user: 提供的汇编代码用C语言表示会是什么样子:

```asm
<line_copy16>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  mov    %edx,%r12d
  add    %edx,%edx
  push   %rbp
  mov    %ecx,%ebp
  push   %rbx
  mov    %rdi,%rbx
  sub    $0x18,%rsp
  call   <memcpy@plt>
  test   %ebp,%ebp
  jle    L89
  movslq %ebp,%r9
  movslq %r12d,%rcx
  lea    -0x1(%r12),%eax
  mov    %ebp,%r11d
  mov    %r9,%rdx
  lea    0x8(,%rcx,4),%r10
  mov    %rcx,%r8
  neg    %rdx
  lea    (%r9,%rcx,1),%rsi
  sub    %r9,%r8
  shl    $0x2,%rdx
  shl    $0x2,%rsi
  cmp    $0x8,%r10
  lea    0x4(,%r9,4),%r15
  seta   %r13b
  cmp    $0x1,%ebp
  mov    %r15,0x8(%rsp)
  mov    %rdx,%r15
  setne  %r10b
  lea    0x0(,%r8,4),%r12
  and    %r10d,%r13d
  add    %rsi,%r15
  lea    -0x4(%r12),%rdi
  setns  %r10b
  cmp    %rdx,%rsi
  setle  %r14b
  or     %r14d,%r10d
  and    %r13d,%r10d
  lea    0x10(%rdx),%r13
  cmp    %r13,%rdi
  setge  %r13b
  add    $0xc,%r12
  cmp    %r12,%rdx
  setge  %r12b
  or     %r12d,%r13d
  test   %r13b,%r10b
  je     L68
  lea    (%r9,%r8,1),%r10
  lea    -0x4(,%r10,4),%r10
  cmp    %r10,%r15
  setge  %r10b
  cmp    %rdi,%rsi
  setle  %r12b
  or     %r12b,%r10b
  je     L68
  cmp    $0x3,%ebp
  jle    L48
  mov    %rbx,%rcx
  mov    %ebp,%r10d
  lea    (%rbx,%rdx,1),%r12
  add    %rbx,%rdi
  sub    %rdx,%rcx
  shr    $0x2,%r10d
  lea    -0x10(%rbx,%rsi,1),%r13
  xor    %r9d,%r9d
  lea    -0xc(%rcx),%r14
  shl    $0x4,%r10
  xor    %ecx,%ecx
  xchg   %ax,%ax
L94:
  movdqu (%r14,%r9,1),%xmm1
  pshufd $0x1b,%xmm1,%xmm0
  movups %xmm0,(%r12,%rcx,1)
  movdqu (%rdi,%rcx,1),%xmm2
  add    $0x10,%rcx
  pshufd $0x1b,%xmm2,%xmm0
  movups %xmm0,0x0(%r13,%r9,1)
  sub    $0x10,%r9
  cmp    %r10,%rcx
  jne    L94
  mov    %ebp,%ecx
  and    $0xfffffffc,%ecx
  sub    %ecx,%ebp
  cmp    %ecx,%r11d
  je     L89
  sub    %ecx,%r11d
  cmp    $0x1,%r11d
  je     L64
L88:
  mov    %rcx,%rdi
  lea    0x0(,%rcx,4),%r9
  add    %rcx,%r8
  sub    $0x8,%rsi
  not    %rdi
  sub    %r9,%rsi
  shl    $0x2,%rdi
  sub    %rdx,%rdi
  mov    %r11d,%edx
  movq   (%rbx,%rdi,1),%xmm0
  and    $0xfffffffe,%edx
  sub    %edx,%ebp
  pshufd $0xe1,%xmm0,%xmm0
  movq   %xmm0,(%r12,%r9,1)
  movq   -0x4(%rbx,%r8,4),%xmm0
  pshufd $0xe1,%xmm0,%xmm0
  movq   %xmm0,(%rbx,%rsi,1)
  cmp    %edx,%r11d
  je     L89
L64:
  movslq %ebp,%rdx
  mov    (%rbx,%rdx,4),%ecx
  lea    0x0(,%rdx,4),%rsi
  mov    %rbx,%rdx
  sub    %rsi,%rdx
  mov    %ecx,(%rdx)
  mov    %eax,%edx
  add    %ebp,%eax
  sub    %ebp,%edx
  cltq
  movslq %edx,%rdx
  mov    (%rbx,%rdx,4),%edx
  mov    %edx,(%rbx,%rax,4)
L89:
  add    $0x18,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   (%rax)
L68:
  mov    0x8(%rsp),%rax
  lea    -0x1(%rbp),%esi
  add    %rbx,%rdx
  sub    %r9,%rsi
  lea    -0x4(%rbx,%rax,1),%rax
  lea    0x4(%rbx,%rsi,4),%rdi
L59:
  mov    (%rax),%esi
  mov    %esi,(%rdx)
  mov    -0x4(%rdx,%rcx,4),%esi
  add    $0x4,%rdx
  mov    %esi,-0x4(%rax,%rcx,4)
  sub    $0x4,%rax
  cmp    %rdi,%rdx
  jne    L59
  add    $0x18,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L48:
  xor    %ecx,%ecx
  lea    (%rbx,%rdx,1),%r12
  jmp    L88
```

assistant: ```c
void line_copy16(uint16_t *line, const uint16_t *srcp, int width, int mergin) {
  memcpy(line, srcp, width * 2);
  for (int i = mergin; i > 0; i--) {
    line[-i] = line[i];
    line[width - 1 + i] = line[width - 1 - i];
  }
}
```