user: Demonstrate the C code that generates the assembly output below:

```asm
<neoscrypt_blkswp>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r14
  push   %r13
  push   %r12
  push   %rbx
  mov    %rdi,-0x48(%rbp)
  mov    %rsi,-0x50(%rbp)
  mov    %edx,-0x54(%rbp)
  mov    -0x48(%rbp),%rax
  mov    %rax,-0x30(%rbp)
  mov    -0x50(%rbp),%rax
  mov    %rax,-0x28(%rbp)
  movl   $0x0,-0x34(%rbp)
  jmp    L1
L0:
  mov    -0x34(%rbp),%eax
  lea    0x0(,%rax,8),%rdx
  mov    -0x30(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%r14
  mov    -0x34(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,%eax
  lea    0x0(,%rax,8),%rdx
  mov    -0x30(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%r13
  mov    -0x34(%rbp),%eax
  add    $0x2,%eax
  mov    %eax,%eax
  lea    0x0(,%rax,8),%rdx
  mov    -0x30(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%r12
  mov    -0x34(%rbp),%eax
  add    $0x3,%eax
  mov    %eax,%eax
  lea    0x0(,%rax,8),%rdx
  mov    -0x30(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%rbx
  mov    -0x34(%rbp),%eax
  lea    0x0(,%rax,8),%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    -0x34(%rbp),%edx
  lea    0x0(,%rdx,8),%rcx
  mov    -0x30(%rbp),%rdx
  add    %rcx,%rdx
  mov    (%rax),%rax
  mov    %rax,(%rdx)
  mov    -0x34(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,%eax
  lea    0x0(,%rax,8),%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    -0x34(%rbp),%edx
  add    $0x1,%edx
  mov    %edx,%edx
  lea    0x0(,%rdx,8),%rcx
  mov    -0x30(%rbp),%rdx
  add    %rcx,%rdx
  mov    (%rax),%rax
  mov    %rax,(%rdx)
  mov    -0x34(%rbp),%eax
  add    $0x2,%eax
  mov    %eax,%eax
  lea    0x0(,%rax,8),%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    -0x34(%rbp),%edx
  add    $0x2,%edx
  mov    %edx,%edx
  lea    0x0(,%rdx,8),%rcx
  mov    -0x30(%rbp),%rdx
  add    %rcx,%rdx
  mov    (%rax),%rax
  mov    %rax,(%rdx)
  mov    -0x34(%rbp),%eax
  add    $0x3,%eax
  mov    %eax,%eax
  lea    0x0(,%rax,8),%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    -0x34(%rbp),%edx
  add    $0x3,%edx
  mov    %edx,%edx
  lea    0x0(,%rdx,8),%rcx
  mov    -0x30(%rbp),%rdx
  add    %rcx,%rdx
  mov    (%rax),%rax
  mov    %rax,(%rdx)
  mov    -0x34(%rbp),%eax
  lea    0x0(,%rax,8),%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    %r14,(%rax)
  mov    -0x34(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,%eax
  lea    0x0(,%rax,8),%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    %r13,(%rax)
  mov    -0x34(%rbp),%eax
  add    $0x2,%eax
  mov    %eax,%eax
  lea    0x0(,%rax,8),%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    %r12,(%rax)
  mov    -0x34(%rbp),%eax
  add    $0x3,%eax
  mov    %eax,%eax
  lea    0x0(,%rax,8),%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    %rbx,(%rax)
  addl   $0x4,-0x34(%rbp)
L1:
  mov    -0x54(%rbp),%eax
  shr    $0x3,%eax
  cmp    %eax,-0x34(%rbp)
  jb     L0
  nop
  nop
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %rbp
  ret
```

assistant: ```c
void neoscrypt_blkswp(void *blkAp, void *blkBp, unsigned int len) {
  size_t *blkA = (size_t *)blkAp;
  size_t *blkB = (size_t *)blkBp;
  register size_t t0, t1, t2, t3;
  unsigned int i;
  for (i = 0; i < (len / sizeof(size_t)); i += 4) {
    t0 = blkA[i];
    t1 = blkA[i + 1];
    t2 = blkA[i + 2];
    t3 = blkA[i + 3];
    blkA[i] = blkB[i];
    blkA[i + 1] = blkB[i + 1];
    blkA[i + 2] = blkB[i + 2];
    blkA[i + 3] = blkB[i + 3];
    blkB[i] = t0;
    blkB[i + 1] = t1;
    blkB[i + 2] = t2;
    blkB[i + 3] = t3;
  }
}
```