#define NULL ((void *)0)
typedef unsigned long size_t; // Customize by platform.
typedef long intptr_t;
typedef unsigned long uintptr_t;
typedef long scalar_t__; // Either arithmetic or pointer type.
/* By default, we understand bool (as a convenience). */
typedef int bool;
#define false 0
#define true 1

/* Forward declarations */

/* Type definitions */
struct timeval {
  unsigned long tv_usec;
  scalar_t__ tv_sec;
};

/* Variables and functions */
int /*<<< orphan*/ free(char *);
int /*<<< orphan*/ gettimeofday(struct timeval *, int /*<<< orphan*/ *);
char *malloc(size_t);
int /*<<< orphan*/ printf(char *, char, char, char, char, char, char, char,
                          char, char, char, char, char);
int rand();
char *realloc(char *, size_t);
int /*<<< orphan*/ srand(scalar_t__);
int main(int argc, char *argv[]) {
  struct timeval tm;
  gettimeofday(&tm, NULL);
  srand(tm.tv_sec + tm.tv_usec * 1000000ul);
  enum { hwaddr_len = 12 };
  enum { hwaddr_glb_len = 16 };
  enum { hwaddr_loc_len = 4 };
  static char hwaddr_glb[hwaddr_glb_len] = {'0', '1', '2', '3', '4', '5',
                                            '6', '7', '8', '9', 'A', 'B',
                                            'C', 'D', 'E', 'F'};
  static char hwaddr_loc[hwaddr_loc_len] = {'2', '6', 'A', 'E'};
  int i;
  size_t space = 1;
  char *mac = malloc(space);
  int local = 0;
  for (i = 0; i < hwaddr_len; i++) {
    if (i == 1 && local == 1) {
      mac[i] = hwaddr_loc[rand() % hwaddr_loc_len];
    } else {
      mac[i] = hwaddr_glb[rand() % hwaddr_glb_len];
    }
    space++;
    mac = realloc(mac, space);
  }
  char *mac_f1 = "%c%c%c%c%c%c%c%c%c%c%c%c\n";
  char *mac_f2 = "%c%c-%c%c-%c%c-%c%c-%c%c-%c%c\n";
  char *mac_f3 = "%c%c:%c%c:%c%c:%c%c:%c%c:%c%c\n";
  char *mac_f4 = "%c%c%c%c.%c%c%c%c.%c%c%c%c\n";
  printf(mac_f1, mac[0], mac[1], mac[2], mac[3], mac[4], mac[5], mac[6], mac[7],
         mac[8], mac[9], mac[10], mac[11]);
  printf(mac_f2, mac[0], mac[1], mac[2], mac[3], mac[4], mac[5], mac[6], mac[7],
         mac[8], mac[9], mac[10], mac[11]);
  printf(mac_f3, mac[0], mac[1], mac[2], mac[3], mac[4], mac[5], mac[6], mac[7],
         mac[8], mac[9], mac[10], mac[11]);
  printf(mac_f4, mac[0], mac[1], mac[2], mac[3], mac[4], mac[5], mac[6], mac[7],
         mac[8], mac[9], mac[10], mac[11]);
  free(mac);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
push   %r15
push   %r14
push   %r12
push   %rbx
sub    $0xa0,%rsp
movl   $0x0,-0x24(%rbp)
mov    %edi,-0x28(%rbp)
mov    %rsi,-0x30(%rbp)
lea    -0x40(%rbp),%rdi
xor    %eax,%eax
mov    %eax,%esi
call   1050 <gettimeofday@plt>
mov    -0x38(%rbp),%rdi
imul   $0xf4240,-0x40(%rbp),%rax
add    %rax,%rdi
call   1060 <srand@plt>
movq   $0x1,-0x50(%rbp)
mov    -0x50(%rbp),%rdi
call   1070 <malloc@plt>
mov    %rax,-0x58(%rbp)
movl   $0x0,-0x5c(%rbp)
movl   $0x0,-0x44(%rbp)
cmpl   $0xc,-0x44(%rbp)
jge    1270 <main+0x100>
cmpl   $0x1,-0x44(%rbp)
jne    121e <main+0xae>
cmpl   $0x1,-0x5c(%rbp)
jne    121e <main+0xae>
mov    $0x0,%al
call   1090 <rand@plt>
mov    $0x4,%ecx
cltd
idiv   %ecx
movslq %edx,%rcx
lea    0x2e65(%rip),%rax
mov    (%rax,%rcx,1),%dl
mov    -0x58(%rbp),%rax
movslq -0x44(%rbp),%rcx
mov    %dl,(%rax,%rcx,1)
jmp    1245 <main+0xd5>
mov    $0x0,%al
call   1090 <rand@plt>
mov    $0x10,%ecx
cltd
idiv   %ecx
movslq %edx,%rcx
lea    0x2e29(%rip),%rax
mov    (%rax,%rcx,1),%dl
mov    -0x58(%rbp),%rax
movslq -0x44(%rbp),%rcx
mov    %dl,(%rax,%rcx,1)
mov    -0x50(%rbp),%rax
add    $0x1,%rax
mov    %rax,-0x50(%rbp)
mov    -0x58(%rbp),%rdi
mov    -0x50(%rbp),%rsi
call   1080 <realloc@plt>
mov    %rax,-0x58(%rbp)
mov    -0x44(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x44(%rbp)
jmp    11d4 <main+0x64>
lea    0xd89(%rip),%rax
mov    %rax,-0x68(%rbp)
lea    0xd98(%rip),%rax
mov    %rax,-0x70(%rbp)
lea    0xdac(%rip),%rax
mov    %rax,-0x78(%rbp)
lea    0xdc0(%rip),%rax
mov    %rax,-0x80(%rbp)
mov    -0x68(%rbp),%rdi
mov    -0x58(%rbp),%rax
mov    (%rax),%sil
mov    -0x58(%rbp),%rax
mov    0x1(%rax),%dl
mov    -0x58(%rbp),%rax
mov    0x2(%rax),%cl
mov    -0x58(%rbp),%rax
mov    0x3(%rax),%r8b
mov    -0x58(%rbp),%rax
mov    0x4(%rax),%r9b
mov    -0x58(%rbp),%rax
mov    0x5(%rax),%r12b
mov    -0x58(%rbp),%rax
mov    0x6(%rax),%r15b
mov    -0x58(%rbp),%rax
mov    0x7(%rax),%r14b
mov    -0x58(%rbp),%rax
mov    0x8(%rax),%bl
mov    -0x58(%rbp),%rax
mov    0x9(%rax),%r11b
mov    -0x58(%rbp),%rax
mov    0xa(%rax),%r10b
mov    -0x58(%rbp),%rax
movsbl %sil,%esi
movsbl %dl,%edx
movsbl %cl,%ecx
movsbl %r8b,%r8d
movsbl %r9b,%r9d
movsbl %r12b,%r12d
mov    %r12d,(%rsp)
movsbl %r15b,%r15d
mov    %r15d,0x8(%rsp)
movsbl %r14b,%r14d
mov    %r14d,0x10(%rsp)
movsbl %bl,%ebx
mov    %ebx,0x18(%rsp)
movsbl %r11b,%r11d
mov    %r11d,0x20(%rsp)
movsbl %r10b,%r10d
mov    %r10d,0x28(%rsp)
movsbl 0xb(%rax),%eax
mov    %eax,0x30(%rsp)
call   1040 <printf@plt>
mov    -0x70(%rbp),%rdi
mov    -0x58(%rbp),%rax
mov    (%rax),%sil
mov    -0x58(%rbp),%rax
mov    0x1(%rax),%dl
mov    -0x58(%rbp),%rax
mov    0x2(%rax),%cl
mov    -0x58(%rbp),%rax
mov    0x3(%rax),%r8b
mov    -0x58(%rbp),%rax
mov    0x4(%rax),%r9b
mov    -0x58(%rbp),%rax
mov    0x5(%rax),%r12b
mov    -0x58(%rbp),%rax
mov    0x6(%rax),%r15b
mov    -0x58(%rbp),%rax
mov    0x7(%rax),%r14b
mov    -0x58(%rbp),%rax
mov    0x8(%rax),%bl
mov    -0x58(%rbp),%rax
mov    0x9(%rax),%r11b
mov    -0x58(%rbp),%rax
mov    0xa(%rax),%r10b
mov    -0x58(%rbp),%rax
movsbl %sil,%esi
movsbl %dl,%edx
movsbl %cl,%ecx
movsbl %r8b,%r8d
movsbl %r9b,%r9d
movsbl %r12b,%r12d
mov    %r12d,(%rsp)
movsbl %r15b,%r15d
mov    %r15d,0x8(%rsp)
movsbl %r14b,%r14d
mov    %r14d,0x10(%rsp)
movsbl %bl,%ebx
mov    %ebx,0x18(%rsp)
movsbl %r11b,%r11d
mov    %r11d,0x20(%rsp)
movsbl %r10b,%r10d
mov    %r10d,0x28(%rsp)
movsbl 0xb(%rax),%eax
mov    %eax,0x30(%rsp)
call   1040 <printf@plt>
mov    -0x78(%rbp),%rdi
mov    -0x58(%rbp),%rax
mov    (%rax),%sil
mov    -0x58(%rbp),%rax
mov    0x1(%rax),%dl
mov    -0x58(%rbp),%rax
mov    0x2(%rax),%cl
mov    -0x58(%rbp),%rax
mov    0x3(%rax),%r8b
mov    -0x58(%rbp),%rax
mov    0x4(%rax),%r9b
mov    -0x58(%rbp),%rax
mov    0x5(%rax),%r12b
mov    -0x58(%rbp),%rax
mov    0x6(%rax),%r15b
mov    -0x58(%rbp),%rax
mov    0x7(%rax),%r14b
mov    -0x58(%rbp),%rax
mov    0x8(%rax),%bl
mov    -0x58(%rbp),%rax
mov    0x9(%rax),%r11b
mov    -0x58(%rbp),%rax
mov    0xa(%rax),%r10b
mov    -0x58(%rbp),%rax
movsbl %sil,%esi
movsbl %dl,%edx
movsbl %cl,%ecx
movsbl %r8b,%r8d
movsbl %r9b,%r9d
movsbl %r12b,%r12d
mov    %r12d,(%rsp)
movsbl %r15b,%r15d
mov    %r15d,0x8(%rsp)
movsbl %r14b,%r14d
mov    %r14d,0x10(%rsp)
movsbl %bl,%ebx
mov    %ebx,0x18(%rsp)
movsbl %r11b,%r11d
mov    %r11d,0x20(%rsp)
movsbl %r10b,%r10d
mov    %r10d,0x28(%rsp)
movsbl 0xb(%rax),%eax
mov    %eax,0x30(%rsp)
call   1040 <printf@plt>
mov    -0x80(%rbp),%rdi
mov    -0x58(%rbp),%rax
mov    (%rax),%sil
mov    -0x58(%rbp),%rax
mov    0x1(%rax),%dl
mov    -0x58(%rbp),%rax
mov    0x2(%rax),%cl
mov    -0x58(%rbp),%rax
mov    0x3(%rax),%r8b
mov    -0x58(%rbp),%rax
mov    0x4(%rax),%r9b
mov    -0x58(%rbp),%rax
mov    0x5(%rax),%r12b
mov    -0x58(%rbp),%rax
mov    0x6(%rax),%r15b
mov    -0x58(%rbp),%rax
mov    0x7(%rax),%r14b
mov    -0x58(%rbp),%rax
mov    0x8(%rax),%bl
mov    -0x58(%rbp),%rax
mov    0x9(%rax),%r11b
mov    -0x58(%rbp),%rax
mov    0xa(%rax),%r10b
mov    -0x58(%rbp),%rax
movsbl %sil,%esi
movsbl %dl,%edx
movsbl %cl,%ecx
movsbl %r8b,%r8d
movsbl %r9b,%r9d
movsbl %r12b,%r12d
mov    %r12d,(%rsp)
movsbl %r15b,%r15d
mov    %r15d,0x8(%rsp)
movsbl %r14b,%r14d
mov    %r14d,0x10(%rsp)
movsbl %bl,%ebx
mov    %ebx,0x18(%rsp)
movsbl %r11b,%r11d
mov    %r11d,0x20(%rsp)
movsbl %r10b,%r10d
mov    %r10d,0x28(%rsp)
movsbl 0xb(%rax),%eax
mov    %eax,0x30(%rsp)
call   1040 <printf@plt>
mov    -0x58(%rbp),%rdi
call   1030 <free@plt>
xor    %eax,%eax
add    $0xa0,%rsp
pop    %rbx
pop    %r12
pop    %r14
pop    %r15
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbp
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
sub    $0x68,%rsp
lea    0x58(%rsp),%rdi
xor    %esi,%esi
call   1050 <gettimeofday@plt>
imul   $0xf4240,0x58(%rsp),%rdi
add    0x60(%rsp),%rdi
call   1060 <srand@plt>
mov    $0x1,%edi
call   1070 <malloc@plt>
mov    %rax,%rbx
mov    $0x2,%ebp
lea    0xe4a(%rip),%r14
cs nopw 0x0(%rax,%rax,1)
xor    %eax,%eax
call   1090 <rand@plt>
lea    0xf(%rax),%ecx
test   %eax,%eax
cmovns %eax,%ecx
and    $0xfffffff0,%ecx
sub    %ecx,%eax
cltq
movzbl (%rax,%r14,1),%eax
mov    %al,-0x2(%rbx,%rbp,1)
mov    %rbx,%rdi
mov    %rbp,%rsi
call   1080 <realloc@plt>
mov    %rax,%rbx
add    $0x1,%rbp
cmp    $0xe,%rbp
jne    11c0 <main+0x50>
movsbl (%rbx),%esi
mov    %esi,0x10(%rsp)
movsbl 0x1(%rbx),%edx
mov    %edx,0x14(%rsp)
movsbl 0x2(%rbx),%ecx
mov    %ecx,0xc(%rsp)
movsbl 0x3(%rbx),%r15d
movsbl 0x4(%rbx),%r12d
movsbl 0x5(%rbx),%eax
mov    %rax,0x40(%rsp)
movsbl 0x6(%rbx),%r11d
mov    %r11,0x28(%rsp)
movsbl 0x7(%rbx),%r14d
movsbl 0x8(%rbx),%r13d
mov    %r13,0x48(%rsp)
movsbl 0x9(%rbx),%r10d
mov    %r10,0x38(%rsp)
movsbl 0xa(%rbx),%ebp
mov    %rbp,0x30(%rsp)
movsbl 0xb(%rbx),%eax
mov    %rax,0x20(%rsp)
sub    $0x8,%rsp
lea    0xdaf(%rip),%rdi
mov    %r15d,%r8d
mov    %r15d,0x24(%rsp)
mov    %r12d,%r9d
mov    %r12d,0x20(%rsp)
push   %rax
push   %rbp
push   %r10
push   %r13
push   %r14
mov    %r14,%r13
mov    %r14,0x80(%rsp)
push   %r11
mov    0x78(%rsp),%rax
push   %rax
call   1040 <printf@plt>
add    $0x38,%rsp
lea    0xd8e(%rip),%rdi
mov    0x18(%rsp),%r14d
mov    %r14d,%esi
mov    0x1c(%rsp),%edx
mov    0x14(%rsp),%ebp
mov    %ebp,%ecx
mov    %r15d,%r8d
mov    %r12d,%r9d
push   0x28(%rsp)
mov    0x40(%rsp),%r12
push   %r12
mov    0x50(%rsp),%r15
push   %r15
push   0x68(%rsp)
push   %r13
push   0x58(%rsp)
mov    0x78(%rsp),%r13
push   %r13
call   1040 <printf@plt>
add    $0x38,%rsp
lea    0xd62(%rip),%rdi
mov    %r14d,%esi
mov    0x1c(%rsp),%r14d
mov    %r14d,%edx
mov    %ebp,%ecx
mov    0x24(%rsp),%r8d
mov    0x20(%rsp),%r9d
push   0x28(%rsp)
push   %r12
push   %r15
mov    0x68(%rsp),%rbp
push   %rbp
mov    0x78(%rsp),%r12
push   %r12
mov    0x58(%rsp),%r15
push   %r15
push   %r13
call   1040 <printf@plt>
add    $0x38,%rsp
lea    0xd3c(%rip),%rdi
mov    0x18(%rsp),%esi
mov    %r14d,%edx
mov    0x14(%rsp),%ecx
mov    0x24(%rsp),%r8d
mov    0x20(%rsp),%r9d
push   0x28(%rsp)
push   0x40(%rsp)
push   0x50(%rsp)
push   %rbp
push   %r12
push   %r15
push   %r13
call   1040 <printf@plt>
add    $0x40,%rsp
mov    %rbx,%rdi
call   1030 <free@plt>
xor    %eax,%eax
add    $0x68,%rsp
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
pop    %rbp
ret

LLVM IR (-O0):
%struct.timeval = type { i64, i64 }
@main.hwaddr_glb = internal global [16 x i8] c"0123456789ABCDEF"
@main.hwaddr_loc = internal global [4 x i8] c"26AE"
@.str = [26 x i8] c"%c%c%c%c%c%c%c%c%c%c%c%c\0A\00"
@.str.1 = [31 x i8] c"%c%c-%c%c-%c%c-%c%c-%c%c-%c%c\0A\00"
@.str.2 = [31 x i8] c"%c%c:%c%c:%c%c:%c%c:%c%c:%c%c\0A\00"
@.str.3 = [28 x i8] c"%c%c%c%c.%c%c%c%c.%c%c%c%c\0A\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
%6 = alloca %struct.timeval
%7 = alloca i32
%8 = alloca i64
%9 = alloca i8*
%10 = alloca i32
%11 = alloca i8*
%12 = alloca i8*
%13 = alloca i8*
%14 = alloca i8*
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
%15 = call i32 @gettimeofday(%struct.timeval* %6, i32* null)
%16 = getelementptr inbounds %struct.timeval, %struct.timeval* %6, i32 0, i32 1
%17 = load i64, i64* %16
%18 = getelementptr inbounds %struct.timeval, %struct.timeval* %6, i32 0, i32 0
%19 = load i64, i64* %18
%20 = mul i64 %19, 1000000
%21 = add i64 %17, %20
%22 = call i32 @srand(i64 %21)
store i64 1, i64* %8
%23 = load i64, i64* %8
%24 = call i8* @malloc(i64 %23)
store i8* %24, i8** %9
store i32 0, i32* %10
store i32 0, i32* %7
br label %25
25: ; preds = %60, %2
%26 = load i32, i32* %7
%27 = icmp slt i32 %26, 12
br i1 %27, label %28, label %63
28: ; preds = %25
%29 = load i32, i32* %7
%30 = icmp eq i32 %29, 1
br i1 %30, label %31, label %44
31: ; preds = %28
%32 = load i32, i32* %10
%33 = icmp eq i32 %32, 1
br i1 %33, label %34, label %44
34: ; preds = %31
%35 = call i32 (...) @rand()
%36 = srem i32 %35, 4
%37 = sext i32 %36 to i64
%38 = getelementptr inbounds [4 x i8], [4 x i8]* @main.hwaddr_loc, i64 0, i64 %37
%39 = load i8, i8* %38
%40 = load i8*, i8** %9
%41 = load i32, i32* %7
%42 = sext i32 %41 to i64
%43 = getelementptr inbounds i8, i8* %40, i64 %42
store i8 %39, i8* %43
br label %54
44: ; preds = %31, %28
%45 = call i32 (...) @rand()
%46 = srem i32 %45, 16
%47 = sext i32 %46 to i64
%48 = getelementptr inbounds [16 x i8], [16 x i8]* @main.hwaddr_glb, i64 0, i64 %47
%49 = load i8, i8* %48
%50 = load i8*, i8** %9
%51 = load i32, i32* %7
%52 = sext i32 %51 to i64
%53 = getelementptr inbounds i8, i8* %50, i64 %52
store i8 %49, i8* %53
br label %54
54: ; preds = %44, %34
%55 = load i64, i64* %8
%56 = add i64 %55, 1
store i64 %56, i64* %8
%57 = load i8*, i8** %9
%58 = load i64, i64* %8
%59 = call i8* @realloc(i8* %57, i64 %58)
store i8* %59, i8** %9
br label %60
60: ; preds = %54
%61 = load i32, i32* %7
%62 = add nsw i32 %61, 1
store i32 %62, i32* %7
br label %25
63: ; preds = %25
store i8* getelementptr inbounds ([26 x i8], [26 x i8]* @.str, i64 0, i64 0), i8** %11
store i8* getelementptr inbounds ([31 x i8], [31 x i8]* @.str.1, i64 0, i64 0), i8** %12
store i8* getelementptr inbounds ([31 x i8], [31 x i8]* @.str.2, i64 0, i64 0), i8** %13
store i8* getelementptr inbounds ([28 x i8], [28 x i8]* @.str.3, i64 0, i64 0), i8** %14
%64 = load i8*, i8** %11
%65 = load i8*, i8** %9
%66 = getelementptr inbounds i8, i8* %65, i64 0
%67 = load i8, i8* %66
%68 = load i8*, i8** %9
%69 = getelementptr inbounds i8, i8* %68, i64 1
%70 = load i8, i8* %69
%71 = load i8*, i8** %9
%72 = getelementptr inbounds i8, i8* %71, i64 2
%73 = load i8, i8* %72
%74 = load i8*, i8** %9
%75 = getelementptr inbounds i8, i8* %74, i64 3
%76 = load i8, i8* %75
%77 = load i8*, i8** %9
%78 = getelementptr inbounds i8, i8* %77, i64 4
%79 = load i8, i8* %78
%80 = load i8*, i8** %9
%81 = getelementptr inbounds i8, i8* %80, i64 5
%82 = load i8, i8* %81
%83 = load i8*, i8** %9
%84 = getelementptr inbounds i8, i8* %83, i64 6
%85 = load i8, i8* %84
%86 = load i8*, i8** %9
%87 = getelementptr inbounds i8, i8* %86, i64 7
%88 = load i8, i8* %87
%89 = load i8*, i8** %9
%90 = getelementptr inbounds i8, i8* %89, i64 8
%91 = load i8, i8* %90
%92 = load i8*, i8** %9
%93 = getelementptr inbounds i8, i8* %92, i64 9
%94 = load i8, i8* %93
%95 = load i8*, i8** %9
%96 = getelementptr inbounds i8, i8* %95, i64 10
%97 = load i8, i8* %96
%98 = load i8*, i8** %9
%99 = getelementptr inbounds i8, i8* %98, i64 11
%100 = load i8, i8* %99
%101 = call i32 @printf(i8* %64, i8 signext %67, i8 signext %70, i8 signext %73, i8 signext %76, i8 signext %79, i8 signext %82, i8 signext %85, i8 signext %88, i8 signext %91, i8 signext %94, i8 signext %97, i8 signext %100)
%102 = load i8*, i8** %12
%103 = load i8*, i8** %9
%104 = getelementptr inbounds i8, i8* %103, i64 0
%105 = load i8, i8* %104
%106 = load i8*, i8** %9
%107 = getelementptr inbounds i8, i8* %106, i64 1
%108 = load i8, i8* %107
%109 = load i8*, i8** %9
%110 = getelementptr inbounds i8, i8* %109, i64 2
%111 = load i8, i8* %110
%112 = load i8*, i8** %9
%113 = getelementptr inbounds i8, i8* %112, i64 3
%114 = load i8, i8* %113
%115 = load i8*, i8** %9
%116 = getelementptr inbounds i8, i8* %115, i64 4
%117 = load i8, i8* %116
%118 = load i8*, i8** %9
%119 = getelementptr inbounds i8, i8* %118, i64 5
%120 = load i8, i8* %119
%121 = load i8*, i8** %9
%122 = getelementptr inbounds i8, i8* %121, i64 6
%123 = load i8, i8* %122
%124 = load i8*, i8** %9
%125 = getelementptr inbounds i8, i8* %124, i64 7
%126 = load i8, i8* %125
%127 = load i8*, i8** %9
%128 = getelementptr inbounds i8, i8* %127, i64 8
%129 = load i8, i8* %128
%130 = load i8*, i8** %9
%131 = getelementptr inbounds i8, i8* %130, i64 9
%132 = load i8, i8* %131
%133 = load i8*, i8** %9
%134 = getelementptr inbounds i8, i8* %133, i64 10
%135 = load i8, i8* %134
%136 = load i8*, i8** %9
%137 = getelementptr inbounds i8, i8* %136, i64 11
%138 = load i8, i8* %137
%139 = call i32 @printf(i8* %102, i8 signext %105, i8 signext %108, i8 signext %111, i8 signext %114, i8 signext %117, i8 signext %120, i8 signext %123, i8 signext %126, i8 signext %129, i8 signext %132, i8 signext %135, i8 signext %138)
%140 = load i8*, i8** %13
%141 = load i8*, i8** %9
%142 = getelementptr inbounds i8, i8* %141, i64 0
%143 = load i8, i8* %142
%144 = load i8*, i8** %9
%145 = getelementptr inbounds i8, i8* %144, i64 1
%146 = load i8, i8* %145
%147 = load i8*, i8** %9
%148 = getelementptr inbounds i8, i8* %147, i64 2
%149 = load i8, i8* %148
%150 = load i8*, i8** %9
%151 = getelementptr inbounds i8, i8* %150, i64 3
%152 = load i8, i8* %151
%153 = load i8*, i8** %9
%154 = getelementptr inbounds i8, i8* %153, i64 4
%155 = load i8, i8* %154
%156 = load i8*, i8** %9
%157 = getelementptr inbounds i8, i8* %156, i64 5
%158 = load i8, i8* %157
%159 = load i8*, i8** %9
%160 = getelementptr inbounds i8, i8* %159, i64 6
%161 = load i8, i8* %160
%162 = load i8*, i8** %9
%163 = getelementptr inbounds i8, i8* %162, i64 7
%164 = load i8, i8* %163
%165 = load i8*, i8** %9
%166 = getelementptr inbounds i8, i8* %165, i64 8
%167 = load i8, i8* %166
%168 = load i8*, i8** %9
%169 = getelementptr inbounds i8, i8* %168, i64 9
%170 = load i8, i8* %169
%171 = load i8*, i8** %9
%172 = getelementptr inbounds i8, i8* %171, i64 10
%173 = load i8, i8* %172
%174 = load i8*, i8** %9
%175 = getelementptr inbounds i8, i8* %174, i64 11
%176 = load i8, i8* %175
%177 = call i32 @printf(i8* %140, i8 signext %143, i8 signext %146, i8 signext %149, i8 signext %152, i8 signext %155, i8 signext %158, i8 signext %161, i8 signext %164, i8 signext %167, i8 signext %170, i8 signext %173, i8 signext %176)
%178 = load i8*, i8** %14
%179 = load i8*, i8** %9
%180 = getelementptr inbounds i8, i8* %179, i64 0
%181 = load i8, i8* %180
%182 = load i8*, i8** %9
%183 = getelementptr inbounds i8, i8* %182, i64 1
%184 = load i8, i8* %183
%185 = load i8*, i8** %9
%186 = getelementptr inbounds i8, i8* %185, i64 2
%187 = load i8, i8* %186
%188 = load i8*, i8** %9
%189 = getelementptr inbounds i8, i8* %188, i64 3
%190 = load i8, i8* %189
%191 = load i8*, i8** %9
%192 = getelementptr inbounds i8, i8* %191, i64 4
%193 = load i8, i8* %192
%194 = load i8*, i8** %9
%195 = getelementptr inbounds i8, i8* %194, i64 5
%196 = load i8, i8* %195
%197 = load i8*, i8** %9
%198 = getelementptr inbounds i8, i8* %197, i64 6
%199 = load i8, i8* %198
%200 = load i8*, i8** %9
%201 = getelementptr inbounds i8, i8* %200, i64 7
%202 = load i8, i8* %201
%203 = load i8*, i8** %9
%204 = getelementptr inbounds i8, i8* %203, i64 8
%205 = load i8, i8* %204
%206 = load i8*, i8** %9
%207 = getelementptr inbounds i8, i8* %206, i64 9
%208 = load i8, i8* %207
%209 = load i8*, i8** %9
%210 = getelementptr inbounds i8, i8* %209, i64 10
%211 = load i8, i8* %210
%212 = load i8*, i8** %9
%213 = getelementptr inbounds i8, i8* %212, i64 11
%214 = load i8, i8* %213
%215 = call i32 @printf(i8* %178, i8 signext %181, i8 signext %184, i8 signext %187, i8 signext %190, i8 signext %193, i8 signext %196, i8 signext %199, i8 signext %202, i8 signext %205, i8 signext %208, i8 signext %211, i8 signext %214)
%216 = load i8*, i8** %9
%217 = call i32 @free(i8* %216)
ret i32 0
}

LLVM IR (-O2):
%struct.timeval = type { i64, i64 }
@main.hwaddr_glb = internal unnamed_addr constant [16 x i8] c"0123456789ABCDEF"
@.str = [26 x i8] c"%c%c%c%c%c%c%c%c%c%c%c%c\0A\00"
@.str.1 = [31 x i8] c"%c%c-%c%c-%c%c-%c%c-%c%c-%c%c\0A\00"
@.str.2 = [31 x i8] c"%c%c:%c%c:%c%c:%c%c:%c%c:%c%c\0A\00"
@.str.3 = [28 x i8] c"%c%c%c%c.%c%c%c%c.%c%c%c%c\0A\00"
define i32 @main(i32 %0, i8** nocapture readnone %1) {
%3 = alloca %struct.timeval
%4 = bitcast %struct.timeval* %3 to i8*
%5 = call i32 @gettimeofday(%struct.timeval* %3, i32* null)
%6 = getelementptr inbounds %struct.timeval, %struct.timeval* %3, i64 0, i32 1
%7 = load i64, i64* %6
%8 = getelementptr inbounds %struct.timeval, %struct.timeval* %3, i64 0, i32 0
%9 = load i64, i64* %8
%10 = mul i64 %9, 1000000
%11 = add i64 %10, %7
%12 = tail call i32 @srand(i64 %11)
%13 = tail call dereferenceable_or_null(1) i8* @malloc(i64 1)
br label %14
14: ; preds = %2, %14
%15 = phi i64 [ 0, %2 ], [ %26, %14 ]
%16 = phi i64 [ 1, %2 ], [ %24, %14 ]
%17 = phi i8* [ %13, %2 ], [ %25, %14 ]
%18 = tail call i32 (...) @rand()
%19 = srem i32 %18, 16
%20 = sext i32 %19 to i64
%21 = getelementptr inbounds [16 x i8], [16 x i8]* @main.hwaddr_glb, i64 0, i64 %20
%22 = load i8, i8* %21
%23 = getelementptr inbounds i8, i8* %17, i64 %15
store i8 %22, i8* %23
%24 = add nuw nsw i64 %16, 1
%25 = tail call i8* @realloc(i8* %17, i64 %24)
%26 = add nuw nsw i64 %15, 1
%27 = icmp eq i64 %26, 12
br i1 %27, label %28, label %14
28: ; preds = %14
%29 = load i8, i8* %25
%30 = getelementptr inbounds i8, i8* %25, i64 1
%31 = load i8, i8* %30
%32 = getelementptr inbounds i8, i8* %25, i64 2
%33 = load i8, i8* %32
%34 = getelementptr inbounds i8, i8* %25, i64 3
%35 = load i8, i8* %34
%36 = getelementptr inbounds i8, i8* %25, i64 4
%37 = load i8, i8* %36
%38 = getelementptr inbounds i8, i8* %25, i64 5
%39 = load i8, i8* %38
%40 = getelementptr inbounds i8, i8* %25, i64 6
%41 = load i8, i8* %40
%42 = getelementptr inbounds i8, i8* %25, i64 7
%43 = load i8, i8* %42
%44 = getelementptr inbounds i8, i8* %25, i64 8
%45 = load i8, i8* %44
%46 = getelementptr inbounds i8, i8* %25, i64 9
%47 = load i8, i8* %46
%48 = getelementptr inbounds i8, i8* %25, i64 10
%49 = load i8, i8* %48
%50 = getelementptr inbounds i8, i8* %25, i64 11
%51 = load i8, i8* %50
%52 = tail call i32 @printf(i8* getelementptr inbounds ([26 x i8], [26 x i8]* @.str, i64 0, i64 0), i8 signext %29, i8 signext %31, i8 signext %33, i8 signext %35, i8 signext %37, i8 signext %39, i8 signext %41, i8 signext %43, i8 signext %45, i8 signext %47, i8 signext %49, i8 signext %51)
%53 = tail call i32 @printf(i8* getelementptr inbounds ([31 x i8], [31 x i8]* @.str.1, i64 0, i64 0), i8 signext %29, i8 signext %31, i8 signext %33, i8 signext %35, i8 signext %37, i8 signext %39, i8 signext %41, i8 signext %43, i8 signext %45, i8 signext %47, i8 signext %49, i8 signext %51)
%54 = tail call i32 @printf(i8* getelementptr inbounds ([31 x i8], [31 x i8]* @.str.2, i64 0, i64 0), i8 signext %29, i8 signext %31, i8 signext %33, i8 signext %35, i8 signext %37, i8 signext %39, i8 signext %41, i8 signext %43, i8 signext %45, i8 signext %47, i8 signext %49, i8 signext %51)
%55 = tail call i32 @printf(i8* getelementptr inbounds ([28 x i8], [28 x i8]* @.str.3, i64 0, i64 0), i8 signext %29, i8 signext %31, i8 signext %33, i8 signext %35, i8 signext %37, i8 signext %39, i8 signext %41, i8 signext %43, i8 signext %45, i8 signext %47, i8 signext %49, i8 signext %51)
%56 = tail call i32 @free(i8* %25)
ret i32 0
}