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[209.51.188.17]) by mx.google.com with ESMTPS id fn5-20020ad45d65000000b0047052b952c1si1142438qvb.509.2022.06.24.03.07.09 for (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Fri, 24 Jun 2022 03:07:09 -0700 (PDT) Received-SPF: pass (google.com: domain of qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=nqa11Ca8; spf=pass (google.com: domain of qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: from localhost ([::1]:49780 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1o4gDU-0007Dz-SS for alex.bennee@linaro.org; Fri, 24 Jun 2022 06:07:08 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60640) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o4gD2-0007Cs-0d for qemu-arm@nongnu.org; Fri, 24 Jun 2022 06:06:40 -0400 Received: from mail-yw1-x1131.google.com ([2607:f8b0:4864:20::1131]:41688) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1o4gD0-0004cO-Dr for qemu-arm@nongnu.org; Fri, 24 Jun 2022 06:06:39 -0400 Received: by mail-yw1-x1131.google.com with SMTP id 00721157ae682-31780ad7535so19688677b3.8 for ; Fri, 24 Jun 2022 03:06:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ngj7kujS66MfNn6Y0gGXaRBCJ9j3t+t6lRC1FxqQ1V8=; b=nqa11Ca8zAqJIexN50nhEF1S6e/eiczn+KGMvOLbhOg9Zu62XmmUoiByTfGoBhvRFE 8xIQVHLRKWcaUq+EHpoHGJ5jYsC8rcNsMSEEKfqHDSnfh/vXwDY3anrmieTyzO9QcfA6 F9pGEux/PbfexO4jwUynLJK7aVCvXNXmOIEb/Ij8CeK8KV3e8aM+lWfej+wBBegXajWH b9EVNsQRCI1nBgYB+wzHZimD55YCMluDa3Bvp6TZFA5iBx1i2ejU0wfT83ogPwmPN3th NxUiM6FtOekzdh+q5GFMmH0vqrzgxsVbA5kkb/92W+glCOuCbWpOULNfuMi3XkX3H1FE NynQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ngj7kujS66MfNn6Y0gGXaRBCJ9j3t+t6lRC1FxqQ1V8=; b=iCMaMhvPGeDmBJ/FhzDZRT4kWnthD+LhLpQo3TCK+6UEUn8A8WqFo7suNkzcp9JMXw P3lpqrbFDODhP2PnTUXt/HgggazZQ+f9sSMFaKyk0fZCGanYoQsdPmzFUoiZyH6emKst NxkchFSFBiW1fgv2nFwz3+eZ9kPcEx7ycMDBXjg5Oc/MbKBEuDiKMVuyYZMW2j05gLhP fbtOUsvkRcmGNKcLIekKwMKOsYPo6nnDH34vvSDqK5L8AGg//9jfS3gyTJ6Bklp0UZNY Hj9kMLINxOOPtg8ce8XJCSawhDWqMUALkF6M4Wrrn/UX64r1b/oTAXJxoLrbhBc7IArG 0ueg== X-Gm-Message-State: AJIora+USA45NindVHNe4+NbuvorHlQQ4HxsCrl+WAK4yRhaSe2RqPxJ S7FrBY3dSB5nLGvkCAcVRYBLBRyU7bxviR3KkZo72A== X-Received: by 2002:a0d:d712:0:b0:317:a108:9778 with SMTP id z18-20020a0dd712000000b00317a1089778mr15914138ywd.64.1656065197148; Fri, 24 Jun 2022 03:06:37 -0700 (PDT) MIME-Version: 1.0 References: <20220620175235.60881-1-richard.henderson@linaro.org> <20220620175235.60881-27-richard.henderson@linaro.org> In-Reply-To: From: Peter Maydell Date: Fri, 24 Jun 2022 11:05:59 +0100 Message-ID: Subject: Re: [PATCH v3 26/51] target/arm: Implement SME LD1, ST1 To: Richard Henderson Cc: qemu-devel@nongnu.org, qemu-arm@nongnu.org Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2607:f8b0:4864:20::1131; envelope-from=peter.maydell@linaro.org; helo=mail-yw1-x1131.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-arm@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-arm-bounces+alex.bennee=linaro.org@nongnu.org Sender: "Qemu-arm" X-TUID: ZyX8EAO6qrAG On Thu, 23 Jun 2022 at 21:36, Richard Henderson wrote: > On 6/23/22 04:41, Peter Maydell wrote: > > We now have several rather long functions that are > > pretty complicated and pretty similar handling the various > > SVE and SME loads and stores. Is there really no hope for > > sharing code ? > > I'm not sure. Maybe. The two issues are: > > (1) sve ld4/st4 -- arm didn't make z29-z31 illegal, but defined wraparound to z0. So I > pass in a Zreg number not a pointer to those routines. So the routines can't be reused > for Zarray without changing that. > > (2) sme ld1/st1 vertical slice, which significantly alters the spacing between the elements. > > One possibility for these cases is to perform the load into env->some_scratch_space, then > copy into the final position afterward, and the reverse for stores. > > Is that preferable? Do you see another alternative? Hmm, loading into a scratch space seems a bit clunky too. I'll leave it to your judgement but I guess since you've already written and tested the code we have here that argues for going with what we have. Maybe we'll come back in six months and realize there's a neater approach. (The GIC ITS code ended up being refactored like that.) -- PMM