| # =========================================================================== |
| # 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 17 |
| |
| 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=$enableval, acx_maxopt_portable=no) |
| |
| # Try to determine "good" native compiler flags if none specified via CFLAGS |
| if test "$ac_test_CFLAGS" != "set"; then |
| CFLAGS="" |
| case $ax_cv_c_compiler_vendor in |
| dec) CFLAGS="-newc -w0 -O5 -ansi_alias -ansi_args -fp_reorder -tune host" |
| if test "x$acx_maxopt_portable" = xno; then |
| CFLAGS="$CFLAGS -arch host" |
| fi;; |
| |
| sun) CFLAGS="-native -fast -xO5 -dalign" |
| if test "x$acx_maxopt_portable" = xyes; then |
| CFLAGS="$CFLAGS -xarch=generic" |
| fi;; |
| |
| hp) CFLAGS="+Oall +Optrs_ansi +DSnative" |
| if test "x$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="-O3 -qansialias -w $xlc_opt", |
| [CFLAGS="-O3 -qansialias -w" |
| echo "******************************************************" |
| echo "* You seem to have the IBM C compiler. It is *" |
| echo "* recommended for best performance that you use: *" |
| echo "* *" |
| echo "* CFLAGS=-O3 -qarch=xxx -qtune=xxx -qansialias -w *" |
| echo "* ^^^ ^^^ *" |
| echo "* where xxx is pwr2, pwr3, 604, or whatever kind of *" |
| echo "* CPU you have. (Set the CFLAGS environment var. *" |
| echo "* and re-run configure.) For more info, man cc. *" |
| echo "******************************************************"]) |
| ;; |
| |
| intel) CFLAGS="-O3 -ansi_alias" |
| if test "x$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 $icc_archflag" |
| fi |
| fi |
| ;; |
| |
| gnu) |
| # default optimization flags for gcc on all systems |
| CFLAGS="-O3 -fomit-frame-pointer" |
| |
| # -malign-double for x86 systems |
| # libffi local change -- don't align double, as it changes the ABI |
| # AX_CHECK_COMPILE_FLAG(-malign-double, CFLAGS="$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($acx_maxopt_portable) |
| ;; |
| |
| microsoft) |
| # default optimization flags for MSVC opt builds |
| CFLAGS="-O2" |
| ;; |
| esac |
| |
| if test -z "$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="-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 "" |
| CFLAGS="" |
| ]) |
| |
| fi |
| ]) |
