extern int zob;
void foo(void) {
    register int i = 42;
    zob += i;
}



% gcc -c pic.c -S -o -
        .file   "pic.c"
        .text
.globl foo
        .type   foo, @function
foo:
        pushl   %ebp
        movl    %esp, %ebp
        movl    $42, %eax
        addl    %eax, zob
        popl    %ebp
        ret
        .size   foo, .-foo
        .section        .note.GNU-stack,"",@progbits
        .ident  "GCC: (GNU) 3.3.4 (Debian 1:3.3.4-9)"




% gcc -fPIC -c pic.c -S -o -
        .file   "pic.c"
        .text
.globl foo
        .type   foo, @function
foo:
        pushl   %ebp
        movl    %esp, %ebp
        pushl   %ebx
        call    __i686.get_pc_thunk.bx
        addl    $_GLOBAL_OFFSET_TABLE_, %ebx
        movl    $42, %edx
        movl    zob@GOT(%ebx), %ecx
        movl    zob@GOT(%ebx), %eax
        movl    (%eax), %eax
        addl    %edx, %eax
        movl    %eax, (%ecx)
        popl    %ebx
        popl    %ebp
        ret
        .size   foo, .-foo
        .section        .gnu.linkonce.t.__i686.get_pc_thunk.bx,"ax",@progbits
.globl __i686.get_pc_thunk.bx
        .hidden __i686.get_pc_thunk.bx
        .type   __i686.get_pc_thunk.bx, @function
__i686.get_pc_thunk.bx:
        movl    (%esp), %ebx
        ret
        .section        .note.GNU-stack,"",@progbits
        .ident  "GCC: (GNU) 3.3.4 (Debian 1:3.3.4-9)"



% gcc -fPIC -finline-functions -O3 -c pic.c -S -o -
        .file   "pic.c"
        .text
        .p2align 4,,15
.globl foo
        .type   foo, @function
foo:
        call    __i686.get_pc_thunk.ax
        addl    $_GLOBAL_OFFSET_TABLE_, %eax
        pushl   %ebp
        movl    zob@GOT(%eax), %edx
        movl    %esp, %ebp
        addl    $42, (%edx)
        popl    %ebp
        ret
        .size   foo, .-foo
        .section        .gnu.linkonce.t.__i686.get_pc_thunk.ax,"ax",@progbits
.globl __i686.get_pc_thunk.ax
        .hidden __i686.get_pc_thunk.ax
        .type   __i686.get_pc_thunk.ax, @function
__i686.get_pc_thunk.ax:
        movl    (%esp), %eax
        ret
        .section        .note.GNU-stack,"",@progbits
        .ident  "GCC: (GNU) 3.3.4 (Debian 1:3.3.4-9)"