From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 327B7C433DF for ; Thu, 6 Aug 2020 18:37:51 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 65D1A22C9F for ; Thu, 6 Aug 2020 18:37:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="E7YcvgAh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 65D1A22C9F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:36928 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k3kly-0001SP-5E for qemu-devel@archiver.kernel.org; Thu, 06 Aug 2020 14:37:50 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34956) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k3kl5-0000La-Hl for qemu-devel@nongnu.org; Thu, 06 Aug 2020 14:36:56 -0400 Received: from mail-pj1-x102e.google.com ([2607:f8b0:4864:20::102e]:35234) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1k3kl3-0001tm-SM for qemu-devel@nongnu.org; Thu, 06 Aug 2020 14:36:55 -0400 Received: by mail-pj1-x102e.google.com with SMTP id t6so7140609pjr.0 for ; Thu, 06 Aug 2020 11:36:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=uAGJ3s7/oS/JbfOCj342ZAHHFm29YEngjZLzAjg7ivg=; b=E7YcvgAhOjjOuFk+axecYpDNHlIfUWxxk54fRnkGseZnHr6U57ygx8BLYpiBTgvif/ i0HsfkWHz8ROoQRgrTDcfaOFpdZ//iubf+roqFuRnfmWoH4TCtSLFnOXxUCZnSlRqMLZ zZqUTDre41XziUbHnqtnbVvpUJfylIIWPdZqMfaF5cHepsV8fHEbSUJy3WqY9w6Vf7r7 x2xQ7uSNxkuzRr6hWfXazDtmjku2X3P3F58niHntM0jgvr48wjY3GLqeIlRKsHrJIyZ3 guGiqy2pmUMJWaCkrVJwjRsTtOdvav6iHaaUxez2PPrfvSFOfLaLovi8mqJ0EN8Q5wRa BFvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=uAGJ3s7/oS/JbfOCj342ZAHHFm29YEngjZLzAjg7ivg=; b=H/pCPYXEjFU79bKZKPriYImBFErph8rH7ptgjYGmQTUJaEr6sAsm3d8AMwvgaEUpgv 0HFZYWxHVHL76Z301kxf9y4GZhQ+YbQVJPveE5/IUrN5eweoEy61/UekNiOdA2y3NZ+P XEX+PYxIsTFlN8oaZmdIL6QYfDZ61VuqmyZ3/kJjELiIYIFrRgqENXJLXgsOwx6itikf x6dKZBIdLBog1npYBGCvUDHpAORzmCBOs8nzOBe9HzWfRjfU8M6eHe5AIPpxOie74ZCB MW3ytyzkBlGbfJ6epiRbyFCfa58VRW+yxpRprUUdUg7CmFQ+kJ7Q9zJ5hNo9dsHWHnen 4A0g== X-Gm-Message-State: AOAM533GRxQahFLVlmGSwJvkMZ6X5+eHbaxbn9UlIkPL/2gdJRwdXyy0 hkOu0L48vEROaUJEqKhjh2WTaw== X-Google-Smtp-Source: ABdhPJxGVPABQA6j+C0zZ6hF1h7YK6z1uQeynva8vUGSVVALCSTIMt6ev1w0X1flp9VeE41ZFH4HeA== X-Received: by 2002:a17:90a:9f44:: with SMTP id q4mr10077049pjv.66.1596739012125; Thu, 06 Aug 2020 11:36:52 -0700 (PDT) Received: from [192.168.1.11] ([71.212.141.89]) by smtp.gmail.com with ESMTPSA id q83sm10126848pfc.31.2020.08.06.11.36.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 06 Aug 2020 11:36:51 -0700 (PDT) Subject: Re: [RFC v3 12/71] target/riscv: rvv-1.0: add fractional LMUL To: frank.chang@sifive.com, qemu-devel@nongnu.org, qemu-riscv@nongnu.org References: <20200806104709.13235-1-frank.chang@sifive.com> <20200806104709.13235-13-frank.chang@sifive.com> From: Richard Henderson Message-ID: Date: Thu, 6 Aug 2020 11:36:49 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200806104709.13235-13-frank.chang@sifive.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2607:f8b0:4864:20::102e; envelope-from=richard.henderson@linaro.org; helo=mail-pj1-x102e.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. 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 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Palmer Dabbelt , Alistair Francis , Sagar Karandikar , Bastian Koppelmann Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 8/6/20 3:46 AM, frank.chang@sifive.com wrote: > + float flmul; int8_t? It seems weird that the translator wouldn't also use... > +/* > + * Encode LMUL to lmul as following: > + * LMUL vlmul lmul > + * 1 000 0 > + * 2 001 1 > + * 4 010 2 > + * 8 011 3 > + * - 100 - > + * 1/8 101 -3 > + * 1/4 110 -2 > + * 1/2 111 -1 > + */ > +static inline int32_t vext_lmul(uint32_t desc) > { > - return FIELD_EX32(simd_data(desc), VDATA, LMUL); > + uint32_t lmul = FIELD_EX32(simd_data(desc), VDATA, LMUL); > + return (int8_t)(lmul << 5) >> 5; > } ... this encoding? Oh, and sextract32(lmul, 0, 3) instead of those shifts. r~