0], 0, nb_temps, nb_globals); + args += 3; + gen_args += 2; + continue; + } + break; + default: + break; + } + /* Simplify expression for "op r, a, 0 => mov r, a" cases */ switch (op) { CASE_OP_32_64(add):