user: Please show me the C implementation that matches the assembly code listed below:

```asm
<dband>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbx
  sub    $0x98,%rsp
  mov    %edi,-0x84(%rbp)
  mov    %esi,-0x88(%rbp)
  mov    %edx,-0x8c(%rbp)
  mov    %rcx,-0x98(%rbp)
  mov    %r8,-0xa0(%rbp)
  mov    %r9,-0xa8(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x38(%rbp)
  xor    %eax,%eax
  movl   $0x7c8,-0x50(%rbp)
  movl   $0x7c9,-0x4c(%rbp)
  movl   $0x7ca,-0x48(%rbp)
  movl   $0x7cb,-0x44(%rbp)
  mov    $0x0,%r13d
  lea    D8(%rip),%rax
  mov    %rax,%rdi
  call   <printf@plt>
  mov    -0xa8(%rbp),%rdi
  mov    -0xa0(%rbp),%rcx
  mov    -0x98(%rbp),%rdx
  mov    -0x8c(%rbp),%esi
  mov    -0x84(%rbp),%eax
  mov    %rdi,%r8
  mov    %eax,%edi
  call   <dallocateA@plt>
  mov    -0x98(%rbp),%rax
  mov    (%rax),%rax
  mov    %rax,-0x78(%rbp)
  mov    -0xa0(%rbp),%rax
  mov    (%rax),%rax
  mov    %rax,-0x70(%rbp)
  mov    -0xa8(%rbp),%rax
  mov    (%rax),%rax
  mov    %rax,-0x68(%rbp)
  mov    -0x88(%rbp),%r14d
  mov    %r14d,-0x90(%rbp)
  mov    $0x0,%ebx
  jmp    L59
L96:
  movslq %ebx,%rax
  mov    -0x50(%rbp,%rax,4),%eax
  mov    %eax,%edx
  neg    %edx
  cmovns %edx,%eax
  and    $0xfff,%eax
  mov    %eax,%edx
  movslq %ebx,%rax
  mov    %edx,-0x50(%rbp,%rax,4)
  add    $0x1,%ebx
L59:
  cmp    $0x3,%ebx
  jle    L96
  mov    -0x44(%rbp),%eax
  cltd
  shr    $0x1f,%edx
  add    %edx,%eax
  and    $0x1,%eax
  sub    %edx,%eax
  cmp    $0x1,%eax
  je     L58
  mov    -0x44(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,-0x44(%rbp)
L58:
  mov    $0x0,%r12d
  jmp    L61
L73:
  movslq %r12d,%rax
  lea    0x0(,%rax,4),%rdx
  mov    -0x68(%rbp),%rax
  add    %rdx,%rax
  mov    %r13d,(%rax)
  movslq %r13d,%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x78(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x60(%rbp)
  movslq %r13d,%rax
  lea    0x0(,%rax,4),%rdx
  mov    -0x70(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x58(%rbp)
  mov    %r12d,%eax
  sub    -0x90(%rbp),%eax
  mov    $0x0,%edx
  test   %eax,%eax
  cmovns %eax,%edx
  mov    %edx,%r15d
  lea    (%r12,%r14,1),%eax
  cmp    %eax,-0x84(%rbp)
  jg     L23
  mov    -0x84(%rbp),%eax
  sub    $0x1,%eax
  jmp    L34
L23:
  lea    (%r12,%r14,1),%eax
L34:
  mov    %eax,-0xb4(%rbp)
  mov    %r15d,%ebx
  jmp    L99
L27:
  mov    %ebx,%eax
  sub    %r15d,%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x60(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0xb0(%rbp)
  lea    -0x50(%rbp),%rax
  mov    %rax,%rdi
  mov    $0x0,%eax
  call   <dlaran_@plt>
  movq   %xmm0,%rax
  mov    -0xb0(%rbp),%rcx
  mov    %rax,(%rcx)
  mov    %ebx,%eax
  sub    %r15d,%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x58(%rbp),%rax
  add    %rdx,%rax
  mov    %ebx,(%rax)
  add    $0x1,%ebx
L99:
  mov    -0xb4(%rbp),%eax
  cmp    %eax,%ebx
  jle    L27
  sub    %r15d,%eax
  add    $0x1,%eax
  add    %eax,%r13d
  add    $0x1,%r12d
L61:
  cmp    -0x84(%rbp),%r12d
  jl     L73
  mov    -0x84(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x68(%rbp),%rax
  add    %rdx,%rax
  mov    %r13d,(%rax)
  nop
  mov    -0x38(%rbp),%rax
  sub    %fs:0x28,%rax
  je     L26
  call   <__stack_chk_fail@plt>
L26:
  add    $0x98,%rsp
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  pop    %rbp
  ret
```

tool_calls: name: read_data
arguments: tag: D8
data_type: string

tool: D8: A banded matrix.

assistant: ```c
void dband(int n, int b, int nonz, double **nzval, int **rowind, int **colptr) {
  int iseed[] = {1992, 1993, 1994, 1995};
  register int i, j, ub, lb, ilow, ihigh, lasta = 0;
  double *a;
  int *asub, *xa;
  double *val;
  int *row;
  extern double dlaran_();
  printf("A banded matrix.");
  dallocateA(n, nonz, nzval, rowind, colptr);
  a = *nzval;
  asub = *rowind;
  xa = *colptr;
  ub = lb = b;
  for (i = 0; i < 4; ++i)
    iseed[i] = abs(iseed[i]) % 4096;
  if (iseed[3] % 2 != 1)
    ++iseed[3];
  for (j = 0; j < n; ++j) {
    xa[j] = lasta;
    val = &a[lasta];
    row = &asub[lasta];
    ilow = ((0) > (j - ub) ? (0) : (j - ub));
    ihigh = ((n - 1) < (j + lb) ? (n - 1) : (j + lb));
    for (i = ilow; i <= ihigh; ++i) {
      val[i - ilow] = dlaran_(iseed);
      row[i - ilow] = i;
    }
    lasta += ihigh - ilow + 1;
  }
  xa[n] = lasta;
}
```