From patchwork Sat Sep 25 02:39:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: liuhongt X-Patchwork-Id: 1532615 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=gcc.gnu.org header.i=@gcc.gnu.org header.a=rsa-sha256 header.s=default header.b=yfnARxTl; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org (client-ip=8.43.85.97; helo=sourceware.org; envelope-from=gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org; receiver=) Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4HGY601hw3z9tk0 for ; Sat, 25 Sep 2021 12:40:06 +1000 (AEST) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 184BA3858428 for ; Sat, 25 Sep 2021 02:40:02 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 184BA3858428 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1632537602; bh=pRTFosdsEL3vmj9zARbkXJ4PpyU91YPSbDTTQBLJxwU=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=yfnARxTlbrICSflDfLn20QPzdp2w6IhlatYRSq/kEzBxbgMBx81ocWkN3ovQU0GX+ ElnRAdO4reIYf99qt3rRYMo0fk4wphmyKQIrjNVecrc/YJJrKXj/99ffKGung6re+9 3B2YFaw3IcOhBaB7j4/ZX58NHmQvkOqKV1kn7LWs= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by sourceware.org (Postfix) with ESMTPS id 0FBB43858403 for ; Sat, 25 Sep 2021 02:39:19 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 0FBB43858403 X-IronPort-AV: E=McAfee;i="6200,9189,10117"; a="309768059" X-IronPort-AV: E=Sophos;i="5.85,321,1624345200"; d="scan'208";a="309768059" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Sep 2021 19:39:18 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.85,321,1624345200"; d="scan'208";a="475370056" Received: from scymds01.sc.intel.com ([10.148.94.138]) by orsmga007.jf.intel.com with ESMTP; 24 Sep 2021 19:39:18 -0700 Received: from shliclel219.sh.intel.com (shliclel219.sh.intel.com [10.239.236.219]) by scymds01.sc.intel.com with ESMTP id 18P2dGTY012306; Fri, 24 Sep 2021 19:39:17 -0700 To: gcc-patches@gcc.gnu.org Subject: [PATCH] [i386] Remove storage only description for _Float16 w/o avx512fp16. Date: Sat, 25 Sep 2021 10:39:16 +0800 Message-Id: <20210925023916.2944122-1-hongtao.liu@intel.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Hi: as discussed in [1]. Bootstrapped on x86_64-linux-gnu{-m32, }. Push to trunk if there's no objection. X-Spam-Status: No, score=-11.5 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_DMARC_NONE, KAM_DMARC_STATUS, KAM_LAZY_DOMAIN_SECURITY, KAM_SHORT, SPF_HELO_NONE, SPF_NONE, 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-Patchwork-Original-From: liuhongt via Gcc-patches From: liuhongt Reply-To: liuhongt Errors-To: gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org Sender: "Gcc-patches" [1] https://gcc.gnu.org/pipermail/gcc-patches/2021-September/580207.html gcc/ChangeLog: * doc/extend.texi (Half-Precision): Remove storage only description for _Float16 w/o avx512fp16. --- gcc/doc/extend.texi | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index 9501a60f20e..79fa1bd4bf8 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -1156,12 +1156,11 @@ It is recommended that portable code use the @code{_Float16} type defined by ISO/IEC TS 18661-3:2015. @xref{Floating Types}. On x86 targets with SSE2 enabled, without @option{-mavx512fp16}, -@code{_Float16} type is storage only, all operations will be emulated by -software emulation and the @code{float} instructions. The default behavior -for @code{FLT_EVAL_METHOD} is to keep the intermediate result of the operation -as 32-bit precision. This may lead to inconsistent behavior between software -emulation and AVX512-FP16 instructions. Using @option{-fexcess-precision=16} -will force round back after each operation. +all operations will be emulated by software emulation and the @code{float} +instructions. The default behavior for @code{FLT_EVAL_METHOD} is to keep the +intermediate result of the operation as 32-bit precision. This may lead to +inconsistent behavior between software emulation and AVX512-FP16 instructions. +Using @option{-fexcess-precision=16} will force round back after each operation. Using @option{-mavx512fp16} will generate AVX512-FP16 instructions instead of software emulation. The default behavior of @code{FLT_EVAL_METHOD} is to round