user: Translate the below assembly code into C programming language:

```asm
<copy_bytes_unaligned>:
  endbr64
  test   %ecx,%ecx
  lea    0x7(%rcx),%eax
  mov    %rsi,%r8
  mov    %ecx,%esi
  cmovns %ecx,%eax
  and    $0x7,%esi
  mov    $0x1,%r11d
  mov    %esi,%ecx
  shl    %cl,%r11d
  sar    $0x3,%eax
  lea    -0x1(%r11),%r9d
  neg    %r11d
  test   %rdx,%rdx
  je     L24
  push   %r14
  mov    $0x8,%r10d
  push   %r12
  sub    %esi,%r10d
  push   %rbp
  push   %rbx
  mov    %rdx,%rbx
  movslq %eax,%rdx
  lea    0x10(%rdi),%rax
  lea    0x14(,%rdx,4),%rbp
  lea    (%r8,%rdx,4),%rcx
  cmp    %rax,%rcx
  lea    (%r8,%rbp,1),%r12
  setae  %al
  cmp    %r12,%rdi
  setae  %r12b
  or     %r12b,%al
  je     L51
  cmp    $0x1,%rbx
  je     L51
  lea    -0x1(%rbx),%rax
  cmp    $0x2,%rax
  jbe    L0
  movslq %esi,%r14
  lea    -0x10(%r8,%rbp,1),%r12
  mov    %rbx,%rbp
  xor    %eax,%eax
  movd   %r11d,%xmm6
  movd   %r9d,%xmm7
  shr    $0x2,%rbp
  movq   %r14,%xmm3
  movslq %r10d,%r14
  pshufd $0x0,%xmm6,%xmm5
  pshufd $0x0,%xmm7,%xmm4
  shl    $0x4,%rbp
  movq   %r14,%xmm2
  nop
L72:
  movdqu (%rcx,%rax,1),%xmm1
  pslld  %xmm3,%xmm1
  pand   %xmm5,%xmm1
  movups %xmm1,(%rdi,%rax,1)
  movdqu (%r12,%rax,1),%xmm0
  psrad  %xmm2,%xmm0
  pand   %xmm4,%xmm0
  por    %xmm1,%xmm0
  movups %xmm0,(%rdi,%rax,1)
  add    $0x10,%rax
  cmp    %rbp,%rax
  jne    L72
  mov    %rbx,%rcx
  and    $0xfffffffffffffffc,%rcx
  test   $0x3,%bl
  je     L53
  sub    %rcx,%rbx
  cmp    $0x1,%rbx
  je     L69
L66:
  lea    (%rdx,%rcx,1),%rbp
  movd   %r11d,%xmm6
  lea    (%rdi,%rcx,4),%rax
  movq   (%r8,%rbp,4),%xmm1
  pshufd $0xe0,%xmm6,%xmm0
  movd   %r9d,%xmm7
  pslld  %xmm3,%xmm1
  pand   %xmm0,%xmm1
  movq   %xmm1,(%rax)
  movq   0x4(%r8,%rbp,4),%xmm0
  psrad  %xmm2,%xmm0
  pshufd $0xe0,%xmm7,%xmm2
  pand   %xmm2,%xmm0
  por    %xmm1,%xmm0
  movq   %xmm0,(%rax)
  mov    %rbx,%rax
  and    $0xfffffffffffffffe,%rax
  add    %rax,%rcx
  cmp    %rax,%rbx
  je     L53
L69:
  lea    (%rdx,%rcx,1),%rax
  lea    (%rdi,%rcx,4),%rdi
  mov    %esi,%ecx
  mov    (%r8,%rax,4),%edx
  shl    %cl,%edx
  mov    %r10d,%ecx
  and    %r11d,%edx
  mov    %edx,(%rdi)
  mov    0x4(%r8,%rax,4),%eax
  sar    %cl,%eax
  and    %r9d,%eax
  or     %edx,%eax
  mov    %eax,(%rdi)
L53:
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r14
  ret
  nopw   0x0(%rax,%rax,1)
L51:
  mov    %rcx,%rdx
  lea    (%rdi,%rbx,4),%rbx
  nopw   0x0(%rax,%rax,1)
L98:
  mov    (%rdx),%r8d
  mov    %esi,%ecx
  add    $0x4,%rdi
  add    $0x4,%rdx
  shl    %cl,%r8d
  mov    %r10d,%ecx
  and    %r11d,%r8d
  mov    %r8d,-0x4(%rdi)
  mov    (%rdx),%eax
  sar    %cl,%eax
  and    %r9d,%eax
  or     %r8d,%eax
  mov    %eax,-0x4(%rdi)
  cmp    %rbx,%rdi
  jne    L98
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r14
  ret
  nopl   0x0(%rax,%rax,1)
L24:
  ret
L0:
  movslq %esi,%rax
  xor    %ecx,%ecx
  movq   %rax,%xmm3
  movslq %r10d,%rax
  movq   %rax,%xmm2
  jmp    L66
```

assistant: ```c
void copy_bytes_unaligned(uint8_t *out, const uint8_t *in, size_t len, uint8_t offset) {
  uint8_t byte_off = offset / 8;
  uint8_t bit_off = offset & 7;
  uint8_t rmask = (1 << bit_off) - 1;
  uint8_t lmask = ~rmask;
  for (size_t i = 0; i < len; i++) {
    out[i] = (in[i + byte_off] << bit_off) & lmask;
    out[i] |= (in[i + byte_off + 1] >> (8 - bit_off)) & rmask;
  }
}
```