[v5,02/12] LoongArch Port: gcc build

diff --git a/gcc/common/config/loongarch/loongarch-common.cc b/gcc/common/config/loongarch/loongarch-common.cc
new file mode 100644
index 00000000000..1d6f370a013
--- /dev/null
+++ b/gcc/common/config/loongarch/loongarch-common.cc
@@ -0,0 +1,73 @@ 
+/* Common hooks for LoongArch.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "common/common-target.h"
+#include "common/common-target-def.h"
+#include "opts.h"
+#include "flags.h"
+#include "diagnostic-core.h"
+
+#undef	TARGET_OPTION_OPTIMIZATION_TABLE
+#define TARGET_OPTION_OPTIMIZATION_TABLE loongarch_option_optimization_table
+
+/* Set default optimization options.  */
+static const struct default_options loongarch_option_optimization_table[] =
+{
+  { OPT_LEVELS_ALL, OPT_fasynchronous_unwind_tables, NULL, 1 },
+  { OPT_LEVELS_NONE, 0, NULL, 0 }
+};
+
+/* Implement TARGET_HANDLE_OPTION.  */
+
+static bool
+loongarch_handle_option (struct gcc_options *opts,
+			 struct gcc_options *opts_set ATTRIBUTE_UNUSED,
+			 const struct cl_decoded_option *decoded,
+			 location_t loc ATTRIBUTE_UNUSED)
+{
+  size_t code = decoded->opt_index;
+  int value = decoded->value;
+
+  switch (code)
+    {
+    case OPT_mmemcpy:
+      if (value)
+	{
+	  if (opts->x_optimize_size)
+	    opts->x_target_flags |= MASK_MEMCPY;
+	}
+      else
+	opts->x_target_flags &= ~MASK_MEMCPY;
+      return true;
+
+    default:
+      return true;
+    }
+}
+
+#undef TARGET_DEFAULT_TARGET_FLAGS
+#define TARGET_DEFAULT_TARGET_FLAGS	MASK_CHECK_ZERO_DIV
+#undef TARGET_HANDLE_OPTION
+#define TARGET_HANDLE_OPTION loongarch_handle_option
+
+struct gcc_targetm_common targetm_common = TARGETM_COMMON_INITIALIZER;
diff --git a/gcc/config.gcc b/gcc/config.gcc
index 2c4266ce7b0..ab1f97ce487 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -454,6 +454,13 @@  mips*-*-*)
 	extra_objs="frame-header-opt.o"
 	extra_options="${extra_options} g.opt fused-madd.opt mips/mips-tables.opt"
 	;;
+loongarch*-*-*)
+	cpu_type=loongarch
+	extra_headers="larchintrin.h"
+	extra_objs="loongarch-c.o loongarch-builtins.o loongarch-cpu.o loongarch-opts.o loongarch-def.o"
+	extra_gcc_objs="loongarch-driver.o loongarch-cpu.o loongarch-opts.o loongarch-def.o"
+	extra_options="${extra_options} g.opt fused-madd.opt"
+	;;
 nds32*)
 	cpu_type=nds32
 	extra_headers="nds32_intrinsic.h nds32_isr.h nds32_init.inc"
@@ -2494,6 +2501,20 @@  riscv*-*-freebsd*)
 	# automatically detect that GAS supports it, yet we require it.
 	gcc_cv_initfini_array=yes
 	;;
+
+loongarch*-*-linux*)
+	tm_file="dbxelf.h elfos.h gnu-user.h linux.h linux-android.h glibc-stdint.h ${tm_file}"
+	tm_file="${tm_file} loongarch/gnu-user.h loongarch/linux.h"
+	extra_options="${extra_options} linux-android.opt"
+	tmake_file="${tmake_file} loongarch/t-linux"
+	gnu_ld=yes
+	gas=yes
+
+	# Force .init_array support.  The configure script cannot always
+	# automatically detect that GAS supports it, yet we require it.
+	gcc_cv_initfini_array=yes
+	;;
+
 mips*-*-netbsd*)			# NetBSD/mips, either endian.
 	target_cpu_default="MASK_ABICALLS"
 	tm_file="elfos.h ${tm_file} mips/elf.h ${nbsd_tm_file} mips/netbsd.h"
@@ -3600,7 +3621,7 @@  case ${target} in
         ;;
 *-*-linux* | *-*-gnu*)
 	case ${target} in
-	aarch64*-* | arm*-* | i[34567]86-* | powerpc*-* | s390*-* | sparc*-* | x86_64-*)
+	aarch64*-* | arm*-* | i[34567]86-* | powerpc*-* | s390*-* | sparc*-* | x86_64-* | loongarch*-*)
 		default_gnu_indirect_function=yes
 		;;
 	esac
@@ -4930,6 +4951,348 @@  case "${target}" in
 		esac
 		;;
 
+	loongarch*-*-*)
+		supported_defaults="abi arch tune fpu"
+
+		# Local variables
+		unset \
+			abi_pattern      abi_default    \
+			abiext_pattern   abiext_default \
+			arch_pattern     arch_default   \
+			fpu_pattern      fpu_default    \
+			tune_pattern     tune_default   \
+			triplet_os       triplet_abi
+
+		# Inferring ABI from the triplet.
+		case ${target} in
+		loongarch64-*-*-*f64)
+			abi_pattern="lp64d"
+			triplet_abi="f64"
+			;;
+		loongarch64-*-*-*f32)
+			abi_pattern="lp64f"
+			triplet_abi="f32"
+			;;
+		loongarch64-*-*-*sf)
+			abi_pattern="lp64s"
+			triplet_abi="sf"
+			;;
+		loongarch64-*-*-*)
+			abi_pattern="lp64[dfs]"
+			abi_default="lp64d"
+			triplet_abi=""
+			;;
+		*)
+			echo "Unsupported target ${target}." 1>&2
+			exit 1
+			;;
+		esac
+
+		abiext_pattern="*"
+		abiext_default="base"
+		triplet_abi+=""
+
+		# Getting the canonical triplet (multiarch specifier).
+		case ${target} in
+		  *-linux-gnu*)  triplet_os="linux-gnu";;
+		  *-linux-musl*) triplet_os="linux-musl";;
+		  *)
+			  echo "Unsupported target ${target}." 1>&2
+			  exit 1
+			  ;;
+		esac
+
+		la_canonical_triplet="loongarch64-${triplet_os}${triplet_abi}"
+
+		## Setting default value for with_abi.
+		case ${with_abi} in
+		"")
+			if test x${abi_default} != x; then
+				with_abi=${abi_default}
+			else
+				with_abi=${abi_pattern}
+			fi
+			;;
+
+		*)
+			if echo "${with_abi}" | grep -E "^${abi_pattern}$"; then
+				: # OK
+			else
+				echo "Incompatible options:" \
+				"--with-abi=${with_abi} and --target=${target}." 1>&2
+				exit 1
+			fi
+			;;
+		esac
+
+		## Setting default value for with_abiext (internal)
+		case ${with_abiext} in
+		"")
+			if test x${abiext_default} != x; then
+				with_abiext=${abiext_default}
+			else
+				with_abiext=${abiext_pattern}
+			fi
+			;;
+
+		*)
+			if echo "${with_abiext}" | grep -E "^${abiext_pattern}$"; then
+				: # OK
+			else
+				echo "The ABI extension type \"${with_abiext}\"" \
+				"is incompatible with --target=${target}." 1>&2
+				exit 1
+			fi
+
+			;;
+		esac
+
+
+		# Inferring ISA-related default options from the ABI: pass 1
+		case ${with_abi}/${with_abiext} in
+		lp64*/base)
+			# architectures that support lp64* ABI
+			arch_pattern="native|loongarch64|la464"
+			# default architecture for lp64* ABI
+			arch_default="loongarch64"
+			;;
+		*)
+			echo "Unsupported ABI type ${with_abi}/${with_abiext}." 1>&2
+			exit 1
+			;;
+		esac
+
+		# Inferring ISA-related default options from the ABI: pass 2
+		case ${with_abi}/${with_abiext} in
+		lp64d/base)
+			fpu_pattern="64"
+			;;
+		lp64f/base)
+			fpu_pattern="32|64"
+			fpu_default="32"
+			;;
+		lp64s/base)
+			fpu_pattern="none|32|64"
+			fpu_default="none"
+			;;
+		*)
+			echo "Unsupported ABI type ${with_abi}/${with_abiext}." 1>&2
+			exit 1
+			;;
+		esac
+
+		## Setting default value for with_arch.
+		case ${with_arch} in
+		"")
+			if test x${arch_default} != x; then
+				with_arch=${arch_default}
+			else
+				with_arch=${arch_pattern}
+			fi
+			;;
+
+		*)
+			if echo "${with_arch}" | grep -E "^${arch_pattern}$"; then
+				: # OK
+			else
+				echo "${with_abi}/${with_abiext} ABI cannot be implemented with" \
+				"--with-arch=${with_arch}." 1>&2
+				exit 1
+			fi
+			;;
+		esac
+
+		## Setting default value for with_fpu.
+		if test x${with_fpu} == xnone; then
+			with_fpu="0"
+		fi
+
+		case ${with_fpu} in
+		"")
+			if test x${fpu_default} != x; then
+				with_fpu=${fpu_default}
+			else
+				with_fpu=${fpu_pattern}
+			fi
+			;;
+
+		*)
+			if echo "${with_fpu}" | grep -E "^${fpu_pattern}$"; then
+				: # OK
+			else
+				echo "${with_abi}/${with_abiext} ABI cannot be implemented with" \
+				"--with-fpu=${with_fpu}." 1>&2
+				exit 1
+			fi
+			;;
+		esac
+
+
+		# Inferring default with_tune from with_arch: pass 1
+		case ${with_arch} in
+		native)
+			tune_pattern="*"
+			tune_default="native"
+			;;
+		loongarch64)
+			tune_pattern="loongarch64 | la464"
+			tune_default="la464"
+			;;
+		*)
+			# By default, $with_tune == $with_arch
+			tune_pattern="$with_arch"
+			;;
+		esac
+
+		## Setting default value for with_tune.
+		case ${with_tune} in
+		"")
+			if test x${tune_default} != x; then
+				with_tune=${tune_default}
+			else
+				with_tune=${tune_pattern}
+			fi
+			;;
+
+		*)
+			if echo "${with_tune}" | grep -E "^${tune_pattern}$"; then
+				: # OK
+			else
+				echo "Incompatible options: --with-tune=${with_tune}" \
+				"and --with-arch=${with_arch}." 1>&2
+				exit 1
+			fi
+			;;
+		esac
+
+
+		# Perform final sanity checks.
+		case ${with_arch} in
+		loongarch64 | la464) ;; # OK, append here.
+		native)
+			if test x${host} != x${target}; then
+				echo "--with-arch=native is illegal for cross-compiler." 1>&2
+				exit 1
+			fi
+			;;
+		"")
+			echo "Please set a default value for \${with_arch}" \
+			     "according to your target triplet \"${target}\"." 1>&2
+			exit 1
+			;;
+		*)
+			echo "Unknown arch in --with-arch=$with_arch" 1>&2
+			exit 1
+			;;
+		esac
+
+		case ${with_abi} in
+		lp64d | lp64f | lp64s) ;; # OK, append here.
+		*)
+			echo "Unsupported ABI given in --with-abi=$with_abi" 1>&2
+			exit 1
+			;;
+		esac
+
+		case ${with_abiext} in
+		base) ;; # OK, append here.
+		*)
+			echo "Unsupported ABI extention type $with_abiext" 1>&2
+			exit 1
+			;;
+		esac
+
+		case ${with_fpu} in
+		none | 32 | 64) ;; # OK, append here.
+		*)
+			echo "Unknown fpu type in --with-fpu=$with_fpu" 1>&2
+			exit 1
+			;;
+		esac
+
+		# Handle --with-multilib-list.
+		if test x${with_multilib_list} == x \
+		   || test x${with_multilib_list} == xno \
+		   || test x${with_multilib_list} == xdefault \
+		   || test x${enable_multilib} != xyes; then
+
+			with_multilib_list="${with_abi}/${with_abiext}"
+		fi
+
+		# Check if the configured default ABI combination is included in
+		# ${with_multilib_list}.
+		loongarch_multilib_list_sane=no
+
+		# This one goes to TM_MULTILIB_CONFIG, for use in t-linux.
+		loongarch_multilib_list_make=""
+
+		# This one goes to tm_defines, for use in loongarch-driver.c.
+		loongarch_multilib_list_c=""
+
+		for e in $(tr ',' ' ' <<< "${with_multilib_list}"); do
+			e=($(tr '/' ' ' <<< "$e"))
+
+			# Base ABI type
+			case ${e[0]} in
+			lp64d) loongarch_multilib_list_c+="ABI_BASE_LP64D,";;
+			lp64f) loongarch_multilib_list_c+="ABI_BASE_LP64F,";;
+			lp64s) loongarch_multilib_list_c+="ABI_BASE_LP64S,";;
+			*)
+				echo "Unknown base ABI \"${e[0]}\" in --with-multilib-list." 1>&2
+				exit 1
+				;;
+			esac
+			loongarch_multilib_list_make+="mabi=${e[0]}"
+
+			# ABI extension type
+			case ${e[1]} in
+			"" | base)
+				loongarch_multilib_list_make+=""
+				loongarch_multilib_list_c+="ABI_EXT_BASE,"
+				e[1]="base"
+				;;
+			*)
+				echo "Unknown ABI extension \"${e[1]}\" in --with-multilib-list." 1>&2
+				exit 1
+				;;
+			esac
+
+			case ${e[2]} in
+			"") ;; # OK
+			*)
+				echo "Unknown ABI in --with-multilib-list." 1>&2
+				exit 1
+				;;
+			esac
+
+			if test x${with_abi} != x && test x${with_abiext} != x; then
+				if test x${e[0]} == x${with_abi} \
+				&& test x${e[1]} == x${with_abiext}; then
+					loongarch_multilib_list_sane=yes
+				fi
+			fi
+
+			loongarch_multilib_list_make+=","
+		done
+
+		# Check if the default ABI combination is in the default list.
+		if test x${loongarch_multilib_list_sane} == xno; then
+			if test x${with_abiext} == xbase; then
+				with_abiext=""
+			else
+				with_abiext="/${with_abiext}"
+			fi
+
+			echo "Default ABI combination (${with_abi}${with_abiext})" \
+			"not found in --with-multilib-list." 1>&2
+			exit 1
+		fi
+
+		# Remove the excessive appending comma.
+		loongarch_multilib_list_c=${loongarch_multilib_list_c:0:-1}
+		loongarch_multilib_list_make=${loongarch_multilib_list_make:0:-1}
+		;;
+
 	nds32*-*-*)
 		supported_defaults="arch cpu nds32_lib float fpu_config"
 
@@ -5367,6 +5730,51 @@  case ${target} in
 		tmake_file="mips/t-mips $tmake_file"
 		;;
 
+	loongarch*-*-*)
+		# Export canonical triplet.
+		tm_defines+=" LA_MULTIARCH_TRIPLET=${la_canonical_triplet}"
+
+		# Define macro __DISABLE_MULTILIB if --disable-multilib
+		tm_defines+=" TM_MULTILIB_LIST=${loongarch_multilib_list_c}"
+		if test x$enable_multilib == xyes; then
+			TM_MULTILIB_CONFIG="${loongarch_multilib_list_make}"
+		else
+			tm_defines+=" __DISABLE_MULTILIB"
+		fi
+
+		# Let --with- flags initialize the enum variables from loongarch.opt.
+		# See macro definitions from loongarch-opts.h and loongarch-cpu.h.
+		case ${with_arch} in
+		native)		tm_defines+=" DEFAULT_CPU_ARCH=CPU_NATIVE" ;;
+		la464)		tm_defines+=" DEFAULT_CPU_ARCH=CPU_LA464" ;;
+		loongarch64)	tm_defines+=" DEFAULT_CPU_ARCH=CPU_LOONGARCH64" ;;
+		esac
+
+		case ${with_tune} in
+		native)		tm_defines+=" DEFAULT_CPU_TUNE=CPU_NATIVE" ;;
+		la464)		tm_defines+=" DEFAULT_CPU_TUNE=CPU_LA464" ;;
+		loongarch64)	tm_defines+=" DEFAULT_CPU_TUNE=CPU_LOONGARCH64" ;;
+		esac
+
+		case ${with_abi} in
+		lp64d)     tm_defines+=" DEFAULT_ABI_BASE=ABI_BASE_LP64D" ;;
+		lp64f)     tm_defines+=" DEFAULT_ABI_BASE=ABI_BASE_LP64F" ;;
+		lp64s)     tm_defines+=" DEFAULT_ABI_BASE=ABI_BASE_LP64S" ;;
+		esac
+
+		case ${with_abiext} in
+		base)      tm_defines+=" DEFAULT_ABI_EXT=ABI_EXT_BASE" ;;
+		esac
+
+		case ${with_fpu} in
+		none)    tm_defines="$tm_defines DEFAULT_ISA_EXT_FPU=ISA_EXT_NOFPU" ;;
+		32)      tm_defines="$tm_defines DEFAULT_ISA_EXT_FPU=ISA_EXT_FPU32" ;;
+		64)      tm_defines="$tm_defines DEFAULT_ISA_EXT_FPU=ISA_EXT_FPU64" ;;
+		esac
+
+		tmake_file="loongarch/t-loongarch $tmake_file"
+		;;
+
 	powerpc*-*-* | rs6000-*-*)
 		# FIXME: The PowerPC port uses the value set at compile time,
 		# although it's only cosmetic.
diff --git a/gcc/config/loongarch/genopts/genstr.sh b/gcc/config/loongarch/genopts/genstr.sh
new file mode 100755
index 00000000000..62a0a0770a2
--- /dev/null
+++ b/gcc/config/loongarch/genopts/genstr.sh
@@ -0,0 +1,91 @@ 
+#!/bin/sh
+# A simple script that generates loongarch-str.h and loongarch.opt
+# from genopt/loongarch-optstr.
+#
+# Copyright (C) 2021 Free Software Foundation, Inc.
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free
+# Software Foundation; either version 3, or (at your option) any later
+# version.
+#
+# GCC is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+# or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+# License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+cd "$(dirname "$0")"
+
+# Generate a header containing definitions from the string table.
+gen_defines() {
+    cat <<EOF
+/* Generated automatically by "genstr" from "loongarch-strings".
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   Contributed by Loongson Ltd.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef LOONGARCH_STR_H
+#define LOONGARCH_STR_H
+EOF
+
+    sed -e '/^$/n' -e 's@#.*$@@' -e '/^$/d' \
+	-e 's@^\([^ \t]\+\)[ \t]*\([^ \t]*\)@#define \1 "\2"@' \
+	loongarch-strings
+
+    echo
+    echo "#endif /* LOONGARCH_STR_H */"
+}
+
+
+# Substitute all "@@<KEY>@@" to "<VALUE>" in loongarch.opt.in
+# according to the key-value pairs defined in loongarch-strings.
+
+gen_options() {
+
+    sed -e '/^$/n' -e 's@#.*$@@' -e '/^$/d' \
+	-e 's@^\([^ \t]\+\)[ \t]*\([^ \t]*\)@\1="\2"@' \
+	loongarch-strings | { \
+
+	# read the definitions
+	while read -r line; do
+	    eval "$line"
+	done
+
+	# make the substitutions
+	sed -e 's@"@\\"@g' -e 's/@@\([^@]\+\)@@/${\1}/g' loongarch.opt.in | \
+	    while read -r line; do
+		eval "echo \"$line\""
+	    done
+    }
+}
+
+main() {
+    case "$1" in
+	header) gen_defines;;
+	opt) gen_options;;
+	*) echo "Unknown Command: \"$1\". Available: header, opt"; exit 1;;
+    esac
+}
+
+main "$@"
diff --git a/gcc/config/loongarch/genopts/loongarch-strings b/gcc/config/loongarch/genopts/loongarch-strings
new file mode 100644
index 00000000000..553304f9b83
--- /dev/null
+++ b/gcc/config/loongarch/genopts/loongarch-strings
@@ -0,0 +1,58 @@ 
+# Defines the key strings for LoongArch compiler options.
+#
+# Copyright (C) 2021 Free Software Foundation, Inc.
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free
+# Software Foundation; either version 3, or (at your option) any later
+# version.
+#
+# GCC is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+# or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+# License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# -march= / -mtune=
+OPTSTR_ARCH	      arch
+OPTSTR_TUNE	      tune
+
+STR_CPU_NATIVE	      native
+STR_CPU_LOONGARCH64   loongarch64
+STR_CPU_LA464	      la464
+
+# Base architecture
+STR_ISA_BASE_LA64V100 la64
+
+# -mfpu
+OPTSTR_ISA_EXT_FPU    fpu
+STR_ISA_EXT_NOFPU     none
+STR_ISA_EXT_FPU0      0
+STR_ISA_EXT_FPU32     32
+STR_ISA_EXT_FPU64     64
+
+OPTSTR_SOFT_FLOAT     soft-float
+OPTSTR_SINGLE_FLOAT   single-float
+OPTSTR_DOUBLE_FLOAT   double-float
+
+# -mabi=
+OPTSTR_ABI_BASE	      abi
+STR_ABI_BASE_LP64D    lp64d
+STR_ABI_BASE_LP64F    lp64f
+STR_ABI_BASE_LP64S    lp64s
+
+# ABI extension types
+STR_ABI_EXT_BASE      base
+
+# -mcmodel=
+OPTSTR_CMODEL	      cmodel
+STR_CMODEL_NORMAL     normal
+STR_CMODEL_TINY	      tiny
+STR_CMODEL_TS	      tiny-static
+STR_CMODEL_LARGE      large
+STR_CMODEL_EXTREME    extreme
diff --git a/gcc/config/loongarch/genopts/loongarch.opt.in b/gcc/config/loongarch/genopts/loongarch.opt.in
new file mode 100644
index 00000000000..08950a32179
--- /dev/null
+++ b/gcc/config/loongarch/genopts/loongarch.opt.in
@@ -0,0 +1,189 @@ 
+; Generated by "genstr" from the template "loongarch.opt.in"
+; and definitions from "loongarch-strings".
+;
+; Copyright (C) 2021 Free Software Foundation, Inc.
+;
+; This file is part of GCC.
+;
+; GCC is free software; you can redistribute it and/or modify it under
+; the terms of the GNU General Public License as published by the Free
+; Software Foundation; either version 3, or (at your option) any later
+; version.
+;
+; GCC is distributed in the hope that it will be useful, but WITHOUT
+; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+; or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+; License for more details.
+;
+; You should have received a copy of the GNU General Public License
+; along with GCC; see the file COPYING3.  If not see
+; <http://www.gnu.org/licenses/>.
+;
+
+; Variables (macros) that should be exported by loongarch.opt:
+;   la_opt_switches,
+;   la_opt_abi_base, la_opt_abi_ext,
+;   la_opt_cpu_arch, la_opt_cpu_tune,
+;   la_opt_fpu,
+;   la_cmodel.
+
+HeaderInclude
+config/loongarch/loongarch-opts.h
+
+HeaderInclude
+config/loongarch/loongarch-str.h
+
+Variable
+HOST_WIDE_INT la_opt_switches = 0
+
+; ISA related options
+;; Base ISA
+Enum
+Name(isa_base) Type(int)
+Basic ISAs of LoongArch:
+
+EnumValue
+Enum(isa_base) String(@@STR_ISA_BASE_LA64V100@@) Value(ISA_BASE_LA64V100)
+
+
+;; ISA extensions / adjustments
+Enum
+Name(isa_ext_fpu) Type(int)
+FPU types of LoongArch:
+
+EnumValue
+Enum(isa_ext_fpu) String(@@STR_ISA_EXT_NOFPU@@) Value(ISA_EXT_NOFPU)
+
+EnumValue
+Enum(isa_ext_fpu) String(@@STR_ISA_EXT_FPU32@@) Value(ISA_EXT_FPU32)
+
+EnumValue
+Enum(isa_ext_fpu) String(@@STR_ISA_EXT_FPU64@@) Value(ISA_EXT_FPU64)
+
+m@@OPTSTR_ISA_EXT_FPU@@=
+Target RejectNegative Joined ToLower Enum(isa_ext_fpu) Var(la_opt_fpu) Init(M_OPTION_NOT_SEEN)
+-m@@OPTSTR_ISA_EXT_FPU@@=FPU	Generate code for the given FPU.
+
+m@@OPTSTR_ISA_EXT_FPU@@=@@STR_ISA_EXT_FPU0@@
+Target RejectNegative Alias(m@@OPTSTR_ISA_EXT_FPU@@=,@@STR_ISA_EXT_NOFPU@@)
+
+m@@OPTSTR_SOFT_FLOAT@@
+Target Driver RejectNegative Var(la_opt_switches) Mask(FORCE_SOFTF) Negative(m@@OPTSTR_SINGLE_FLOAT@@)
+Prevent the use of all hardware floating-point instructions.
+
+m@@OPTSTR_SINGLE_FLOAT@@
+Target Driver RejectNegative Var(la_opt_switches) Mask(FORCE_F32) Negative(m@@OPTSTR_DOUBLE_FLOAT@@)
+Restrict the use of hardware floating-point instructions to 32-bit operations.
+
+m@@OPTSTR_DOUBLE_FLOAT@@
+Target Driver RejectNegative Var(la_opt_switches) Mask(FORCE_F64) Negative(m@@OPTSTR_SOFT_FLOAT@@)
+Allow hardware floating-point instructions to cover both 32-bit and 64-bit operations.
+
+
+;; Base target models (implies ISA & tune parameters)
+Enum
+Name(cpu_type) Type(int)
+LoongArch CPU types:
+
+EnumValue
+Enum(cpu_type) String(@@STR_CPU_NATIVE@@) Value(CPU_NATIVE)
+
+EnumValue
+Enum(cpu_type) String(@@STR_CPU_LOONGARCH64@@) Value(CPU_LOONGARCH64)
+
+EnumValue
+Enum(cpu_type) String(@@STR_CPU_LA464@@) Value(CPU_LA464)
+
+m@@OPTSTR_ARCH@@=
+Target RejectNegative Joined Enum(cpu_type) Var(la_opt_cpu_arch) Init(M_OPTION_NOT_SEEN)
+-m@@OPTSTR_ARCH@@=PROCESSOR	Generate code for the given PROCESSOR ISA.
+
+m@@OPTSTR_TUNE@@=
+Target RejectNegative Joined Enum(cpu_type) Var(la_opt_cpu_tune) Init(M_OPTION_NOT_SEEN)
+-m@@OPTSTR_TUNE@@=PROCESSOR	Generate optimized code for PROCESSOR.
+
+
+; ABI related options
+; (ISA constraints on ABI are handled dynamically)
+
+;; Base ABI
+Enum
+Name(abi_base) Type(int)
+Base ABI types for LoongArch:
+
+EnumValue
+Enum(abi_base) String(@@STR_ABI_BASE_LP64D@@) Value(ABI_BASE_LP64D)
+
+EnumValue
+Enum(abi_base) String(@@STR_ABI_BASE_LP64F@@) Value(ABI_BASE_LP64F)
+
+EnumValue
+Enum(abi_base) String(@@STR_ABI_BASE_LP64S@@) Value(ABI_BASE_LP64S)
+
+m@@OPTSTR_ABI_BASE@@=
+Target RejectNegative Joined ToLower Enum(abi_base) Var(la_opt_abi_base) Init(M_OPTION_NOT_SEEN)
+-m@@OPTSTR_ABI_BASE@@=BASEABI	Generate code that conforms to the given BASEABI.
+
+;; ABI Extension
+Variable
+int la_opt_abi_ext = M_OPTION_NOT_SEEN
+
+
+mbranch-cost=
+Target RejectNegative Joined UInteger Var(loongarch_branch_cost)
+-mbranch-cost=COST	Set the cost of branches to roughly COST instructions.
+
+mcheck-zero-division
+Target Mask(CHECK_ZERO_DIV)
+Trap on integer divide by zero.
+
+mcond-move-int
+Target Var(TARGET_COND_MOVE_INT) Init(1)
+Conditional moves for integral are enabled.
+
+mcond-move-float
+Target Var(TARGET_COND_MOVE_FLOAT) Init(1)
+Conditional moves for float are enabled.
+
+mmemcpy
+Target Mask(MEMCPY)
+Don't optimize block moves.
+
+mlra
+Target Var(loongarch_lra_flag) Init(1) Save
+Use LRA instead of reload.
+
+noasmopt
+Driver
+
+mstrict-align
+Target Mask(STRICT_ALIGN) Save
+Do not generate unaligned memory accesses.
+
+mmax-inline-memcpy-size=
+Target Joined RejectNegative UInteger Var(loongarch_max_inline_memcpy_size) Init(1024)
+-mmax-inline-memcpy-size=SIZE	Set the max size of memcpy to inline, default is 1024.
+
+; The code model option names for -mcmodel.
+Enum
+Name(cmodel) Type(int)
+The code model option names for -mcmodel:
+
+EnumValue
+Enum(cmodel) String(@@STR_CMODEL_NORMAL@@) Value(CMODEL_NORMAL)
+
+EnumValue
+Enum(cmodel) String(@@STR_CMODEL_TINY@@) Value(CMODEL_TINY)
+
+EnumValue
+Enum(cmodel) String(@@STR_CMODEL_TS@@) Value(CMODEL_TINY_STATIC)
+
+EnumValue
+Enum(cmodel) String(@@STR_CMODEL_LARGE@@) Value(CMODEL_LARGE)
+
+EnumValue
+Enum(cmodel) String(@@STR_CMODEL_EXTREME@@) Value(CMODEL_EXTREME)
+
+mcmodel=
+Target RejectNegative Joined Enum(cmodel) Var(la_opt_cmodel) Init(CMODEL_NORMAL)
+Specify the code model.
diff --git a/gcc/config/loongarch/gnu-user.h b/gcc/config/loongarch/gnu-user.h
new file mode 100644
index 00000000000..22c3b3cbdbc
--- /dev/null
+++ b/gcc/config/loongarch/gnu-user.h
@@ -0,0 +1,84 @@ 
+/* Definitions for LoongArch systems using GNU (glibc-based) userspace,
+   or other userspace with libc derived from glibc.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+/* Define the size of the wide character type.  */
+#undef WCHAR_TYPE
+#define WCHAR_TYPE "int"
+
+#undef WCHAR_TYPE_SIZE
+#define WCHAR_TYPE_SIZE 32
+
+
+/* GNU-specific SPEC definitions.  */
+#define GNU_USER_LINK_EMULATION "elf" ABI_GRLEN_SPEC "loongarch"
+
+#undef GLIBC_DYNAMIC_LINKER
+#define GLIBC_DYNAMIC_LINKER \
+  "/lib" ABI_GRLEN_SPEC "/ld-linux-loongarch-" ABI_SPEC ".so.1"
+
+#undef MUSL_DYNAMIC_LINKER
+#define MUSL_DYNAMIC_LINKER \
+  "/lib" ABI_GRLEN_SPEC "/ld-musl-loongarch-" ABI_SPEC ".so.1"
+
+#undef GNU_USER_TARGET_LINK_SPEC
+#define GNU_USER_TARGET_LINK_SPEC \
+  "%{G*} %{shared} -m " GNU_USER_LINK_EMULATION \
+  "%{!shared: %{static} %{!static: %{rdynamic:-export-dynamic} " \
+  "-dynamic-linker " GNU_USER_DYNAMIC_LINKER "}}"
+
+
+/* Similar to standard Linux, but adding -ffast-math support.  */
+#undef GNU_USER_TARGET_MATHFILE_SPEC
+#define GNU_USER_TARGET_MATHFILE_SPEC \
+  "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s}"
+
+#undef LIB_SPEC
+#define LIB_SPEC GNU_USER_TARGET_LIB_SPEC
+
+#undef LINK_SPEC
+#define LINK_SPEC GNU_USER_TARGET_LINK_SPEC
+
+#undef ENDFILE_SPEC
+#define ENDFILE_SPEC \
+  GNU_USER_TARGET_MATHFILE_SPEC " " \
+  GNU_USER_TARGET_ENDFILE_SPEC
+
+#undef SUBTARGET_CPP_SPEC
+#define SUBTARGET_CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}"
+
+/* A standard GNU/Linux mapping.  On most targets, it is included in
+   CC1_SPEC itself by config/linux.h, but loongarch.h overrides CC1_SPEC
+   and provides this hook instead.  */
+#undef SUBTARGET_CC1_SPEC
+#define SUBTARGET_CC1_SPEC GNU_USER_TARGET_CC1_SPEC
+
+#define TARGET_OS_CPP_BUILTINS() \
+  do \
+    { \
+      GNU_USER_TARGET_OS_CPP_BUILTINS (); \
+      /* The GNU C++ standard library requires this.  */ \
+      if (c_dialect_cxx ()) \
+       builtin_define ("_GNU_SOURCE"); \
+    } \
+  while (0)
+
+
+#undef ASM_DECLARE_OBJECT_NAME
+#define ASM_DECLARE_OBJECT_NAME loongarch_declare_object_name
diff --git a/gcc/config/loongarch/linux.h b/gcc/config/loongarch/linux.h
new file mode 100644
index 00000000000..a6206de2681
--- /dev/null
+++ b/gcc/config/loongarch/linux.h
@@ -0,0 +1,50 @@ 
+/* Definitions for Linux-based systems with libraries in ELF format.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+/* Default system library search paths.
+ * This ensures that a compiler configured with --disable-multilib
+ * can work in a multilib environment.  */
+
+#if defined(__DISABLE_MULTILIB) && defined(__DISABLE_MULTIARCH)
+
+  #if DEFAULT_ABI_BASE == ABI_BASE_LP64D
+    #define ABI_LIBDIR "lib64"
+  #elif DEFAULT_ABI_BASE == ABI_BASE_LP64F
+    #define ABI_LIBDIR "lib64/f32"
+  #elif DEFAULT_ABI_BASE == ABI_BASE_LP64S
+    #define ABI_LIBDIR "lib64/sf"
+  #endif
+
+#endif
+
+#ifndef ABI_LIBDIR
+#define ABI_LIBDIR "lib"
+#endif
+
+#define STANDARD_STARTFILE_PREFIX_1 "/" ABI_LIBDIR "/"
+#define STANDARD_STARTFILE_PREFIX_2 "/usr/" ABI_LIBDIR "/"
+
+
+/* Define this to be nonzero if static stack checking is supported.  */
+#define STACK_CHECK_STATIC_BUILTIN 1
+
+/* The default value isn't sufficient in 64-bit mode.  */
+#define STACK_CHECK_PROTECT (TARGET_64BIT ? 16 * 1024 : 12 * 1024)
+
+#define TARGET_ASM_FILE_END file_end_indicate_exec_stack
diff --git a/gcc/config/loongarch/loongarch-cpu.cc b/gcc/config/loongarch/loongarch-cpu.cc
new file mode 100644
index 00000000000..384fb54392c
--- /dev/null
+++ b/gcc/config/loongarch/loongarch-cpu.cc
@@ -0,0 +1,206 @@ 
+/* Definitions for LoongArch CPU properties.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   Contributed by Loongson Ltd.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#define IN_TARGET_CODE 1
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "diagnostic-core.h"
+
+#include "loongarch-opts.h"
+#include "loongarch-cpu.h"
+#include "loongarch-str.h"
+
+/* Native CPU detection with "cpucfg" */
+#define N_CPUCFG_WORDS 0x15
+static uint32_t cpucfg_cache[N_CPUCFG_WORDS] = { 0 };
+static const int cpucfg_useful_idx[] = {0, 1, 2, 16, 17, 18, 19};
+
+static uint32_t
+read_cpucfg_word (int wordno)
+{
+  /* To make cross-compiler shut up.  */
+  (void) wordno;
+  uint32_t ret = 0;
+
+  #ifdef __loongarch__
+  __asm__ __volatile__ ("cpucfg %0,%1\n\t"
+			:"=r"(ret)
+			:"r"(wordno)
+			:);
+  #endif
+
+  return ret;
+}
+
+void
+cache_cpucfg (void)
+{
+  for (unsigned int i = 0; i < sizeof (cpucfg_useful_idx) / sizeof (int); i++)
+    {
+      cpucfg_cache[cpucfg_useful_idx[i]]
+	= read_cpucfg_word (cpucfg_useful_idx[i]);
+    }
+}
+
+uint32_t
+get_native_prid (void)
+{
+  /* Fill loongarch_cpu_default_config[CPU_NATIVE] with cpucfg data,
+     see "Loongson Architecture Reference Manual"
+     (Volume 1, Section 2.2.10.5) */
+  return cpucfg_cache[0];
+}
+
+const char*
+get_native_prid_str (void)
+{
+  static char prid_str[9];
+  sprintf (prid_str, "%08x", cpucfg_cache[0]);
+  return (const char*) prid_str;
+}
+
+/* Fill property tables for CPU_NATIVE.  */
+unsigned int
+fill_native_cpu_config (int p_arch_native, int p_tune_native)
+{
+  int ret_cpu_type;
+
+  /* Nothing needs to be done unless "-march/tune=native"
+     is given or implied.  */
+  if (!(p_arch_native || p_tune_native))
+    return CPU_NATIVE;
+
+  /* Fill cpucfg_cache with the "cpucfg" instruction.  */
+  cache_cpucfg ();
+
+
+  /* Fill: loongarch_cpu_default_isa[CPU_NATIVE].base
+     With: base architecture (ARCH)
+     At:   cpucfg_words[1][1:0] */
+
+  #define NATIVE_BASE_ISA (loongarch_cpu_default_isa[CPU_NATIVE].base)
+  switch (cpucfg_cache[1] & 0x3)
+    {
+      case 0x02:
+	NATIVE_BASE_ISA = ISA_BASE_LA64V100;
+	break;
+
+      default:
+	if (p_arch_native)
+	  fatal_error (UNKNOWN_LOCATION,
+		       "unknown base architecture %<0x%x%>, %qs failed",
+		       (unsigned int) (cpucfg_cache[1] & 0x3),
+		       "-m" OPTSTR_ARCH "=" STR_CPU_NATIVE);
+    }
+
+  /* Fill: loongarch_cpu_default_isa[CPU_NATIVE].fpu
+     With: FPU type (FP, FP_SP, FP_DP)
+     At:   cpucfg_words[2][2:0] */
+
+  #define NATIVE_FPU (loongarch_cpu_default_isa[CPU_NATIVE].fpu)
+  switch (cpucfg_cache[2] & 0x7)
+    {
+      case 0x07:
+	NATIVE_FPU = ISA_EXT_FPU64;
+	break;
+
+      case 0x03:
+	NATIVE_FPU = ISA_EXT_FPU32;
+	break;
+
+      case 0x00:
+	NATIVE_FPU = ISA_EXT_NOFPU;
+	break;
+
+      default:
+	if (p_arch_native)
+	  fatal_error (UNKNOWN_LOCATION,
+		       "unknown FPU type %<0x%x%>, %qs failed",
+		       (unsigned int) (cpucfg_cache[2] & 0x7),
+		       "-m" OPTSTR_ARCH "=" STR_CPU_NATIVE);
+    }
+
+  /* Fill: loongarch_cpu_cache[CPU_NATIVE]
+     With: cache size info
+     At:   cpucfg_words[16:20][31:0] */
+
+  int l1d_present = 0, l1u_present = 0;
+  int l2d_present = 0;
+  uint32_t l1_szword, l2_szword;
+
+  l1u_present |= cpucfg_cache[16] & 3;	      /* bit[1:0]: unified l1 cache */
+  l1d_present |= cpucfg_cache[16] & 4;	      /* bit[2:2]: l1 dcache */
+  l1_szword = l1d_present ? 18 : (l1u_present ? 17 : 0);
+  l1_szword = l1_szword ? cpucfg_cache[l1_szword]: 0;
+
+  l2d_present |= cpucfg_cache[16] & 24;	      /* bit[4:3]: unified l2 cache */
+  l2d_present |= cpucfg_cache[16] & 128;      /* bit[7:7]: l2 dcache */
+  l2_szword = l2d_present ? cpucfg_cache[19]: 0;
+
+  loongarch_cpu_cache[CPU_NATIVE].l1d_line_size
+    = 1 << ((l1_szword & 0x7f000000) >> 24);  /* bit[30:24]: log2(linesize) */
+
+  loongarch_cpu_cache[CPU_NATIVE].l1d_size
+    = (1 << ((l1_szword & 0x00ff0000) >> 16)) /* bit[23:16]: log2(idx) */
+    * ((l1_szword & 0x0000ffff) + 1)	      /* bit[15:0]:  sets - 1 */
+    * (1 << ((l1_szword & 0x7f000000) >> 24)) /* bit[30:24]: log2(linesize) */
+    >> 10;				      /* in kilobytes */
+
+  loongarch_cpu_cache[CPU_NATIVE].l2d_size
+    = (1 << ((l2_szword & 0x00ff0000) >> 16)) /* bit[23:16]: log2(idx) */
+    * ((l2_szword & 0x0000ffff) + 1)	      /* bit[15:0]:  sets - 1 */
+    * (1 << ((l2_szword & 0x7f000000) >> 24)) /* bit[30:24]: log2(linesize) */
+    >> 10;				      /* in kilobytes */
+
+  /* Fill: ret_cpu_type
+     With: processor ID (PRID)
+     At:   cpucfg_words[0][31:0] */
+
+  switch (cpucfg_cache[0] & 0x00ffff00)
+  {
+    case 0x0014c000:   /* LA464 */
+      ret_cpu_type = CPU_LA464;
+      break;
+
+    default:
+      /* Unknown PRID.  This is generally harmless as long as
+	 the properties above can be obtained via "cpucfg".  */
+      if (p_tune_native)
+	inform (UNKNOWN_LOCATION, "unknown processor ID %<0x%x%>, "
+		"some tuning parameters will fall back to default",
+		cpucfg_cache[0]);
+      break;
+  }
+
+  /* Properties that cannot be looked up directly using cpucfg.  */
+  loongarch_cpu_issue_rate[CPU_NATIVE]
+    = loongarch_cpu_issue_rate[ret_cpu_type];
+
+  loongarch_cpu_multipass_dfa_lookahead[CPU_NATIVE]
+    = loongarch_cpu_multipass_dfa_lookahead[ret_cpu_type];
+
+  loongarch_cpu_rtx_cost_data[CPU_NATIVE]
+    = loongarch_cpu_rtx_cost_data[ret_cpu_type];
+
+  return ret_cpu_type;
+}
diff --git a/gcc/config/loongarch/loongarch-cpu.h b/gcc/config/loongarch/loongarch-cpu.h
new file mode 100644
index 00000000000..93d656f70f5
--- /dev/null
+++ b/gcc/config/loongarch/loongarch-cpu.h
@@ -0,0 +1,30 @@ 
+/* Definitions for loongarch native cpu property detection routines.
+   Copyright (C) 2020-2021 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef LOONGARCH_CPU_H
+#define LOONGARCH_CPU_H
+
+#include "system.h"
+
+void cache_cpucfg (void);
+unsigned int fill_native_cpu_config (int p_arch_native, int p_tune_native);
+uint32_t get_native_prid (void);
+const char* get_native_prid_str (void);
+
+#endif /* LOONGARCH_CPU_H */
diff --git a/gcc/config/loongarch/loongarch-def.c b/gcc/config/loongarch/loongarch-def.c
new file mode 100644
index 00000000000..bc22a55edb0
--- /dev/null
+++ b/gcc/config/loongarch/loongarch-def.c
@@ -0,0 +1,164 @@ 
+/* LoongArch static properties.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   Contributed by Loongson Ltd.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "loongarch-def.h"
+#include "loongarch-str.h"
+
+/* CPU property tables.  */
+const char*
+loongarch_cpu_strings[N_TUNE_TYPES] = {
+  [CPU_NATIVE]		  = STR_CPU_NATIVE,
+  [CPU_LOONGARCH64]	  = STR_CPU_LOONGARCH64,
+  [CPU_LA464]		  = STR_CPU_LA464,
+};
+
+struct loongarch_isa
+loongarch_cpu_default_isa[N_ARCH_TYPES] = {
+  [CPU_LOONGARCH64] = {
+      .base = ISA_BASE_LA64V100,
+      .fpu = ISA_EXT_FPU64,
+  },
+  [CPU_LA464] = {
+      .base = ISA_BASE_LA64V100,
+      .fpu = ISA_EXT_FPU64,
+  },
+};
+
+struct loongarch_cache
+loongarch_cpu_cache[N_TUNE_TYPES] = {
+  [CPU_LOONGARCH64] = {
+      .l1d_line_size = 64,
+      .l1d_size = 64,
+      .l2d_size = 256,
+  },
+  [CPU_LA464] = {
+      .l1d_line_size = 64,
+      .l1d_size = 64,
+      .l2d_size = 256,
+  },
+};
+
+/* The following properties cannot be looked up directly using "cpucfg".
+ So it is necessary to provide a default value for "unknown native"
+ tune targets (i.e. -mtune=native while PRID does not correspond to
+ any known "-mtune" type).  */
+
+struct loongarch_rtx_cost_data
+loongarch_cpu_rtx_cost_data[N_TUNE_TYPES] = {
+  [CPU_NATIVE] = {
+      DEFAULT_COSTS
+  },
+  [CPU_LOONGARCH64] = {
+      DEFAULT_COSTS
+  },
+  [CPU_LA464] = {
+      DEFAULT_COSTS
+  },
+};
+
+/* RTX costs to use when optimizing for size.  */
+extern const struct loongarch_rtx_cost_data
+loongarch_rtx_cost_optimize_size = {
+    .fp_add	      = 4,
+    .fp_mult_sf	      = 4,
+    .fp_mult_df	      = 4,
+    .fp_div_sf	      = 4,
+    .fp_div_df	      = 4,
+    .int_mult_si      = 4,
+    .int_mult_di      = 4,
+    .int_div_si	      = 4,
+    .int_div_di	      = 4,
+    .branch_cost      = 2,
+    .memory_latency   = 4,
+};
+
+int
+loongarch_cpu_issue_rate[N_TUNE_TYPES] = {
+  [CPU_NATIVE]	      = 4,
+  [CPU_LOONGARCH64]   = 4,
+  [CPU_LA464]	      = 4,
+};
+
+int
+loongarch_cpu_multipass_dfa_lookahead[N_TUNE_TYPES] = {
+  [CPU_NATIVE]	      = 4,
+  [CPU_LOONGARCH64]   = 4,
+  [CPU_LA464]	      = 4,
+};
+
+/* Wiring string definitions from loongarch-str.h to global arrays
+   with standard index values from loongarch-opts.h, so we can
+   print config-related messages and do ABI self-spec filtering
+   from the driver in a self-consistent manner.  */
+
+const char*
+loongarch_isa_base_strings[N_ISA_BASE_TYPES] = {
+  [ISA_BASE_LA64V100] = STR_ISA_BASE_LA64V100,
+};
+
+const char*
+loongarch_isa_ext_strings[N_ISA_EXT_TYPES] = {
+  [ISA_EXT_FPU64] = STR_ISA_EXT_FPU64,
+  [ISA_EXT_FPU32] = STR_ISA_EXT_FPU32,
+  [ISA_EXT_NOFPU] = STR_ISA_EXT_NOFPU,
+};
+
+const char*
+loongarch_abi_base_strings[N_ABI_BASE_TYPES] = {
+  [ABI_BASE_LP64D] = STR_ABI_BASE_LP64D,
+  [ABI_BASE_LP64F] = STR_ABI_BASE_LP64F,
+  [ABI_BASE_LP64S] = STR_ABI_BASE_LP64S,
+};
+
+const char*
+loongarch_abi_ext_strings[N_ABI_EXT_TYPES] = {
+  [ABI_EXT_BASE] = STR_ABI_EXT_BASE,
+};
+
+const char*
+loongarch_cmodel_strings[] = {
+  [CMODEL_NORMAL]	  = STR_CMODEL_NORMAL,
+  [CMODEL_TINY]		  = STR_CMODEL_TINY,
+  [CMODEL_TINY_STATIC]	  = STR_CMODEL_TS,
+  [CMODEL_LARGE]	  = STR_CMODEL_LARGE,
+  [CMODEL_EXTREME]	  = STR_CMODEL_EXTREME,
+};
+
+const char*
+loongarch_switch_strings[] = {
+  [SW_SOFT_FLOAT]	  = OPTSTR_SOFT_FLOAT,
+  [SW_SINGLE_FLOAT]	  = OPTSTR_SINGLE_FLOAT,
+  [SW_DOUBLE_FLOAT]	  = OPTSTR_DOUBLE_FLOAT,
+};
+
+
+/* ABI-related definitions.  */
+const struct loongarch_isa
+abi_minimal_isa[N_ABI_BASE_TYPES][N_ABI_EXT_TYPES] = {
+  [ABI_BASE_LP64D] = {
+      [ABI_EXT_BASE] = {.base = ISA_BASE_LA64V100, .fpu = ISA_EXT_FPU64},
+  },
+  [ABI_BASE_LP64F] = {
+      [ABI_EXT_BASE] = {.base = ISA_BASE_LA64V100, .fpu = ISA_EXT_FPU32},
+  },
+  [ABI_BASE_LP64S] = {
+      [ABI_EXT_BASE] = {.base = ISA_BASE_LA64V100, .fpu = ISA_EXT_NOFPU},
+  },
+};
diff --git a/gcc/config/loongarch/loongarch-def.h b/gcc/config/loongarch/loongarch-def.h
new file mode 100644
index 00000000000..84c27271a69
--- /dev/null
+++ b/gcc/config/loongarch/loongarch-def.h
@@ -0,0 +1,151 @@ 
+/* LoongArch definitions.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   Contributed by Loongson Ltd.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+/* Definition of standard codes for:
+    - base architecture types	(isa_base),
+    - ISA extensions		(isa_ext),
+    - base ABI types		(abi_base),
+    - ABI extension types	(abi_ext).
+
+    - code models		      (cmodel)
+    - other command-line switches     (switch)
+
+   These values are primarily used for implementing option handling
+   logic in "loongarch.opt", "loongarch-driver.c" and "loongarch-opt.c".
+
+   As for the result of this option handling process, the following
+   scheme is adopted to represent the final configuration:
+
+    - The target ABI is encoded with a tuple (abi_base, abi_ext)
+      using the code defined below.
+
+    - The target ISA is encoded with a "struct loongarch_isa" defined
+      in loongarch-cpu.h.
+
+    - The target microarchitecture is represented with a cpu model
+      index defined in loongarch-cpu.h.
+*/
+
+#ifndef LOONGARCH_DEF_H
+#define LOONGARCH_DEF_H
+
+#include "loongarch-tune.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* enum isa_base */
+extern const char* loongarch_isa_base_strings[];
+#define ISA_BASE_LA64V100     0
+#define N_ISA_BASE_TYPES      1
+
+/* enum isa_ext_* */
+extern const char* loongarch_isa_ext_strings[];
+#define ISA_EXT_NOFPU	      0
+#define ISA_EXT_FPU32	      1
+#define ISA_EXT_FPU64	      2
+#define N_ISA_EXT_FPU_TYPES   3
+#define N_ISA_EXT_TYPES	      3
+
+/* enum abi_base */
+extern const char* loongarch_abi_base_strings[];
+#define ABI_BASE_LP64D	      0
+#define ABI_BASE_LP64F	      1
+#define ABI_BASE_LP64S	      2
+#define N_ABI_BASE_TYPES      3
+
+/* enum abi_ext */
+extern const char* loongarch_abi_ext_strings[];
+#define ABI_EXT_BASE	      0
+#define N_ABI_EXT_TYPES	      1
+
+/* enum cmodel */
+extern const char* loongarch_cmodel_strings[];
+#define CMODEL_NORMAL	      0
+#define CMODEL_TINY	      1
+#define CMODEL_TINY_STATIC    2
+#define CMODEL_LARGE	      3
+#define CMODEL_EXTREME	      4
+#define N_CMODEL_TYPES	      5
+
+/* enum switches */
+/* The "SW_" codes represent command-line switches (options that
+   accept no parameters). Definition for other switches that affects
+   the target ISA / ABI configuration will also be appended here
+   in the future.  */
+
+extern const char* loongarch_switch_strings[];
+#define SW_SOFT_FLOAT	      0
+#define SW_SINGLE_FLOAT	      1
+#define SW_DOUBLE_FLOAT	      2
+#define N_SWITCH_TYPES	      3
+
+/* The common default value for variables whose assignments
+   are triggered by command-line options.  */
+
+#define M_OPTION_NOT_SEEN -1
+#define M_OPT_ABSENT(opt_enum)  ((opt_enum) == M_OPTION_NOT_SEEN)
+
+
+/* Internal representation of the target.  */
+struct loongarch_isa
+{
+  unsigned char base;	    /* ISA_BASE_ */
+  unsigned char fpu;	    /* ISA_EXT_FPU_ */
+};
+
+struct loongarch_abi
+{
+  unsigned char base;	    /* ABI_BASE_ */
+  unsigned char ext;	    /* ABI_EXT_ */
+};
+
+struct loongarch_target
+{
+  struct loongarch_isa isa;
+  struct loongarch_abi abi;
+  unsigned char cpu_arch;   /* CPU_ */
+  unsigned char cpu_tune;   /* same */
+  unsigned char cpu_native; /* same */
+  unsigned char cmodel;	    /* CMODEL_ */
+};
+
+/* CPU properties.  */
+/* index */
+#define CPU_NATIVE	  0
+#define CPU_LOONGARCH64	  1
+#define CPU_LA464	  2
+#define N_ARCH_TYPES	  3
+#define N_TUNE_TYPES	  3
+
+/* parallel tables.  */
+extern const char* loongarch_cpu_strings[];
+extern struct loongarch_isa loongarch_cpu_default_isa[];
+extern int loongarch_cpu_issue_rate[];
+extern int loongarch_cpu_multipass_dfa_lookahead[];
+
+extern struct loongarch_cache loongarch_cpu_cache[];
+extern struct loongarch_rtx_cost_data loongarch_cpu_rtx_cost_data[];
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* LOONGARCH_DEF_H */
diff --git a/gcc/config/loongarch/loongarch-driver.cc b/gcc/config/loongarch/loongarch-driver.cc
new file mode 100644
index 00000000000..79ab0b9138a
--- /dev/null
+++ b/gcc/config/loongarch/loongarch-driver.cc
@@ -0,0 +1,187 @@ 
+/* Subroutines for the gcc driver.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   Contributed by Loongson Ltd.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#define IN_TARGET_CODE 1
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "obstack.h"
+#include "diagnostic-core.h"
+
+#include "loongarch-opts.h"
+#include "loongarch-driver.h"
+
+static int
+  opt_arch_driver = M_OPTION_NOT_SEEN,
+  opt_tune_driver = M_OPTION_NOT_SEEN,
+  opt_fpu_driver = M_OPTION_NOT_SEEN,
+  opt_abi_base_driver = M_OPTION_NOT_SEEN,
+  opt_abi_ext_driver = M_OPTION_NOT_SEEN,
+  opt_cmodel_driver = M_OPTION_NOT_SEEN;
+
+int opt_switches = 0;
+
+/* This flag is set to 1 if we believe that the user might be avoiding
+   linking (implicitly) against something from the startfile search paths.  */
+static int no_link = 0;
+
+#define LARCH_DRIVER_SET_M_FLAG(OPTS_ARRAY, N_OPTS, FLAG, STR)	\
+  for (int i = 0; i < (N_OPTS); i++)				\
+  {								\
+    if ((OPTS_ARRAY)[i] != 0)					\
+      if (strcmp ((STR), (OPTS_ARRAY)[i]) == 0)			\
+	(FLAG) = i;						\
+  }
+
+/* Use the public obstack from the gcc driver (defined in gcc.c).
+   This is for allocating space for the returned string.  */
+extern struct obstack opts_obstack;
+
+#define APPEND_LTR(S)				      \
+  obstack_grow (&opts_obstack, (const void*) (S),     \
+		sizeof ((S)) / sizeof (char) -1)
+
+#define APPEND_VAL(S) \
+  obstack_grow (&opts_obstack, (const void*) (S), strlen ((S)))
+
+
+const char*
+driver_set_m_flag (int argc, const char **argv)
+{
+  int parm_off = 0;
+
+  if (argc != 1)
+    return "%eset_m_flag requires exactly 1 argument.";
+
+#undef PARM
+#define PARM (argv[0] + parm_off)
+
+/* Note: sizeof (OPTSTR_##NAME) equals the length of "<option>=".  */
+#undef MATCH_OPT
+#define MATCH_OPT(NAME) \
+  (strncmp (argv[0], OPTSTR_##NAME "=", \
+	    (parm_off = sizeof (OPTSTR_##NAME))) == 0)
+
+  if (strcmp (argv[0], "no_link") == 0)
+    {
+      no_link = 1;
+    }
+  else if (MATCH_OPT (ABI_BASE))
+    {
+      LARCH_DRIVER_SET_M_FLAG (
+	loongarch_abi_base_strings, N_ABI_BASE_TYPES,
+	opt_abi_base_driver, PARM)
+    }
+  else if (MATCH_OPT (ISA_EXT_FPU))
+    {
+      LARCH_DRIVER_SET_M_FLAG (loongarch_isa_ext_strings, N_ISA_EXT_FPU_TYPES,
+			       opt_fpu_driver, PARM)
+    }
+  else if (MATCH_OPT (ARCH))
+    {
+      LARCH_DRIVER_SET_M_FLAG (loongarch_cpu_strings, N_ARCH_TYPES,
+			       opt_arch_driver, PARM)
+    }
+  else if (MATCH_OPT (TUNE))
+    {
+      LARCH_DRIVER_SET_M_FLAG (loongarch_cpu_strings, N_TUNE_TYPES,
+			       opt_tune_driver, PARM)
+    }
+  else if (MATCH_OPT (CMODEL))
+    {
+      LARCH_DRIVER_SET_M_FLAG (loongarch_cmodel_strings, N_CMODEL_TYPES,
+			       opt_cmodel_driver, PARM)
+    }
+  else /* switches */
+    {
+      int switch_idx = M_OPTION_NOT_SEEN;
+
+      LARCH_DRIVER_SET_M_FLAG (loongarch_switch_strings, N_SWITCH_TYPES,
+			       switch_idx, argv[0])
+
+      if (switch_idx != M_OPTION_NOT_SEEN)
+	opt_switches |= loongarch_switch_mask[switch_idx];
+    }
+  return "";
+}
+
+const char*
+driver_get_normalized_m_opts (int argc, const char **argv)
+{
+  if (argc != 0)
+    {
+      (void) argv;  /* To make compiler shut up about unused argument.  */
+      return " %eget_normalized_m_opts requires no argument.\n";
+    }
+
+  loongarch_config_target (& la_target,
+			   opt_switches,
+			   opt_arch_driver,
+			   opt_tune_driver,
+			   opt_fpu_driver,
+			   opt_abi_base_driver,
+			   opt_abi_ext_driver,
+			   opt_cmodel_driver,
+			   !no_link /* follow_multilib_list */);
+
+  /* Output normalized option strings.  */
+  obstack_blank (&opts_obstack, 0);
+
+#undef APPEND_LTR
+#define APPEND_LTR(S) \
+  obstack_grow (&opts_obstack, (const void*) (S), \
+		sizeof ((S)) / sizeof (char) -1)
+
+#undef APPEND_VAL
+#define APPEND_VAL(S) \
+  obstack_grow (&opts_obstack, (const void*) (S), strlen ((S)))
+
+#undef APPEND_OPT
+#define APPEND_OPT(NAME) \
+   APPEND_LTR (" %<m" OPTSTR_##NAME "=* " \
+	       " -m" OPTSTR_##NAME "=")
+
+  for (int i = 0; i < N_SWITCH_TYPES; i++)
+    {
+      APPEND_LTR (" %<m");
+      APPEND_VAL (loongarch_switch_strings[i]);
+    }
+
+  APPEND_OPT (ABI_BASE);
+  APPEND_VAL (loongarch_abi_base_strings[la_target.abi.base]);
+
+  APPEND_OPT (ARCH);
+  APPEND_VAL (loongarch_cpu_strings[la_target.cpu_arch]);
+
+  APPEND_OPT (ISA_EXT_FPU);
+  APPEND_VAL (loongarch_isa_ext_strings[la_target.isa.fpu]);
+
+  APPEND_OPT (CMODEL);
+  APPEND_VAL (loongarch_cmodel_strings[la_target.cmodel]);
+
+  APPEND_OPT (TUNE);
+  APPEND_VAL (loongarch_cpu_strings[la_target.cpu_tune]);
+
+  obstack_1grow (&opts_obstack, '\0');
+
+  return XOBFINISH (&opts_obstack, const char *);
+}
diff --git a/gcc/config/loongarch/loongarch-driver.h b/gcc/config/loongarch/loongarch-driver.h
new file mode 100644
index 00000000000..ce0222748dd
--- /dev/null
+++ b/gcc/config/loongarch/loongarch-driver.h
@@ -0,0 +1,69 @@ 
+/* Subroutine headers for the gcc driver.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   Contributed by Loongson Ltd.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef LOONGARCH_DRIVER_H
+#define LOONGARCH_DRIVER_H
+
+#include "loongarch-str.h"
+
+extern const char*
+driver_set_m_flag (int argc, const char **argv);
+
+extern const char*
+driver_get_normalized_m_opts (int argc, const char **argv);
+
+#define EXTRA_SPEC_FUNCTIONS \
+  { "set_m_flag", driver_set_m_flag  }, \
+  { "get_normalized_m_opts", driver_get_normalized_m_opts  },
+
+/* Pre-process ABI-related options.  */
+#define LA_SET_PARM_SPEC(NAME) \
+  " %{m" OPTSTR_##NAME  "=*: %:set_m_flag(" OPTSTR_##NAME "=%*)}" \
+
+#define LA_SET_FLAG_SPEC(NAME) \
+  " %{m" OPTSTR_##NAME  ": %:set_m_flag(" OPTSTR_##NAME ")}" \
+
+#define DRIVER_HANDLE_MACHINE_OPTIONS			      \
+  " %{c|S|E|nostdlib: %:set_m_flag(no_link)}"		      \
+  " %{nostartfiles: %{nodefaultlibs: %:set_m_flag(no_link)}}" \
+  LA_SET_PARM_SPEC (ABI_BASE)				      \
+  LA_SET_PARM_SPEC (ARCH)				      \
+  LA_SET_PARM_SPEC (TUNE)				      \
+  LA_SET_PARM_SPEC (ISA_EXT_FPU)			      \
+  LA_SET_PARM_SPEC (CMODEL)				      \
+  LA_SET_FLAG_SPEC (SOFT_FLOAT)				      \
+  LA_SET_FLAG_SPEC (SINGLE_FLOAT)			      \
+  LA_SET_FLAG_SPEC (DOUBLE_FLOAT)			      \
+  " %:get_normalized_m_opts()"
+
+#define DRIVER_SELF_SPECS \
+  DRIVER_HANDLE_MACHINE_OPTIONS
+
+/* ABI spec strings.  */
+#define ABI_GRLEN_SPEC \
+  "%{mabi=lp64*:64}"   \
+
+#define ABI_SPEC \
+  "%{mabi=lp64d:lp64d}" \
+  "%{mabi=lp64f:lp64f}" \
+  "%{mabi=lp64s:lp64s}" \
+
+#endif /* LOONGARCH_DRIVER_H */
+
diff --git a/gcc/config/loongarch/loongarch-opts.cc b/gcc/config/loongarch/loongarch-opts.cc
new file mode 100644
index 00000000000..4bd498fd62b
--- /dev/null
+++ b/gcc/config/loongarch/loongarch-opts.cc
@@ -0,0 +1,580 @@ 
+/* Subroutines for loongarch-specific option handling.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   Contributed by Loongson Ltd.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#define IN_TARGET_CODE 1
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "obstack.h"
+#include "diagnostic-core.h"
+
+#include "loongarch-cpu.h"
+#include "loongarch-opts.h"
+#include "loongarch-str.h"
+
+struct loongarch_target la_target;
+
+/* ABI-related configuration.  */
+#define ABI_COUNT (sizeof(abi_priority_list)/sizeof(struct loongarch_abi))
+static const struct loongarch_abi
+abi_priority_list[] = {
+    {ABI_BASE_LP64D, ABI_EXT_BASE},
+    {ABI_BASE_LP64F, ABI_EXT_BASE},
+    {ABI_BASE_LP64S, ABI_EXT_BASE},
+};
+
+/* Initialize enabled_abi_types from TM_MULTILIB_LIST.  */
+#ifdef __DISABLE_MULTILIB
+#define MULTILIB_LIST_LEN 1
+#else
+#define MULTILIB_LIST_LEN (sizeof (tm_multilib_list) / sizeof (int) / 2)
+static const int tm_multilib_list[] = { TM_MULTILIB_LIST };
+#endif
+static int enabled_abi_types[N_ABI_BASE_TYPES][N_ABI_EXT_TYPES] = { 0 };
+
+#define isa_required(ABI) (abi_minimal_isa[(ABI).base][(ABI).ext])
+extern "C" const struct loongarch_isa
+abi_minimal_isa[N_ABI_BASE_TYPES][N_ABI_EXT_TYPES];
+
+static inline int
+is_multilib_enabled (struct loongarch_abi abi)
+{
+  return enabled_abi_types[abi.base][abi.ext];
+}
+
+static void
+init_enabled_abi_types ()
+{
+#ifdef __DISABLE_MULTILIB
+  enabled_abi_types[DEFAULT_ABI_BASE][DEFAULT_ABI_EXT] = 1;
+#else
+  int abi_base, abi_ext;
+  for (unsigned int i = 0; i < MULTILIB_LIST_LEN; i++)
+    {
+      abi_base = tm_multilib_list[i << 1];
+      abi_ext = tm_multilib_list[(i << 1) + 1];
+      enabled_abi_types[abi_base][abi_ext] = 1;
+    }
+#endif
+}
+
+/* Switch masks.  */
+#undef M
+#define M(NAME) OPTION_MASK_##NAME
+const int loongarch_switch_mask[N_SWITCH_TYPES] = {
+  /* SW_SOFT_FLOAT */    M(FORCE_SOFTF),
+  /* SW_SINGLE_FLOAT */  M(FORCE_F32),
+  /* SW_DOUBLE_FLOAT */  M(FORCE_F64),
+};
+#undef M
+
+/* String processing.  */
+static struct obstack msg_obstack;
+#define APPEND_STRING(STR) obstack_grow (&msg_obstack, STR, strlen(STR));
+#define APPEND1(CH) obstack_1grow(&msg_obstack, CH);
+
+static const char* abi_str (struct loongarch_abi abi);
+static const char* isa_str (const struct loongarch_isa *isa, char separator);
+static const char* arch_str (const struct loongarch_target *target);
+static const char* multilib_enabled_abi_list ();
+
+/* Misc */
+static struct loongarch_abi isa_default_abi (const struct loongarch_isa *isa);
+static int isa_base_compat_p (const struct loongarch_isa *set1,
+			      const struct loongarch_isa *set2);
+static int isa_fpu_compat_p (const struct loongarch_isa *set1,
+			     const struct loongarch_isa *set2);
+static int abi_compat_p (const struct loongarch_isa *isa,
+			 struct loongarch_abi abi);
+static int abi_default_cpu_arch (struct loongarch_abi abi);
+
+/* Checking configure-time defaults.  */
+#ifndef DEFAULT_ABI_BASE
+#error missing definition of DEFAULT_ABI_BASE in ${tm_defines}.
+#endif
+
+#ifndef DEFAULT_ABI_EXT
+#error missing definition of DEFAULT_ABI_EXT in ${tm_defines}.
+#endif
+
+#ifndef DEFAULT_CPU_ARCH
+#error missing definition of DEFAULT_CPU_ARCH in ${tm_defines}.
+#endif
+
+#ifndef DEFAULT_ISA_EXT_FPU
+#error missing definition of DEFAULT_ISA_EXT_FPU in ${tm_defines}.
+#endif
+
+/* Handle combinations of -m machine option values
+   (see loongarch.opt and loongarch-opts.h).  */
+void
+loongarch_config_target (struct loongarch_target *target,
+			 HOST_WIDE_INT opt_switches,
+			 int opt_arch, int opt_tune, int opt_fpu,
+			 int opt_abi_base, int opt_abi_ext,
+			 int opt_cmodel, int follow_multilib_list)
+{
+  struct loongarch_target t;
+
+  if (!target)
+    return;
+
+  /* Initialization */
+  init_enabled_abi_types ();
+  obstack_init (&msg_obstack);
+
+  struct {
+    int arch, tune, fpu, abi_base, abi_ext, cmodel;
+  } constrained = {
+      M_OPT_ABSENT(opt_arch)     ? 0 : 1,
+      M_OPT_ABSENT(opt_tune)     ? 0 : 1,
+      M_OPT_ABSENT(opt_fpu)      ? 0 : 1,
+      M_OPT_ABSENT(opt_abi_base) ? 0 : 1,
+      M_OPT_ABSENT(opt_abi_ext)  ? 0 : 1,
+      M_OPT_ABSENT(opt_cmodel)   ? 0 : 1,
+  };
+
+#define on(NAME) ((loongarch_switch_mask[(SW_##NAME)] & opt_switches) \
+		  && (on_switch = (SW_##NAME), 1))
+  int on_switch;
+
+  /* 1.  Target ABI */
+  t.abi.base = constrained.abi_base ? opt_abi_base : DEFAULT_ABI_BASE;
+
+  t.abi.ext = constrained.abi_ext ? opt_abi_ext : DEFAULT_ABI_EXT;
+
+  /* Extra switch handling.  */
+  if (on (SOFT_FLOAT) || on (SINGLE_FLOAT) || on (DOUBLE_FLOAT))
+    {
+      switch (on_switch)
+	{
+	  case SW_SOFT_FLOAT:
+	    opt_fpu = ISA_EXT_NOFPU;
+	    break;
+
+	  case SW_SINGLE_FLOAT:
+	    opt_fpu = ISA_EXT_FPU32;
+	    break;
+
+	  case SW_DOUBLE_FLOAT:
+	    opt_fpu = ISA_EXT_FPU64;
+	    break;
+
+	  default:
+	    gcc_unreachable();
+	}
+      constrained.fpu = 1;
+
+      /* The target ISA is not ready yet, but (isa_required (t.abi)
+	 + forced fpu) is enough for computing the forced base ABI.  */
+      struct loongarch_isa default_isa = isa_required (t.abi);
+      struct loongarch_isa force_isa = default_isa;
+      struct loongarch_abi force_abi = t.abi;
+      force_isa.fpu = opt_fpu;
+      force_abi.base = isa_default_abi (&force_isa).base;
+
+      if (isa_fpu_compat_p (&default_isa, &force_isa));
+	/* Keep quiet if -m*-float does not promote the FP ABI.  */
+      else if (constrained.abi_base && (t.abi.base != force_abi.base))
+	inform (UNKNOWN_LOCATION,
+		"%<-m%s%> overrides %<-m%s=%s%>, promoting ABI to %qs",
+		loongarch_switch_strings[on_switch],
+		OPTSTR_ABI_BASE, loongarch_abi_base_strings[t.abi.base],
+		abi_str (force_abi));
+
+      t.abi.base = force_abi.base;
+    }
+
+#ifdef __DISABLE_MULTILIB
+  if (follow_multilib_list)
+    if (t.abi.base != DEFAULT_ABI_BASE || t.abi.ext != DEFAULT_ABI_EXT)
+      {
+	static const struct loongarch_abi default_abi
+	  = {DEFAULT_ABI_BASE, DEFAULT_ABI_EXT};
+
+	warning (0, "ABI changed (%qs to %qs) while multilib is disabled",
+		 abi_str (default_abi), abi_str (t.abi));
+      }
+#endif
+
+  /* 2.  Target CPU */
+  t.cpu_arch = constrained.arch ? opt_arch : DEFAULT_CPU_ARCH;
+
+  t.cpu_tune = constrained.tune ? opt_tune
+    : (constrained.arch ? DEFAULT_CPU_ARCH : DEFAULT_CPU_TUNE);
+
+#ifdef __loongarch__
+  /* For native compilers, gather local CPU information
+     and fill the "CPU_NATIVE" index of arrays defined in
+     loongarch-cpu.c.  */
+
+  t.cpu_native = fill_native_cpu_config (t.cpu_arch == CPU_NATIVE,
+					 t.cpu_tune == CPU_NATIVE);
+
+#else
+  if (t.cpu_arch == CPU_NATIVE)
+    fatal_error (UNKNOWN_LOCATION,
+		 "%qs does not work on a cross compiler",
+		 "-m" OPTSTR_ARCH "=" STR_CPU_NATIVE);
+
+  else if (t.cpu_tune == CPU_NATIVE)
+    fatal_error (UNKNOWN_LOCATION,
+		 "%qs does not work on a cross compiler",
+		 "-m" OPTSTR_TUNE "=" STR_CPU_NATIVE);
+#endif
+
+  /* 3.  Target ISA */
+config_target_isa:
+
+  /* Get default ISA from "-march" or its default value.  */
+  t.isa = loongarch_cpu_default_isa[__ACTUAL_ARCH];
+
+  /* Apply incremental changes.  */
+  /* "-march=native" overrides the default FPU type.  */
+  t.isa.fpu = constrained.fpu ? opt_fpu :
+    ((t.cpu_arch == CPU_NATIVE && constrained.arch) ?
+     t.isa.fpu : DEFAULT_ISA_EXT_FPU);
+
+
+  /* 4.  ABI-ISA compatibility */
+  /* Note:
+     - There IS a unique default -march value for each ABI type
+       (config.gcc: triplet -> abi -> default arch).
+
+     - If the base ABI is incompatible with the default arch,
+       try using the default -march it implies (and mark it
+       as "constrained" this time), then re-apply step 3.
+  */
+  struct loongarch_abi abi_tmp;
+  const struct loongarch_isa* isa_min;
+
+  abi_tmp = t.abi;
+  isa_min = &isa_required (abi_tmp);
+
+  if (isa_base_compat_p (&t.isa, isa_min)); /* OK.  */
+  else if (!constrained.arch)
+    {
+      /* Base architecture can only be implied by -march,
+	 so we adjust that first if it is not constrained.  */
+      int fallback_arch = abi_default_cpu_arch (t.abi);
+
+      if (t.cpu_arch == CPU_NATIVE)
+	warning (0, "your native CPU architecture (%qs) "
+		 "does not support %qs ABI, falling back to %<-m%s=%s%>",
+		 arch_str (&t), abi_str (t.abi), OPTSTR_ARCH,
+		 loongarch_cpu_strings[fallback_arch]);
+      else
+	warning (0, "default CPU architecture (%qs) "
+		 "does not support %qs ABI, falling back to %<-m%s=%s%>",
+		 arch_str (&t), abi_str (t.abi), OPTSTR_ARCH,
+		 loongarch_cpu_strings[fallback_arch]);
+
+      t.cpu_arch = fallback_arch;
+      constrained.arch = 1;
+      goto config_target_isa;
+    }
+  else if (!constrained.abi_base)
+    {
+      /* If -march is given while -mabi is not,
+	 try selecting another base ABI type.  */
+      abi_tmp.base = isa_default_abi (&t.isa).base;
+    }
+  else
+    goto fatal;
+
+  if (isa_fpu_compat_p (&t.isa, isa_min)); /* OK.  */
+  else if (!constrained.fpu)
+    t.isa.fpu = isa_min->fpu;
+  else if (!constrained.abi_base)
+      /* If -march is compatible with the default ABI
+	 while -mfpu is not.  */
+    abi_tmp.base = isa_default_abi (&t.isa).base;
+  else
+    goto fatal;
+
+  if (0)
+fatal:
+    fatal_error (UNKNOWN_LOCATION,
+		 "unable to implement ABI %qs with instruction set %qs",
+		 abi_str (t.abi), isa_str (&t.isa, '/'));
+
+
+  /* Using the fallback ABI.  */
+  if (abi_tmp.base != t.abi.base || abi_tmp.ext != t.abi.ext)
+    {
+      /* This flag is only set in the GCC driver.  */
+      if (follow_multilib_list)
+	{
+
+	  /* Continue falling back until we find a feasible ABI type
+	     enabled by TM_MULTILIB_LIST.  */
+	  if (!is_multilib_enabled (abi_tmp))
+	    {
+	      for (unsigned int i = 0; i < ABI_COUNT; i++)
+		{
+		  if (is_multilib_enabled (abi_priority_list[i])
+		      && abi_compat_p (&t.isa, abi_priority_list[i]))
+		    {
+		      abi_tmp = abi_priority_list[i];
+
+		      warning (0, "ABI %qs cannot be implemented due to "
+			       "limited instruction set %qs, "
+			       "falling back to %qs", abi_str (t.abi),
+			       isa_str (&t.isa, '/'), abi_str (abi_tmp));
+
+		      goto fallback;
+		    }
+		}
+
+	      /* Otherwise, keep using abi_tmp with a warning.  */
+#ifdef __DISABLE_MULTILIB
+	      warning (0, "instruction set %qs cannot implement "
+		       "default ABI %qs, falling back to %qs",
+		       isa_str (&t.isa, '/'), abi_str (t.abi),
+		       abi_str (abi_tmp));
+#else
+	      warning (0, "no multilib-enabled ABI (%qs) can be implemented "
+		       "with instruction set %qs, falling back to %qs",
+		       multilib_enabled_abi_list (),
+		       isa_str (&t.isa, '/'), abi_str (abi_tmp));
+#endif
+	    }
+	}
+
+fallback:
+      t.abi = abi_tmp;
+    }
+  else if (follow_multilib_list)
+    {
+      if (!is_multilib_enabled (t.abi))
+	{
+	  inform (UNKNOWN_LOCATION,
+		  "ABI %qs is not enabled at configure-time, "
+		  "the linker might report an error", abi_str (t.abi));
+
+	  inform (UNKNOWN_LOCATION, "ABI with startfiles: %s",
+		  multilib_enabled_abi_list ());
+	}
+    }
+
+
+  /* 5.  Target code model */
+  t.cmodel = constrained.cmodel ? opt_cmodel : CMODEL_NORMAL;
+
+  /* cleanup and return */
+  obstack_free (&msg_obstack, NULL);
+  *target = t;
+}
+
+/* Returns the default ABI for the given instruction set.  */
+static inline struct loongarch_abi
+isa_default_abi (const struct loongarch_isa *isa)
+{
+  struct loongarch_abi abi;
+
+  switch (isa->fpu)
+    {
+      case ISA_EXT_FPU64:
+	if (isa->base == ISA_BASE_LA64V100)
+	  abi.base = ABI_BASE_LP64D;
+	break;
+
+      case ISA_EXT_FPU32:
+	if (isa->base == ISA_BASE_LA64V100)
+	  abi.base = ABI_BASE_LP64F;
+	break;
+
+      case ISA_EXT_NOFPU:
+	if (isa->base == ISA_BASE_LA64V100)
+	  abi.base = ABI_BASE_LP64S;
+	break;
+
+      default:
+	gcc_unreachable ();
+    }
+
+  abi.ext = ABI_EXT_BASE;
+  return abi;
+}
+
+/* Check if set2 is a subset of set1.  */
+static inline int
+isa_base_compat_p (const struct loongarch_isa *set1,
+		   const struct loongarch_isa *set2)
+{
+  switch (set2->base)
+    {
+      case ISA_BASE_LA64V100:
+	return (set1->base == ISA_BASE_LA64V100);
+
+      default:
+	gcc_unreachable ();
+    }
+}
+
+static inline int
+isa_fpu_compat_p (const struct loongarch_isa *set1,
+		  const struct loongarch_isa *set2)
+{
+  switch (set2->fpu)
+    {
+      case ISA_EXT_FPU64:
+	return set1->fpu == ISA_EXT_FPU64;
+
+      case ISA_EXT_FPU32:
+	return set1->fpu == ISA_EXT_FPU32 || set1->fpu == ISA_EXT_FPU64;
+
+      case ISA_EXT_NOFPU:
+	return 1;
+
+      default:
+	gcc_unreachable ();
+    }
+
+}
+
+static inline int
+abi_compat_p (const struct loongarch_isa *isa, struct loongarch_abi abi)
+{
+  int compatible = 1;
+  const struct loongarch_isa *isa2 = &isa_required (abi);
+
+  /* Append conditionals for new ISA components below.  */
+  compatible = compatible && isa_base_compat_p (isa, isa2);
+  compatible = compatible && isa_fpu_compat_p (isa, isa2);
+  return compatible;
+}
+
+/* The behavior of this function should be consistent
+   with config.gcc.  */
+static inline int
+abi_default_cpu_arch (struct loongarch_abi abi)
+{
+  switch (abi.base)
+    {
+      case ABI_BASE_LP64D:
+      case ABI_BASE_LP64F:
+      case ABI_BASE_LP64S:
+	if (abi.ext == ABI_EXT_BASE)
+	  return CPU_LOONGARCH64;
+    }
+  gcc_unreachable ();
+}
+
+static const char*
+abi_str (struct loongarch_abi abi)
+{
+  /* "/base" can be omitted */
+  if (abi.ext == ABI_EXT_BASE)
+    return (const char*)
+      obstack_copy0 (&msg_obstack, loongarch_abi_base_strings[abi.base],
+		     strlen (loongarch_abi_base_strings[abi.base]));
+  else
+    {
+      APPEND_STRING (loongarch_abi_base_strings[abi.base])
+      APPEND1 ('/')
+      APPEND_STRING (loongarch_abi_ext_strings[abi.ext])
+      APPEND1 ('\0')
+
+      return XOBFINISH (&msg_obstack, const char *);
+    }
+}
+
+static const char*
+isa_str (const struct loongarch_isa *isa, char separator)
+{
+  APPEND_STRING (loongarch_isa_base_strings[isa->base])
+  APPEND1 (separator)
+
+  if (isa->fpu == ISA_EXT_NOFPU)
+    {
+      APPEND_STRING ("no" OPTSTR_ISA_EXT_FPU)
+    }
+  else
+    {
+      APPEND_STRING (OPTSTR_ISA_EXT_FPU)
+      APPEND_STRING (loongarch_isa_ext_strings[isa->fpu])
+    }
+  APPEND1 ('\0')
+
+  /* Add more here.  */
+
+  return XOBFINISH (&msg_obstack, const char *);
+}
+
+static const char*
+arch_str (const struct loongarch_target *target)
+{
+  if (target->cpu_arch == CPU_NATIVE)
+    {
+      if (target->cpu_native == CPU_NATIVE)
+	{
+	  /* Describe a native CPU with unknown PRID.  */
+	  const char* isa_string = isa_str (&target->isa, ',');
+	  APPEND_STRING ("PRID: 0x")
+	  APPEND_STRING (get_native_prid_str ())
+	  APPEND_STRING (", ISA features: ")
+	  APPEND_STRING (isa_string)
+	  APPEND1 ('\0')
+	}
+      else
+	APPEND_STRING (loongarch_cpu_strings[target->cpu_native]);
+    }
+  else
+    APPEND_STRING (loongarch_cpu_strings[target->cpu_arch]);
+
+  APPEND1 ('\0')
+  return XOBFINISH (&msg_obstack, const char *);
+}
+
+static const char*
+multilib_enabled_abi_list ()
+{
+  int enabled_abi_idx[MULTILIB_LIST_LEN] = { 0 };
+  const char* enabled_abi_str[MULTILIB_LIST_LEN] = { NULL };
+  unsigned int j = 0;
+
+  for (unsigned int i = 0; i < ABI_COUNT && j < MULTILIB_LIST_LEN; i++)
+    {
+      if (enabled_abi_types[abi_priority_list[i].base]
+	  [abi_priority_list[i].ext])
+	{
+	  enabled_abi_idx[j++] = i;
+	}
+    }
+
+  for (unsigned int k = 0; k < j; k++)
+    {
+      enabled_abi_str[k] = abi_str (abi_priority_list[enabled_abi_idx[k]]);
+    }
+
+  for (unsigned int k = 0; k < j - 1; k++)
+    {
+      APPEND_STRING (enabled_abi_str[k])
+      APPEND1 (',')
+      APPEND1 (' ')
+    }
+  APPEND_STRING (enabled_abi_str[j - 1])
+  APPEND1 ('\0')
+
+  return XOBFINISH (&msg_obstack, const char *);
+}
diff --git a/gcc/config/loongarch/loongarch-opts.h b/gcc/config/loongarch/loongarch-opts.h
new file mode 100644
index 00000000000..9c205e01980
--- /dev/null
+++ b/gcc/config/loongarch/loongarch-opts.h
@@ -0,0 +1,86 @@ 
+/* Definitions for loongarch-specific option handling.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   Contributed by Loongson Ltd.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef LOONGARCH_OPTS_H
+#define LOONGARCH_OPTS_H
+
+
+/* Target configuration */
+extern struct loongarch_target la_target;
+
+/* Switch masks */
+extern const int loongarch_switch_mask[];
+
+#include "loongarch-def.h"
+
+#if !defined(IN_LIBGCC2) && !defined(IN_TARGET_LIBS) && !defined(IN_RTS)
+/* Handler for "-m" option combinations,
+   shared by the driver and the compiler proper.  */
+void
+loongarch_config_target (struct loongarch_target *target,
+  HOST_WIDE_INT opt_switches,
+  int opt_arch, int opt_tune, int opt_fpu,
+  int opt_abi_base, int opt_abi_ext,
+  int opt_cmodel, int follow_multilib_list);
+#endif
+
+
+/* Macros for common conditional expressions used in loongarch.{c,h,md} */
+#define TARGET_CMODEL_NORMAL	    (la_target.cmodel == CMODEL_NORMAL)
+#define TARGET_CMODEL_TINY	    (la_target.cmodel == CMODEL_TINY)
+#define TARGET_CMODEL_TINY_STATIC   (la_target.cmodel == CMODEL_TINY_STATIC)
+#define TARGET_CMODEL_LARGE	    (la_target.cmodel == CMODEL_LARGE)
+#define TARGET_CMODEL_EXTREME	    (la_target.cmodel == CMODEL_EXTREME)
+
+#define TARGET_HARD_FLOAT	    (la_target.isa.fpu != ISA_EXT_NOFPU)
+#define TARGET_HARD_FLOAT_ABI	    (la_target.abi.base == ABI_BASE_LP64D \
+				     || la_target.abi.base == ABI_BASE_LP64F)
+
+#define TARGET_SOFT_FLOAT	  (la_target.isa.fpu == ISA_EXT_NOFPU)
+#define TARGET_SOFT_FLOAT_ABI	  (la_target.abi.base == ABI_BASE_LP64S)
+#define TARGET_SINGLE_FLOAT	  (la_target.isa.fpu == ISA_EXT_FPU32)
+#define TARGET_SINGLE_FLOAT_ABI	  (la_target.abi.base == ABI_BASE_LP64F)
+#define TARGET_DOUBLE_FLOAT	  (la_target.isa.fpu == ISA_EXT_FPU64)
+#define TARGET_DOUBLE_FLOAT_ABI	  (la_target.abi.base == ABI_BASE_LP64D)
+
+#define TARGET_64BIT		  (la_target.isa.base == ISA_BASE_LA64V100)
+#define TARGET_ABI_LP64	  (la_target.abi.base == ABI_BASE_LP64D \
+				   || la_target.abi.base == ABI_BASE_LP64F \
+				   || la_target.abi.base == ABI_BASE_LP64S)
+
+#define TARGET_ARCH_NATIVE	  (la_target.cpu_arch == CPU_NATIVE)
+#define __ACTUAL_ARCH		  (TARGET_ARCH_NATIVE \
+				   ? (la_target.cpu_native < N_ARCH_TYPES \
+				      ? (la_target.cpu_native) : (CPU_NATIVE)) \
+				      : (la_target.cpu_arch))
+
+#define TARGET_TUNE_NATIVE	(la_target.cpu_tune == CPU_NATIVE)
+#define __ACTUAL_TUNE		(TARGET_TUNE_NATIVE \
+				 ? (la_target.cpu_native < N_TUNE_TYPES \
+				    ? (la_target.cpu_native) : (CPU_NATIVE)) \
+				    : (la_target.cpu_tune))
+
+#define TARGET_ARCH_LOONGARCH64	  (__ACTUAL_ARCH == CPU_LOONGARCH64)
+#define TARGET_ARCH_LA464	  (__ACTUAL_ARCH == CPU_LA464)
+
+#define TARGET_TUNE_LOONGARCH64	  (__ACTUAL_TUNE == CPU_LOONGARCH64)
+#define TARGET_TUNE_LA464	  (__ACTUAL_TUNE == CPU_LA464)
+
+#endif /* LOONGARCH_OPTS_H */
diff --git a/gcc/config/loongarch/loongarch-str.h b/gcc/config/loongarch/loongarch-str.h
new file mode 100644
index 00000000000..4f0a76cdc28
--- /dev/null
+++ b/gcc/config/loongarch/loongarch-str.h
@@ -0,0 +1,57 @@ 
+/* Generated automatically by "genstr" from "loongarch-strings".
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   Contributed by Loongson Ltd.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef LOONGARCH_STR_H
+#define LOONGARCH_STR_H
+
+#define OPTSTR_ARCH "arch"
+#define OPTSTR_TUNE "tune"
+
+#define STR_CPU_NATIVE "native"
+#define STR_CPU_LOONGARCH64 "loongarch64"
+#define STR_CPU_LA464 "la464"
+
+#define STR_ISA_BASE_LA64V100 "la64"
+
+#define OPTSTR_ISA_EXT_FPU "fpu"
+#define STR_ISA_EXT_NOFPU "none"
+#define STR_ISA_EXT_FPU0 "0"
+#define STR_ISA_EXT_FPU32 "32"
+#define STR_ISA_EXT_FPU64 "64"
+
+#define OPTSTR_SOFT_FLOAT "soft-float"
+#define OPTSTR_SINGLE_FLOAT "single-float"
+#define OPTSTR_DOUBLE_FLOAT "double-float"
+
+#define OPTSTR_ABI_BASE "abi"
+#define STR_ABI_BASE_LP64D "lp64d"
+#define STR_ABI_BASE_LP64F "lp64f"
+#define STR_ABI_BASE_LP64S "lp64s"
+
+#define STR_ABI_EXT_BASE "base"
+
+#define OPTSTR_CMODEL "cmodel"
+#define STR_CMODEL_NORMAL "normal"
+#define STR_CMODEL_TINY "tiny"
+#define STR_CMODEL_TS "tiny-static"
+#define STR_CMODEL_LARGE "large"
+#define STR_CMODEL_EXTREME "extreme"
+
+#endif /* LOONGARCH_STR_H */
diff --git a/gcc/config/loongarch/loongarch.opt b/gcc/config/loongarch/loongarch.opt
new file mode 100644
index 00000000000..0511d08c261
--- /dev/null
+++ b/gcc/config/loongarch/loongarch.opt
@@ -0,0 +1,189 @@ 
+; Generated by "genstr" from the template "loongarch.opt.in"
+; and definitions from "loongarch-strings".
+;
+; Copyright (C) 2021 Free Software Foundation, Inc.
+;
+; This file is part of GCC.
+;
+; GCC is free software; you can redistribute it and/or modify it under
+; the terms of the GNU General Public License as published by the Free
+; Software Foundation; either version 3, or (at your option) any later
+; version.
+;
+; GCC is distributed in the hope that it will be useful, but WITHOUT
+; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+; or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+; License for more details.
+;
+; You should have received a copy of the GNU General Public License
+; along with GCC; see the file COPYING3.  If not see
+; <http://www.gnu.org/licenses/>.
+;
+
+; Variables (macros) that should be exported by loongarch.opt:
+;   la_opt_switches,
+;   la_opt_abi_base, la_opt_abi_ext,
+;   la_opt_cpu_arch, la_opt_cpu_tune,
+;   la_opt_fpu,
+;   la_cmodel.
+
+HeaderInclude
+config/loongarch/loongarch-opts.h
+
+HeaderInclude
+config/loongarch/loongarch-str.h
+
+Variable
+HOST_WIDE_INT la_opt_switches = 0
+
+; ISA related options
+;; Base ISA
+Enum
+Name(isa_base) Type(int)
+Basic ISAs of LoongArch:
+
+EnumValue
+Enum(isa_base) String(la64) Value(ISA_BASE_LA64V100)
+
+
+;; ISA extensions / adjustments
+Enum
+Name(isa_ext_fpu) Type(int)
+FPU types of LoongArch:
+
+EnumValue
+Enum(isa_ext_fpu) String(none) Value(ISA_EXT_NOFPU)
+
+EnumValue
+Enum(isa_ext_fpu) String(32) Value(ISA_EXT_FPU32)
+
+EnumValue
+Enum(isa_ext_fpu) String(64) Value(ISA_EXT_FPU64)
+
+mfpu=
+Target RejectNegative Joined ToLower Enum(isa_ext_fpu) Var(la_opt_fpu) Init(M_OPTION_NOT_SEEN)
+-mfpu=FPU	Generate code for the given FPU.
+
+mfpu=0
+Target RejectNegative Alias(mfpu=,none)
+
+msoft-float
+Target Driver RejectNegative Var(la_opt_switches) Mask(FORCE_SOFTF) Negative(msingle-float)
+Prevent the use of all hardware floating-point instructions.
+
+msingle-float
+Target Driver RejectNegative Var(la_opt_switches) Mask(FORCE_F32) Negative(mdouble-float)
+Restrict the use of hardware floating-point instructions to 32-bit operations.
+
+mdouble-float
+Target Driver RejectNegative Var(la_opt_switches) Mask(FORCE_F64) Negative(msoft-float)
+Allow hardware floating-point instructions to cover both 32-bit and 64-bit operations.
+
+
+;; Base target models (implies ISA & tune parameters)
+Enum
+Name(cpu_type) Type(int)
+LoongArch CPU types:
+
+EnumValue
+Enum(cpu_type) String(native) Value(CPU_NATIVE)
+
+EnumValue
+Enum(cpu_type) String(loongarch64) Value(CPU_LOONGARCH64)
+
+EnumValue
+Enum(cpu_type) String(la464) Value(CPU_LA464)
+
+march=
+Target RejectNegative Joined Enum(cpu_type) Var(la_opt_cpu_arch) Init(M_OPTION_NOT_SEEN)
+-march=PROCESSOR	Generate code for the given PROCESSOR ISA.
+
+mtune=
+Target RejectNegative Joined Enum(cpu_type) Var(la_opt_cpu_tune) Init(M_OPTION_NOT_SEEN)
+-mtune=PROCESSOR	Generate optimized code for PROCESSOR.
+
+
+; ABI related options
+; (ISA constraints on ABI are handled dynamically)
+
+;; Base ABI
+Enum
+Name(abi_base) Type(int)
+Base ABI types for LoongArch:
+
+EnumValue
+Enum(abi_base) String(lp64d) Value(ABI_BASE_LP64D)
+
+EnumValue
+Enum(abi_base) String(lp64f) Value(ABI_BASE_LP64F)
+
+EnumValue
+Enum(abi_base) String(lp64s) Value(ABI_BASE_LP64S)
+
+mabi=
+Target RejectNegative Joined ToLower Enum(abi_base) Var(la_opt_abi_base) Init(M_OPTION_NOT_SEEN)
+-mabi=BASEABI	Generate code that conforms to the given BASEABI.
+
+;; ABI Extension
+Variable
+int la_opt_abi_ext = M_OPTION_NOT_SEEN
+
+
+mbranch-cost=
+Target RejectNegative Joined UInteger Var(loongarch_branch_cost)
+-mbranch-cost=COST	Set the cost of branches to roughly COST instructions.
+
+mcheck-zero-division
+Target Mask(CHECK_ZERO_DIV)
+Trap on integer divide by zero.
+
+mcond-move-int
+Target Var(TARGET_COND_MOVE_INT) Init(1)
+Conditional moves for integral are enabled.
+
+mcond-move-float
+Target Var(TARGET_COND_MOVE_FLOAT) Init(1)
+Conditional moves for float are enabled.
+
+mmemcpy
+Target Mask(MEMCPY)
+Don't optimize block moves.
+
+mlra
+Target Var(loongarch_lra_flag) Init(1) Save
+Use LRA instead of reload.
+
+noasmopt
+Driver
+
+mstrict-align
+Target Var(TARGET_STRICT_ALIGN) Init(0)
+Do not generate unaligned memory accesses.
+
+mmax-inline-memcpy-size=
+Target Joined RejectNegative UInteger Var(loongarch_max_inline_memcpy_size) Init(1024)
+-mmax-inline-memcpy-size=SIZE	Set the max size of memcpy to inline, default is 1024.
+
+; The code model option names for -mcmodel.
+Enum
+Name(cmodel) Type(int)
+The code model option names for -mcmodel:
+
+EnumValue
+Enum(cmodel) String(normal) Value(CMODEL_NORMAL)
+
+EnumValue
+Enum(cmodel) String(tiny) Value(CMODEL_TINY)
+
+EnumValue
+Enum(cmodel) String(tiny-static) Value(CMODEL_TINY_STATIC)
+
+EnumValue
+Enum(cmodel) String(large) Value(CMODEL_LARGE)
+
+EnumValue
+Enum(cmodel) String(extreme) Value(CMODEL_EXTREME)
+
+mcmodel=
+Target RejectNegative Joined Enum(cmodel) Var(la_opt_cmodel) Init(CMODEL_NORMAL)
+Specify the code model.
diff --git a/gcc/config/loongarch/t-linux b/gcc/config/loongarch/t-linux
new file mode 100644
index 00000000000..7be867d2351
--- /dev/null
+++ b/gcc/config/loongarch/t-linux
@@ -0,0 +1,53 @@ 
+# Copyright (C) 2021 Free Software Foundation, Inc.
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GCC is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# Multilib
+MULTILIB_OPTIONS = mabi=lp64d/mabi=lp64f/mabi=lp64s
+MULTILIB_DIRNAMES = base/lp64d base/lp64f base/lp64s
+
+# The GCC driver always gets all abi-related options on the command line.
+# (see loongarch-driver.c:driver_get_normalized_m_opts)
+comma=,
+MULTILIB_REQUIRED = $(subst $(comma), ,$(TM_MULTILIB_CONFIG))
+
+# Multiarch
+ifneq ($(call if_multiarch,yes),yes)
+    # Define __DISABLE_MULTIARCH if multiarch is disabled.
+    tm_defines += __DISABLE_MULTIARCH
+else
+    # Only define MULTIARCH_DIRNAME when multiarch is enabled,
+    # or it would always introduce ${target} into the search path.
+    MULTIARCH_DIRNAME = $(LA_MULTIARCH_TRIPLET)
+endif
+
+# Don't define MULTILIB_OSDIRNAMES if multilib is disabled.
+ifeq ($(filter __DISABLE_MULTILIB,$(tm_defines)),)
+
+    MULTILIB_OSDIRNAMES = \
+      mabi.lp64d=../lib64$\
+      $(call if_multiarch,:loongarch64-linux-gnuf64)
+
+    MULTILIB_OSDIRNAMES += \
+      mabi.lp64f=../lib64/f32$\
+      $(call if_multiarch,:loongarch64-linux-gnuf32)
+
+    MULTILIB_OSDIRNAMES += \
+      mabi.lp64s=../lib64/sf$\
+      $(call if_multiarch,:loongarch64-linux-gnusf)
+
+endif
diff --git a/gcc/config/loongarch/t-loongarch b/gcc/config/loongarch/t-loongarch
new file mode 100644
index 00000000000..7708449827a
--- /dev/null
+++ b/gcc/config/loongarch/t-loongarch
@@ -0,0 +1,59 @@ 
+# Copyright (C) 2021 Free Software Foundation, Inc.
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GCC is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# Canonical target triplet from config.gcc
+LA_MULTIARCH_TRIPLET = $(patsubst LA_MULTIARCH_TRIPLET=%,%,$\
+$(filter LA_MULTIARCH_TRIPLET=%,$(tm_defines)))
+
+# String definition header
+LA_STR_H = $(srcdir)/config/loongarch/loongarch-str.h
+
+loongarch-c.o: $(srcdir)/config/loongarch/loongarch-c.cc $(CONFIG_H) $(SYSTEM_H) \
+	coretypes.h $(TM_H) $(TREE_H) output.h $(C_COMMON_H) $(TARGET_H)
+	$(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) \
+	$(srcdir)/config/loongarch/loongarch-c.cc
+
+loongarch-builtins.o: $(srcdir)/config/loongarch/loongarch-builtins.cc $(CONFIG_H) \
+	$(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) $(TREE_H) $(RECOG_H) langhooks.h \
+	$(DIAGNOSTIC_CORE_H) $(OPTABS_H) $(srcdir)/config/loongarch/loongarch-ftypes.def \
+	$(srcdir)/config/loongarch/loongarch-modes.def
+	$(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) \
+	$(srcdir)/config/loongarch/loongarch-builtins.cc
+
+loongarch-driver.o : $(srcdir)/config/loongarch/loongarch-driver.cc $(LA_STR_H) \
+	$(CONFIG_H) $(SYSTEM_H)
+	$(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) $<
+
+loongarch-opts.o: $(srcdir)/config/loongarch/loongarch-opts.cc $(LA_STR_H)
+	$(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) $<
+
+loongarch-cpu.o: $(srcdir)/config/loongarch/loongarch-cpu.cc $(LA_STR_H)
+	$(COMPILER) -c $(ALL_COMPILERFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) $<
+
+loongarch-def.o: $(srcdir)/config/loongarch/loongarch-def.c $(LA_STR_H)
+	$(CC) -c $(ALL_CFLAGS) $(INCLUDES) $<
+
+$(srcdir)/config/loongarch/loongarch.opt: \
+	$(srcdir)/config/loongarch/genopts/genstr.sh \
+	$(srcdir)/config/loongarch/genopts/loongarch.opt.in
+	$(SHELL) $< opt > $@
+
+$(LA_STR_H): \
+	$(srcdir)/config/loongarch/genopts/genstr.sh \
+	$(srcdir)/config/loongarch/genopts/loongarch-strings
+	$(SHELL) $< header > $@
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 1171c946e6e..3129bca6496 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -951,6 +951,9 @@  AC_ARG_ENABLE(fixed-point,
     mips*-*-*)
       enable_fixed_point=yes
       ;;
+    loongarch*-*-*)
+      enable_fixed_point=yes
+      ;;
     *)
       AC_MSG_WARN([fixed-point is not supported for this target, ignored])
       enable_fixed_point=no
@@ -3830,6 +3833,17 @@  foo:	data8	25
 	movl	r24 = @tprel(foo#)'
 	tls_as_opt=--fatal-warnings
 	;;
+  loongarch*-*-*)
+    conftest_s='
+	.section .tdata,"awT",@progbits
+x:	.word 2
+	.text
+	la.tls.gd $a0,x
+	bl __tls_get_addr'
+	tls_first_major=0
+	tls_first_minor=0
+	tls_as_opt='--fatal-warnings'
+	;;
   microblaze*-*-*)
     conftest_s='
 	.section .tdata,"awT",@progbits
@@ -5290,6 +5304,17 @@  configured with --enable-newlib-nano-formatted-io.])
       [AC_DEFINE(HAVE_AS_MARCH_ZIFENCEI, 1,
 		 [Define if the assembler understands -march=rv*_zifencei.])])
     ;;
+  loongarch*-*-*)
+    gcc_GAS_CHECK_FEATURE([.dtprelword support],
+      gcc_cv_as_loongarch_dtprelword, [2,18,0],,
+      [.section .tdata,"awT",@progbits
+x:
+	.word 2
+	.text
+	.dtprelword x+0x8000],,
+      [AC_DEFINE(HAVE_AS_DTPRELWORD, 1,
+	  [Define if your assembler supports .dtprelword.])])
+    ;;
     s390*-*-*)
     gcc_GAS_CHECK_FEATURE([.gnu_attribute support],
       gcc_cv_as_s390_gnu_attribute,,
@@ -5323,11 +5348,11 @@  configured with --enable-newlib-nano-formatted-io.])
     ;;
 esac
 
-# Mips and HP-UX need the GNU assembler.
+# Mips, LoongArch and HP-UX need the GNU assembler.
 # Linux on IA64 might be able to use the Intel assembler.
 
 case "$target" in
-  mips*-*-* | *-*-hpux* )
+  mips*-*-* | loongarch*-*-* | *-*-hpux* )
     if test x$gas_flag = xyes \
        || test x"$host" != x"$build" \
        || test ! -x "$gcc_cv_as" \
@@ -5484,8 +5509,8 @@  esac
 # ??? Once 2.11 is released, probably need to add first known working
 # version to the per-target configury.
 case "$cpu_type" in
-  aarch64 | alpha | arc | arm | avr | bfin | cris | csky | i386 | m32c | m68k \
-  | microblaze | mips | nds32 | nios2 | pa | riscv | rs6000 | score | sparc \
+  aarch64 | alpha | arc | arm | avr | bfin | cris | csky | i386 | loongarch | m32c \
+  | m68k | microblaze | mips | nds32 | nios2 | pa | riscv | rs6000 | score | sparc \
   | tilegx | tilepro | visium | xstormy16 | xtensa)
     insn="nop"
     ;;