如何查看哪些标志-march = native将激活？

-Q --help=target

gcc -march=native -Q --help=target ...

-v

--help

gcc -march=native -E -v - </dev/null 2>&1 | grep cc1

echo | gcc -dM -E - -march=native

-###

-v

echo | gcc -### -E - -march=native 

gcc -### -E - -march=native 2>&1 | sed -r '/cc1/!d;s/(")|(^.* - )//g'

gcc -### -E - -march=native 2>&1 | sed -r '/cc1/!d;s/(")|(^.* - )|( -mno-[^ ]+)//g'

% gcc -march=native -Q --help=target | grep march
-march=                               core-avx-i

% gcc -march=core-avx-i ...

gcc -march=native -v -E - < /dev/null

-mno-*

gcc -march=native -v -E - < /dev/null 2>&1 | grep cc1 | perl -pe 's/ -mno-S+//g; s/^.* - //g;'

-mno-*

#!/bin/bash

gcc_cmd="gcc"

# Optionally supply path to gcc as first argument
if (($#)); then
    gcc_cmd="$1"
fi

with_mno=$(
    "${gcc_cmd}" -march=native -mtune=native -v -E - < /dev/null 2>&1 |
    grep cc1 |
    perl -pe 's/^.* - //g;'
)
without_mno=$(echo "${with_mno}" | perl -pe 's/ -mno-S+//g;')

"${gcc_cmd}" ${with_mno}    -dM -E - < /dev/null > /tmp/gcctest.a.$$
"${gcc_cmd}" ${without_mno} -dM -E - < /dev/null > /tmp/gcctest.b.$$

if diff -u /tmp/gcctest.{a,b}.$$; then
    echo "Safe to strip -mno-* options."
else
    echo
    echo "WARNING! Some -mno-* options are needed!"
    exit 1
fi

rm /tmp/gcctest.{a,b}.$$

gcc -march=native -v -E - < /dev/null

gcc -march=native -### -E - < /dev/null

--march=native