Weird C stuff

asm

    .file   "test.c"
    .local  a
    .comm   a,4,4
    .section    .rodata
.LC0:
    .string "%p\n%p\n"
.LC1:
    .string "%d\n%d\n"
    .text
    .globl  main
    .type   main, @function
main:
.LFB0:
    .cfi_startproc
    pushq   %rbp
    .cfi_def_cfa_offset 16
    .cfi_offset 6, -16 
    movq    %rsp, %rbp
    .cfi_def_cfa_register 6
    subq    $16, %rsp
    movq    $a, -8(%rbp)
    movq    -8(%rbp), %rax
    movl    $a, %edx
    movq    %rax, %rsi
    movl    $.LC0, %edi
    movl    $0, %eax
    call    printf
    movq    -8(%rbp), %rax
    movl    $6, (%rax)
    movl    a(%rip), %edx
    movq    -8(%rbp), %rax
    movl    (%rax), %eax
    movl    %eax, %esi
    movl    $.LC1, %edi
    movl    $0, %eax
    call    printf
    leave
    .cfi_def_cfa 7, 8
    ret 
    .cfi_endproc
.LFE0:
    .size   main, .-main
    .ident  "GCC: (GNU) 4.9.1 20140903 (prerelease)"
    .section    .note.GNU-stack,"",@progbits                                                   

gistfile1.txt

GCC output:
0x600954
0x600954
6
0

Clang output:
0x4005e4
0x4005e4
Segmentation fault (core dumped)

Weirdness

#include <stdio.h>

static const int a;

int main(void) {
    int *b = (int *) &a;
    printf("%p\n%p\n", b, &a);
    *b = 6;
    printf("%d\n%d\n", *b, a);
}