From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by sourceware.org (Postfix) with ESMTPS id 01A133858C66 for ; Wed, 10 May 2023 09:10:01 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 01A133858C66 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=1683709802; x=1715245802; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=rRVRofPh+Dy2h3QnlTIb0D1qexajDMQmt4TqwVAw1FE=; b=hvn2+WFW9LW/OtMYEZi1ijBupTKWiW1phhnUmeTKrvwKMzdTPML4h0SL MEgMOKtxS/dk5sOq0P19X+lgDY5td8Ttyc9KgSxejRvUTf+QJ191G7O3D VkW6Sg0jBWX7tjLKCYAbEQLR5UtbGgjUkpKIdWb/d3Th2ZsAInSdqaajq OfOTff+c0YAfeCiiCOOFZ8PZ14wmEpwzJuLGxrRdNRvNZKMilZt4N9aIA boXWXKYpbqNCqFW0GwwQsAZwuzyWI5tRf+LByBaNTxt/FxrvrLG2sYlVm OJwhfbL2AvuIfZwNzdD0C3xwIx4mACa8bYJM/lHziGLN0+hPm2utIuI0t g==; X-IronPort-AV: E=McAfee;i="6600,9927,10705"; a="330531334" X-IronPort-AV: E=Sophos;i="5.99,264,1677571200"; d="scan'208";a="330531334" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 May 2023 02:10:00 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10705"; a="1029134136" X-IronPort-AV: E=Sophos;i="5.99,264,1677571200"; d="scan'208";a="1029134136" Received: from shvmail03.sh.intel.com ([10.239.245.20]) by fmsmga005.fm.intel.com with ESMTP; 10 May 2023 02:09:59 -0700 Received: from shliclel4217.sh.intel.com (shliclel4217.sh.intel.com [10.239.240.127]) by shvmail03.sh.intel.com (Postfix) with ESMTP id 7751F10081D6; Wed, 10 May 2023 17:09:58 +0800 (CST) From: liuhongt To: gcc-patches@gcc.gnu.org Cc: crazylht@gmail.com, hjl.tools@gmail.com Subject: [PATCH] x86: Add a new option -mdaz-ftz to enable FTZ and DAZ flags in MXCSR. Date: Wed, 10 May 2023 17:07:58 +0800 Message-Id: <20230510090758.3737162-1-hongtao.liu@intel.com> X-Mailer: git-send-email 2.39.1.388.g2fc9e9ca3c In-Reply-To: References: 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,SPF_HELO_NONE,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE 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: > The quoted patch shows -shared in context and you didn't post a > backport version > to look at. But yes, we shouldn't change -shared behavior on a > branch, even less so make it > inconsistent between targets. Here's the patch. Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}. Ok for GCC 11/12 backport? if (mdaz-ftz) link crtfastmath.o else if ((Ofast || ffast-math || funsafe-math-optimizations) && !mno-daz-ftz) link crtfastmath.o else Don't link crtfastmath.o gcc/ChangeLog: * config/i386/cygwin.h (ENDFILE_SPEC): Link crtfastmath.o whenever -mdaz-ftz is specified. Don't link crtfastmath.o when -mno-daz-ftz is specified. * config/i386/darwin.h (ENDFILE_SPEC): Ditto. * config/i386/gnu-user-common.h (GNU_USER_TARGET_MATHFILE_SPEC): Ditto. * config/i386/mingw32.h (ENDFILE_SPEC): Ditto. * config/i386/i386.opt (mdaz-ftz): New option. * doc/invoke.texi (x86 options): Document mftz-daz. --- gcc/config/i386/cygwin.h | 2 +- gcc/config/i386/darwin.h | 4 ++-- gcc/config/i386/gnu-user-common.h | 2 +- gcc/config/i386/i386.opt | 4 ++++ gcc/config/i386/mingw32.h | 2 +- gcc/doc/invoke.texi | 11 ++++++++++- 6 files changed, 19 insertions(+), 6 deletions(-) diff --git a/gcc/config/i386/cygwin.h b/gcc/config/i386/cygwin.h index d06eda369cf..5412c5d4479 100644 --- a/gcc/config/i386/cygwin.h +++ b/gcc/config/i386/cygwin.h @@ -57,7 +57,7 @@ along with GCC; see the file COPYING3. If not see #undef ENDFILE_SPEC #define ENDFILE_SPEC \ - "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s}\ + "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz:crtfastmath.o%s}} \ %{!shared:%:if-exists(default-manifest.o%s)}\ %{fvtable-verify=none:%s; \ fvtable-verify=preinit:vtv_end.o%s; \ diff --git a/gcc/config/i386/darwin.h b/gcc/config/i386/darwin.h index a55f6b2b874..2f773924d6e 100644 --- a/gcc/config/i386/darwin.h +++ b/gcc/config/i386/darwin.h @@ -109,8 +109,8 @@ along with GCC; see the file COPYING3. If not see "%{!force_cpusubtype_ALL:-force_cpusubtype_ALL} " #undef ENDFILE_SPEC -#define ENDFILE_SPEC \ - "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \ +#define ENDFILE_SPEC +\ "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz:crtfastmath.o%s}} \ %{mpc32:crtprec32.o%s} \ %{mpc64:crtprec64.o%s} \ %{mpc80:crtprec80.o%s}" TM_DESTRUCTOR diff --git a/gcc/config/i386/gnu-user-common.h b/gcc/config/i386/gnu-user-common.h index 23b54c5be52..3d2a33f1714 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} \ + "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz: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 a3675e515bc..5cfb7cdcbc2 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 +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/config/i386/mingw32.h b/gcc/config/i386/mingw32.h index d3ca0cd0279..ddbe6a4054b 100644 --- a/gcc/config/i386/mingw32.h +++ b/gcc/config/i386/mingw32.h @@ -197,7 +197,7 @@ along with GCC; see the file COPYING3. If not see #undef ENDFILE_SPEC #define ENDFILE_SPEC \ - "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \ + "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz:crtfastmath.o%s}} \ %{!shared:%:if-exists(default-manifest.o%s)}\ %{fvtable-verify=none:%s; \ fvtable-verify=preinit:vtv_end.o%s; \ diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index cb83dd8a1cc..87eedfffa6c 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -1434,7 +1434,7 @@ 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 @@ -32078,6 +32078,15 @@ 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. Don't set FTZ/DAZ flags +when @option{-mno-daz-ftz} is specified. + @item -mstackrealign @opindex mstackrealign Realign the stack at entry. On the x86, the @option{-mstackrealign} -- 2.39.1.388.g2fc9e9ca3c