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 E8AEF3858D20 for ; Wed, 6 Dec 2023 22:03:38 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org E8AEF3858D20 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 E8AEF3858D20 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=1701900220; cv=none; b=MqL8mILqTV+qoUT/J5lCW24s+AFxanpZw7vvTvi8r+hQsRUgeD+SY4F5H3d4aDbYJ9+L9zTLzhpk87Vns7kaNqZJpPBp1z9Q2Ti+FLRvAQu7GY4dxjrNQLKgMrsyUXUh5j/2W7SK+0u8FsiaFZL8LIw0vlaC+8vIbKTTLBqjWDM= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1701900220; c=relaxed/simple; bh=2u/bIoIi0ablJQmrGuqRjorrT9S4B9or2GfULsdF8c4=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=qLBETmBn4GiNljheCRBKsdnJ5jBcPcpGd88pKZzrVZ1KaAxFIkgl4YYQ4UlugP3skbFPqW6MKMQ8ySxccR3xZO1YwQInt7fy97tWdV6x4k64lzOTtDKRKz3bT5crPyQJlE4l3d3K+aswrNlKaahUY0+FpDvVu6vVVlu1tJcBMHE= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1701900218; 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; bh=XJqc5aljx0QepBurECHOxyOINM9aItQqazLxdRqG6pE=; b=RRU5SfgWqXWBgxOw0E/jQ32J0Kp5Obwk2XkEnJ3yusVjafVDTktUvJMJkPJ1asOuIm2fZE lCtdmYcBoncgZ3bnLvWactMecfDsclP1NSIeuzBT1BHgq7WfFLHLCuMk5mUgaGk59wudRh U2LZkQ1dALD5mJsybHYjCAjwtWfIa/8= 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-447-Ei0kll1qOx6l-0n_eNQqgg-1; Wed, 06 Dec 2023 17:03:33 -0500 X-MC-Unique: Ei0kll1qOx6l-0n_eNQqgg-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (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 0DE7F29ABA36; Wed, 6 Dec 2023 22:03:33 +0000 (UTC) Received: from greed.delorie.com (unknown [10.22.9.77]) by smtp.corp.redhat.com (Postfix) with ESMTPS id ECFE51C060AF; Wed, 6 Dec 2023 22:03:32 +0000 (UTC) Received: from greed.delorie.com.redhat.com (localhost [127.0.0.1]) by greed.delorie.com (8.15.2/8.15.2) with ESMTP id 3B6M3WBA999328; Wed, 6 Dec 2023 17:03:32 -0500 From: DJ Delorie To: Alexandre Oliva Cc: jeffreyalaw@gmail.com, gcc@gcc.gnu.org Subject: Re: strub causing libgcc to fail to build on rl78-elf In-Reply-To: (message from Alexandre Oliva on Wed, 06 Dec 2023 18:24:58 -0300) Date: Wed, 06 Dec 2023 17:03:32 -0500 Message-ID: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.7 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-4.7 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,T_SCC_BODY_TEXT_LINE 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: Alexandre Oliva writes: > This looks like a latent bug in the port. I'm not surprised, that port was weird. > This was just a plain asm insn in strub.c: > > /* Make sure the stack overwrites are not optimized away. */ > asm ("" : : "m" (end[0])); > > whose constraint passes during reload, rl78_alloc_physical_registers > leaves it alone and clears virt_insns_ok, so when cprog_hardreg attempts > to extract constraints again, rl78_as_legitimate_address rejects r8 as > the address because virt insns are no longer ok. Some background: the "virtual" registers are memory-mapped registers that use a common addressing scheme to access non-mapped registers. When we convert from virtual to physical, we can map that reg to a physical reg, or we replace the reg with a mem, but then usually have to split up the insn. For this insn, "converting" should have mapped or reloaded r8 to a valid address register. I doubt we have a way to have two patterns for user asms like we do for, say, addhi3. I suspect that something in the virt->phys logic just doesn't know how to check for mem constraints in user asms. > I'm not at all familiar with this port, and I don't know what was > supposed to happen here, but ISTM that either physical registers should > be allocated for asms, or non-B0 regs should be accepted in asms. non-bank-zero registers aren't valid as real address registers, because in gcc's reality they *are* mems. The chip can bank switch them, but gcc doesn't (the interrupt handlers, being asm, can do so, which is why one bank is reserved for that).