From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <joseph_myers@mentor.com>
Received: from esa2.mentor.iphmx.com (esa2.mentor.iphmx.com [68.232.141.98])
 by sourceware.org (Postfix) with ESMTPS id A751E3858C56
 for <gcc-patches@gcc.gnu.org>; Tue, 26 Jul 2022 21:42:47 +0000 (GMT)
DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org A751E3858C56
Authentication-Results: sourceware.org; dmarc=none (p=none dis=none)
 header.from=codesourcery.com
Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=mentor.com
X-IronPort-AV: E=Sophos;i="5.93,194,1654588800"; d="scan'208";a="80327215"
Received: from orw-gwy-02-in.mentorg.com ([192.94.38.167])
 by esa2.mentor.iphmx.com with ESMTP; 26 Jul 2022 13:42:46 -0800
IronPort-SDR: nuGZUeWnKM35PP+w8NgB6Ty/D2GisdCRIIknakp4NYCvprpb3224TXmwjNtDJH0U5avmZAn6uX
 YNMHbAjpd78ZevaSBz1s+KNkv08cNNI0padKEEnPWrBABEMdbCzvl/54qjKpinrauLV/g84fSc
 sIMTOQ41fxNhKiYkdY9OLJpZM+cJX5h6EHsiaiSITIaGw5fSraEd/2nXdWbNWygUkVva9ve9+2
 lHQxFckk+ea0wHL7GctrZz1Z99Y01wlBwWYDueQaBaKffmvEsnfNKOh+FUenPvR1YkW/xsiBCQ
 DI4=
Date: Tue, 26 Jul 2022 21:42:39 +0000
From: Joseph Myers <joseph@codesourcery.com>
X-X-Sender: jsm28@digraph.polyomino.org.uk
To: Kito Cheng <kito.cheng@sifive.com>
CC: <gcc-patches@gcc.gnu.org>, <kito.cheng@gmail.com>,
 <jim.wilson.gcc@gmail.com>, <palmer@dabbelt.com>, <andrew@sifive.com>,
 <juzhe.zhong@rivai.ai>
Subject: Re: [PATCH 1/2] RISC-V: Support _Float16 type.
In-Reply-To: <20220707085231.68930-2-kito.cheng@sifive.com>
Message-ID: <alpine.DEB.2.22.394.2207262138470.480542@digraph.polyomino.org.uk>
References: <20220707085231.68930-1-kito.cheng@sifive.com>
 <20220707085231.68930-2-kito.cheng@sifive.com>
User-Agent: Alpine 2.22 (DEB 394 2020-01-19)
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
X-Originating-IP: [137.202.0.90]
X-ClientProxiedBy: svr-ies-mbx-15.mgc.mentorg.com (139.181.222.15) To
 svr-ies-mbx-10.mgc.mentorg.com (139.181.222.10)
X-Spam-Status: No, score=-3112.2 required=5.0 tests=BAYES_00,
 HEADER_FROM_DIFFERENT_DOMAINS, KAM_DMARC_STATUS, RCVD_IN_MSPIKE_H2,
 SPF_HELO_PASS, SPF_PASS, TXREP autolearn=no autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) 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 <gcc-patches.gcc.gnu.org>
List-Unsubscribe: <https://gcc.gnu.org/mailman/options/gcc-patches>,
 <mailto:gcc-patches-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-patches/>
List-Post: <mailto:gcc-patches@gcc.gnu.org>
List-Help: <mailto:gcc-patches-request@gcc.gnu.org?subject=help>
List-Subscribe: <https://gcc.gnu.org/mailman/listinfo/gcc-patches>,
 <mailto:gcc-patches-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Tue, 26 Jul 2022 21:42:49 -0000

On Thu, 7 Jul 2022, Kito Cheng wrote:

> +/* Implement TARGET_MANGLE_TYPE.  */
> +
> +static const char *
> +riscv_mangle_type (const_tree type)
> +{
> +  /* Half-precision float.  */
> +  if (TREE_CODE (type) == REAL_TYPE && TYPE_PRECISION (type) == 16)
> +    return "Dh";

Are you sure you wish to use "Dh" instead of "DF16_" used on x86?  The C++ 
ABI lists both

                 ::= Dh # IEEE 754r half-precision floating point (16 bits)
                 ::= DF <number> _ # ISO/IEC TS 18661 binary floating point type _FloatN (N bits)

without distinguishing which should be used when - maybe the choice made 
for _Float16 on RISC-V needs documenting in the RISC-V psABI?

-- 
Joseph S. Myers
joseph@codesourcery.com