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 A8A5538582A5 for ; Fri, 16 Feb 2024 14:10:09 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org A8A5538582A5 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 A8A5538582A5 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=1708092613; cv=none; b=Jh4MQLRlaMlyurAHkLVkbhjurVutoBL918XL28sZrl5dlEn6DsudGqDVRuhvr8JdnIC6t014moCJIma6UcaNiYByYQ/T72S1KOoyai7lHGwP4Vr+TXg7pOXGgYNDQ+s7jt1hyodqERNQw6U0MxOrNOWZHVH08bz/wfJstTY/mXI= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1708092613; c=relaxed/simple; bh=SCd1KgCblU/I1tNfAgXHUSVaw4CjR2IDidulvSIQHbw=; h=DKIM-Signature:Date:From:To:Subject:Message-ID:MIME-Version; b=qDfKYBy4xyt0tL78yn1D00bcuiRlrWiKS/8PpvFjcIUUetCuvx8AcsA5hvkeahkK1bufP5OuaCC4IbKD56D3DBR5CJGBqfC0Kv4k9g2eRI4j9ej37/1+2NRYmSGuWQiciwkcRf4J/o+2U6HnJBO2irbg/SuWiUEWsu2iylaNIG4= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1708092609; h=from:from:reply-to: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=M5sxq0EhXQC6QXuXNoqGmxOh1P0uIx6JWONhBUQhjQQ=; b=cpXIX1pAwCyIt4lYe0R63L2jGX3z9ZwcYNyZ3urHFQZZAARb55U4MgKJgAZqKHistfppr9 aOEyTWopVDpCWbu1EKmgp3aN/Dyf/VCAr0KB99vNffPtjF7o5rSsxcvdyoP8jCwNbUvni6 cWfAjasFugomsl2LQgxpgla2QGsoS7k= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-397-SrlA_0PIOIyPb5OviUyIYg-1; Fri, 16 Feb 2024 09:10:05 -0500 X-MC-Unique: SrlA_0PIOIyPb5OviUyIYg-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 058A43C0C489; Fri, 16 Feb 2024 14:10:05 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.192.8]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B91E9112131D; Fri, 16 Feb 2024 14:10:04 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.17.1/8.17.1) with ESMTPS id 41GEA2Ei165077 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Fri, 16 Feb 2024 15:10:02 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 41GEA1DL165076; Fri, 16 Feb 2024 15:10:01 +0100 Date: Fri, 16 Feb 2024 15:10:01 +0100 From: Jakub Jelinek To: Jonathan Wakely Cc: xndcn , Xi Ruoyao , "H.J. Lu" , GCC Patches , libstdc++@gcc.gnu.org Subject: Re: [PATCH] libstdc++: atomic: Add missing clear_padding in __atomic_float constructor Message-ID: Reply-To: Jakub Jelinek References: <9f2bdd3a973d98199bb5b322baa575ab2fba8a58.camel@xry111.site> MIME-Version: 1.0 In-Reply-To: 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; charset=us-ascii Content-Disposition: inline X-Spam-Status: No, score=-3.8 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_H2,SPF_HELO_NONE,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE autolearn=unavailable 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 Fri, Feb 16, 2024 at 01:51:54PM +0000, Jonathan Wakely wrote: > Ah, although __atomic_compare_exchange only takes pointers, the > compiler replaces that with a call to __atomic_compare_exchange_n > which takes the newval by value, which presumably uses an 80-bit FP > register and so the padding bits become indeterminate again. __atomic_compare_exchange_n only works with integers, so I guess it is doing VIEW_CONVERT_EXPR (aka union-style type punning) on the argument. Do you have preprocessed source for the testcase? Jakub