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

```asm
<divbwt>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  mov    %rdx,%r12
  mov    %ecx,%edx
  push   %rbp
  push   %rbx
  sub    $0x18,%rsp
  test   %rsi,%rsi
  sete   %al
  shr    $0x1f,%edx
  or     %dl,%al
  jne    L436
  mov    %rdi,%r15
  test   %rdi,%rdi
  je     L436
  mov    %rsi,%rbp
  mov    %ecx,%ebx
  cmp    $0x1,%ecx
  jle    L572
  test   %r12,%r12
  je     L569
  mov    $0x400,%edi
  call   <malloc@plt>
  mov    $0x40000,%edi
  mov    %rax,%r13
  call   <malloc@plt>
  mov    %rax,%r14
  test   %r13,%r13
  je     L497
  mov    %r13,(%rsp)
  test   %rax,%rax
  jne    L247
  xor    %edi,%edi
  mov    $0xfffffffe,%ebx
  call   <free@plt>
  mov    %r13,%rdi
  call   <free@plt>
  jmp    L489
  nopl   0x0(%rax)
L497:
  mov    %r14,%rdi
  mov    $0xfffffffe,%ebx
  call   <free@plt>
  xor    %edi,%edi
  call   <free@plt>
L489:
  add    $0x18,%rsp
  mov    %ebx,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   (%rax)
L572:
  mov    $0x0,%ebx
  jne    L489
  movzbl (%rdi),%eax
  mov    $0x1,%ebx
  mov    %al,(%rsi)
  jmp    L489
  nopl   0x0(%rax,%rax,1)
L569:
  lea    0x4(,%rcx,4),%edi
  call   <malloc@plt>
  mov    $0x400,%edi
  mov    %rax,%r13
  call   <malloc@plt>
  mov    $0x40000,%edi
  mov    %rax,(%rsp)
  mov    %rax,0x8(%rsp)
  call   <malloc@plt>
  test   %r13,%r13
  mov    0x8(%rsp),%r8
  mov    %rax,%rdi
  mov    %rax,%r14
  je     L384
  test   %r8,%r8
  je     L384
  test   %rax,%rax
  jne    L410
  mov    %r8,(%rsp)
  xor    %edi,%edi
  jmp    L403
  nopl   0x0(%rax)
L247:
  mov    %r12,%r13
L410:
  mov    (%rsp),%rdx
  mov    %ebx,%r8d
  mov    %r14,%rcx
  mov    %r13,%rsi
  mov    %r15,%rdi
  call   <sort_typeBstar@plt>
  mov    (%rsp),%rdx
  mov    %ebx,%r8d
  mov    %r14,%rcx
  mov    %eax,%r9d
  mov    %r13,%rsi
  mov    %r15,%rdi
  call   <construct_BWT@plt>
  movslq %ebx,%rdx
  movzbl -0x1(%r15,%rdx,1),%edx
  mov    %dl,0x0(%rbp)
  test   %eax,%eax
  jle    L352
  movslq %eax,%rdx
  lea    0x1(%rbp),%rcx
  lea    0x0(%r13,%rdx,4),%rsi
  lea    0x1(%rbp,%rdx,1),%rdx
  cmp    %rsi,%rcx
  setae  %sil
  cmp    %rdx,%r13
  setae  %dl
  or     %dl,%sil
  je     L357
  lea    -0x1(%rax),%edx
  cmp    $0xe,%edx
  jbe    L357
  mov    %eax,%esi
  movdqa D18(%rip),%xmm2
  mov    %r13,%rdx
  shr    $0x4,%esi
  sub    $0x1,%esi
  shl    $0x6,%rsi
  lea    0x40(%r13,%rsi,1),%rsi
  nopl   0x0(%rax,%rax,1)
L346:
  movdqu (%rdx),%xmm0
  movdqu 0x10(%rdx),%xmm5
  add    $0x40,%rdx
  add    $0x10,%rcx
  movdqu -0x10(%rdx),%xmm7
  movdqa %xmm0,%xmm1
  punpcklwd %xmm5,%xmm0
  punpckhwd %xmm5,%xmm1
  movdqa %xmm0,%xmm3
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm0
  movdqu -0x20(%rdx),%xmm1
  punpcklwd %xmm3,%xmm0
  movdqa %xmm1,%xmm3
  punpcklwd %xmm7,%xmm1
  pand   %xmm2,%xmm0
  punpckhwd %xmm7,%xmm3
  movdqa %xmm1,%xmm4
  punpckhwd %xmm3,%xmm4
  punpcklwd %xmm3,%xmm1
  punpcklwd %xmm4,%xmm1
  pand   %xmm2,%xmm1
  packuswb %xmm1,%xmm0
  movups %xmm0,-0x10(%rcx)
  cmp    %rsi,%rdx
  jne    L346
  mov    %eax,%ecx
  and    $0xfffffff0,%ecx
  test   $0xf,%al
  je     L504
  mov    %ecx,%edx
  mov    0x0(%r13,%rdx,4),%edi
  lea    0x0(,%rdx,4),%rsi
  mov    %dil,0x1(%rbp,%rdx,1)
  lea    0x1(%rcx),%edi
  cmp    %edi,%eax
  jle    L504
  mov    0x4(%r13,%rsi,1),%edi
  mov    %dil,0x2(%rbp,%rdx,1)
  lea    0x2(%rcx),%edi
  cmp    %edi,%eax
  jle    L504
  mov    0x8(%r13,%rsi,1),%edi
  mov    %dil,0x3(%rbp,%rdx,1)
  lea    0x3(%rcx),%edi
  cmp    %edi,%eax
  jle    L504
  mov    0xc(%r13,%rsi,1),%edi
  mov    %dil,0x4(%rbp,%rdx,1)
  lea    0x4(%rcx),%edi
  cmp    %edi,%eax
  jle    L504
  mov    0x10(%r13,%rsi,1),%edi
  mov    %dil,0x5(%rbp,%rdx,1)
  lea    0x5(%rcx),%edi
  cmp    %edi,%eax
  jle    L504
  mov    0x14(%r13,%rsi,1),%edi
  mov    %dil,0x6(%rbp,%rdx,1)
  lea    0x6(%rcx),%edi
  cmp    %edi,%eax
  jle    L504
  mov    0x18(%r13,%rsi,1),%edi
  mov    %dil,0x7(%rbp,%rdx,1)
  lea    0x7(%rcx),%edi
  cmp    %edi,%eax
  jle    L504
  mov    0x1c(%r13,%rsi,1),%edi
  mov    %dil,0x8(%rbp,%rdx,1)
  lea    0x8(%rcx),%edi
  cmp    %edi,%eax
  jle    L504
  mov    0x20(%r13,%rsi,1),%edi
  mov    %dil,0x9(%rbp,%rdx,1)
  lea    0x9(%rcx),%edi
  cmp    %edi,%eax
  jle    L504
  mov    0x24(%r13,%rsi,1),%edi
  mov    %dil,0xa(%rbp,%rdx,1)
  lea    0xa(%rcx),%edi
  cmp    %edi,%eax
  jle    L504
  mov    0x28(%r13,%rsi,1),%edi
  mov    %dil,0xb(%rbp,%rdx,1)
  lea    0xb(%rcx),%edi
  cmp    %edi,%eax
  jle    L504
  mov    0x2c(%r13,%rsi,1),%edi
  mov    %dil,0xc(%rbp,%rdx,1)
  lea    0xc(%rcx),%edi
  cmp    %edi,%eax
  jle    L504
  mov    0x30(%r13,%rsi,1),%edi
  mov    %dil,0xd(%rbp,%rdx,1)
  lea    0xd(%rcx),%edi
  cmp    %edi,%eax
  jle    L504
  mov    0x34(%r13,%rsi,1),%edi
  add    $0xe,%ecx
  mov    %dil,0xe(%rbp,%rdx,1)
  cmp    %ecx,%eax
  jle    L504
  mov    0x38(%r13,%rsi,1),%ecx
  mov    %cl,0xf(%rbp,%rdx,1)
  nopw   0x0(%rax,%rax,1)
L504:
  add    $0x1,%eax
  mov    %eax,%esi
  cmp    %eax,%ebx
  jle    L317
L72:
  mov    %ebx,%r10d
  mov    $0x4,%r15d
  movslq %esi,%rdi
  sub    %esi,%r10d
  cmp    %esi,%ebx
  lea    0x0(,%rdi,4),%r11
  mov    %r10d,%r8d
  lea    0x0(%rbp,%rdi,1),%rcx
  lea    0x0(%r13,%r11,1),%rdx
  lea    0x0(,%r8,4),%r9
  cmovle %r15,%r9
  add    %r11,%r9
  mov    $0x1,%r11d
  add    %r13,%r9
  cmp    %r9,%rcx
  setae  %r9b
  cmp    %esi,%ebx
  cmovle %r11,%r8
  add    %rdi,%r8
  add    %rbp,%r8
  cmp    %r8,%rdx
  setae  %r8b
  or     %r9b,%r8b
  je     L407
  lea    -0x1(%r10),%r8d
  cmp    $0xe,%r8d
  seta   %r9b
  cmp    %esi,%ebx
  setg   %r8b
  test   %r8b,%r9b
  je     L407
  cmp    %esi,%ebx
  mov    $0x1,%r8d
  movdqa D18(%rip),%xmm2
  cmovg  %r10d,%r8d
  mov    %r8d,%edi
  shr    $0x4,%edi
  sub    $0x1,%edi
  shl    $0x6,%rdi
  lea    0x40(%rdx,%rdi,1),%rdi
  nop
L241:
  movdqu (%rdx),%xmm0
  movdqu 0x10(%rdx),%xmm6
  add    $0x40,%rdx
  add    $0x10,%rcx
  movdqu -0x10(%rdx),%xmm5
  movdqa %xmm0,%xmm1
  punpcklwd %xmm6,%xmm0
  punpckhwd %xmm6,%xmm1
  movdqa %xmm0,%xmm3
  punpckhwd %xmm1,%xmm3
  punpcklwd %xmm1,%xmm0
  movdqu -0x20(%rdx),%xmm1
  punpcklwd %xmm3,%xmm0
  movdqa %xmm1,%xmm3
  punpcklwd %xmm5,%xmm1
  pand   %xmm2,%xmm0
  punpckhwd %xmm5,%xmm3
  movdqa %xmm1,%xmm4
  punpckhwd %xmm3,%xmm4
  punpcklwd %xmm3,%xmm1
  punpcklwd %xmm4,%xmm1
  pand   %xmm2,%xmm1
  packuswb %xmm1,%xmm0
  movups %xmm0,-0x10(%rcx)
  cmp    %rdx,%rdi
  jne    L241
  mov    %r8d,%edx
  and    $0xfffffff0,%edx
  add    %edx,%esi
  cmp    %edx,%r8d
  je     L317
  movslq %esi,%rdx
  mov    0x0(%r13,%rdx,4),%ecx
  mov    %cl,0x0(%rbp,%rdx,1)
  lea    0x1(%rsi),%ecx
  cmp    %ecx,%ebx
  jle    L317
  movslq %ecx,%rcx
  mov    0x0(%r13,%rcx,4),%edi
  lea    0x0(,%rcx,4),%rdx
  mov    %dil,0x0(%rbp,%rcx,1)
  lea    0x2(%rsi),%ecx
  cmp    %ecx,%ebx
  jle    L317
  mov    0x4(%r13,%rdx,1),%edi
  movslq %ecx,%rcx
  mov    %dil,0x0(%rbp,%rcx,1)
  lea    0x3(%rsi),%ecx
  cmp    %ecx,%ebx
  jle    L317
  mov    0x8(%r13,%rdx,1),%edi
  movslq %ecx,%rcx
  mov    %dil,0x0(%rbp,%rcx,1)
  lea    0x4(%rsi),%ecx
  cmp    %ecx,%ebx
  jle    L317
  mov    0xc(%r13,%rdx,1),%edi
  movslq %ecx,%rcx
  mov    %dil,0x0(%rbp,%rcx,1)
  lea    0x5(%rsi),%ecx
  cmp    %ecx,%ebx
  jle    L317
  mov    0x10(%r13,%rdx,1),%edi
  movslq %ecx,%rcx
  mov    %dil,0x0(%rbp,%rcx,1)
  lea    0x6(%rsi),%ecx
  cmp    %ecx,%ebx
  jle    L317
  mov    0x14(%r13,%rdx,1),%edi
  movslq %ecx,%rcx
  mov    %dil,0x0(%rbp,%rcx,1)
  lea    0x7(%rsi),%ecx
  cmp    %ecx,%ebx
  jle    L317
  mov    0x18(%r13,%rdx,1),%edi
  movslq %ecx,%rcx
  mov    %dil,0x0(%rbp,%rcx,1)
  lea    0x8(%rsi),%ecx
  cmp    %ecx,%ebx
  jle    L317
  mov    0x1c(%r13,%rdx,1),%edi
  movslq %ecx,%rcx
  mov    %dil,0x0(%rbp,%rcx,1)
  lea    0x9(%rsi),%ecx
  cmp    %ecx,%ebx
  jle    L317
  mov    0x20(%r13,%rdx,1),%edi
  movslq %ecx,%rcx
  mov    %dil,0x0(%rbp,%rcx,1)
  lea    0xa(%rsi),%ecx
  cmp    %ecx,%ebx
  jle    L317
  mov    0x24(%r13,%rdx,1),%edi
  movslq %ecx,%rcx
  mov    %dil,0x0(%rbp,%rcx,1)
  lea    0xb(%rsi),%ecx
  cmp    %ecx,%ebx
  jle    L317
  mov    0x28(%r13,%rdx,1),%edi
  movslq %ecx,%rcx
  mov    %dil,0x0(%rbp,%rcx,1)
  lea    0xc(%rsi),%ecx
  cmp    %ecx,%ebx
  jle    L317
  mov    0x2c(%r13,%rdx,1),%edi
  movslq %ecx,%rcx
  mov    %dil,0x0(%rbp,%rcx,1)
  lea    0xd(%rsi),%ecx
  cmp    %ecx,%ebx
  jle    L317
  mov    0x30(%r13,%rdx,1),%edi
  movslq %ecx,%rcx
  add    $0xe,%esi
  mov    %dil,0x0(%rbp,%rcx,1)
  cmp    %esi,%ebx
  jle    L317
  mov    0x34(%r13,%rdx,1),%edx
  movslq %esi,%rsi
  mov    %dl,0x0(%rbp,%rsi,1)
  nopl   0x0(%rax)
L317:
  mov    %r14,%rdi
  mov    %eax,%ebx
  call   <free@plt>
  mov    (%rsp),%rdi
  call   <free@plt>
  test   %r12,%r12
  jne    L489
  mov    %r13,%rdi
  call   <free@plt>
  jmp    L489
  nopl   0x0(%rax)
L407:
  mov    0x0(%r13,%rdi,4),%edx
  mov    %dl,0x0(%rbp,%rdi,1)
  add    $0x1,%rdi
  cmp    %edi,%ebx
  jg     L407
  jmp    L317
  nopl   0x0(%rax,%rax,1)
L384:
  mov    %r8,(%rsp)
L403:
  call   <free@plt>
  mov    (%rsp),%rdi
  mov    $0xfffffffe,%ebx
  call   <free@plt>
  mov    %r13,%rdi
  call   <free@plt>
  jmp    L489
  nopl   0x0(%rax)
L357:
  mov    %eax,%esi
  xor    %edx,%edx
  nopl   0x0(%rax)
L567:
  mov    0x0(%r13,%rdx,4),%ecx
  mov    %cl,0x1(%rbp,%rdx,1)
  add    $0x1,%rdx
  cmp    %rdx,%rsi
  jne    L567
  jmp    L504
  nopw   0x0(%rax,%rax,1)
L436:
  mov    $0xffffffff,%ebx
  jmp    L489
  nopw   0x0(%rax,%rax,1)
L352:
  mov    $0x1,%esi
  add    $0x1,%eax
  jmp    L72
```

tool_calls: name: unpack_data
arguments: data_label: D18
datatype: byte[16]

tool: {"D18": [0xff,0x00,0xff,0x00,0xff,0x00,0xff,0x00,0xff,0x00,0xff,0x00,0xff,0x00,0xff,0x00]}

assistant: ```c
int divbwt(const unsigned char *T, unsigned char *U, int *A, int n) {
  int *B;
  int *bucket_A, *bucket_B;
  int m, pidx, i;
  if ((T == NULL) || (U == NULL) || (n < 0)) {
    return -1;
  } else if (n <= 1) {
    if (n == 1) {
      U[0] = T[0];
    }
    return n;
  }
  if ((B = A) == NULL) {
    B = (int *)malloc((size_t)(n + 1) * sizeof(int));
  }
  bucket_A = (int *)malloc(((256)) * sizeof(int));
  bucket_B = (int *)malloc(((256) * (256)) * sizeof(int));
  if ((B != NULL) && (bucket_A != NULL) && (bucket_B != NULL)) {
    m = sort_typeBstar(T, B, bucket_A, bucket_B, n);
    pidx = construct_BWT(T, B, bucket_A, bucket_B, n, m);
    U[0] = T[n - 1];
    for (i = 0; i < pidx; ++i) {
      U[i + 1] = (unsigned char)B[i];
    }
    for (i += 1; i < n; ++i) {
      U[i] = (unsigned char)B[i];
    }
    pidx += 1;
  } else {
    pidx = -2;
  }
  free(bucket_B);
  free(bucket_A);
  if (A == NULL) {
    free(B);
  }
  return pidx;
}
```