From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id B697E3858D20 for ; Wed, 17 Apr 2024 10:26:15 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org B697E3858D20 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org B697E3858D20 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1713349577; cv=none; b=WxR4Rxf+C5F5TZf5vA5+2BcnWcj+F9R2ax1y2ZIuBDHhE08gntReHUDuQDyXlUJWlUSnlTJeXOqJdBDF9G0Uc5gM+Pnq14GGDvS6Kgbe0oXu7KtRDXIClA/d7UsGp97cfCGIydjRSqMdiSfVcVJDGTIE91/1ad1EmqOT1lF7yxQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1713349577; c=relaxed/simple; bh=wyyf0IUUMX004f1MjtA6QmuQOxjlkzIkWJQGHBazjHs=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=dQeFFHighMXG7Jx/hhQ5Q/1mV1WbpTew5xNjdtuX37tV77LarKoF4J1tUC0FIjX3fNlqfxXnA1oDgyeijLWJvV6QGFK+wAGlF/t+PAZBqe6SjgfpB3+deHOpTi0D8ms5To4KQIwF8gsf6HnFd7RHMrXax7l8G6s4K+wLNxLyLYw= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1713349575; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=9lamQ51k1kAA6Qh4kAm36+z19Zhiv9Ow8OucpOMZnpY=; b=XHsFQrp5mfCGI14VWbvWOtgTQI+OjJJUfowMX9prwpPRU//XnYrI1ElQRZ+2hIYMZ9UyCq 1FGG6bjmPb7bDkU2Jm823JvUwONRU2QaGvrCS0fpj5Q0ck6z7Qy2BuOVvS6I8Q2z4AMiTT zfHiV234IDf/CqwRK+DFVj3Ha9KJ2L4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-265-RIVDbF1qMA2pW8j9zerJwQ-1; Wed, 17 Apr 2024 06:26:14 -0400 X-MC-Unique: RIVDbF1qMA2pW8j9zerJwQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A3361188ACA0; Wed, 17 Apr 2024 10:26:13 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.193.229]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B21DB1121312; Wed, 17 Apr 2024 10:26:12 +0000 (UTC) From: Florian Weimer To: Michael Hudson-Doyle Cc: Palmer Dabbelt , libc-alpha@sourceware.org Subject: Re: [RFC] build-many-glibcs: Add a rv64gcbv-on-rv64gc/lp64d sub-variant In-Reply-To: (Michael Hudson-Doyle's message of "Tue, 16 Apr 2024 19:01:31 +1200") References: <20240415192414.14155-2-palmer@rivosinc.com> Date: Wed, 17 Apr 2024 12:26:06 +0200 Message-ID: <87cyqogu9t.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-5.5 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,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: * Michael Hudson-Doyle: > On Tue, 16 Apr 2024 at 07:28, Palmer Dabbelt wrote: > >> Unfortunately I don't think we can drop support for the other base >> ISAs: the distros appear to be targeting rv64gc and that's the only >> common base for most hardware that's out there. > > This is certainly the case for Ubuntu for now but I certainly hope > that by 26.04 we are able to be a bit more aggressive here, fwiw. You might want to add an early check to ld.so to report CPU compatibilities, similar to what we do using gcc-macros.h in sysdeps/powerpc/powerpc64/le/dl-hwcap-check.h, sysdeps/s390/s390-64/dl-hwcap-check.h, sysdeps/x86/dl-get-cpu-features.c. This requires configure glibc withe the appropriate --with-rtld-early-cflags option, as GCC does not provide a way to force the compiler to use the baseline ISA once the defaults have changed (either within GCC itself, based on its configuration, or earlier on the command line). Thanks, Florian