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@thulio
Created July 24, 2012 12:21
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Get GCC optimal compile flags
#!/bin/sh
# Print the gcc cpu specific options tailored for the current CPU
# Author:
# http://www.pixelbeat.org/
# Notes:
# This script currently supports Linux,FreeBSD,Cygwin
# This script is x86 (32 bit) specific
# It should work on any gcc >= 2.95 at least
# It only returns CPU specific options. You probably also want -03 etc.
# Changes:
# V0.1, 12 Mar 2003, Initial release
# V0.2, 01 Jun 2005, Added support for 3.2>=gcc<=4.0
# V0.3, 03 Jun 2005, Added support for pentium-m
# V0.4, 03 Jun 2005, Fix silly bugs
# V0.5, 07 Jun 2005, Clarify/Simplify confusing floating point expr usage
# Print warning when CPU only supported on a newer gcc
# V0.6, 15 Dec 2006, Added support for Intel Core and Core 2 processors
# Added support for 4.1>=gcc<=4.3
# Added support for gcc -msse3 option
# Added support for new gcc -march=native option
# V0.7, 18 Dec 2006, Changes from Conor McDermottroe
# Added support for FreeBSD
# Remove bash specific constructs
# Better error handling
# V0.8, 19 Dec 2006, Give warnings and 32 bit -march on 64 bit platforms.
# Previously it just gave an invalid blank -march.
# Reported and tested by Ewan Oughton.
# V0.9, 30 Apr 2007, Give error if compiler not present.
# Warn about rather than default to -march=native option.
# V0.92, 08 Nov 2007, Change from Krzysztof Jankowski to support Cygwin.
# Added support for AMD family 10 processors.
# Add support for gcc -msse4 & -msse5 options.
# Use "prescott" rather than "pentium4" for all
# models >= 3 in intel family 15, not just model 3.
# V0.93, 13 Nov 2007, Oops, actually not all intel family 15, model >= 3
# are prescotts. Use the sse3 flag to distinguish.
# V0.94, 31 Dec 2007, Oops, actually all intel family 15, model >= 3
# are prescotts. This was indicated by Adam Drzewiecki.
# I was confused by a bug in older linux kernels where pni
# was not reported for my intel "F41" processor at least.
# V0.95, 18 Jan 2008, Changes from Conor McDermottroe
# Support for Mac OS X
# Support for FreeBSD base system
# V0.96, 17 Dec 2008, Following a report from Alfredo Pons, add support
# for newer intel core2 processors (models 23,26,29,...)
# by assuming models >= 15 are core2.
# Report details of unrecognised CPUs.
# V0.97, 19 Dec 2008, Use prescott for Intel Atom (model 28).
# Ensure all errors are output to stderr.
# V0.98, 24 Feb 2009, Actually Intel Atom (model 28) is core2 ISA compliant.
# It's an in-order core (like i586) so mtune as such.
# V0.99, 30 Apr 2009, Intel Atom (model 28) is getting a corresponding "atom"
# option in GCC 4.5
# V0.99.3, 11 Aug 2009, Support for AMD Geode LX processor.
# V0.99.4, 24 Oct 2009, Following a report from Maxime de Roucy, add support
# for AMD family 17 (griffin).
# V0.99.9, 05 May 2012
# http://github.com/pixelb/scripts/commits/master/scripts/gcccpuopt
if [ "$1" = "--version" ]; then
echo "0.99.9" && exit
fi
# This table shows when -march options were introduced into _official_ gcc releases.
# Note there are vendor deviations that complicate this.
# For e.g. Red Hat introduced the prescott option in 3.3-13.
# gcc-2.95 = i386, i486, i586,pentium, i686,pentiumpro, k6
# gcc-3.0 += athlon
# gcc-3.1 += pentium-mmx, pentium2, pentium3, pentium4, k6-2, k6-3, athlon-{tbird, 4,xp,mp}
# gcc-3.3 += winchip-c6, winchip2, c3
# gcc-3.4.0 += k8,opteron,athlon64,athlon-fx, c3-2
# gcc-3.4.1 += pentium-m, pentium3m, pentium4m, prescott, nocona
# gcc-4.3 += core2, amdfam10, geode
# gcc-4.5 += atom
# gcc-4.6 += corei7, corei7-avx, bdver1, btver1
# gcc-4.7 += core-avx-i, core-avx2, bdver2
[ -z "$CC" ] && CC=gcc
try_gcc_options() {
$CC $* -S -o /dev/null -xc /dev/null >/dev/null 2>&1
}
if ! try_gcc_options; then
echo "Error: Couldn't execute your compiler ($CC)" >&2
exit 1
fi
if try_gcc_options -march=native; then
echo "Warning: Your compiler supports the -march=native option which you may prefer" >&2
#gcc -march=native --verbose -xc /dev/null 2>&1 | sed -n 's|.*/dev/null \(-march.*-mtune[^ ]*\).*|\1|p' >&2
fi
if ! try_gcc_options -march=i386; then
if ! try_gcc_options -m32 -march=i386; then
echo "Error: This script only supports 32 bit x86 architectures" >&2
exit 1
else
echo "Warning: The optimum *32 bit* architecture is reported" >&2
m32="-m32 "
fi
fi
try_line() {
skip=0
for arch in $1; do
if try_gcc_options $m32 -march=$arch; then
echo $arch
return
elif [ "$skip" = "0" ] && [ "$arch" != "native" ]; then
skip=1
echo "Warning: Newer versions of GCC better support your CPU with -march=$arch" >&2
fi
done
return 1
}
read_cpu_data_linux() {
IFS=":"
while read name value; do
unset IFS
name=`echo $name` #strip spaces
value=`echo $value` #strip spaces
if [ "$name" = "vendor_id" ]; then
value=`echo $value | sed 's/\([^ ]*\).*/\1/'` #take first word
fi
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"
break #flags last so break early
fi
done < /proc/cpuinfo
unset IFS
}
read_cpu_data_freebsd() {
local _line _cpu_id
if [ ! -r /var/run/dmesg.boot ]; then
echo "Error: /var/run/dmesg.boot does not exist!" >&2
exit 1;
fi
IFS="
"
for _line in `grep -A2 '^CPU: ' /var/run/dmesg.boot`; do
if [ -n "`echo $_line | grep '^ Origin = '`" ]; then
vendor_id="`echo $_line | sed -e 's/^ Origin = .//' -e 's/[^A-Za-z0-9].*$//'`"
_cpu_id="`echo $_line | sed -e 's/^.*Id = //' -e 's/ .*$//' -e 'y/abcdef/ABCDEF/'`"
cpu_family=$(( ($_cpu_id & 0xF0F) >> 8 )) #FreeBSD 5.0 sh doesn't support 0x
cpu_model=$(( (($_cpu_id & 0xF0) >> 4) + (($_cpu_id & 0xF0000) >> 12) ))
fi
if [ -n "`echo $_line | grep '^ Features='`" ]; then
flags="`echo $_line | sed -e 's/^.*<//' -e 's/>.*//' -e 's/,/ /g' | tr 'A-Z' 'a-z'`"
fi
done
unset IFS
}
read_cpu_data_darwin() {
vendor_id="`/usr/sbin/sysctl -n machdep.cpu.vendor`"
cpu_family="`/usr/sbin/sysctl -n machdep.cpu.family`"
cpu_model="`/usr/sbin/sysctl -n machdep.cpu.model`"
flags="`/usr/sbin/sysctl -n machdep.cpu.features | tr 'A-Z' 'a-z'`"
}
read_cpu_data() {
# Default values
vendor_id="NotFound"
cpu_family="-1"
cpu_model="-1"
flags=""
case "$(uname)" in
Linux|CYGWIN*)
read_cpu_data_linux ;;
FreeBSD)
read_cpu_data_freebsd ;;
Darwin)
read_cpu_data_darwin ;;
*)
echo "Error: $(uname) is not a supported operating system" >&2
exit 1 ;;
esac
}
read_cpu_data
if [ "$vendor_id" = "AuthenticAMD" ]; then
if [ $cpu_family -eq 4 ]; then
_CFLAGS="-march=i486"
elif [ $cpu_family -eq 5 ]; then
if [ $cpu_model -lt 4 ]; then
_CFLAGS="-march=pentium"
elif [ \( $cpu_model -eq 6 \) -o \( $cpu_model -eq 7 \) ]; then
_CFLAGS="-march=k6"
elif [ \( $cpu_model -eq 8 \) -o \( $cpu_model -eq 12 \) ]; then
line="k6-2 k6"
elif [ \( $cpu_model -eq 9 \) -o \( $cpu_model -eq 13 \) ]; then
line="k6-3 k6-2 k6"
elif [ $cpu_model -eq 10 ]; then #geode LX
line="geode k6-2 k6"
#The LX supports 3dnowext in addition to the k6-2 instructions,
#however gcc doesn't support explicitly selecting that.
fi
elif [ $cpu_family -eq 6 ]; then
if [ $cpu_model -le 3 ]; then
line="athlon k6-3 k6-2 k6"
elif [ $cpu_model -eq 4 ]; then
line="athlon-tbird athlon k6-3 k6-2 k6"
elif [ $cpu_model -ge 6 ]; then #athlon-{4,xp,mp} (also geode NX)
line="athlon-4 athlon k6-3 k6-2 k6"
fi
elif [ $cpu_family -eq 15 ]; then #k8,opteron,athlon64,athlon-fx
line="k8 athlon-4 athlon k6-3 k6-2 k6"
elif [ $cpu_family -eq 16 ] || #barcelona,amdfam10
[ $cpu_family -eq 17 ] || #griffin
[ $cpu_family -eq 18 ]; then #llano
line="amdfam10 k8 athlon-4 athlon k6-3 k6-2 k6"
elif [ $cpu_family -eq 20 ]; then #bobcat
line="btver1 amdfam10 k8 athlon-4 athlon k6-3 k6-2 k6"
elif [ $cpu_family -eq 21 ]; then #bulldozer
if echo "$flags" | grep -q bmi; then #piledriver
line="bdver2 bdver1 btver1 amdfam10 k8 athlon-4 athlon k6-3 k6-2 k6"
else
line="bdver1 btver1 amdfam10 k8 athlon-4 athlon k6-3 k6-2 k6"
fi
fi
elif [ "$vendor_id" = "CentaurHauls" ]; then
if [ $cpu_family -eq 5 ]; then
if [ $cpu_model -eq 4 ]; then
line="winchip-c6 pentium"
elif [ $cpu_model -eq 8 ]; then
line="winchip2 winchip-c6 pentium"
elif [ $cpu_model -ge 9 ]; then
line="winchip2 winchip-c6 pentium" #actually winchip3 but gcc doesn't support this currently
fi
elif [ $cpu_family -eq 6 ]; then
if echo "$flags" | grep -q cmov; then
fallback=pentiumpro
else
fallback=pentium #gcc incorrectly assumes i686 always has cmov
fi
if [ $cpu_model -eq 6 ]; then
_CFLAGS="-march=pentium" # ? Cyrix 3 (samuel)
elif [ $cpu_model -eq 7 ] || [ $cpu_model -eq 8 ]; then
line="c3 winchip2 winchip-c6 $fallback"
elif [ $cpu_model -ge 9 ]; then
line="c3-2 c3 winchip2 winchip-c6 $fallback"
fi
fi
elif [ "$vendor_id" = "GenuineIntel" ]; then
if [ $cpu_family -eq 3 ]; then
_CFLAGS="-march=i386"
elif [ $cpu_family -eq 4 ]; then
_CFLAGS="-march=i486"
elif [ $cpu_family -eq 5 ]; then
if [ $cpu_model -ne 4 ]; then
_CFLAGS="-march=pentium"
else
line="pentium-mmx pentium" #No overlap with other vendors
fi
elif [ $cpu_family -eq 6 ]; then
if [ \( $cpu_model -eq 0 \) -o \( $cpu_model -eq 1 \) ]; then
_CFLAGS="-march=pentiumpro"
elif [ \( $cpu_model -ge 3 \) -a \( $cpu_model -le 6 \) ]; then #4=TM5600 at least
line="pentium2 pentiumpro pentium-mmx pentium i486 i386"
elif [ \( $cpu_model -eq 9 \) -o \( $cpu_model -eq 13 \) ]; then #centrino
line="pentium-m pentium4 pentium3 pentium2 pentiumpro pentium-mmx pentium i486 i386"
elif [ \( $cpu_model -eq 14 \) ]; then #Core
line="prescott pentium-m pentium4 pentium3 pentium2 pentiumpro pentium-mmx pentium i486 i386"
elif [ $cpu_model -eq 28 ] || # pine
[ $cpu_model -eq 38 ] || # oak
[ $cpu_model -eq 54 ]; then # cedar
line="atom core2 pentium-m pentium4 pentium3 pentium2 pentiumpro pentium-mmx pentium i486 i386"
elif [ $cpu_model -eq 26 ] ||
[ $cpu_model -eq 30 ] ||
[ $cpu_model -eq 31 ] ||
[ $cpu_model -eq 46 ] ||
# ^ Nehalem ^
[ $cpu_model -eq 37 ] ||
[ $cpu_model -eq 44 ] ||
[ $cpu_model -eq 47 ]; then
# ^ Westmere ^
line="corei7 core2 pentium-m pentium4 pentium3 pentium2 pentiumpro pentium-mmx pentium i486 i386"
elif [ $cpu_model -eq 42 ] || #Sandy Bridge
[ $cpu_model -eq 45 ]; then #Sandy Bridge E
line="corei7-avx corei7 core2 pentium-m pentium4 pentium3 pentium2 pentiumpro pentium-mmx pentium i486 i386"
elif [ $cpu_model -eq 58 ]; then #Ivy Bridge
line="core-avx-i corei7-avx corei7 core2 pentium-m pentium4 pentium3 pentium2 pentiumpro pentium-mmx pentium i486 i386"
elif [ $cpu_model -eq 15 ] ||
# ^ Merom ^
[ $cpu_model -eq 22 ] ||
# ^ Conroe-L ^
[ $cpu_model -eq 23 ] ||
[ $cpu_model -eq 29 ]; then
# ^ Penryn ^
line="core2 pentium-m pentium4 pentium3 pentium2 pentiumpro pentium-mmx pentium i486 i386"
elif [ \( $cpu_model -ge 7 \) -a \( $cpu_model -le 11 \) ]; then
line="pentium3 pentium2 pentiumpro pentium-mmx pentium i486 i386"
fi
elif [ $cpu_family -eq 15 ]; then
line="pentium4 pentium3 pentium2 pentiumpro pentium-mmx pentium i486 i386"
if [ $cpu_model -ge 3 ]; then
line="prescott $line"
fi
fi
elif [ "$vendor_id" = "Geode" ]; then #by NSC
if [ $cpu_family -eq 5 ]; then
if [ \( $cpu_model -eq 4 \) -o \( $cpu_model -eq 9 \) ]; then
# Note both models 4 and 9 have cmov.
# In addition, model 9 has cxmmx.
# Note also, the "geode" gcc arch is for newer AMD geode cores
# and is not appropriate for this older core.
line="pentium-mmx pentium"
fi
fi
fi
if [ \( -z "$_CFLAGS" \) -a \( -z "$line" \) ]; then
echo "\
Unrecognised CPU. Please email the following to: [email protected]
Vendor:$vendor_id family:$cpu_family model:$cpu_model
flags:$flags" >&2
exit 1
fi
[ -z "$_CFLAGS" ] && _CFLAGS="-march=`try_line "$line"`"
#The Atom CPU supports the full core2 instruction set,
#but it's an in-order core, the last one of those being the i586.
#Therefore if gcc hasn't explicit support for the Atom,
#tune it for the i586 architecture.
if ! echo "$_CFLAGS" | grep -q "atom"; then #gcc hasn't specific Atom support
if echo "$line" | grep -q "core2"; then #atom ISA line
if [ $cpu_model -eq 28 ]; then #atom
if echo "$_CFLAGS" | grep -E -q "(core2|pentium[^ ])"; then #gcc chose out of order arch
_CFLAGS="$_CFLAGS -mtune=pentium" #tune for last in-order core
fi
fi
fi
fi
#SSE is not used for floating point by default in gcc 32 bit
#so turn that on here.
if echo "$flags" | grep -q "sse"; then
if try_gcc_options "-mfpmath=sse"; then #gcc >= 3.1
_CFLAGS="$_CFLAGS -mfpmath=sse"
fi
fi
#The SSE options are mostly selected automatically
#when a particular march option is selected.
#There are a few exceptions unfortunately, which we handle here.
#Note the sse instruction lines are:
# intel: [sse4.2] [sse4.1] ssse3 sse3 sse2 sse ...
# amd: [sse5] sse4a [sse3] sse2 sse ...
# The bracketed ones are only available on some cpus
# in a particular family and so need to be added explicitly.
if echo "$_CFLAGS" | grep -q "amdfam10"; then
if echo "$flags" | grep -q "sse5"; then
if try_gcc_options "-msse5"; then #gcc >= 4.3
_CFLAGS="$_CFLAGS -msse5"
fi
fi
elif echo "$_CFLAGS" | grep -E -q "(k8|c3-2)"; then
if echo "$flags" | grep -E -q "(sse3|pni)"; then
if try_gcc_options "-msse3"; then #gcc >= 3.3.3
_CFLAGS="$_CFLAGS -msse3"
fi
fi
elif echo "$_CFLAGS" | grep -q "core2"; then
if echo "$flags" | grep -q "sse4_2"; then
if try_gcc_options "-msse4"; then #gcc >= 4.3
_CFLAGS="$_CFLAGS -msse4"
fi
elif echo "$flags" | grep -q "sse4_1"; then
if try_gcc_options "-msse4.1"; then #gcc >= 4.3
_CFLAGS="$_CFLAGS -msse4.1"
fi
fi
fi
echo "$m32$_CFLAGS"
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