gcc/libatomic/configure.tgt

# -*- shell-script -*-
#  Copyright (C) 2012-2023 Free Software Foundation, Inc.
#  Contributed by Richard Henderson <rth@redhat.com>.
#
#  This file is part of the GNU Atomic Library (libatomic).
#
#  Libatomic 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 of the License, or
#  (at your option) any later version.
#
#  Libatomic 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.
#
#  Under Section 7 of GPL version 3, you are granted additional
#  permissions described in the GCC Runtime Library Exception, version
#  3.1, as published by the Free Software Foundation.
#
#  You should have received a copy of the GNU General Public License and
#  a copy of the GCC Runtime Library Exception along with this program;
#  see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
#  <http://www.gnu.org/licenses/>.

# Map the target cpu to an ARCH sub-directory.  At the same time,
# work out any special compilation flags as necessary.

# Give operating systems the opportunity to discard XCFLAGS modifications based
# on ${target_cpu}.  For example to allow proper use of multilibs.
configure_tgt_pre_target_cpu_XCFLAGS="${XCFLAGS}"

case "${target_cpu}" in
  alpha*)
	# fenv.c needs this option to generate inexact exceptions.
	XCFLAGS="${XCFLAGS} -mfp-trap-mode=sui"
	ARCH=alpha
	;;
  rs6000 | powerpc*)	ARCH=powerpc ;;
  riscv*)		ARCH=riscv ;;
  sh*)			ARCH=sh ;;

  aarch64*)
	ARCH=aarch64
	case "${target}" in
	    aarch64*-*-linux*)
		if test -n "$enable_aarch64_lse"; then
		    try_ifunc=yes
		fi
		;;
	esac
	XCFLAGS="${XCFLAGS} -mno-outline-atomics"
	;;
  arm*)
	ARCH=arm
	case "${target}" in
            arm*-*-freebsd* | arm*-*-netbsd*)
                ;;
            *)
                # ??? Detect when -march=armv7 is already enabled.
                try_ifunc=yes
                ;;
        esac
        ;;
  sparc)
	case " ${CC} ${CFLAGS} " in
	  *" -m64 "*)
	    ;;
	  *)
	    if test -z "$with_cpu"; then
	      XCFLAGS="${XCFLAGS} -mcpu=v9"
	    fi
	esac
	ARCH=sparc
	;;
  sparc64|sparcv9)
	case " ${CC} ${CFLAGS} " in
	  *" -m32 "*)
	    XCFLAGS="${XCFLAGS} -mcpu=v9"
	    ;;
	esac
	ARCH=sparc
	;;

  i[3456]86 | x86_64)
	cat > conftestx.c <<EOF
#ifndef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4
#error need -march=i486
#endif
EOF
	if ${CC} ${CFLAGS} -E conftestx.c > /dev/null 2>&1; then
	  :
	else
	  if test "${target_cpu}" = x86_64; then
	    XCFLAGS="${XCFLAGS} -march=i486 -mtune=generic"
	  else
	    XCFLAGS="${XCFLAGS} -march=i486 -mtune=${target_cpu}"
	  fi
	  XCFLAGS="${XCFLAGS} -fomit-frame-pointer"
	fi
	cat > conftestx.c <<EOF
#ifdef __x86_64__
#error ifunc is always wanted for 16B atomic load
#else
#ifndef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_8
#error need -march=i686
#endif
#endif
EOF
	if ${CC} ${CFLAGS} -E conftestx.c > /dev/null 2>&1; then
	  try_ifunc=no
	else
	  try_ifunc=yes
	fi
	rm -f conftestx.c
	ARCH=x86
	;;

  *)			ARCH="${target_cpu}" ;;
esac

# The cpu configury is always most relevant.
if test -d ${srcdir}/config/$ARCH ; then
  config_path="$ARCH"
fi

tmake_file=
# Other system configury
case "${target}" in
  aarch64*-*-linux*)
	# OS support for atomic primitives.
	config_path="${config_path} linux/aarch64 posix"
	;;

  arm*-*-linux* | arm*-*-uclinux*)
	# OS support for atomic primitives.
	config_path="${config_path} linux/arm posix"
	;;

  s390*-*-linux*)
	# OS support for atomic primitives.
	config_path="${config_path} s390 posix"
	;;

  powerpc*-*-aix*)
	config_path="${config_path} posix"
	tmake_file="t-aix"
	;;

  *-*-linux* | *-*-gnu* | *-*-k*bsd*-gnu \
  | *-*-netbsd* | *-*-freebsd* | *-*-openbsd* | *-*-dragonfly* \
  | *-*-solaris2* | *-*-sysv4* | *-*-irix6* | *-*-osf* | *-*-hpux11* \
  | *-*-darwin* | *-*-aix* | *-*-cygwin*)
	# POSIX system.  The OS is supported.
	config_path="${config_path} posix"
	;;

  *-*-mingw*)
	# OS support for atomic primitives.
        case ${target_thread_file} in
          win32 | mcf | single)
            config_path="${config_path} mingw"
            ;;
          posix)
            config_path="${config_path} posix"
            ;;
        esac
	;;

  *-*-rtems*)
	XCFLAGS="${configure_tgt_pre_target_cpu_XCFLAGS}"
	config_path="rtems"
	;;

  *-*-elf*)
	# ??? No target OS.  We could be targeting bare-metal kernel-mode,
	# or user-mode for some custom OS.  If the target supports TAS,
	# we can build our own spinlocks, given there are no signals.
	# If the target supports disabling interrupts, we can work in
	# kernel-mode, given the system is not multi-processor.
	UNSUPPORTED=1
	;;

  nvptx*-*-*)
	;;

  *)
	# Who are you?
	UNSUPPORTED=1
	;;
esac

# glibc will pass hwcap to ifunc resolver functions as an argument.
# The type may be different on different architectures.
case "${target}" in
  aarch64*-*-*)
	IFUNC_RESOLVER_ARGS="uint64_t hwcap"
	;;
  *)
	IFUNC_RESOLVER_ARGS="void"
	;;
esac