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

```asm
<merge>:
  endbr64
  push   %r15
  mov    %rsi,%rax
  mov    %rcx,%r15
  push   %r14
  sub    %rdi,%rax
  push   %r13
  mov    %rax,%r14
  mov    %rdi,%r13
  push   %r12
  push   %rbp
  mov    %rsi,%rbp
  push   %rbx
  sub    $0x48,%rsp
  add    %rcx,%r14
  setb   %bl
  sub    %rsi,%rdx
  mov    %rdi,0x28(%rsp)
  lea    (%r15,%r14,1),%rdi
  mov    %rdx,%r12
  mov    %r14,0x30(%rsp)
  movzbl %bl,%ebx
  add    %rcx,%r12
  setb   %cl
  mov    %r12,0x38(%rsp)
  movzbl %cl,%ecx
  mov    %rcx,(%rsp)
  call   <malloc@plt>
  lea    (%r15,%r12,1),%rdi
  mov    %rax,0x8(%rsp)
  call   <malloc@plt>
  mov    0x8(%rsp),%rdi
  mov    %r14,%rdx
  mov    %r13,%rsi
  mov    %rax,0x10(%rsp)
  call   <memcpy@plt>
  mov    0x10(%rsp),%rdi
  mov    %r12,%rdx
  mov    %rbp,%rsi
  call   <memcpy@plt>
  mov    %r14,%rax
  xor    %edx,%edx
  div    %r15
  mov    %rax,0x18(%rsp)
  test   %rbx,%rbx
  jne    L20
  mov    %r12,%rax
  xor    %edx,%edx
  mov    (%rsp),%rcx
  div    %r15
  mov    %rax,0x20(%rsp)
  test   %rcx,%rcx
  jne    L59
  movl   $0x0,(%rsp)
  mov    %r13,%rbp
  xor    %eax,%eax
  xor    %r12d,%r12d
  jmp    L43
  nopl   0x0(%rax)
L25:
  mov    %r14,%rsi
  mov    %rbp,%rdi
  add    $0x1,%r12d
  call   <memcpy@plt>
  movslq (%rsp),%rcx
  cmp    0x18(%rsp),%rcx
  jae    L58
L34:
  movslq %r12d,%rax
  add    %r15,%rbp
  cmp    0x20(%rsp),%rax
  jae    L62
L43:
  imul   %r15,%rax
  mov    0x10(%rsp),%rdx
  add    $0x1,%ebx
  imul   %r15,%rcx
  lea    (%rdx,%rax,1),%r14
  mov    0x8(%rsp),%rax
  mov    %r14,%rsi
  lea    (%rax,%rcx,1),%r13
  mov    %r13,%rdi
  call   <compare@plt>
  mov    %r15,%rdx
  test   %rax,%rax
  jns    L25
  mov    %r13,%rsi
  mov    %rbp,%rdi
  call   <memcpy@plt>
  addl   $0x1,(%rsp)
  movslq (%rsp),%rcx
  cmp    0x18(%rsp),%rcx
  jb     L34
L58:
  movslq %ebx,%rbx
  imul   %r15,%rbx
  add    %rbx,0x28(%rsp)
  cmp    0x18(%rsp),%rcx
  jne    L100
  movslq %r12d,%r12
  imul   %r15,%r12
  add    %r12,0x10(%rsp)
L33:
  mov    0x30(%rsp),%rdx
  add    0x38(%rsp),%rdx
  mov    0x10(%rsp),%rsi
  sub    %rbx,%rdx
  jmp    L14
  nopl   0x0(%rax,%rax,1)
L62:
  movslq %ebx,%rbx
  imul   %r15,%rcx
  add    %rcx,0x8(%rsp)
  imul   %r15,%rbx
  add    %rbx,0x28(%rsp)
L59:
  mov    0x30(%rsp),%rdx
  mov    0x8(%rsp),%rsi
  add    0x38(%rsp),%rdx
  sub    %rbx,%rdx
L14:
  mov    0x28(%rsp),%rdi
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  jmp    1070 <memcpy@plt>
  nop
L100:
  imul   %r15,%rcx
  add    %rcx,0x8(%rsp)
  jmp    L59
L20:
  xor    %ebx,%ebx
  jmp    L33
```

assistant: ```c
void merge(void *low, void *mid, void *high, size_t width, int (*comp)(const void *, const void *)) {
  size_t nl = (char *)mid - (char *)low + width;
  size_t nr = (char *)high - (char *)mid + width;
  char *left = malloc(nl + width);
  char *right = malloc(nr + width);
  memcpy(left, low, nl);
  memcpy(right, mid, nr);
  int i = 0, j = 0, k = 0;
  char *clow = (char *)low;
  while (i < nl / width && j < nr / width) {
    if (compare(left + i * width, right + j * width) < 0) {
      memcpy(clow + k * width, left + i * width, width);
      ++k;
      ++i;
    } else {
      memcpy(clow + k * width, right + j * width, width);
      ++k;
      ++j;
    }
  }
  if (i == nl / width) {
    memcpy(clow + k * width, right + j * width, nl + nr - k * width);
  } else {
    memcpy(clow + k * width, left + i * width, nr + nl - k * width);
  }
}
```