From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ua1-x92f.google.com (mail-ua1-x92f.google.com [IPv6:2607:f8b0:4864:20::92f]) by sourceware.org (Postfix) with ESMTPS id 75B5D3858D32 for ; Wed, 12 Apr 2023 09:31:59 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 75B5D3858D32 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-ua1-x92f.google.com with SMTP id a38so6805892uax.12 for ; Wed, 12 Apr 2023 02:31:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1681291919; x=1683883919; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=mZc5nAeG8+K31+tSVSz7IxU3v7GdNtBRKfEfeGUJTos=; b=P6Ze7ckeVBpt1rXHIOlVG73uiHgQSKiQm7j9kO/337rGqqlB1xWkSmJVQZtoHc6rh9 1dYg0WoyBgs3gkPIe5OWxdNPe9xJuZfP0P+Qngog8zgFEaDLzFmiN05YATM7JQVhEfiD LzdBkmoxj9ik1c1EI+mC5pO36jlEqyrVY3jZ1w5g93+ICktR4ewjMFupsfPn4O6vSHu/ PlLkR5HescLjYyZz6wtc8jMGz+tCh0WII7Iv+StXJcF/+0ovQDoIswxdBFaXINMlpJAj EbvW3cjQXlFlmDNaCMqxkofV9xQ1AEBsWW/vJNC92Mu6KsWHZJn3JEImXOJEyqKCcgi/ W9NQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681291919; x=1683883919; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=mZc5nAeG8+K31+tSVSz7IxU3v7GdNtBRKfEfeGUJTos=; b=jf92atmBqynQYDbwXaHWLQmuNdvRQcjY8ypsCGkc4rBjx9rTVB53boHvSokvTmGQ9M DbfC9VliusyWAO6cHLyBv8B7o23S3bWoUlEVCMttKsa+fE4mR5zJRXFaEmScNs2J7Ne1 hGVi+X9WFYNPHigY3TOXVKfhJzOvHfOEW80m4t62v7yAmbejEiG6sJKWOHjhhY8TYQ6r q6Hx50jVnSXcHn5XAf44R1oLD7n14nIEPL3P2Zw7uMItpLUifWW5vW1AC1VxzuYHDUxr hb6IfFvUBitgGrAVgT0qvwSi3hMSCUED/IRCeS1DVAn/7Hd0nAedUV+EoKO5vXrLemxk uWJg== X-Gm-Message-State: AAQBX9ddTNE1E9gIX+pB+5WIPRJi9M4IV39ZK1CzoCEjnuMmMDL2+axS sASbXcvZQOzwRQOTqq/WWS+v8biszHBkhKLoJ2U= X-Google-Smtp-Source: AKy350Y03wGgnXZLMN/pflRE6MWZzvX909a9unnJWVCuEZNBT3lqPSOVS0eq9xnvSXhh0ChNW5ZA3vGsR4FsYPWD6Z4= X-Received: by 2002:a1f:9f51:0:b0:43c:aa3:bf3d with SMTP id i78-20020a1f9f51000000b0043c0aa3bf3dmr3442454vke.1.1681291918546; Wed, 12 Apr 2023 02:31:58 -0700 (PDT) MIME-Version: 1.0 References: <20230410144808.324346-1-juzhe.zhong@rivai.ai> <89f088ec-8692-01f5-0395-5a66ddf085d7@gmail.com> <47D962C7C724E3A2+20230410231445834316202@rivai.ai> <0AEFD2378C3DF89B+202304111919556577872@rivai.ai> In-Reply-To: From: Kito Cheng Date: Wed, 12 Apr 2023 17:31:47 +0800 Message-ID: Subject: Re: Re: [PATCH] machine_mode type size: Extend enum size from 8-bit to 16-bit To: Richard Biener Cc: "juzhe.zhong@rivai.ai" , "richard.sandiford" , jeffreyalaw , gcc-patches , palmer , jakub Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-2.9 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: > > The concept of fractional LMUL is the same as the concept of AArch64's > > partial SVE vectors, > > so they can only access the lowest part, like SVE's partial vector. > > > > We want to spill/restore the exact size of those modes (1/2, 1/4, > > 1/8), so adding dedicated modes for those partial vector modes should > > be unavoidable IMO. > > > > And even if we use sub-vector, we still need to define those partial > > vector types. > > Could you use integer modes for the fractional vectors? You mean using the scalar integer mode like using (subreg:SI (reg:VNx4SI) 0) to represent LMUL=1/4? (Assume VNx4SI is mode for M1) If so I think it might not be able to model that right - it seems like we are using 32-bits but actually we are using poly_int16(1, 1) * 32 bits. > For computation you can always appropriately limit the LEN? RVV provide zvl*b extension like zvlb (e.g.zvl128b or zvl256b) to guarantee the vector length is at least larger than N bits, but it's just guarantee the minimal length like SVE guarantee the minimal vector length is 128 bits