AC_MSG_CHECKING([for number of cores])

  NUM_CORES=1

  FOUND_CORES=no

  if test -f /proc/cpuinfo; then

    # Looks like a Linux (or cygwin) system

    NUM_CORES=`cat /proc/cpuinfo  | grep -c processor`

    FOUND_CORES=yes

  elif test -x /usr/sbin/psrinfo; then

    # Looks like a Solaris system

    NUM_CORES=`LC_MESSAGES=C /usr/sbin/psrinfo -v | grep -c on-line`

    FOUND_CORES=yes

  elif test -x /usr/sbin/system_profiler; then

    # Looks like a MacOSX system

    NUM_CORES=`/usr/sbin/system_profiler -detailLevel full SPHardwareDataType | grep 'Cores' | awk  '{print [$]5}'`

    FOUND_CORES=yes

  elif test -n "$NUMBER_OF_PROCESSORS"; then

    # On windows, look in the env

    NUM_CORES=$NUMBER_OF_PROCESSORS

    FOUND_CORES=yes

  fi

  if test "x$FOUND_CORES" = xyes; then

    AC_MSG_RESULT([$NUM_CORES])

  else

    AC_MSG_RESULT([could not detect number of cores, defaulting to 1])

    AC_MSG_WARN([This will disable all parallelism from build!])

  fi

  AC_MSG_CHECKING([for memory size])

  # Default to 1024 MB

  MEMORY_SIZE=1024

  FOUND_MEM=no

  if test -f /proc/meminfo; then

    # Looks like a Linux (or cygwin) system

    MEMORY_SIZE=`cat /proc/meminfo | grep MemTotal | awk '{print [$]2}'`

    MEMORY_SIZE=`expr $MEMORY_SIZE / 1024`

    FOUND_MEM=yes

  elif test -x /usr/sbin/prtconf; then

    # Looks like a Solaris system

    MEMORY_SIZE=`/usr/sbin/prtconf | grep "Memory size" | awk '{ print [$]3 }'`

    FOUND_MEM=yes

  elif test -x /usr/sbin/system_profiler; then

    # Looks like a MacOSX system

    MEMORY_SIZE=`/usr/sbin/system_profiler -detailLevel full SPHardwareDataType | grep 'Memory' | awk  '{print [$]2}'`

    MEMORY_SIZE=`expr $MEMORY_SIZE \* 1024`

    FOUND_MEM=yes

  elif test "x$OPENJDK_BUILD_OS" = xwindows; then

    # Windows, but without cygwin

    MEMORY_SIZE=`wmic computersystem get totalphysicalmemory -value | grep = | cut -d "=" -f 2-`

    MEMORY_SIZE=`expr $MEMORY_SIZE / 1024 / 1024`

    FOUND_MEM=yes

  fi

  if test "x$FOUND_MEM" = xyes; then

    AC_MSG_RESULT([$MEMORY_SIZE MB])

  else

    AC_MSG_RESULT([could not detect memory size, defaulting to 1024 MB])

    AC_MSG_WARN([This might seriously impact build performance!])

  fi

      [number of cores in the build system, e.g. --with-num-cores=8 @<:@probed@:>@])])

      [memory (in MB) available in the build system, e.g. --with-memory-size=1024 @<:@probed@:>@])])

  # Provide a decent default number of parallel jobs for make depending on

      [number of parallel jobs to let make run @<:@calculated based on cores and memory@:>@])])

  AC_ARG_ENABLE([ccache],

      [AS_HELP_STRING([--disable-ccache],

      [disable using ccache to speed up recompilations @<:@enabled@:>@])],

      [ENABLE_CCACHE=${enable_ccache}], [ENABLE_CCACHE=yes])

  if test "x$ENABLE_CCACHE" = xyes; then

    OLD_PATH="$PATH"

    if test "x$TOOLS_DIR" != x; then

      PATH=$TOOLS_DIR:$PATH

    fi

    AC_PATH_PROG(CCACHE, ccache)

    PATH="$OLD_PATH"

  else

    AC_MSG_CHECKING([for ccache])

    AC_MSG_RESULT([explicitly disabled])

    CCACHE=

  fi

  AC_SUBST(CCACHE)

  AC_ARG_WITH([ccache-dir],

      [AS_HELP_STRING([--with-ccache-dir],

      [where to store ccache files @<:@~/.ccache@:>@])])

  if test "x$with_ccache_dir" != x; then

    # When using a non home ccache directory, assume the use is to share ccache files

    # with other users. Thus change the umask.

    SET_CCACHE_DIR="CCACHE_DIR=$with_ccache_dir CCACHE_UMASK=002"

  fi

  CCACHE_FOUND=""

  if test "x$CCACHE" != x; then

    BPERF_SETUP_CCACHE_USAGE

  fi

  if test "x$CCACHE" != x; then

    CCACHE_FOUND="true"

    # Only use ccache if it is 3.1.4 or later, which supports

    # precompiled headers.

    AC_MSG_CHECKING([if ccache supports precompiled headers])

    HAS_GOOD_CCACHE=`($CCACHE --version | head -n 1 | grep -E 3.1.@<:@456789@:>@) 2> /dev/null`

    if test "x$HAS_GOOD_CCACHE" = x; then

      AC_MSG_RESULT([no, disabling ccache])

      CCACHE=

    else

      AC_MSG_RESULT([yes])

      AC_MSG_CHECKING([if C-compiler supports ccache precompiled headers])

      PUSHED_FLAGS="$CXXFLAGS"

      CXXFLAGS="-fpch-preprocess $CXXFLAGS"

      AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [])], [CC_KNOWS_CCACHE_TRICK=yes], [CC_KNOWS_CCACHE_TRICK=no])

      CXXFLAGS="$PUSHED_FLAGS"

      if test "x$CC_KNOWS_CCACHE_TRICK" = xyes; then

        AC_MSG_RESULT([yes])

      else

        AC_MSG_RESULT([no, disabling ccaching of precompiled headers])

        CCACHE=

      fi

  fi

  if test "x$CCACHE" != x; then

    CCACHE_SLOPPINESS=time_macros

    CCACHE="CCACHE_COMPRESS=1 $SET_CCACHE_DIR CCACHE_SLOPPINESS=$CCACHE_SLOPPINESS $CCACHE"

    CCACHE_FLAGS=-fpch-preprocess

    if test "x$SET_CCACHE_DIR" != x; then

      mkdir -p $CCACHE_DIR > /dev/null 2>&1

      chmod a+rwxs $CCACHE_DIR > /dev/null 2>&1

  fi

  ###############################################################################

  #

  # Can the C/C++ compiler use precompiled headers?

  #

  AC_ARG_ENABLE([precompiled-headers], [AS_HELP_STRING([--disable-precompiled-headers],

      [disable using precompiled headers when compiling C++ @<:@enabled@:>@])],

      [ENABLE_PRECOMPH=${enable_precompiled_headers}], [ENABLE_PRECOMPH=yes])

  USE_PRECOMPILED_HEADER=1

  if test "x$ENABLE_PRECOMPH" = xno; then

  fi

  if test "x$ENABLE_PRECOMPH" = xyes; then

      AC_MSG_CHECKING([that precompiled headers work])

      echo "int alfa();" > conftest.h

      $CXX -x c++-header conftest.h -o conftest.hpp.gch 2>&AS_MESSAGE_LOG_FD >&AS_MESSAGE_LOG_FD

      if test ! -f conftest.hpp.gch; then

        USE_PRECOMPILED_HEADER=0

        AC_MSG_RESULT([no])

      else

        AC_MSG_RESULT([yes])

      fi

      rm -f conftest.h conftest.hpp.gch

  fi

  AC_SUBST(USE_PRECOMPILED_HEADER)

  AC_ARG_WITH(sjavac-server-java, [AS_HELP_STRING([--with-sjavac-server-java],

      [use this java binary for running the sjavac background server @<:@Boot JDK java@:>@])])

  if test "x$with_sjavac_server_java" != x; then

      AC_MSG_ERROR([Could not execute server java: $SJAVAC_SERVER_JAVA])

  else

  fi

  AC_SUBST(SJAVAC_SERVER_JAVA)

  if test "$MEMORY_SIZE" -gt "2500"; then

      JVM_64BIT=true

      JVM_ARG_OK=false

  fi

  if test "$JVM_64BIT" = true; then

      ADD_JVM_ARG_IF_OK([-Xms10G -Xmx10G],SJAVAC_SERVER_JAVA,[$SJAVAC_SERVER_JAVA])

      ADD_JVM_ARG_IF_OK([-Xms6G -Xmx6G],SJAVAC_SERVER_JAVA,[$SJAVAC_SERVER_JAVA])

      ADD_JVM_ARG_IF_OK([-Xms1G -Xmx3G],SJAVAC_SERVER_JAVA,[$SJAVAC_SERVER_JAVA])

      ADD_JVM_ARG_IF_OK([-Xms1G -Xmx2500M],SJAVAC_SERVER_JAVA,[$SJAVAC_SERVER_JAVA])

  fi

  if test "$MEMORY_SIZE" -gt "2500" && test "$JVM_ARG_OK" = false; then

  fi

  if test "$MEMORY_SIZE" -gt "1000" && test "$JVM_ARG_OK" = false; then

  fi

  if test "$JVM_ARG_OK" = false; then

  fi

  AC_MSG_CHECKING([whether to use sjavac])

  AC_ARG_ENABLE([sjavac], [AS_HELP_STRING([--enable-sjavac],

      [use sjavac to do fast incremental compiles @<:@disabled@:>@])],

      [ENABLE_SJAVAC="${enableval}"], [ENABLE_SJAVAC='no'])

  AC_MSG_RESULT([$ENABLE_SJAVAC])

  AC_SUBST(ENABLE_SJAVAC)

  if test "x$ENABLE_SJAVAC" = xyes; then

  else

  fi

  AC_SUBST(SJAVAC_SERVER_DIR)