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

```asm
<longdivision>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %rbx
  sub    $0x68,%rsp
  mov    %rdi,-0x48(%rbp)
  mov    %rsi,-0x50(%rbp)
  mov    %rdx,-0x58(%rbp)
  mov    %rcx,-0x60(%rbp)
  mov    %r8,-0x68(%rbp)
  mov    %r9d,-0x6c(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x18(%rbp)
  xor    %eax,%eax
  movl   $0x0,-0x24(%rbp)
  movl   $0x0,-0x20(%rbp)
  movl   $0x0,-0x1c(%rbp)
  mov    -0x48(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x1,%al
  jne    L18
  mov    -0x60(%rbp),%rax
  movb   $0x0,(%rax)
  mov    -0x60(%rbp),%rax
  add    $0x1,%rax
  movb   $0x0,(%rax)
  mov    -0x50(%rbp),%rax
  add    $0x1,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  mov    %eax,%edi
  call   <miLookup@plt>
  mov    %al,-0x35(%rbp)
  movl   $0x0,-0x34(%rbp)
  jmp    L74
L35:
  mov    -0x34(%rbp),%eax
  cltq
  lea    0x2(%rax),%rdx
  mov    -0x50(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%edx
  movzbl -0x35(%rbp),%eax
  mov    %edx,%esi
  mov    %eax,%edi
  call   <bd@plt>
  mov    -0x34(%rbp),%edx
  movslq %edx,%rdx
  mov    %al,-0x24(%rbp,%rdx,1)
  addl   $0x1,-0x34(%rbp)
L74:
  cmpl   $0x2,-0x34(%rbp)
  jle    L35
  mov    -0x48(%rbp),%rax
  movzbl 0x4(%rax),%eax
  mov    %al,-0x21(%rbp)
  mov    -0x60(%rbp),%rax
  lea    0x2(%rax),%rdx
  movzbl -0x35(%rbp),%eax
  mov    %al,(%rdx)
  movzbl -0x24(%rbp),%eax
  movzbl %al,%edx
  movzbl -0x35(%rbp),%eax
  mov    %edx,%esi
  mov    %eax,%edi
  call   <bd@plt>
  mov    %al,-0x35(%rbp)
  mov    -0x60(%rbp),%rax
  lea    0x3(%rax),%rdx
  movzbl -0x35(%rbp),%eax
  mov    %al,(%rdx)
  movl   $0x0,-0x34(%rbp)
  jmp    L81
L100:
  mov    -0x34(%rbp),%eax
  cltq
  lea    0x1(%rax),%rdx
  mov    -0x50(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%edx
  movzbl -0x35(%rbp),%eax
  mov    %edx,%esi
  mov    %eax,%edi
  call   <bd@plt>
  mov    -0x34(%rbp),%edx
  movslq %edx,%rdx
  mov    %al,-0x20(%rbp,%rdx,1)
  addl   $0x1,-0x34(%rbp)
L81:
  cmpl   $0x3,-0x34(%rbp)
  jle    L100
  mov    -0x58(%rbp),%rax
  movb   $0x0,(%rax)
  movl   $0x0,-0x34(%rbp)
  jmp    L72
L287:
  mov    -0x34(%rbp),%eax
  cltq
  movzbl -0x24(%rbp,%rax,1),%ecx
  mov    -0x34(%rbp),%eax
  cltq
  movzbl -0x20(%rbp,%rax,1),%edx
  mov    -0x34(%rbp),%eax
  cltq
  lea    0x1(%rax),%rsi
  mov    -0x58(%rbp),%rax
  add    %rsi,%rax
  xor    %ecx,%edx
  mov    %dl,(%rax)
  addl   $0x1,-0x34(%rbp)
L72:
  cmpl   $0x3,-0x34(%rbp)
  jle    L287
  mov    -0x6c(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x68(%rbp),%rax
  lea    (%rdx,%rax,1),%rcx
  lea    -0x1c(%rbp),%rdx
  mov    -0x60(%rbp),%rax
  mov    %rax,%rsi
  mov    %rcx,%rdi
  call   <modprod@plt>
  movl   $0x0,-0x34(%rbp)
  jmp    L67
L201:
  mov    -0x6c(%rbp),%eax
  cltq
  shl    $0x2,%rax
  lea    -0x4(%rax),%rdx
  mov    -0x68(%rbp),%rax
  add    %rax,%rdx
  mov    -0x34(%rbp),%eax
  cltq
  movzbl (%rdx,%rax,1),%esi
  mov    -0x34(%rbp),%eax
  cltq
  movzbl -0x1c(%rbp,%rax,1),%ecx
  mov    -0x6c(%rbp),%eax
  cltq
  add    $0x1,%rax
  lea    0x0(,%rax,4),%rdx
  mov    -0x68(%rbp),%rax
  add    %rax,%rdx
  xor    %esi,%ecx
  mov    -0x34(%rbp),%eax
  cltq
  mov    %cl,(%rdx,%rax,1)
  addl   $0x1,-0x34(%rbp)
L67:
  cmpl   $0x3,-0x34(%rbp)
  jle    L201
  jmp    L177
L18:
  mov    -0x60(%rbp),%rax
  movb   $0x0,(%rax)
  mov    -0x60(%rbp),%rax
  add    $0x1,%rax
  movb   $0x0,(%rax)
  movl   $0x0,-0x2c(%rbp)
  jmp    L13
L216:
  mov    -0x2c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  test   %al,%al
  jne    L155
  addl   $0x1,-0x2c(%rbp)
L13:
  cmpl   $0x4,-0x2c(%rbp)
  jle    L216
  jmp    L117
L155:
  nop
L117:
  movl   $0x0,-0x28(%rbp)
  jmp    L80
L22:
  mov    -0x28(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x50(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  test   %al,%al
  jne    L106
  addl   $0x1,-0x28(%rbp)
L80:
  cmpl   $0x4,-0x28(%rbp)
  jle    L22
  jmp    L144
L106:
  nop
L144:
  mov    -0x28(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x50(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  mov    %eax,%edi
  call   <miLookup@plt>
  mov    %al,-0x35(%rbp)
  mov    -0x2c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%edx
  movzbl -0x35(%rbp),%eax
  mov    -0x60(%rbp),%rcx
  lea    0x2(%rcx),%rbx
  mov    %edx,%esi
  mov    %eax,%edi
  call   <bd@plt>
  mov    %al,(%rbx)
  movl   $0x0,-0x30(%rbp)
  mov    -0x2c(%rbp),%eax
  sub    $0x1,%eax
  mov    %eax,-0x34(%rbp)
  jmp    L258
L9:
  mov    -0x28(%rbp),%edx
  mov    -0x30(%rbp),%eax
  add    %edx,%eax
  movslq %eax,%rdx
  mov    -0x50(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%edx
  mov    -0x60(%rbp),%rax
  add    $0x2,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  mov    %edx,%esi
  mov    %eax,%edi
  call   <bd@plt>
  mov    -0x34(%rbp),%edx
  movslq %edx,%rdx
  mov    %al,-0x24(%rbp,%rdx,1)
  addl   $0x1,-0x34(%rbp)
  addl   $0x1,-0x30(%rbp)
L258:
  mov    $0x4,%eax
  sub    -0x28(%rbp),%eax
  mov    %eax,%edx
  mov    -0x2c(%rbp),%eax
  add    %edx,%eax
  cmp    %eax,-0x34(%rbp)
  jl     L9
  movl   $0x0,-0x30(%rbp)
  mov    -0x2c(%rbp),%eax
  sub    $0x1,%eax
  mov    %eax,-0x34(%rbp)
  jmp    L107
L289:
  mov    -0x2c(%rbp),%edx
  mov    -0x30(%rbp),%eax
  add    %edx,%eax
  movslq %eax,%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%edx
  mov    -0x34(%rbp),%eax
  cltq
  movzbl -0x24(%rbp,%rax,1),%eax
  xor    %eax,%edx
  mov    -0x34(%rbp),%eax
  cltq
  mov    %dl,-0x20(%rbp,%rax,1)
  addl   $0x1,-0x34(%rbp)
  addl   $0x1,-0x30(%rbp)
L107:
  mov    $0x4,%eax
  sub    -0x28(%rbp),%eax
  mov    %eax,%edx
  mov    -0x2c(%rbp),%eax
  add    %edx,%eax
  cmp    %eax,-0x34(%rbp)
  jl     L289
  mov    -0x48(%rbp),%rax
  movzbl 0x4(%rax),%eax
  mov    %al,-0x1d(%rbp)
  mov    -0x2c(%rbp),%eax
  cltq
  movzbl -0x20(%rbp,%rax,1),%eax
  movzbl %al,%edx
  movzbl -0x35(%rbp),%eax
  mov    -0x60(%rbp),%rcx
  lea    0x3(%rcx),%rbx
  mov    %edx,%esi
  mov    %eax,%edi
  call   <bd@plt>
  mov    %al,(%rbx)
  movl   $0x0,-0x34(%rbp)
  jmp    L99
L158:
  mov    -0x34(%rbp),%eax
  cltq
  lea    0x1(%rax),%rdx
  mov    -0x50(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%edx
  mov    -0x60(%rbp),%rax
  add    $0x3,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  mov    %edx,%esi
  mov    %eax,%edi
  call   <bd@plt>
  mov    -0x34(%rbp),%edx
  movslq %edx,%rdx
  mov    %al,-0x24(%rbp,%rdx,1)
  addl   $0x1,-0x34(%rbp)
L99:
  cmpl   $0x3,-0x34(%rbp)
  jle    L158
  mov    -0x58(%rbp),%rax
  movb   $0x0,(%rax)
  movl   $0x0,-0x34(%rbp)
  jmp    L272
L84:
  mov    -0x34(%rbp),%eax
  cltq
  movzbl -0x24(%rbp,%rax,1),%ecx
  mov    -0x34(%rbp),%eax
  cltq
  movzbl -0x20(%rbp,%rax,1),%edx
  mov    -0x34(%rbp),%eax
  cltq
  lea    0x1(%rax),%rsi
  mov    -0x58(%rbp),%rax
  add    %rsi,%rax
  xor    %ecx,%edx
  mov    %dl,(%rax)
  addl   $0x1,-0x34(%rbp)
L272:
  cmpl   $0x3,-0x34(%rbp)
  jle    L84
  mov    -0x6c(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x68(%rbp),%rax
  lea    (%rdx,%rax,1),%rcx
  lea    -0x1c(%rbp),%rdx
  mov    -0x60(%rbp),%rax
  mov    %rax,%rsi
  mov    %rcx,%rdi
  call   <modprod@plt>
  movl   $0x0,-0x34(%rbp)
  jmp    L85
L202:
  mov    -0x6c(%rbp),%eax
  cltq
  shl    $0x2,%rax
  lea    -0x4(%rax),%rdx
  mov    -0x68(%rbp),%rax
  add    %rax,%rdx
  mov    -0x34(%rbp),%eax
  cltq
  movzbl (%rdx,%rax,1),%esi
  mov    -0x34(%rbp),%eax
  cltq
  movzbl -0x1c(%rbp,%rax,1),%ecx
  mov    -0x6c(%rbp),%eax
  cltq
  add    $0x1,%rax
  lea    0x0(,%rax,4),%rdx
  mov    -0x68(%rbp),%rax
  add    %rax,%rdx
  xor    %esi,%ecx
  mov    -0x34(%rbp),%eax
  cltq
  mov    %cl,(%rdx,%rax,1)
  addl   $0x1,-0x34(%rbp)
L85:
  cmpl   $0x3,-0x34(%rbp)
  jle    L202
L177:
  nop
  mov    -0x18(%rbp),%rax
  sub    %fs:0x28,%rax
  je     L266
  call   <__stack_chk_fail@plt>
L266:
  mov    -0x8(%rbp),%rbx
  leave
  ret
```

assistant: ```c
void longdivision(unsigned char a[5], unsigned char b[5], unsigned char dest[5], unsigned char quo[4], unsigned char x[6][4], int round) {
  int i, j;
  int index_a;
  int index_b;
  unsigned char inv;
  unsigned char prod[4] = {0, 0, 0, 0};
  unsigned char temp[4] = {0, 0, 0, 0};
  unsigned char tempx[4] = {0, 0, 0, 0};
  if (a[0] == 1) {
    quo[0] = 0;
    quo[1] = 0;
    inv = miLookup(b[1]);
    for (i = 0; i < 3; i++) {
      prod[i] = bd(inv, b[i + 2]);
    }
    prod[3] = a[4];
    quo[2] = inv;
    inv = bd(inv, prod[0]);
    quo[3] = inv;
    for (i = 0; i < 4; i++) {
      temp[i] = bd(inv, b[i + 1]);
    }
    dest[0] = 0x0;
    for (i = 0; i < 4; i++) {
      dest[i + 1] = prod[i] ^ temp[i];
    }
    modprod(x[round], quo, tempx);
    for (i = 0; i < 4; i++) {
      x[round + 1][i] = x[round - 1][i] ^ tempx[i];
    }
  } else {
    quo[0] = 0;
    quo[1] = 0;
    for (index_a = 0; index_a < 5; index_a++) {
      if (a[index_a] != 0) {
        break;
      }
    }
    for (index_b = 0; index_b < 5; index_b++) {
      if (b[index_b] != 0x0) {
        break;
      }
    }
    inv = miLookup(b[index_b]);
    quo[2] = bd(inv, a[index_a]);
    j = 0;
    for (i = index_a - 1; i < 4 - index_b + index_a; i++, j++) {
      prod[i] = bd(quo[2], b[index_b + j]);
    }
    j = 0;
    for (i = index_a - 1; i < 4 - index_b + index_a; i++, j++) {
      temp[i] = a[index_a + j] ^ prod[i];
    }
    temp[3] = a[4];
    quo[3] = bd(inv, temp[index_a]);
    for (i = 0; i < 4; i++) {
      prod[i] = bd(quo[3], b[i + 1]);
    }
    dest[0] = 0x0;
    for (i = 0; i < 4; i++) {
      dest[i + 1] = prod[i] ^ temp[i];
    }
    modprod(x[round], quo, tempx);
    for (i = 0; i < 4; i++) {
      x[round + 1][i] = x[round - 1][i] ^ tempx[i];
    }
  }
}
```