Установка Gentoo(как узнать свои параметры компиляции)

#!/bin/sh

# Author: pixelbeat

#This script is Linux specific
#It should work on any gcc >= 2.95 at least

#these apply to any arch (just here for reference)
unsafe_math_opts="-ffast-math -fno-math-errno -funsafe-math-optimizations -fno-trapping-math"

gcc_version=`gcc -dumpversion | sed 's/\([0-9]\{1,\}\.[0-9]\{1,\}\)\.*\([0-9]\{1,\}\)\{0,1\}/\1\2/'`

IFS=":"
while read name value; do
    unset IFS
    name=`echo $name`
    value=`echo $value`
    IFS=":"
    if [ "$name" == "vendor_id" ]; then
        vendor_id="$value"
    elif [ "$name" == "cpu family" ]; then
        cpu_family="$value"
    elif [ "$name" == "model" ]; then
        cpu_model="$value"
    elif [ "$name" == "flags" ]; then
        flags="$value"
    fi
done < /proc/cpuinfo
unset IFS

if [ "$vendor_id" == "AuthenticAMD" ]; then
    if [ "$cpu_family" == "4" ]; then
        _CFLAGS="$_CFLAGS -march=i486"
    elif [ "$cpu_family" == "5" ]; then
        if [ "$cpu_model" -lt "4" ]; then
            _CFLAGS="$_CFLAGS -march=pentium"
        elif [ "$cpu_model" == "6" ] || [ "$cpu_model" == "7" ]; then
            _CFLAGS="$_CFLAGS -march=k6"
        elif [ "$cpu_model" == "8" ] || [ "$cpu_model" == "12" ]; then
            if expr $gcc_version '>=' 3.1 >/dev/null; then
                _CFLAGS="$_CFLAGS -march=k6-2"
            else
                _CFLAGS="$_CFLAGS -march=k6"
            fi
        elif [ "$cpu_model" == "9" ] || [ "$cpu_model" == "13" ]; then
            if expr $gcc_version '>=' 3.1 >/dev/null; then
                _CFLAGS="$_CFLAGS -march=k6-3"
            else
                _CFLAGS="$_CFLAGS -march=k6"
            fi
        fi
    elif [ "$cpu_family" == "6" ]; then
        if [ "$cpu_model" -le "3" ]; then
            if expr $gcc_version '>=' 3.0 >/dev/null; then
                _CFLAGS="$_CFLAGS -march=athlon"
            else
                _CFLAGS="$_CFLAGS -march=k6"
            fi
        elif [ "$cpu_model" == "4" ]; then
            if expr $gcc_version '>=' 3.1 >/dev/null; then
                _CFLAGS="$_CFLAGS -march=athlon-tbird"
            elif expr $gcc_version '>=' 3.0 >/dev/null; then
                _CFLAGS="$_CFLAGS -march=athlon"
            else
                _CFLAGS="$_CFLAGS -march=k6"
            fi
        elif [ "$cpu_model" -ge "6" ]; then #athlon-{4,xp,mp}
            if expr $gcc_version '>=' 3.1 >/dev/null; then
                _CFLAGS="$_CFLAGS -march=athlon-xp"
            elif expr $gcc_version '>=' 3.0 >/dev/null; then
                _CFLAGS="$_CFLAGS -march=athlon"
            else
                _CFLAGS="$_CFLAGS -march=k6"
            fi
        fi
    fi
else #everything else "GenuineIntel"
    if [ "$cpu_family" == "3" ]; then
        _CFLAGS="$_CFLAGS -march=i386"
    elif [ "$cpu_family" == "4" ]; then
        _CFLAGS="$_CFLAGS -march=i486"
    elif [ "$cpu_family" == "5" ] && expr $gcc_version '<' 3.1 >/dev/null; then
        _CFLAGS="$_CFLAGS -march=pentium"
    elif [ "$cpu_family" -ge "6" ] && expr $gcc_version '<' 3.1 >/dev/null; then
        _CFLAGS="$_CFLAGS -march=pentiumpro"
    elif [ "$cpu_family" == "5" ]; then
        if [ "$cpu_model" != "4" ]; then
            _CFLAGS="$_CFLAGS -march=pentium"
        else
            _CFLAGS="$_CFLAGS -march=pentium-mmx" #No overlap with other vendors
        fi
    elif [ "$cpu_family" == "6" ]; then
        if echo "$flags" | grep -vq cmov; then #gcc incorrectly assumes i686 always has cmov
            _CFLAGS="$_CFLAGS -march=pentium -mcpu=pentiumpro" #VIA CPUs exhibit this
        else
            if [ "$cpu_model" == "0" ] || [ "$cpu_model" == "1" ]; then
                _CFLAGS="$_CFLAGS -march=pentiumpro"
            elif [ "$cpu_model" -ge "3" ] && [ "$cpu_model" -le "6" ]; then #4=TM5600 at least
                _CFLAGS="$_CFLAGS -march=pentium2"
            elif [ "$cpu_model" -ge "7" ] && [ "$cpu_model" -le "11" ]; then #9 invalid
                _CFLAGS="$_CFLAGS -march=pentium3"
            fi
        fi
    elif [ "$cpu_family" == "15" ]; then
        _CFLAGS="$_CFLAGS -march=pentium4"
    fi
fi

if expr $gcc_version '>=' 3.1 >/dev/null; then
    if echo "$flags" | grep -q sse2; then
        _CFLAGS="$_CFLAGS -mfpmath=sse -msse2"
    elif echo "$flags" | grep -q sse; then
        _CFLAGS="$_CFLAGS -mfpmath=sse -msse"
    fi
    if echo "$flags" | grep -q mmx; then
        _CFLAGS="$_CFLAGS -mmmx"
    fi
    if echo "$flags" | grep -q 3dnow; then
        _CFLAGS="$_CFLAGS -m3dnow"
    fi
fi

echo "$_CFLAGS"

Оригинал есть еще статьи
http://simple.linux.by/etc/flag_gcc.html
http://www.paradicesoftware.com/specs/cpuid/index.htm
http://www.freehackers.org/gentoo/gccflags/flag_gcc3.html