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kc3-lang/libffi/m4/ax_cc_maxopt.m4

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  • Author : Anthony Green
    Date : 2022-08-31 09:49:21
    Hash : 7b1dd8ce
    Message : Don't -malign-double for x86-32

  • m4/ax_cc_maxopt.m4
  • # ===========================================================================
    #       https://www.gnu.org/software/autoconf-archive/ax_cc_maxopt.html
    # ===========================================================================
    #
    # SYNOPSIS
    #
    #   AX_CC_MAXOPT
    #
    # DESCRIPTION
    #
    #   Try to turn on "good" C optimization flags for various compilers and
    #   architectures, for some definition of "good". (In our case, good for
    #   FFTW and hopefully for other scientific codes. Modify as needed.)
    #
    #   The user can override the flags by setting the CFLAGS environment
    #   variable. The user can also specify --enable-portable-binary in order to
    #   disable any optimization flags that might result in a binary that only
    #   runs on the host architecture.
    #
    #   Note also that the flags assume that ANSI C aliasing rules are followed
    #   by the code (e.g. for gcc's -fstrict-aliasing), and that floating-point
    #   computations can be re-ordered as needed.
    #
    #   Requires macros: AX_CHECK_COMPILE_FLAG, AX_COMPILER_VENDOR,
    #   AX_GCC_ARCHFLAG, AX_GCC_X86_CPUID.
    #
    # LICENSE
    #
    #   Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu>
    #   Copyright (c) 2008 Matteo Frigo
    #
    #   This program 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.
    #
    #   This program 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 this program. If not, see <https://www.gnu.org/licenses/>.
    #
    #   As a special exception, the respective Autoconf Macro's copyright owner
    #   gives unlimited permission to copy, distribute and modify the configure
    #   scripts that are the output of Autoconf when processing the Macro. You
    #   need not follow the terms of the GNU General Public License when using
    #   or distributing such scripts, even though portions of the text of the
    #   Macro appear in them. The GNU General Public License (GPL) does govern
    #   all other use of the material that constitutes the Autoconf Macro.
    #
    #   This special exception to the GPL applies to versions of the Autoconf
    #   Macro released by the Autoconf Archive. When you make and distribute a
    #   modified version of the Autoconf Macro, you may extend this special
    #   exception to the GPL to apply to your modified version as well.
    
    #serial 22
    
    AC_DEFUN([AX_CC_MAXOPT],
    [
    AC_REQUIRE([AC_PROG_CC])
    AC_REQUIRE([AX_COMPILER_VENDOR])
    AC_REQUIRE([AC_CANONICAL_HOST])
    
    AC_ARG_ENABLE(portable-binary, [AS_HELP_STRING([--enable-portable-binary], [disable compiler optimizations that would produce unportable binaries])],
    	acx_maxopt_portable=$enableval, acx_maxopt_portable=no)
    
    # Try to determine "good" native compiler flags if none specified via CFLAGS
    if test "x$ac_test_CFLAGS" = "x"; then
      case $ax_cv_c_compiler_vendor in
        dec) CFLAGS="$CFLAGS -newc -w0 -O5 -ansi_alias -ansi_args -fp_reorder -tune host"
    	 if test "x$acx_maxopt_portable" = xno; then
               CFLAGS="$CFLAGS -arch host"
             fi;;
    
        sun) CFLAGS="$CFLAGS -native -fast -xO5 -dalign"
    	 if test "x$acx_maxopt_portable" = xyes; then
    	   CFLAGS="$CFLAGS -xarch=generic"
             fi;;
    
        hp)  CFLAGS="$CFLAGS +Oall +Optrs_ansi +DSnative"
    	 if test "x$acx_maxopt_portable" = xyes; then
    	   CFLAGS="$CFLAGS +DAportable"
    	 fi;;
    
        ibm) if test "x$acx_maxopt_portable" = xno; then
               xlc_opt="-qarch=auto -qtune=auto"
    	 else
               xlc_opt="-qtune=auto"
    	 fi
             AX_CHECK_COMPILE_FLAG($xlc_opt,
    		CFLAGS="$CFLAGS -O3 -qansialias -w $xlc_opt",
                   [CFLAGS="$CFLAGS -O3 -qansialias -w"
                    echo "******************************************************"
                    echo "*  You seem to have the IBM  C compiler.  It is      *"
                    echo "*  recommended for best performance that you use:    *"
                    echo "*                                                    *"
                    echo "*    CFLAGS=-O3 -qarch=xxx -qtune=xxx -qansialias -w *"
                    echo "*                      ^^^        ^^^                *"
                    echo "*  where xxx is pwr2, pwr3, 604, or whatever kind of *"
                    echo "*  CPU you have.  (Set the CFLAGS environment var.   *"
                    echo "*  and re-run configure.)  For more info, man cc.    *"
                    echo "******************************************************"])
             ;;
    
        intel) CFLAGS="$CFLAGS -O3 -ansi_alias"
    	if test "x$acx_maxopt_portable" = xno; then
    	  icc_archflag=unknown
    	  icc_flags=""
    	  case $host_cpu in
    	    i686*|x86_64*)
                  # icc accepts gcc assembly syntax, so these should work:
    	      AX_GCC_X86_CPUID(0)
                  AX_GCC_X86_CPUID(1)
    	      case $ax_cv_gcc_x86_cpuid_0 in # see AX_GCC_ARCHFLAG
                    *:756e6547:6c65746e:49656e69) # Intel
                      case $ax_cv_gcc_x86_cpuid_1 in
    		    *0?6[[78ab]]?:*:*:*|?6[[78ab]]?:*:*:*|6[[78ab]]?:*:*:*) icc_flags="-xK" ;;
    		    *0?6[[9d]]?:*:*:*|?6[[9d]]?:*:*:*|6[[9d]]?:*:*:*|*1?65?:*:*:*) icc_flags="-xSSE2 -xB -xK" ;;
    		    *0?6e?:*:*:*|?6e?:*:*:*|6e?:*:*:*) icc_flags="-xSSE3 -xP -xO -xB -xK" ;;
    		    *0?6f?:*:*:*|?6f?:*:*:*|6f?:*:*:*|*1?66?:*:*:*) icc_flags="-xSSSE3 -xT -xB -xK" ;;
    		    *1?6[[7d]]?:*:*:*) icc_flags="-xSSE4.1 -xS -xT -xB -xK" ;;
    		    *1?6[[aef]]?:*:*:*|*2?6[[5cef]]?:*:*:*) icc_flags="-xSSE4.2 -xS -xT -xB -xK" ;;
    		    *2?6[[ad]]?:*:*:*) icc_flags="-xAVX -SSE4.2 -xS -xT -xB -xK" ;;
    		    *3?6[[ae]]?:*:*:*) icc_flags="-xCORE-AVX-I -xAVX -SSE4.2 -xS -xT -xB -xK" ;;
    		    *3?6[[cf]]?:*:*:*|*4?6[[56]]?:*:*:*) icc_flags="-xCORE-AVX2 -xCORE-AVX-I -xAVX -SSE4.2 -xS -xT -xB -xK" ;;
    		    *000?f[[346]]?:*:*:*|?f[[346]]?:*:*:*|f[[346]]?:*:*:*) icc_flags="-xSSE3 -xP -xO -xN -xW -xK" ;;
    		    *00??f??:*:*:*|??f??:*:*:*|?f??:*:*:*|f??:*:*:*) icc_flags="-xSSE2 -xN -xW -xK" ;;
                      esac ;;
                  esac ;;
              esac
              if test "x$icc_flags" != x; then
                for flag in $icc_flags; do
                  AX_CHECK_COMPILE_FLAG($flag, [icc_archflag=$flag; break])
                done
              fi
              AC_MSG_CHECKING([for icc architecture flag])
    	  AC_MSG_RESULT($icc_archflag)
              if test "x$icc_archflag" != xunknown; then
                CFLAGS="$CFLAGS $icc_archflag"
              fi
            fi
    	;;
    
        nvhpc)
         # default optimization flags for nvhpc
         CFLAGS="$CFLAGS -O3"
         ;;
    
        gnu)
         # default optimization flags for gcc on all systems
         CFLAGS="$CFLAGS -O3 -fomit-frame-pointer"
    
         # -malign-double for x86 systems
         # LIBFFI_LOCAL: don't do this.
         # The testsuite doesn't use these flags and we'll get test failures.
         # AX_CHECK_COMPILE_FLAG(-malign-double, CFLAGS="$CFLAGS -malign-double")
    
         #  -fstrict-aliasing for gcc-2.95+
         AX_CHECK_COMPILE_FLAG(-fstrict-aliasing,
    	CFLAGS="$CFLAGS -fstrict-aliasing")
    
         # note that we enable "unsafe" fp optimization with other compilers, too
         AX_CHECK_COMPILE_FLAG(-ffast-math, CFLAGS="$CFLAGS -ffast-math")
    
         AX_GCC_ARCHFLAG($acx_maxopt_portable)
         ;;
    
        microsoft)
         # default optimization flags for MSVC opt builds
         CFLAGS="$CFLAGS -O2"
         ;;
      esac
    
      if test -z "$CFLAGS"; then
    	echo ""
    	echo "********************************************************"
            echo "* WARNING: Don't know the best CFLAGS for this system  *"
            echo "* Use ./configure CFLAGS=... to specify your own flags *"
    	echo "* (otherwise, a default of CFLAGS=-O3 will be used)    *"
    	echo "********************************************************"
    	echo ""
            CFLAGS="$CFLAGS -O3"
      fi
    
      AX_CHECK_COMPILE_FLAG($CFLAGS, [], [
    	echo ""
            echo "********************************************************"
            echo "* WARNING: The guessed CFLAGS don't seem to work with  *"
            echo "* your compiler.                                       *"
            echo "* Use ./configure CFLAGS=... to specify your own flags *"
            echo "********************************************************"
            echo ""
      ])
    
    fi
    ])