user: What is the c source code of the assembly code below:

```asm
<filtre_3_opt>:
  endbr64
  push   %r15
  mov    %rcx,%r15
  push   %r14
  mov    %esi,%r14d
  push   %r13
  push   %r12
  push   %rbp
  mov    %edx,%ebp
  push   %rbx
  mov    %rdi,%rbx
  mov    $0x40000000,%edi
  sub    $0x38,%rsp
  mov    %esi,0x2c(%rsp)
  call   <coproc_reset@plt>
  lea    -0x2(%rbp),%eax
  mov    %eax,0x28(%rsp)
  test   %eax,%eax
  jle    L48
  lea    0x2(%rbx),%rax
  movl   $0x0,0xc(%rsp)
  mov    %rax,0x10(%rsp)
  movslq %r14d,%rax
  mov    %rax,0x18(%rsp)
  lea    (%r14,%r14,1),%eax
  cltq
  movl   $0x0,0x20(%rsp)
  add    %rax,%rbx
  lea    -0x2(%r14),%eax
  mov    %eax,0x24(%rsp)
  nopl   0x0(%rax)
L13:
  mov    0x10(%rsp),%r14
  mov    0x18(%rsp),%r13
  mov    $0x40000004,%edi
  mov    %rbx,%rbp
  addl   $0x1,0xc(%rsp)
  movzbl -0x2(%r14),%esi
  movzbl -0x2(%r14,%r13,1),%eax
  sub    %r13,%rbp
  mov    %r14,%r12
  shl    $0x8,%eax
  shl    $0x10,%esi
  or     %eax,%esi
  movzbl (%rbx),%eax
  or     %eax,%esi
  call   <coproc_write@plt>
  movzbl -0x1(%r14),%esi
  movzbl -0x1(%r14,%r13,1),%eax
  mov    $0x40000004,%edi
  add    %r13,%r14
  shl    $0x8,%eax
  shl    $0x10,%esi
  or     %eax,%esi
  movzbl 0x1(%rbx),%eax
  or     %eax,%esi
  call   <coproc_write@plt>
  cmpl   $0x2,0x2c(%rsp)
  mov    %r14,0x10(%rsp)
  jle    L21
  mov    0x24(%rsp),%eax
  movslq 0x20(%rsp),%r13
  xor    %r14d,%r14d
  mov    %rax,(%rsp)
  mov    %r13,%rax
  mov    %r14,%r13
  mov    %rax,%r14
  nopl   (%rax)
L45:
  movzbl (%r12,%r13,1),%esi
  movzbl 0x2(%rbp,%r13,1),%eax
  mov    $0x40000004,%edi
  shl    $0x8,%eax
  shl    $0x10,%esi
  or     %eax,%esi
  movzbl 0x2(%rbx,%r13,1),%eax
  or     %eax,%esi
  call   <coproc_write@plt>
  mov    $0x40000004,%edi
  call   <coproc_read@plt>
  mov    $0xffffffff,%ecx
  sub    $0xffffff80,%eax
  cmp    $0xff,%eax
  jg     L18
  xor    %ecx,%ecx
  test   %eax,%eax
  cmovns %eax,%ecx
L18:
  lea    (%r15,%r14,1),%rax
  mov    %cl,(%rax,%r13,1)
  add    $0x1,%r13
  cmp    (%rsp),%r13
  jne    L45
  mov    0x24(%rsp),%edx
  add    %edx,0x20(%rsp)
L21:
  mov    0x28(%rsp),%edx
  add    0x18(%rsp),%rbx
  cmp    %edx,0xc(%rsp)
  jne    L13
L48:
  add    $0x38,%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++;
    }
  }
}
```