int main(void) {
  int a;
  int b;
  int c;
  {
    a = 6;
    b = 6;
    c = 6;
    a = 0;
    {
      while (1) {
      while_0_continue:;
        if (a < 6) {
        } else {
          goto while_0_break;
        }
        b = 0;
        {
          while (1) {
          while_1_continue:;
            if (b < 6) {
            } else {
              goto while_1_break;
            }
            c = 0;
            {
              while (1) {
              while_2_continue:;
                if (c < 6) {
                } else {
                  goto while_2_break;
                }
                c = c + 1;
              }
            while_2_break:;
            }
            b = b + 1;
          }
        while_1_break:;
        }
        a = a + 1;
      }
    while_0_break:;
    }
    if (a == 6) {
      if (b == 6) {
        if (c == 6) {
        } else {
          goto ERROR;
        }
      } else {
        goto ERROR;
      }
    } else {
    ERROR:
      goto ERROR;
    }
    return (1);
  }
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
movl   $0x0,-0x4(%rbp)
movl   $0x6,-0x8(%rbp)
movl   $0x6,-0xc(%rbp)
movl   $0x6,-0x10(%rbp)
movl   $0x0,-0x8(%rbp)
jmp    112c <main+0x2c>
cmpl   $0x6,-0x8(%rbp)
jge    113b <main+0x3b>
jmp    1140 <main+0x40>
jmp    11aa <main+0xaa>
movl   $0x0,-0xc(%rbp)
jmp    114c <main+0x4c>
cmpl   $0x6,-0xc(%rbp)
jge    115b <main+0x5b>
jmp    1160 <main+0x60>
jmp    119c <main+0x9c>
movl   $0x0,-0x10(%rbp)
jmp    116c <main+0x6c>
cmpl   $0x6,-0x10(%rbp)
jge    117b <main+0x7b>
jmp    1180 <main+0x80>
jmp    118e <main+0x8e>
mov    -0x10(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x10(%rbp)
jmp    1167 <main+0x67>
mov    -0xc(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0xc(%rbp)
jmp    1147 <main+0x47>
mov    -0x8(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x8(%rbp)
jmp    1127 <main+0x27>
cmpl   $0x6,-0x8(%rbp)
jne    11e1 <main+0xe1>
cmpl   $0x6,-0xc(%rbp)
jne    11d7 <main+0xd7>
cmpl   $0x6,-0x10(%rbp)
jne    11cd <main+0xcd>
jmp    11d2 <main+0xd2>
jmp    11e6 <main+0xe6>
jmp    11dc <main+0xdc>
jmp    11e6 <main+0xe6>
jmp    11eb <main+0xeb>
jmp    11e6 <main+0xe6>
jmp    11e6 <main+0xe6>
mov    $0x1,%eax
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
mov    $0x1,%eax
ret

LLVM IR (-O0):
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i32
%4 = alloca i32
store i32 0, i32* %1
store i32 6, i32* %2
store i32 6, i32* %3
store i32 6, i32* %4
store i32 0, i32* %2
br label %5
5: ; preds = %0, %31
br label %6
6: ; preds = %5
%7 = load i32, i32* %2
%8 = icmp slt i32 %7, 6
br i1 %8, label %9, label %10
9: ; preds = %6
br label %11
10: ; preds = %6
br label %34
11: ; preds = %9
store i32 0, i32* %3
br label %12
12: ; preds = %11, %28
br label %13
13: ; preds = %12
%14 = load i32, i32* %3
%15 = icmp slt i32 %14, 6
br i1 %15, label %16, label %17
16: ; preds = %13
br label %18
17: ; preds = %13
br label %31
18: ; preds = %16
store i32 0, i32* %4
br label %19
19: ; preds = %18, %25
br label %20
20: ; preds = %19
%21 = load i32, i32* %4
%22 = icmp slt i32 %21, 6
br i1 %22, label %23, label %24
23: ; preds = %20
br label %25
24: ; preds = %20
br label %28
25: ; preds = %23
%26 = load i32, i32* %4
%27 = add nsw i32 %26, 1
store i32 %27, i32* %4
br label %19
28: ; preds = %24
%29 = load i32, i32* %3
%30 = add nsw i32 %29, 1
store i32 %30, i32* %3
br label %12
31: ; preds = %17
%32 = load i32, i32* %2
%33 = add nsw i32 %32, 1
store i32 %33, i32* %2
br label %5
34: ; preds = %10
%35 = load i32, i32* %2
%36 = icmp eq i32 %35, 6
br i1 %36, label %37, label %48
37: ; preds = %34
%38 = load i32, i32* %3
%39 = icmp eq i32 %38, 6
br i1 %39, label %40, label %46
40: ; preds = %37
%41 = load i32, i32* %4
%42 = icmp eq i32 %41, 6
br i1 %42, label %43, label %44
43: ; preds = %40
br label %45
44: ; preds = %40
br label %49
45: ; preds = %43
br label %47
46: ; preds = %37
br label %49
47: ; preds = %45
br label %50
48: ; preds = %34
br label %49
49: ; preds = %49, %48, %46, %44
br label %49
50: ; preds = %47
ret i32 1
}

LLVM IR (-O2):
define i32 @main() {
ret i32 1
}