From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vs1-xe33.google.com (mail-vs1-xe33.google.com [IPv6:2607:f8b0:4864:20::e33]) by sourceware.org (Postfix) with ESMTPS id 9D7723857433; Fri, 29 Apr 2022 06:51:35 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 9D7723857433 Received: by mail-vs1-xe33.google.com with SMTP id v139so6764078vsv.0; Thu, 28 Apr 2022 23:51:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=qwzwxYTRUAuJmN3HMh9u3uYnyffFLQjjU4noT1feO/M=; b=gUCur2xiyHyt4v+YtGe9W7VAu/dOK8O/d/U2Th4uyFs5K3SDEA1LoLMciNc9/Kk5fI coJW66hxMAAgy3i6jmcRdyvXXWrvnTYEQqReJz7lFRoFG3xRQPUMiNCLgiuZj9eSX3Zk wTUrdZ1g8vnMZYpIOcI1dcd2kKNvhbiAjUN4b149ubAOTj57dp/qY9UDYHexW/sxU/tI c3s1o212RUhyjrG4qka2NUVzS5etufukQ+l6xHK6ajLpgV9cgtDjGWtpl7sfPuhJVXDe nBpsVUqDgzBmEPVdk7XiVFYmGStzIbBoRnFJ9a99xpbC64TxDC25qBJLXbW6E3G1qQzi 1bPQ== X-Gm-Message-State: AOAM533hrUlooppdqVOmZaI0QO5F/LmrLucNDGa6dWFuibi+2ViO9Jlw vaYcAsV8l8KUrHkcItUXfnU4w7ZwXGZJHsHAaHA= X-Google-Smtp-Source: ABdhPJxhyDCqLqJXxZam7NeZVrymJ/H9IiIGUTKNovAKYOYKZstuiKEnimGCz0NlmFEopkQqWHC22mPO0OcCx5GrxA8= X-Received: by 2002:a05:6102:7c4:b0:32c:d1f6:1bba with SMTP id y4-20020a05610207c400b0032cd1f61bbamr7438457vsg.0.1651215094867; Thu, 28 Apr 2022 23:51:34 -0700 (PDT) MIME-Version: 1.0 References: <6144a58c030ee034e7f4d9cf481045c7b7c07af2.camel@mengyan1223.wang> <3c787bfed0fc49ba418b893b2057cbb7c3994508.camel@mengyan1223.wang> In-Reply-To: <3c787bfed0fc49ba418b893b2057cbb7c3994508.camel@mengyan1223.wang> From: Richard Biener Date: Fri, 29 Apr 2022 08:51:23 +0200 Message-ID: Subject: Re: [PING wwwdocs PATCH v2] document zero-width field ABI changes on MIPS To: Xi Ruoyao Cc: GCC Patches , Richard Sandiford , Jakub Jelinek , YunQiang Su Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-8.3 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 29 Apr 2022 06:51:37 -0000 On Thu, Apr 28, 2022 at 7:30 PM Xi Ruoyao via Gcc-patches wrote: > > Ping. OK. > On Wed, 2022-04-06 at 23:26 +0800, Xi Ruoyao via Gcc-patches wrote: > > Document ABI changes in r12-7961, 7962, and 8023. Ok for wwwdocs? > > > > --- > > htdocs/gcc-12/changes.html | 25 ++++++++++++++++++++++++- > > 1 file changed, 24 insertions(+), 1 deletion(-) > > > > diff --git a/htdocs/gcc-12/changes.html b/htdocs/gcc-12/changes.html > > index 4f2ee77f..c924bca3 100644 > > --- a/htdocs/gcc-12/changes.html > > +++ b/htdocs/gcc-12/changes.html > > @@ -50,6 +50,10 @@ a work-in-progress.

> > (so there is a C++ ABI incompatibility, GCC 4.4 and earlier compatible > > with GCC 12 or later, incompatible with GCC 4.5 through GCC 11). > > RISC-V has changed the handling of these already starting with GCC 10. > > + As the ABI requires, MIPS takes them into account handling function > > + return values so there is a C++ ABI incompatibility with GCC 4.5 > > + through 11. For function arguments on MIPS, refer to > > + the MIPS specific entry. > > GCC 12 on the above targets will report such incompatibilities as > > warnings or other diagnostics unless -Wno-psabi is used. > > > > @@ -549,7 +553,26 @@ a work-in-progress.

> > > > > > > > - > > +

MIPS

> > +
    > > +
  • The ABI passing arguments > > + containing zero-width fields (for example, C/C++ zero-width > > + bit-fields, GNU C/C++ zero-length arrays, and GNU C empty structs) > > + has changed. Now a zero-width field will not prevent an aligned > > + 64-bit floating-point field next to it from being passed through > > + FPR. This is compatible with LLVM, but incompatible with previous > > + GCC releases. GCC 12 on MIPS will report such incompatibilities as > > + an inform unless -Wno-psabi is used. > > +
    • > > +
  • The ABI returning values > > + containing C++17 empty bases has changed. Now an empty base will > > + not prevent an aggregate containing only one or two floating-point > > + fields from being returned through FPR. This is compatible with > > + GCC 6 and earlier, but incompatible with GCC 7 through 11. GCC 12 on > > + MIPS will report such incompatibilities as an inform unless > > + -Wno-psabi is used. > > +
    • > > +
> > > > > > > > -- > Xi Ruoyao > School of Aerospace Science and Technology, Xidian University