Script to detect best cpuflags settings for CC

cpuflags.sh

#!/bin/sh

COMPILERS="clang gcc gcc45 gcc46 gcc47 gcc48 gcc49 gcc5 gcc6"

check_compilers()
{
 echo "Looking for available C compilers..."
 for C in ${COMPILERS}
 do
   P=`which ${C} 2>&1`
   RES=$?
   if [ $RES -eq 0 ]; then
     echo " - Found ${C} at ${P}"
     check_flags ${P}
     echo
   fi
 done
}

check_flags()
{
 C=$1; shift;
 printf "   Compiler flags:\t"
 if `echo ${C} | grep -q clang$`
 then
        ${C} -march=native -E -v - < /dev/null 2>&1 | grep cc1 | grep -o -E '\-target-cpu ([a-zA-Z0-9=\-]+)'
 else
        ${C} -march=native -E -v - < /dev/null 2>&1 | grep cc1 | grep -o -E '\-march[=]*[a-zA-Z0-9]+'
 fi
}


check_compilers