From patchwork Fri Sep 6 05:16:03 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 13793295 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 526D0C54FC6 for ; Fri, 6 Sep 2024 05:27:15 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1smRLv-00060Y-Oc; Fri, 06 Sep 2024 01:17:47 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1smRLt-0005of-8S; Fri, 06 Sep 2024 01:17:45 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1smRLq-000827-Gd; Fri, 06 Sep 2024 01:17:44 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 2D05C8C123; Fri, 6 Sep 2024 08:15:17 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id D1565133369; Fri, 6 Sep 2024 08:16:34 +0300 (MSK) Received: (nullmailer pid 10430 invoked by uid 1000); Fri, 06 Sep 2024 05:16:33 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Peter Maydell , Richard Henderson , Michael Tokarev Subject: [Stable-7.2.14 15/40] target/arm: Don't assert for 128-bit tile accesses when SVL is 128 Date: Fri, 6 Sep 2024 08:16:03 +0300 Message-Id: <20240906051633.10288-15-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Peter Maydell For an instruction which accesses a 128-bit element tile when the SVL is also 128 (for example MOV z0.Q, p0/M, ZA0H.Q[w0,0]), we will assert in get_tile_rowcol(): qemu-system-aarch64: ../../tcg/tcg-op.c:926: tcg_gen_deposit_z_i32: Assertion `len > 0' failed. This happens because we calculate len = ctz32(streaming_vec_reg_size(s)) - esz;$ but if the SVL and the element size are the same len is 0, and the deposit operation asserts. In this case the ZA storage contains exactly one 128 bit element ZA tile, and the horizontal or vertical slice is just that tile. This means that regardless of the index value in the Ws register, we always access that tile. (In pseudocode terms, we calculate (index + offset) MOD 1, which is 0.) Special case the len == 0 case to avoid hitting the assertion in tcg_gen_deposit_z_i32(). Cc: qemu-stable@nongnu.org Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20240722172957.1041231-2-peter.maydell@linaro.org (cherry picked from commit 56f1c0db928aae0b83fd91c89ddb226b137e2b21) Signed-off-by: Michael Tokarev diff --git a/target/arm/translate-sme.c b/target/arm/translate-sme.c index 8cce34e117..0fcd4ad950 100644 --- a/target/arm/translate-sme.c +++ b/target/arm/translate-sme.c @@ -56,7 +56,15 @@ static TCGv_ptr get_tile_rowcol(DisasContext *s, int esz, int rs, /* Prepare a power-of-two modulo via extraction of @len bits. */ len = ctz32(streaming_vec_reg_size(s)) - esz; - if (vertical) { + if (!len) { + /* + * SVL is 128 and the element size is 128. There is exactly + * one 128x128 tile in the ZA storage, and so we calculate + * (Rs + imm) MOD 1, which is always 0. We need to special case + * this because TCG doesn't allow deposit ops with len 0. + */ + tcg_gen_movi_i32(tmp, 0); + } else if (vertical) { /* * Compute the byte offset of the index within the tile: * (index % (svl / size)) * size