From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt1-x829.google.com (mail-qt1-x829.google.com [IPv6:2607:f8b0:4864:20::829]) by sourceware.org (Postfix) with ESMTPS id 6E52C3830FEB for ; Sat, 17 Dec 2022 10:16:22 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 6E52C3830FEB Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=sifive.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=sifive.com Received: by mail-qt1-x829.google.com with SMTP id fu10so4697036qtb.0 for ; Sat, 17 Dec 2022 02:16:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sifive.com; s=google; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=PjREPY9ZVBkCrD1j0BRgnUUS/IECLH3knQE48PiJufE=; b=TsGOneg+0JMqNsSkwirXWg2pf3HaRxc02+puBJuFdrSAg9CpONKctOnUuhyPzD0U2v fh7yENiszXF50MZMRWOsr2XyYiE/wQlDp7851ikKTgwkDXb5KF3qHCr+LCgeP9jvePYl CT4YkkBlcG+URaD0l4CrxacAo0SNqbG2f8Mq9KUl0rBv3yEsQ+c0wxZSpchGXsI/JEd7 P37LdXMZudKHSVqPK+RPeceD9BJmiIXnHe7hPUHr6+ppb234d4rS58zmfA2Od+blb4VF YMKbC8WCrqeuL7O0jcBwbxMWa2PZV3wiKqbojeS9ru4jWH9OvFQDI31NvuDtt7USKSTd YPKg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; 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=PjREPY9ZVBkCrD1j0BRgnUUS/IECLH3knQE48PiJufE=; b=56tl233DysvqOopE4A4ksDWy5Eyiiroejz6UQkuFetK9UnnHo5Du1ih7CHGdvnjraj KF8CySH74DzFehP3dbNZWT0oITfInnna//OANbEnt3ukKoxheFH0yyaUNcmu4H8otuK9 xYdLFqcIS9Zc27xivLHIYty0yJo1BeWXHCDcWnX0x7OiSIag0hoXJqclJVkYd7QKQfga Ic9ejz8r+VP418i32SBmf0MiQT2uK0DqzBt5RZoWo+tRs7+7LpdasEHYmpoSJuh8n/lZ 5+JdcfO4NOn90Gk+7uCXhi4+sGTU5q7e3/WVpc8T01uarvGkPK850gG3YEAifiLFimpI IxHg== X-Gm-Message-State: ANoB5pmsuQozcMnM7EFquurWRP4X4oHExPy1o8jdukdTPwQSftL7zrFg NtZ5cFeynyLwgxBg19EewhO5GSLPIm2QPI7jUmGoZF0VzTOs7okIUeHVgatokbVundkeeHEO0AH Ts5C60wo6RKhCF1PB9a0JOIrSyxEgRliKQCQs+ElxmfSUFga0IUVvu56u5fbeaHB0mYtdai8= X-Google-Smtp-Source: AA0mqf7vhlGou8pxVM1GXFhW3vJzO2+QXU/9tjxAe/g1FMx1Nhrl+4T6ALmy+MA+VGgey7DUxWGXNQ== X-Received: by 2002:a05:622a:514d:b0:3a5:2610:748d with SMTP id ew13-20020a05622a514d00b003a52610748dmr48381045qtb.17.1671272181385; Sat, 17 Dec 2022 02:16:21 -0800 (PST) Received: from mail-yb1-f170.google.com (mail-yb1-f170.google.com. [209.85.219.170]) by smtp.gmail.com with ESMTPSA id b4-20020ac86bc4000000b0039a610a04b1sm2770912qtt.37.2022.12.17.02.16.19 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 17 Dec 2022 02:16:20 -0800 (PST) Received: by mail-yb1-f170.google.com with SMTP id o127so4866784yba.5 for ; Sat, 17 Dec 2022 02:16:19 -0800 (PST) X-Received: by 2002:a25:25c2:0:b0:706:ba81:7944 with SMTP id l185-20020a2525c2000000b00706ba817944mr10862673ybl.561.1671272179647; Sat, 17 Dec 2022 02:16:19 -0800 (PST) MIME-Version: 1.0 References: <87r0wypcgw.fsf@linux-m68k.org> In-Reply-To: <87r0wypcgw.fsf@linux-m68k.org> From: Andrew Waterman Date: Sat, 17 Dec 2022 02:16:08 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] RISC-V: Note that __builtin_riscv_pause() implies Xgnuzihintpausestate To: Andreas Schwab Cc: Palmer Dabbelt , Kito Cheng , gcc-patches@gcc.gnu.org, Greg Favor Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-3.9 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,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: On Sat, Dec 17, 2022 at 2:10 AM Andreas Schwab wrote: > > On Dez 17 2022, Andrew Waterman wrote: > > > It took me a few minutes to understand the purpose of this chicanery, but > > there's indeed a contradiction in the ISA spec. HINT instructions _do_ > > affect architectural state in a limited fashion--namely, updating the PC. > > How can an insn _not_ affect the PC? (Other than the trivial infinite > loop.) Heh, yeah, that's roughly what I meant by "common-sense reading" (and that's my rationale for simply clarifying the spec and nuking this Xgnuzihintpausestate extension). > > -- > Andreas Schwab, schwab@linux-m68k.org > GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1 > "And now for something completely different."