From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by sourceware.org (Postfix) with ESMTPS id 4AE56385782A for ; Mon, 4 Jan 2021 23:20:30 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 4AE56385782A Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 104N1hq9122433 for ; Mon, 4 Jan 2021 18:20:30 -0500 Received: from ppma02dal.us.ibm.com (a.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.10]) by mx0b-001b2d01.pphosted.com with ESMTP id 35vaqnjm7c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 04 Jan 2021 18:20:29 -0500 Received: from pps.filterd (ppma02dal.us.ibm.com [127.0.0.1]) by ppma02dal.us.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 104NI0XG004670 for ; Mon, 4 Jan 2021 23:20:29 GMT Received: from b01cxnp23034.gho.pok.ibm.com (b01cxnp23034.gho.pok.ibm.com [9.57.198.29]) by ppma02dal.us.ibm.com with ESMTP id 35tgf960a3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 04 Jan 2021 23:20:29 +0000 Received: from b01ledav001.gho.pok.ibm.com (b01ledav001.gho.pok.ibm.com [9.57.199.106]) by b01cxnp23034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 104NKSRK44564838 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 4 Jan 2021 23:20:28 GMT Received: from b01ledav001.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6E1CF2805A; Mon, 4 Jan 2021 23:20:28 +0000 (GMT) Received: from b01ledav001.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 355DB28058; Mon, 4 Jan 2021 23:20:28 +0000 (GMT) Received: from [9.85.179.155] (unknown [9.85.179.155]) by b01ledav001.gho.pok.ibm.com (Postfix) with ESMTP; Mon, 4 Jan 2021 23:20:28 +0000 (GMT) Subject: Re: [PATCH] powerpc: Add optimized ilogbf128 for POWER9 To: Raphael Moreira Zinsly , libc-alpha@sourceware.org Cc: tuliom@linux.ibm.com References: <20201222153039.17722-1-rzinsly@linux.ibm.com> From: Paul E Murphy Message-ID: <0214e95f-54ee-79f3-23b1-3825b74e6fef@linux.ibm.com> Date: Mon, 4 Jan 2021 17:20:27 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20201222153039.17722-1-rzinsly@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.343, 18.0.737 definitions=2021-01-04_14:2021-01-04, 2021-01-04 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 bulkscore=0 phishscore=0 mlxscore=0 lowpriorityscore=0 malwarescore=0 suspectscore=0 clxscore=1011 impostorscore=0 priorityscore=1501 spamscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2101040134 X-Spam-Status: No, score=-12.2 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_EF, GIT_PATCH_0, KAM_NUMSUBJECT, NICE_REPLY_A, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H2, 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: Mon, 04 Jan 2021 23:20:31 -0000 On 12/22/20 9:30 AM, Raphael Moreira Zinsly via Libc-alpha wrote: > The instruction xsxexpqp introduced on POWER9 extracts the exponent > from a quad-precision floating-point, thus it can be used to improve > ilogbf128 and llogbf128. > --- > .../powerpc/powerpc64/le/fpu/e_ilogbf128.c | 22 +++++++++++++++++++ > 1 file changed, 22 insertions(+) > create mode 100644 sysdeps/powerpc/powerpc64/le/fpu/e_ilogbf128.c > > diff --git a/sysdeps/powerpc/powerpc64/le/fpu/e_ilogbf128.c b/sysdeps/powerpc/powerpc64/le/fpu/e_ilogbf128.c > new file mode 100644 > index 0000000000..47558bbadc > --- /dev/null > +++ b/sysdeps/powerpc/powerpc64/le/fpu/e_ilogbf128.c > @@ -0,0 +1,22 @@ > +#ifdef _ARCH_PWR9 > +int _ilogbf128 (_Float128 __x); This should be a locally (static) scoped function. > + > +int > +#if defined(_F128_ENABLE_IFUNC) > +__ieee754_ilogbf128_power9 (_Float128 __x) > +#else > +__ieee754_ilogbf128 (_Float128 __x) > +#endif > +{ > + /* Check for exceptional cases. */ > + if (!__builtin_vsx_scalar_test_data_class_qp (__x, 0x7f)) > + return __builtin_vsx_scalar_extract_expq (__x) - 0x3fff; > + else > + /* Fallback to the generic ilogb if __x is NaN, Inf or subnormal. */ > + return _ilogbf128(__x); > +} > + > +#define __ieee754_ilogbf128 _ilogbf128 > +#endif > + > +#include A space seems to be missing between include and <. Otherwise, LGTM. As a side note, I think the benchtests are not too impressive. I am surprised normal values don't show better results.