From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io1-xd41.google.com (mail-io1-xd41.google.com [IPv6:2607:f8b0:4864:20::d41]) by sourceware.org (Postfix) with ESMTPS id 668733850417 for ; Tue, 8 Sep 2020 19:58:23 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 668733850417 Received: by mail-io1-xd41.google.com with SMTP id b6so682656iof.6 for ; Tue, 08 Sep 2020 12:58:23 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=T6jUfmIRBqfA5IFCewXC6xHqT4Ns4xXpDCGWjD5czo4=; b=fxY3MldkDToRBQI5s7QMQLE5kIa84x6HW7l6HyLcLF18dnb0N17vP9kkrsmiHnpMTW 7zVqE+SdYpROYbXl+vWn7iWy2lkDoZeuWNNokuxh15hMIHIqoDGScn0MgENBa7Yykxkb 7d4Ui+EemwZRW1WRGtEQl+3KMTM10112SxUtd4DEKFMDSCKns8+23N5e4FCQPkzlQfHT 490mZOTbYoRPwW5ge3U1ZjxbHigZr2ND3C1Yh0HkTgM/wN+8q9nFTDq4PEvz/FFqJkPS PhdmUCjyyF/Kwa9RbdITYKIx+j6+wmZpD5iTeXjmjPdDOmoBKp+szB7aHRn5eVMT8jjI JkBw== X-Gm-Message-State: AOAM531CxKHyjd7ZxSRp/uEej0eg/VE/xikAKDpy8qgvjsRRXHLnegqu vIfY8LRRrj69fATxY/kla6xN+tS+V3jCgXAbLXc= X-Google-Smtp-Source: ABdhPJxX67Y3E6UfoKTJpchDotN6YkhhbQr87Rf2sbBGvMV/bTEqb/Q+14FITPYQKDcwMkT+gI1KBQx1LxuBJjWkR78= X-Received: by 2002:a6b:3e84:: with SMTP id l126mr480286ioa.118.1599595102960; Tue, 08 Sep 2020 12:58:22 -0700 (PDT) MIME-Version: 1.0 References: <20200907151057.196cdb1b@jawa> <0076afe3-0e43-a570-9358-9d00c88c0067@gmail.com> In-Reply-To: From: Alistair Francis Date: Tue, 8 Sep 2020 12:47:24 -0700 Message-ID: Subject: Re: Problem with RISC-V To: Joseph Myers Cc: "H.J. Lu" , "Maciej W. Rozycki" , Alistair Francis , GNU C Library Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_ENVFROM_END_DIGIT, FREEMAIL_FROM, KAM_SHORT, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 08 Sep 2020 19:58:24 -0000 On Tue, Sep 8, 2020 at 9:39 AM Joseph Myers wrote: > > On Tue, 8 Sep 2020, H.J. Lu via Libc-alpha wrote: > > > > Also, that particular binutils commit doesn't actually seem to fix things > > > - there is still > > > > > > Extra PLT reference: libc.so: memset You are right, the failure is still there. I'm sure I tested this and it didn't fail. > > > > Is this related? > > > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67220 > > I don't see why it would be. > > All the references to the PLT entry for memset are from libgcc soft-fp > code for TFmode. This isn't a matter of visibility attributes not being > acted on, libgcc.a can't use such visibility for memset because the same > libgcc.a gets used outside of libc as well. > > I'm not sure it actually makes much sense for GCC to be generating memset > calls for whatever memory clearing takes place inside soft-fp (soft-fp > never calls memset explicitly from the C sources; libgcc.a for RV64 > doesn't have any such memset references, for example; any clearing should > be of small aligned pieces of memory that would make more sense to clear > inline). So there may be an issue with questionable GCC code generation > choices for RV32 that should be investigated. But when libgcc functions > reference libc functions, those generally need to be listed in > localplt.data for that glibc configuration (with a '?' to make the > reference optional, see e.g. the > sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data entries for I sent a patch to do exactly that, but it was never accepted. Should I look at merging it? > abort and memset - in this case, the RV32 failures don't appear with GCC > 9, which both means the '?' is required to avoid making the tests fail > there, and suggest there may be a GCC regression). Yep, it does look like a GCC regression between 9 and 10. I'm bisecting now. Alistair > > -- > Joseph S. Myers > joseph@codesourcery.com