user: 下面的汇编指令对应的C源代码是什么:

```asm
<memcpy>:
  endbr64
  mov    %rdi,%rcx
  cmp    $0x7,%edx
  jle    L74
  lea    0x4(%rsi),%rdi
  mov    %rcx,%rax
  lea    -0x8(%rdx),%r9d
  sub    %rdi,%rax
  cmp    $0x8,%rax
  jbe    L9
  cmp    $0x17,%r9d
  jbe    L9
  mov    %r9d,%r8d
  xor    %eax,%eax
  shr    $0x3,%r8d
  add    $0x1,%r8d
  mov    %r8d,%edi
  shr    $0x2,%edi
  shl    $0x4,%rdi
  nopl   0x0(%rax)
L159:
  movdqu (%rsi,%rax,1),%xmm0
  movups %xmm0,(%rcx,%rax,1)
  add    $0x10,%rax
  cmp    %rdi,%rax
  jne    L159
  mov    %r8d,%edi
  and    $0xfffffffc,%edi
  mov    %edi,%eax
  neg    %eax
  lea    (%rdx,%rax,8),%r10d
  mov    %edi,%eax
  shl    $0x2,%rax
  lea    (%rsi,%rax,1),%rdx
  add    %rcx,%rax
  cmp    %edi,%r8d
  je     L29
  mov    (%rdx),%edi
  mov    %edi,(%rax)
  lea    -0x8(%r10),%edi
  cmp    $0x7,%edi
  jle    L29
  mov    0x4(%rdx),%edi
  mov    %edi,0x4(%rax)
  cmp    $0x17,%r10d
  jle    L29
  mov    0x8(%rdx),%edx
  mov    %edx,0x8(%rax)
L29:
  mov    %r9d,%edx
  and    $0x7,%edx
L74:
  test   %edx,%edx
  je     L225
  mov    %edx,%edi
  sub    $0x1,%edi
  js     L225
  lea    0x1(%rsi),%r8
  mov    %rcx,%rax
  mov    %edx,%r9d
  sub    %r8,%rax
  cmp    $0xe,%rax
  jbe    L53
  cmp    $0x6,%edi
  jbe    L53
  cmp    $0xe,%edi
  jbe    L94
  mov    %edx,%r8d
  xor    %eax,%eax
  shr    $0x4,%r8d
  shl    $0x4,%r8
L238:
  movdqu (%rsi,%rax,1),%xmm1
  movups %xmm1,(%rcx,%rax,1)
  add    $0x10,%rax
  cmp    %rax,%r8
  jne    L238
  mov    %edx,%r11d
  and    $0xfffffff0,%r11d
  mov    %r11d,%r10d
  sub    %r11d,%edi
  lea    (%rsi,%r10,1),%r8
  lea    (%rcx,%r10,1),%rax
  cmp    %r11d,%edx
  je     L225
  sub    %r11d,%edx
  mov    %edx,%r9d
  lea    -0x1(%rdx),%edx
  cmp    $0x6,%edx
  jbe    L73
L179:
  mov    (%rsi,%r10,1),%rdx
  mov    %rdx,(%rcx,%r10,1)
  mov    %r9d,%edx
  and    $0xfffffff8,%edx
  mov    %edx,%ecx
  sub    %edx,%edi
  add    %rcx,%r8
  add    %rcx,%rax
  cmp    %edx,%r9d
  je     L225
L73:
  movzbl (%r8),%edx
  mov    %edi,%ecx
  sub    $0x1,%ecx
  mov    %dl,(%rax)
  js     L225
  movzbl 0x1(%r8),%edx
  mov    %dl,0x1(%rax)
  cmp    $0x1,%edi
  je     L225
  movzbl 0x2(%r8),%edx
  mov    %dl,0x2(%rax)
  cmp    $0x2,%edi
  je     L225
  movzbl 0x3(%r8),%edx
  mov    %dl,0x3(%rax)
  cmp    $0x3,%edi
  je     L225
  movzbl 0x4(%r8),%edx
  mov    %dl,0x4(%rax)
  cmp    $0x4,%edi
  je     L225
  movzbl 0x5(%r8),%edx
  mov    %dl,0x5(%rax)
  cmp    $0x5,%edi
  je     L225
  movzbl 0x6(%r8),%edx
  mov    %dl,0x6(%rax)
  ret
  nopw   0x0(%rax,%rax,1)
L53:
  mov    %edx,%edx
  xor    %eax,%eax
  nopl   0x0(%rax)
L245:
  movzbl (%rsi,%rax,1),%edi
  mov    %dil,(%rcx,%rax,1)
  add    $0x1,%rax
  cmp    %rdx,%rax
  jne    L245
L225:
  ret
  nopw   0x0(%rax,%rax,1)
L9:
  mov    %r9d,%edi
  xor    %eax,%eax
  shr    $0x3,%edi
  add    $0x1,%edi
  shl    $0x2,%rdi
  nopw   0x0(%rax,%rax,1)
L237:
  mov    (%rsi,%rax,1),%edx
  mov    %edx,(%rcx,%rax,1)
  add    $0x4,%rax
  cmp    %rdi,%rax
  jne    L237
  jmp    L29
L94:
  mov    %rcx,%rax
  mov    %rsi,%r8
  xor    %r10d,%r10d
  jmp    L179
```

assistant: ```c
memcpy(to, from, count) char *from, *to;
{
  register *f, *t;
  f = (int *)from;
  t = (int *)to;
  if ((char *)f == from && (char *)t == to) {
    while (count >= 8)
      *t++ = *f++, count -= 8;
    if (!count)
      return;
  }
  while (--count >= 0)
    *to++ = *from++;
}
```