user: What would the C source look like for the assembly code provided here?

```asm
<filtre_3_opt>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x48,%rsp
  mov    %rdi,%rbp
  mov    %esi,%r14d
  mov    %esi,0x24(%rsp)
  mov    %edx,%ebx
  mov    %rcx,0x30(%rsp)
  mov    $0x40000000,%edi
  call   <coproc_reset@plt>
  cmp    $0x2,%ebx
  jle    L25
  mov    %r14d,%eax
  movslq %r14d,%rcx
  mov    %rcx,0x28(%rsp)
  mov    %rbp,0x8(%rsp)
  add    %rcx,%rbp
  mov    %rbp,0x10(%rsp)
  add    %rcx,%rbp
  mov    %rbp,0x18(%rsp)
  lea    -0x2(%rbx),%ecx
  mov    %ecx,0x38(%rsp)
  movl   $0x0,0x4(%rsp)
  movl   $0x0,0x20(%rsp)
  sub    $0x2,%eax
  mov    %eax,0x3c(%rsp)
  jmp    L91
L48:
  test   %eax,%eax
  js     L15
  mov    %al,0x0(%rbp)
L30:
  add    $0x1,%rbp
  add    $0x1,%rbx
  cmp    %rbx,%r15
  je     L36
L66:
  movzbl (%r12,%rbx,1),%esi
  shl    $0x10,%esi
  movzbl 0x0(%r13,%rbx,1),%eax
  shl    $0x8,%eax
  or     %eax,%esi
  movzbl (%r14,%rbx,1),%eax
  or     %eax,%esi
  mov    $0x40000004,%edi
  call   <coproc_write@plt>
  mov    $0x40000004,%edi
  call   <coproc_read@plt>
  sub    $0xffffff80,%eax
  cmp    $0xff,%eax
  jle    L48
  movb   $0xff,0x0(%rbp)
  jmp    L30
L15:
  movb   $0x0,0x0(%rbp)
  jmp    L30
L36:
  mov    0x3c(%rsp),%edx
  add    %edx,0x20(%rsp)
L61:
  mov    0x28(%rsp),%rax
  add    %rax,0x8(%rsp)
  add    %rax,0x10(%rsp)
  add    %rax,0x18(%rsp)
  mov    0x38(%rsp),%ecx
  cmp    %ecx,0x4(%rsp)
  je     L25
L91:
  mov    0x8(%rsp),%rbx
  mov    %rbx,%r12
  addl   $0x1,0x4(%rsp)
  mov    0x10(%rsp),%r15
  mov    %r15,%r13
  mov    0x18(%rsp),%rbp
  mov    %rbp,%r14
  movzbl (%rbx),%esi
  shl    $0x10,%esi
  movzbl (%r15),%eax
  shl    $0x8,%eax
  or     %eax,%esi
  movzbl 0x0(%rbp),%eax
  or     %eax,%esi
  mov    $0x40000004,%edi
  call   <coproc_write@plt>
  movzbl 0x1(%rbx),%esi
  shl    $0x10,%esi
  movzbl 0x1(%r15),%eax
  shl    $0x8,%eax
  or     %eax,%esi
  movzbl 0x1(%rbp),%eax
  or     %eax,%esi
  mov    $0x40000004,%edi
  call   <coproc_write@plt>
  mov    0x24(%rsp),%eax
  cmp    $0x2,%eax
  jle    L61
  movslq 0x20(%rsp),%rbp
  add    0x30(%rsp),%rbp
  mov    %eax,%r15d
  mov    $0x2,%ebx
  jmp    L66
L25:
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void filtre_3_opt(char *data, int largeur, int hauteur, char *data_sortie) {
  int cpt_out, tmp_i;
  int x, y;
  unsigned char *pt0, *pt1, *pt2, *pt3, *pt4, *pt5, *pt6, *pt7, *pt8;
  int coef[9];
  int alpha, beta;
  unsigned int op_a, op_b;
  int pixel_concat;
  coef[0] = -1;
  coef[1] = -1;
  coef[2] = 0;
  coef[3] = -1;
  coef[4] = 0;
  coef[5] = +1;
  coef[6] = 0;
  coef[7] = +1;
  coef[8] = +1;
  alpha = 1;
  beta = 128;
  cpt_out = 0;
  coproc_reset(0x40000000);
  for (y = 0; y < hauteur - 2; y++) {
    pt0 = data + largeur * y;
    pt1 = data + largeur * (y + 1);
    pt2 = data + largeur * (y + 2);
    pixel_concat = (*pt0) << 16 | (*pt1) << 8 | (*pt2);
    coproc_write(0x40000004, pixel_concat);
    pt0++;
    pt1++;
    pt2++;
    pixel_concat = (*pt0) << 16 | (*pt1) << 8 | (*pt2);
    coproc_write(0x40000004, pixel_concat);
    pt0++;
    pt1++;
    pt2++;
    for (x = 2; x < largeur; x++) {
      pixel_concat = (*pt0) << 16 | (*pt1) << 8 | (*pt2);
      coproc_write(0x40000004, pixel_concat);
      tmp_i = coproc_read(0x40000004) + 128;
      pt0++;
      pt1++;
      pt2++;
      if (tmp_i > 255)
        data_sortie[cpt_out] = 255;
      else if (tmp_i < 0)
        data_sortie[cpt_out] = 0;
      else
        data_sortie[cpt_out] = (unsigned char)tmp_i;
      cpt_out++;
    }
  }
}
```