From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by sourceware.org (Postfix) with ESMTPS id 08E0F383A0F6 for ; Wed, 14 Dec 2022 02:20:45 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 08E0F383A0F6 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=intel.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1670984446; x=1702520446; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=dnC3erTQZPg2BvQcW1XX1TJeXk7R4AmzcKErBDGjOyU=; b=ZfoUj2MXWgK/d0/sROjnsX1uAsw4rvj6c60TIh9dhvX9wCwL+ZgBcBoA Fa3Flx2M/NX78OFwCr6zTAR04/bi6d3El4BRIsJ3U6k/KCbKtYSxSLyU6 0fbB9x/X8DxuZjjpKn5z6TMuzrYS3WZ7+sOLCDIOGVKQQ4Ufe54aFGNn2 +09hiSeCAb3xq1srPRqV9ar0ymjsOqWL89jAxDnocMnu0EPtX5KzWnq8m JOh/nexV9+tJiUIrjDdOdR+guPDZCvA4ZPE4SdE8rW0/fPl4IQv7gvEB2 4n6YbDl253tR91gQgFu1YFWTLmFd2kKokNMgpUJIqn7gdYZDwQlJfQA3T A==; X-IronPort-AV: E=McAfee;i="6500,9779,10560"; a="305933314" X-IronPort-AV: E=Sophos;i="5.96,243,1665471600"; d="scan'208";a="305933314" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Dec 2022 18:20:44 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10560"; a="755733763" X-IronPort-AV: E=Sophos;i="5.96,243,1665471600"; d="scan'208";a="755733763" Received: from shvmail03.sh.intel.com ([10.239.245.20]) by fmsmga002.fm.intel.com with ESMTP; 13 Dec 2022 18:20:43 -0800 Received: from shliclel4051.sh.intel.com (shliclel4051.sh.intel.com [10.239.240.51]) by shvmail03.sh.intel.com (Postfix) with ESMTP id 5D454100571F; Wed, 14 Dec 2022 10:20:42 +0800 (CST) From: liuhongt To: gcc-patches@gcc.gnu.org Cc: crazylht@gmail.com, hjl.tools@gmail.com, ubizjak@gmail.com Subject: [PATCH] [x86] x86: Don't add crtfastmath.o for -shared and add a new option -mdaz-ftz to enable FTZ and DAZ flags in MXCSR. Date: Wed, 14 Dec 2022 10:18:42 +0800 Message-Id: <20221214021842.1015348-1-hongtao.liu@intel.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-12.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Don't add crtfastmath.o for -shared to avoid changing the MXCSR register when loading a shared library. crtfastmath.o will be used only when building executables. Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}. Ok for trunk? gcc/ChangeLog: PR target/55522 PR target/36821 * config/i386/gnu-user-common.h (GNU_USER_TARGET_MATHFILE_SPEC): Link crtfastmath.o when -mdaz-ftz is specified, not link it when -shared is specified. * config/i386/i386.opt (mdaz-ftz): New option. * doc/invoke.texi (x86 options): Document mftz-daz. --- gcc/config/i386/gnu-user-common.h | 2 +- gcc/config/i386/i386.opt | 4 ++++ gcc/doc/invoke.texi | 10 +++++++++- 3 files changed, 14 insertions(+), 2 deletions(-) diff --git a/gcc/config/i386/gnu-user-common.h b/gcc/config/i386/gnu-user-common.h index cab9be2bfb7..02e4a2192a4 100644 --- a/gcc/config/i386/gnu-user-common.h +++ b/gcc/config/i386/gnu-user-common.h @@ -47,7 +47,7 @@ along with GCC; see the file COPYING3. If not see /* Similar to standard GNU userspace, but adding -ffast-math support. */ #define GNU_USER_TARGET_MATHFILE_SPEC \ - "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \ + "%{Ofast|ffast-math|funsafe-math-optimizations|mdaz-ftz:%{!shared:crtfastmath.o%s}} \ %{mpc32:crtprec32.o%s} \ %{mpc64:crtprec64.o%s} \ %{mpc80:crtprec80.o%s}" diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt index fb4e57ada7c..8fd222db857 100644 --- a/gcc/config/i386/i386.opt +++ b/gcc/config/i386/i386.opt @@ -420,6 +420,10 @@ mpc80 Target RejectNegative Set 80387 floating-point precision to 80-bit. +mdaz-ftz +Target RejectNegative +Set the FTZ and DAZ Flags. + mpreferred-stack-boundary= Target RejectNegative Joined UInteger Var(ix86_preferred_stack_boundary_arg) Attempt to keep stack aligned to this power of 2. diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index cb40b38b73a..670e3767fbd 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -1433,7 +1433,7 @@ See RS/6000 and PowerPC Options. -m96bit-long-double -mlong-double-64 -mlong-double-80 -mlong-double-128 @gol -mregparm=@var{num} -msseregparm @gol -mveclibabi=@var{type} -mvect8-ret-in-mem @gol --mpc32 -mpc64 -mpc80 -mstackrealign @gol +-mpc32 -mpc64 -mpc80 -mdaz-ftz -mstackrealign @gol -momit-leaf-frame-pointer -mno-red-zone -mno-tls-direct-seg-refs @gol -mcmodel=@var{code-model} -mabi=@var{name} -maddress-mode=@var{mode} @gol -m32 -m64 -mx32 -m16 -miamcu -mlarge-data-threshold=@var{num} @gol @@ -32752,6 +32752,14 @@ are enabled by default; routines in such libraries could suffer significant loss of accuracy, typically through so-called ``catastrophic cancellation'', when this option is used to set the precision to less than extended precision. +@item -mdaz-ftz +@opindex mdaz-ftz + +the flush-to-zero (FTZ) and denormals-are-zero (DAZ) flags in the MXCSR register +are used to control floating-point calculations.SSE and AVX instructions +including scalar and vector instructions could benefit from enabling the FTZ +and DAZ flags when @option{-mdaz-ftz} is specified. + @item -mstackrealign @opindex mstackrealign Realign the stack at entry. On the x86, the @option{-mstackrealign} -- 2.27.0