-fno-pic and -fPIC are the same? Or how to turn off PIC?

[Peng Yu <pengyu dot ut at gmail dot com>]

Hi,

-fno-pic and -fPIC are the same. Why are they the same. How to turn
off PIC? Thanks.

$ cat main.sh
#!/usr/bin/env bash
# vim: set noexpandtab tabstop=2:

set -v
function cmd {
$CC -fno-pic f.c -c -o nopic.o
$CC -fPIC f.c -c -o pic.o
cmp nopic.o pic.o
echo "$?"
}

CC=clang cmd
CC=gcc cmd
$ cat f.c
/* vim: set noexpandtab tabstop=2: */
void f() { }
$ ./main.sh
function cmd {
$CC -fno-pic f.c -c -o nopic.o
$CC -fPIC f.c -c -o pic.o
cmp nopic.o pic.o
echo "$?"
}

CC=clang cmd
0
CC=gcc cmd
0
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/7/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
7.3.0-27ubuntu1~18.04'
--with-bugurl=file:///usr/share/doc/gcc-7/README.Bugs
--enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++
--prefix=/usr --with-gcc-major-version-only --program-suffix=-7
--program-prefix=x86_64-linux-gnu- --enable-shared
--enable-linker-build-id --libexecdir=/usr/lib
--without-included-gettext --enable-threads=posix --libdir=/usr/lib
--enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-libmpx --enable-plugin
--enable-default-pie --with-system-zlib --with-target-system-zlib
--enable-objc-gc=auto --enable-multiarch --disable-werror
--with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32
--enable-multilib --with-tune=generic
--enable-offload-targets=nvptx-none --without-cuda-driver
--enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 7.3.0 (Ubuntu 7.3.0-27ubuntu1~18.04)

-- 
Regards,
Peng