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

```asm
<gradient>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  mov    %rdi,-0x28(%rbp)
  mov    %rsi,-0x30(%rbp)
  mov    %rdx,-0x38(%rbp)
  mov    %rcx,-0x40(%rbp)
  mov    %r8,-0x48(%rbp)
  mov    -0x48(%rbp),%rax
  mov    %rax,-0x10(%rbp)
  mov    -0x38(%rbp),%rax
  mov    %rax,-0x8(%rbp)
  movl   $0x0,-0x18(%rbp)
  jmp    L23
L33:
  mov    -0x8(%rbp),%rax
  add    $0x8,%rax
  movsd  (%rax),%xmm0
  mov    -0x8(%rbp),%rax
  movsd  (%rax),%xmm1
  subsd  %xmm1,%xmm0
  mov    -0x40(%rbp),%rax
  movsd  (%rax),%xmm1
  divsd  %xmm1,%xmm0
  mov    -0x10(%rbp),%rax
  movsd  %xmm0,(%rax)
  mov    -0x28(%rbp),%rax
  mov    (%rax),%eax
  cltq
  shl    $0x3,%rax
  lea    -0x8(%rax),%rdx
  mov    -0x8(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  mov    -0x28(%rbp),%rax
  mov    (%rax),%eax
  cltq
  shl    $0x3,%rax
  lea    -0x10(%rax),%rdx
  mov    -0x8(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm1
  subsd  %xmm1,%xmm0
  mov    -0x40(%rbp),%rax
  movsd  (%rax),%xmm1
  mov    -0x28(%rbp),%rax
  mov    (%rax),%eax
  cltq
  shl    $0x3,%rax
  lea    -0x8(%rax),%rdx
  mov    -0x10(%rbp),%rax
  add    %rdx,%rax
  divsd  %xmm1,%xmm0
  movsd  %xmm0,(%rax)
  mov    -0x28(%rbp),%rax
  mov    (%rax),%eax
  cltq
  shl    $0x3,%rax
  add    %rax,-0x10(%rbp)
  mov    -0x28(%rbp),%rax
  mov    (%rax),%eax
  cltq
  shl    $0x3,%rax
  add    %rax,-0x8(%rbp)
  addl   $0x1,-0x18(%rbp)
L23:
  mov    -0x30(%rbp),%rax
  mov    (%rax),%eax
  cmp    %eax,-0x18(%rbp)
  jl     L33
  mov    -0x48(%rbp),%rax
  mov    %rax,-0x10(%rbp)
  mov    -0x38(%rbp),%rax
  mov    %rax,-0x8(%rbp)
  movl   $0x0,-0x18(%rbp)
  jmp    L12
L9:
  movl   $0x1,-0x14(%rbp)
  jmp    L21
L0:
  mov    -0x14(%rbp),%eax
  cltq
  add    $0x1,%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x8(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  mov    -0x14(%rbp),%eax
  cltq
  shl    $0x3,%rax
  lea    -0x8(%rax),%rdx
  mov    -0x8(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm2
  movapd %xmm0,%xmm1
  subsd  %xmm2,%xmm1
  mov    -0x40(%rbp),%rax
  movsd  (%rax),%xmm0
  movapd %xmm0,%xmm2
  addsd  %xmm0,%xmm2
  mov    -0x14(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x10(%rbp),%rax
  add    %rdx,%rax
  divsd  %xmm2,%xmm1
  movapd %xmm1,%xmm0
  movsd  %xmm0,(%rax)
  addl   $0x1,-0x14(%rbp)
L21:
  mov    -0x28(%rbp),%rax
  mov    (%rax),%eax
  sub    $0x1,%eax
  cmp    %eax,-0x14(%rbp)
  jl     L0
  mov    -0x28(%rbp),%rax
  mov    (%rax),%eax
  cltq
  shl    $0x3,%rax
  add    %rax,-0x10(%rbp)
  mov    -0x28(%rbp),%rax
  mov    (%rax),%eax
  cltq
  shl    $0x3,%rax
  add    %rax,-0x8(%rbp)
  addl   $0x1,-0x18(%rbp)
L12:
  mov    -0x30(%rbp),%rax
  mov    (%rax),%eax
  cmp    %eax,-0x18(%rbp)
  jl     L9
  nop
  nop
  pop    %rbp
  ret
```

assistant: ```c
void gradient(int *m, int *n, double *f, double *binsize, double *g) {
  int k, j;
  double *g_ptr, *f_ptr;
  g_ptr = g;
  f_ptr = f;
  for (k = 0; k < *n; k++) {
    g_ptr[0] = (f_ptr[1] - f_ptr[0]) / *binsize;
    g_ptr[*m - 1] = (f_ptr[*m - 1] - f_ptr[*m - 2]) / *binsize;
    g_ptr += *m;
    f_ptr += *m;
  }
  g_ptr = g;
  f_ptr = f;
  for (k = 0; k < *n; k++) {
    for (j = 1; j < *m - 1; j++)
      g_ptr[j] = (f_ptr[j + 1] - f_ptr[j - 1]) / (2.0 * *binsize);
    g_ptr += *m;
    f_ptr += *m;
  }
}
```