Dynamically detect avx2 capabilities

.travis.yml

@@ -13,8 +13,6 @@ matrix:
           packages:
             - libblas-dev
             - liblapack-dev
-            - python-numpy
-            - python-scipy
             - python-dev
 #            - swig3.0
       env:
@@ -26,8 +24,6 @@ matrix:
           packages:
             - libatlas-base-dev
             - liblapack-dev
-            - python-numpy
-            - python-scipy
             - python-dev
 #            - swig3.0
       env:
@@ -39,42 +35,61 @@ matrix:
           packages:
             - libopenblas-dev
             - liblapack-dev
-            - python-numpy
-            - python-scipy
             - python-dev
 #            - swig3.0
       env:
         - PYTHON_CFLAGS="-I/usr/include/python2.7"
     - os: linux
+      dist: xenial  # To ensure clang 7 for __builtin_cpu_init().
       compiler: clang
       addons:
         apt:
           packages:
             - libopenblas-dev
             - liblapack-dev
-            - python-numpy
-            - python-scipy
             - python-dev
 #            - swig3.0
       env:
         - PYTHON_CFLAGS="-I/usr/include/python2.7"
         # NOTE: Hack, c.f. https://github.com/travis-ci/travis-ci/issues/8613
         - LD_LIBRARY_PATH="/usr/local/clang/lib"
     - os: osx
+      compiler: gcc
+      addons:
+        homebrew:
+          packages:
+            - gcc
+            - swig
+          update: true
       env:
-        - MATRIX_EVAL="brew update && brew install gcc@6 numpy scipy swig; brew link --overwrite gcc@6; export CC=gcc-6 CXX=g++-6"
+        - MATRIX_EVAL="which gcc; export CC=/usr/local/bin/gcc CXX=/usr/local/bin/g++"
     - os: osx
+      compiler: clang
+      addons:
+        homebrew:
+          packages:
+            - llvm
+            - swig
+          update: true
       env:
-        - MATRIX_EVAL="brew update && brew install llvm numpy scipy swig; brew link --overwrite llvm; export CC=/usr/local/opt/llvm/bin/clang CXX=/usr/local/opt/llvm/bin/clang++"
+        - MATRIX_EVAL="brew link --overwrite llvm; export CC=/usr/local/opt/llvm/bin/clang CXX=/usr/local/opt/llvm/bin/clang++"
         - LDFLAGS="-L/usr/local/opt/llvm/lib"
         - CPPFLAGS="-I/usr/local/opt/llvm/include"
   allow_failures:
     - os: osx
+      compiler: gcc
+      addons:
+        homebrew:
+          packages:
+            - gcc
+            - swig
+          update: true
       env:
-        - MATRIX_EVAL="brew update && brew install gcc@6 numpy scipy swig; brew link --overwrite gcc@6; export CC=gcc-6 CXX=g++-6"
+        - MATRIX_EVAL="which gcc; export CC=/usr/local/bin/gcc CXX=/usr/local/bin/g++"
 
 before_install:
   - eval "$MATRIX_EVAL"
+  - pip install --user scipy
 
 install:
   - ./.travis/install.sh

acinclude/ax_check_cpu.m4

@@ -1,4 +1,3 @@
-
 # serial 1
 
 AC_DEFUN([AX_CPU_ARCH], [
@@ -8,8 +7,12 @@ AC_CANONICAL_TARGET
 
 case $target in
   amd64-* | x86_64-*)
-    ARCH_CPUFLAGS="-msse4 -mpopcnt"
+    ARCH_CPUFLAGS="-mpopcnt"
     ARCH_CXXFLAGS="-m64"
+
+    AX_GCC_X86_CPU_SUPPORTS(avx2,
+        [ARCH_CPUFLAGS+=" -mavx2 -mf16c"],
+        [ARCH_CPUFLAGS+=" -msse4"])
     ;;
   aarch64*-*)
 dnl This is an arch for Nvidia Xavier a proper detection would be nice.

acinclude/ax_gcc_x86_cpu_supports.m4

@@ -0,0 +1,104 @@
+# ============================================================================
+#  https://www.gnu.org/software/autoconf-archive/ax_gcc_x86_cpu_supports.html
+# ============================================================================
+#
+# SYNOPSIS
+#
+#   AX_GCC_X86_CPU_SUPPORTS(X86-INSTRUCTION-SET,
+#     [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND])
+#
+# DESCRIPTION
+#
+#   Checks if the host cpu supports X86-INSTRUCTION-SET. The instruction set
+#   that can be tested are "mmx, popcnt, sse, sse2, sse3, sse4.1, sse4.2,
+#   sse4a, avx, avx2, avx512f, fma, fma4, bmi, bmi2". If the instruction set
+#   is supported by the host cpu, the C preprocessor macro
+#   HAVE_XXX_INSTRUCTIONS is set to 1. The XXX is up-cased instruction case
+#   with dot replaced by underscore. For example, the test for "sse4.2"
+#   would export HAVE_SSE4_2_INSTRUCTIONS=1. This macro requires gcc
+#   extended builtin function "__builtin_cpu_init" and
+#   "__builtin_cpu_supports" to detect the cpu features. It will error out
+#   if the compiler doesn't has these builtins.
+#
+#   If the test for the instruction set succeeded, the hook ACTION-IF-FOUND
+#   would run. Otherwise the hook ACTION-IF-NOT-FOUND would run if
+#   specified.
+#
+#   See also AX_CHECK_X86_FEATURES, which checks all the possible
+#   instruction set and export the corresponding CFLAGS.
+#
+# LICENSE
+#
+#   Copyright (c) 2016 Felix Chern <idryman@gmail.com>
+#
+#   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 2 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 3
+
+AC_DEFUN_ONCE([_AX_GCC_X86_CPU_INIT],
+ [AC_LANG_PUSH([C])
+  AC_CACHE_CHECK([for gcc __builtin_cpu_init function],
+    [ax_cv_gcc_check_x86_cpu_init],
+    [AC_RUN_IFELSE(
+      [AC_LANG_PROGRAM([#include <stdlib.h>],
+        [__builtin_cpu_init ();])
+      ],
+      [ax_cv_gcc_check_x86_cpu_init=yes],
+      [ax_cv_gcc_check_x86_cpu_init=no])])
+  AS_IF([test "X$ax_cv_gcc_check_x86_cpu_init" = "Xno"],
+    [AC_MSG_ERROR([Need GCC to support X86 CPU features tests])])
+])
+
+AC_DEFUN([AX_GCC_X86_CPU_SUPPORTS],
+  [AC_REQUIRE([AC_PROG_CC])
+   AC_REQUIRE([_AX_GCC_X86_CPU_INIT])
+   AC_LANG_PUSH([C])
+   AS_VAR_PUSHDEF([gcc_x86_feature], [AS_TR_SH([ax_cv_gcc_x86_cpu_supports_$1])])
+   AC_CACHE_CHECK([for x86 $1 instruction support],
+     [gcc_x86_feature],
+     [AC_RUN_IFELSE(
+       [AC_LANG_PROGRAM( [#include <stdlib.h> ],
+       [ __builtin_cpu_init ();
+         if (__builtin_cpu_supports("$1"))
+           return 0;
+         return 1;
+        ])],
+        [gcc_x86_feature=yes],
+        [gcc_x86_feature=no]
+     )]
+   )
+   AC_LANG_POP([C])
+   AS_VAR_IF([gcc_x86_feature],[yes],
+         [AC_DEFINE(
+           AS_TR_CPP([HAVE_$1_INSTRUCTIONS]),
+           [1],
+           [Define if $1 instructions are supported])
+          $2],
+          [$3]
+         )
+   AS_VAR_POPDEF([gcc_x86_feature])
+])

configure

@@ -2065,6 +2065,48 @@ $as_echo "$ac_res" >&6; }
   eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
 
 } # ac_fn_cxx_check_func
+
+# ac_fn_c_try_run LINENO
+# ----------------------
+# Try to link conftest.$ac_ext, and return whether this succeeded. Assumes
+# that executables *can* be run.
+ac_fn_c_try_run ()
+{
+  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+  if { { ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_link") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; } && { ac_try='./conftest$ac_exeext'
+  { { case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
+$as_echo "$ac_try_echo"; } >&5
+  (eval "$ac_try") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }; then :
+  ac_retval=0
+else
+  $as_echo "$as_me: program exited with status $ac_status" >&5
+       $as_echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+       ac_retval=$ac_status
+fi
+  rm -rf conftest.dSYM conftest_ipa8_conftest.oo
+  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
+  as_fn_set_status $ac_retval
+
+} # ac_fn_c_try_run
 cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
@@ -6807,15 +6849,128 @@ test -n "$target_alias" &&
     NONENONEs,x,x, &&
   program_prefix=${target_alias}-
 
+ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for gcc __builtin_cpu_init function" >&5
+$as_echo_n "checking for gcc __builtin_cpu_init function... " >&6; }
+if ${ax_cv_gcc_check_x86_cpu_init+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test "$cross_compiling" = yes; then :
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "cannot run test program while cross compiling
+See \`config.log' for more details" "$LINENO" 5; }
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <stdlib.h>
+int
+main ()
+{
+__builtin_cpu_init ();
+  ;
+  return 0;
+}
+
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  ax_cv_gcc_check_x86_cpu_init=yes
+else
+  ax_cv_gcc_check_x86_cpu_init=no
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_gcc_check_x86_cpu_init" >&5
+$as_echo "$ax_cv_gcc_check_x86_cpu_init" >&6; }
+  if test "X$ax_cv_gcc_check_x86_cpu_init" = "Xno"; then :
+  as_fn_error $? "Need GCC to support X86 CPU features tests" "$LINENO" 5
+fi
+
+
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for cpu arch" >&5
 $as_echo_n "checking for cpu arch... " >&6; }
 
 
 case $target in
   amd64-* | x86_64-*)
-    ARCH_CPUFLAGS="-msse4 -mpopcnt"
+    ARCH_CPUFLAGS="-mpopcnt"
     ARCH_CXXFLAGS="-m64"
+
+
+
+   ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+
+   { $as_echo "$as_me:${as_lineno-$LINENO}: checking for x86 avx2 instruction support" >&5
+$as_echo_n "checking for x86 avx2 instruction support... " >&6; }
+if ${ax_cv_gcc_x86_cpu_supports_avx2+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test "$cross_compiling" = yes; then :
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "cannot run test program while cross compiling
+See \`config.log' for more details" "$LINENO" 5; }
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <stdlib.h>
+int
+main ()
+{
+ __builtin_cpu_init ();
+         if (__builtin_cpu_supports("avx2"))
+           return 0;
+         return 1;
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  ax_cv_gcc_x86_cpu_supports_avx2=yes
+else
+  ax_cv_gcc_x86_cpu_supports_avx2=no
+
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+fi
+
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_gcc_x86_cpu_supports_avx2" >&5
+$as_echo "$ax_cv_gcc_x86_cpu_supports_avx2" >&6; }
+   ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+   if test "x$ax_cv_gcc_x86_cpu_supports_avx2" = xyes; then :
+
+$as_echo "#define HAVE_AVX2_INSTRUCTIONS 1" >>confdefs.h
+
+          ARCH_CPUFLAGS+=" -mavx2 -mf16c"
+else
+  ARCH_CPUFLAGS+=" -msse4"
+
+fi
+
+
     ;;
   aarch64*-*)
     ARCH_CPUFLAGS="-march=armv8.2-a"

makefile.inc.in

@@ -7,7 +7,7 @@ CXX          = @CXX@
 CXXCPP       = @CXXCPP@
 CPPFLAGS     = -DFINTEGER=int @CPPFLAGS@ @OPENMP_CXXFLAGS@ @NVCC_CPPFLAGS@
 CXXFLAGS     = -fPIC @ARCH_CXXFLAGS@ -Wno-sign-compare @CXXFLAGS@
-CPUFLAGS     = -mavx2 -mf16c @ARCH_CPUFLAGS@
+CPUFLAGS     = @ARCH_CPUFLAGS@
 LDFLAGS      = @OPENMP_CXXFLAGS@ @LDFLAGS@ @NVCC_LDFLAGS@
 LIBS         = @BLAS_LIBS@ @LAPACK_LIBS@ @LIBS@ @NVCC_LIBS@
 PYTHONCFLAGS = @PYTHON_CFLAGS@ -I@NUMPY_INCLUDE@