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 2BE29393D79F; Mon, 12 Dec 2022 10:20:27 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 2BE29393D79F Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=linux.ibm.com Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 2BC8gchr006586; Mon, 12 Dec 2022 10:20:25 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : date : subject : references : from : to : cc : in-reply-to : content-type : content-transfer-encoding : mime-version; s=pp1; bh=9PX1SgFGvS5EVznl3OARpJ8T5YbPNFmwHrlq78Grwfw=; b=RRKJ0j65NZQDBlH8nqsMQXs6Iqaj3/ae9t9Esr3j8N10eIuMwCiWM5w0xppVMggFkYnM yxKcUkXphlZJKgAn5UD5MRrLozeY+Ni/IkqobSwrMy0UrZgSTQiG95ovHTrK6BEPQiJh C1Z91pREvvsL60YcX+O0kPoAF+JbKfgGkW8B27rJ4aACpJ9nvY6KzbcLrF92AC2w5GNk M1hiC1/ClQJeUJAJq25AhZyi3ZWD+U4ZvlFPRUD0KVAvvxY845mYmpzyvtygAgjL/Umf I+cKeXgz4nxBCo1sPBABDDUJUkt/gsEX6MsaYhCvqOlqXnpjuln3MYDS+iHNCGEIDtq4 KA== Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com (PPS) with ESMTPS id 3md421da00-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 12 Dec 2022 10:20:25 +0000 Received: from m0098420.ppops.net (m0098420.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 2BCA2XdW011499; Mon, 12 Dec 2022 10:20:25 GMT Received: from ppma03fra.de.ibm.com (6b.4a.5195.ip4.static.sl-reverse.com [149.81.74.107]) by mx0b-001b2d01.pphosted.com (PPS) with ESMTPS id 3md421d9y6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 12 Dec 2022 10:20:25 +0000 Received: from pps.filterd (ppma03fra.de.ibm.com [127.0.0.1]) by ppma03fra.de.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 2BC00CH4030674; Mon, 12 Dec 2022 10:20:23 GMT Received: from smtprelay03.fra02v.mail.ibm.com ([9.218.2.224]) by ppma03fra.de.ibm.com (PPS) with ESMTPS id 3mchr5sru1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 12 Dec 2022 10:20:23 +0000 Received: from smtpav02.fra02v.mail.ibm.com (smtpav02.fra02v.mail.ibm.com [10.20.54.101]) by smtprelay03.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 2BCAKIdI31981958 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 12 Dec 2022 10:20:19 GMT Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BA3A720077; Mon, 12 Dec 2022 10:20:18 +0000 (GMT) Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 15FA120078; Mon, 12 Dec 2022 10:20:16 +0000 (GMT) Received: from [9.200.41.74] (unknown [9.200.41.74]) by smtpav02.fra02v.mail.ibm.com (Postfix) with ESMTP; Mon, 12 Dec 2022 10:20:15 +0000 (GMT) Message-ID: Date: Mon, 12 Dec 2022 18:20:14 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [PATCH 1/3] Rework 128-bit complex multiply and divide, PR target/107299 Content-Language: en-US References: <997752a6-8cd4-abc5-d6e3-2e75eaa37d57@linux.ibm.com> From: "Kewen.Lin" To: Michael Meissner Cc: gcc-patches@gcc.gnu.org, Segher Boessenkool , David Edelsohn , William Seurer , Will Schmidt , Peter Bergner In-Reply-To: Content-Type: text/plain; charset=UTF-8 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: oqWZaAiys64pDwWqZWPob80-tXn3Exwe X-Proofpoint-GUID: D5iHbwWetDwsRnwGQKLacZcGOcaQ05fi Content-Transfer-Encoding: 8bit X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.923,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-12-12_02,2022-12-08_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 suspectscore=0 spamscore=0 clxscore=1015 bulkscore=0 mlxlogscore=701 impostorscore=0 phishscore=0 priorityscore=1501 adultscore=0 malwarescore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2210170000 definitions=main-2212120093 X-Spam-Status: No, score=-4.0 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_EF,KAM_NUMSUBJECT,KAM_SHORT,NICE_REPLY_A,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS,TXREP,WEIRD_PORT autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: on 2022/12/9 06:04, Michael Meissner wrote: > On Wed, Dec 07, 2022 at 03:55:41PM +0800, Kewen.Lin wrote: >> Hi Mike, >> >> on 2022/12/7 14:44, Michael Meissner wrote: >>> On Tue, Dec 06, 2022 at 05:36:54PM +0800, Kewen.Lin wrote: >>>> Hi Mike, >>>> >>>> Thanks for fixing this! >>>> >>>> Could you help to elaborate why we need to disable it during libgcc building? >>> >>> When you are building libgcc, you are building the __mulkc3, __divkc3 >>> functions. The mapping in the compiler interferes with those functions, >>> because at the moment, libgcc uses an alternate IEEE 128-bit type. >>> >> >> But I'm still confused. For __mulkc3 (__divkc3 is similar), >> >> 1) with -mabi=ieeelongdouble (TARGET_IEEEQUAD true, define __LONG_DOUBLE_IEEE128__), >> the used types are: >> >> typedef float TFtype __attribute__ ((mode (TF))); >> typedef __complex float TCtype __attribute__ ((mode (TC))); >> >> 2) with -mabi=ibmlongdouble (TARGET_IEEEQUAD false, not __LONG_DOUBLE_IEEE128__ defined), >> the used types are: >> >> typedef float TFtype __attribute__ ((mode (KF))); >> typedef __complex float TCtype __attribute__ ((mode (KC))); >> >> The proposed mapping in the current patch is: >> >> + >> + if (id == complex_multiply_builtin_code (KCmode)) >> + newname = "__mulkc3"; >> + >> + else if (id == complex_multiply_builtin_code (ICmode)) >> + newname = "__multc3"; >> + >> + else if (id == complex_multiply_builtin_code (TCmode)) >> + newname = (TARGET_IEEEQUAD) ? "__mulkc3" : "__multc3"; >> >> for 1), TCmode && TARGET_IEEEQUAD => "__mulkc3" >> for 2), KCmode => "__mulkc3" >> >> Both should be still with name "__mulkc3", do I miss anything? >> >> BR, >> Kewen > > The reason is due to the different internal types, the value range propigation > pass throws an error when we are trying to build libgcc. This is due to the > underlying problem of different IEEE 128-bit types within the compiler. > But this is the reason why we need patch #2 and #3, not the reason why we need the special handling for building_libgcc in patch #1, right? Without or with patch #1, the below ICE in libgcc exists, the ICE should have nothing to do with the special handling for building_libgcc in patch #1. I think patch #2 which makes _Float128 and __float128 use the same internal type fixes that ICE. I still don't get the point why we need the special handling for building_libgcc, I also tested on top of patch #1 and #2 w/ and w/o the special handling for building_libgcc, both bootstrapped and regress-tested. Could you have a double check? > The 128-bit IEEE support in libgcc was written before _Float128 was added to > GCC. One consequence is that you can't get to the complex variant of > __float128. So libgcc needs to use the attribute mode to get to that type. > > But with the support for IEEE 128-bit long double changing things, it makes the > libgcc code use the wrong code. > > /home/meissner/fsf-src/work102/libgcc/config/rs6000/_mulkc3.c: In function ‘__mulkc3_sw’: > /home/meissner/fsf-src/work102/libgcc/config/rs6000/_mulkc3.c:97:1: internal compiler error: in fold_stmt, at gimple-range-fold.cc:522 > 97 | } > | ^ > 0x122784f3 fold_using_range::fold_stmt(vrange&, gimple*, fur_source&, tree_node*) > /home/meissner/fsf-src/work102/gcc/gimple-range-fold.cc:522 > 0x1226477f gimple_ranger::fold_range_internal(vrange&, gimple*, tree_node*) > /home/meissner/fsf-src/work102/gcc/gimple-range.cc:257 > 0x12264b1f gimple_ranger::range_of_stmt(vrange&, gimple*, tree_node*) > /home/meissner/fsf-src/work102/gcc/gimple-range.cc:318 > 0x113bdd8b range_query::value_of_stmt(gimple*, tree_node*) > /home/meissner/fsf-src/work102/gcc/value-query.cc:134 > 0x1134838f rvrp_folder::value_of_stmt(gimple*, tree_node*) > /home/meissner/fsf-src/work102/gcc/tree-vrp.cc:1023 > 0x111344cf substitute_and_fold_dom_walker::before_dom_children(basic_block_def*) > /home/meissner/fsf-src/work102/gcc/tree-ssa-propagate.cc:819 > 0x121ecbd3 dom_walker::walk(basic_block_def*) > /home/meissner/fsf-src/work102/gcc/domwalk.cc:311 > 0x11134ee7 substitute_and_fold_engine::substitute_and_fold(basic_block_def*) > /home/meissner/fsf-src/work102/gcc/tree-ssa-propagate.cc:998 > 0x11346bb7 execute_ranger_vrp(function*, bool, bool) > /home/meissner/fsf-src/work102/gcc/tree-vrp.cc:1084 > 0x11347063 execute > /home/meissner/fsf-src/work102/gcc/tree-vrp.cc:1165 > Please submit a full bug report, with preprocessed source (by using -freport-bug). > Please include the complete backtrace with any bug report. > See for instructions. > make[1]: *** [/home/meissner/fsf-src/work102/libgcc/shared-object.mk:14: _mulkc3.o] Error 1 > make[1]: Leaving directory '/home/meissner/fsf-build-ppc64le/work102/powerpc64le-unknown-linux-gnu/libgcc' > make: *** [Makefile:20623: all-target-libgcc] Error 2 > >>> I have a patch for making libgcc use the 'right' type that I haven't submitted >>> yet. This is because the more general fix that these 3 patches do impacts other >>> functions (due to __float128 and _Float128 being different in the current >>> compiler when -mabi=ieeelongdouble). >>> > > The patch is to use _Float128 and _Complex _Float128 in libgcc.h instead of > trying to use attribute((mode(TF))) and attribute((mode(TC))) in libgcc. > Since your patch #2 (and #3) fixes ICE and some exposed problems, and _Float128 is to use the same internal type as __float128, types with attribute((mode(TF))) and attribute((mode(TC))) should be correct, I assume that this patch is just to make the types explicit be with _Float128 (for better readability and maintainance), but not for any correctness issues. > Now, this patch fixes the specific problem of not being able to build libgcc > (along with patch #1 of the series). But other things show the differences > from time time because we are using different internal types and the middle end > doesn't know that these types are really the same bits. > > It is better long term (IMHO) if we have the two types (__float128 and > _Float128) use the same internal type (which is what is done in patches #2 and > #3). This fixes the other issues that show up, such as creating signaling NaNs > for one internal type, and converting it to the other internal type, loses that > the NaN is signalling. > I see, nice! BR, Kewen