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 [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 297F43858D20 for ; Fri, 1 Sep 2023 08:27:14 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 297F43858D20 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1693556833; 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=4Kvv5XY8X6xPYgwcqmnX7W/PeZY+XhCJXRffIgIQe68=; b=cGay9aDhB6CUSkJqSEtqL5+0VLb5jEQGEGw/aLv5owLrHTMbPz53kNDBFHiJA2s8Bv5qHQ GFbi3hbQkAFOk6r1E03fKMIa5mwTUQ8lpgyj2C5qjNvS9axVk2o98PH9Xpa2K3+ZEQTuA1 v4QmSlWF5h9bWC9zmmR8ak0d2Yj8MLI= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-576-HT1BFbiJNq-4r4Vh-FpQzg-1; Fri, 01 Sep 2023 04:27:10 -0400 X-MC-Unique: HT1BFbiJNq-4r4Vh-FpQzg-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 12A3F80027F; Fri, 1 Sep 2023 08:27:10 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.45.224.16]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C9EEE401E63; Fri, 1 Sep 2023 08:27:09 +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 3818R84O296495 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Fri, 1 Sep 2023 10:27:08 +0200 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 3818R7EM296494; Fri, 1 Sep 2023 10:27:07 +0200 Date: Fri, 1 Sep 2023 10:27:07 +0200 From: Jakub Jelinek To: Richard Biener Cc: Krister Walfridsson , Andrew MacLeod , gcc@gcc.gnu.org Subject: Re: CLZ when CLZ_DEFINED_VALUE_AT_ZERO is false Message-ID: Reply-To: Jakub Jelinek References: MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 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=-3.4 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,KAM_SHORT,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: On Fri, Sep 01, 2023 at 10:13:40AM +0200, Richard Biener via Gcc wrote: > The value of .CLZ (0) is undefined then. I belive your analysis is correct in > that both 63 - _35 might overflow and that dom3 (thus ranger) mis-computes > the range for _35. I wonder why we don't elide _36 ? _31 : 1 with that info > (possibly no range-op for .CLZ?), of course it would be wrong to do so. > > Can you open a bugreport please? Seems similar to https://gcc.gnu.org/pipermail/gcc-patches/2023-February/thread.html#612214 except that case is at RTL level. But arguably, I think at least at GIMPLE level we should just emit here GIMPLE_COND + separate bb around it rather than COND_EXPR. Jakub