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

```asm
<merge>:
  endbr64
  mov    %rdx,%r9
  test   %rdx,%rdx
  je     L239
  test   %rdi,%rdi
  je     L239
  lea    (%rsi,%rcx,1),%eax
  movslq %esi,%rsi
  movslq %ecx,%rcx
  cltq
  lea    -0x4(%rdi,%rsi,4),%rdx
  lea    -0x4(%r9,%rcx,4),%rcx
  lea    -0x4(%rdi,%rax,4),%rax
  cmp    %rdx,%rdi
  ja     L249
  cmp    %rcx,%r9
  jbe    L83
  jmp    L39
  nopl   0x0(%rax,%rax,1)
L147:
  sub    $0x4,%rdx
  mov    %r8d,0x4(%rax)
  cmp    %rdx,%rdi
  ja     L249
L220:
  cmp    %r9,%rcx
  jb     L39
L83:
  mov    (%rdx),%r8d
  mov    (%rcx),%esi
  sub    $0x4,%rax
  cmp    %r8d,%esi
  jl     L147
  mov    %esi,0x4(%rax)
  sub    $0x4,%rcx
  cmp    %rdi,%rdx
  jae    L220
L39:
  cmp    %rdx,%rdi
  ja     L249
  lea    -0x4(%rdx),%rsi
  mov    %rax,%r8
  mov    %rdx,%r10
  sub    %rsi,%r8
  sub    %rdi,%r10
  add    $0x8,%r8
  cmp    $0x8,%r8
  jbe    L209
  cmp    $0xb,%r10
  jbe    L209
  mov    %r10,%r11
  xor    %esi,%esi
  shr    $0x2,%r11
  add    $0x1,%r11
  mov    %r11,%r8
  shr    $0x2,%r8
  neg    %r8
  shl    $0x4,%r8
  nopl   0x0(%rax)
L197:
  movdqu -0xc(%rdx,%rsi,1),%xmm0
  movups %xmm0,-0xc(%rax,%rsi,1)
  sub    $0x10,%rsi
  cmp    %rsi,%r8
  jne    L197
  mov    %r11,%r8
  and    $0xfffffffffffffffc,%r8
  mov    %r8,%rsi
  neg    %rsi
  shl    $0x2,%rsi
  add    %rsi,%rdx
  add    %rax,%rsi
  cmp    %r8,%r11
  je     L127
  mov    (%rdx),%r8d
  mov    %r8d,(%rsi)
  lea    -0x4(%rdx),%r8
  cmp    %r8,%rdi
  ja     L127
  mov    -0x4(%rdx),%r8d
  mov    %r8d,-0x4(%rsi)
  lea    -0x8(%rdx),%r8
  cmp    %r8,%rdi
  ja     L127
  mov    -0x8(%rdx),%edx
  mov    %edx,-0x8(%rsi)
L127:
  not    %r10
  and    $0xfffffffffffffffc,%r10
  add    %r10,%rax
L249:
  cmp    %rcx,%r9
  ja     L239
  lea    -0x4(%rcx),%rdx
  mov    %rax,%rsi
  mov    %rcx,%rdi
  sub    %rdx,%rsi
  sub    %r9,%rdi
  add    $0x8,%rsi
  cmp    $0x8,%rsi
  jbe    L157
  cmp    $0xb,%rdi
  jbe    L157
  shr    $0x2,%rdi
  xor    %edx,%edx
  add    $0x1,%rdi
  mov    %rdi,%rsi
  shr    $0x2,%rsi
  neg    %rsi
  shl    $0x4,%rsi
  nopl   (%rax)
L128:
  movdqu -0xc(%rcx,%rdx,1),%xmm1
  movups %xmm1,-0xc(%rax,%rdx,1)
  sub    $0x10,%rdx
  cmp    %rsi,%rdx
  jne    L128
  mov    %rdi,%rsi
  and    $0xfffffffffffffffc,%rsi
  mov    %rsi,%rdx
  neg    %rdx
  shl    $0x2,%rdx
  add    %rdx,%rcx
  add    %rdx,%rax
  cmp    %rsi,%rdi
  je     L239
  mov    (%rcx),%edx
  mov    %edx,(%rax)
  lea    -0x4(%rcx),%rdx
  cmp    %rdx,%r9
  ja     L239
  mov    -0x4(%rcx),%edx
  mov    %edx,-0x4(%rax)
  lea    -0x8(%rcx),%rdx
  cmp    %rdx,%r9
  ja     L239
  mov    -0x8(%rcx),%edx
  mov    %edx,-0x8(%rax)
  ret
  nopl   0x0(%rax,%rax,1)
L261:
  sub    $0x4,%rdx
L157:
  mov    0x4(%rdx),%ecx
  sub    $0x4,%rax
  mov    %ecx,0x4(%rax)
  cmp    %rdx,%r9
  jbe    L261
L239:
  ret
  nopl   0x0(%rax)
L209:
  mov    %rax,%rdx
  jmp    L161
  nopl   (%rax)
L68:
  sub    $0x4,%rsi
L161:
  mov    0x4(%rsi),%r8d
  sub    $0x4,%rdx
  mov    %r8d,0x4(%rdx)
  cmp    %rsi,%rdi
  jbe    L68
  jmp    L127
```

assistant: ```c
void merge(int *nums1, int m, int *nums2, int n) {
  int *p1, *p2, *insert;
  if (!nums1)
    return nums2;
  else if (!nums2)
    return nums1;
  insert = nums1 + (m + n - 1);
  p1 = nums1 + (m - 1);
  p2 = nums2 + (n - 1);
  while (p1 >= nums1 && p2 >= nums2) {
    if (*p1 > *p2)
      *insert-- = *p1--;
    else
      *insert-- = *p2--;
  }
  while (p1 >= nums1)
    *insert-- = *p1--;
  while (p2 >= nums2)
    *insert-- = *p2--;
}
```