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

```asm
<get_pawn_moves_black>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x30,%rsp
  mov    %rdi,-0x18(%rbp)
  mov    %rsi,-0x20(%rbp)
  mov    %rdx,-0x28(%rbp)
  movl   $0x0,-0x4(%rbp)
  movb   $0x61,-0x7(%rbp)
  jmp    L158
L37:
  movb   $0x31,-0x6(%rbp)
  jmp    L156
L105:
  movsbl -0x6(%rbp),%edx
  movsbl -0x7(%rbp),%ecx
  mov    -0x20(%rbp),%rax
  mov    %ecx,%esi
  mov    %rax,%rdi
  call   <get_piece@plt>
  mov    %al,-0x5(%rbp)
  cmpb   $0x70,-0x5(%rbp)
  jne    L32
  cmpb   $0x37,-0x6(%rbp)
  jne    L6
  movzbl -0x6(%rbp),%eax
  sub    $0x1,%eax
  movsbl %al,%edx
  movsbl -0x7(%rbp),%ecx
  mov    -0x20(%rbp),%rax
  mov    %ecx,%esi
  mov    %rax,%rdi
  call   <is_occupied@plt>
  test   %eax,%eax
  jne    L6
  movzbl -0x6(%rbp),%eax
  sub    $0x2,%eax
  movsbl %al,%edx
  movsbl -0x7(%rbp),%ecx
  mov    -0x20(%rbp),%rax
  mov    %ecx,%esi
  mov    %rax,%rdi
  call   <is_occupied@plt>
  test   %eax,%eax
  jne    L6
  movzbl -0x6(%rbp),%eax
  sub    $0x2,%eax
  movsbl %al,%edi
  movsbl -0x7(%rbp),%ecx
  movsbl -0x6(%rbp),%r9d
  movsbl -0x7(%rbp),%r8d
  mov    -0x28(%rbp),%rdx
  mov    -0x20(%rbp),%rsi
  mov    -0x18(%rbp),%rax
  push   %rdi
  push   %rcx
  mov    %rdx,%rcx
  mov    $0x0,%edx
  mov    %rax,%rdi
  call   <store_move@plt>
  add    $0x10,%rsp
  mov    %rax,-0x18(%rbp)
  addl   $0x1,-0x4(%rbp)
L6:
  cmpb   $0x31,-0x6(%rbp)
  jle    L151
  movzbl -0x6(%rbp),%eax
  sub    $0x1,%eax
  movsbl %al,%edx
  movsbl -0x7(%rbp),%ecx
  mov    -0x20(%rbp),%rax
  mov    %ecx,%esi
  mov    %rax,%rdi
  call   <is_occupied@plt>
  test   %eax,%eax
  jne    L151
  movzbl -0x6(%rbp),%eax
  sub    $0x1,%eax
  movsbl %al,%edi
  movsbl -0x7(%rbp),%ecx
  movsbl -0x6(%rbp),%r9d
  movsbl -0x7(%rbp),%r8d
  mov    -0x28(%rbp),%rdx
  mov    -0x20(%rbp),%rsi
  mov    -0x18(%rbp),%rax
  push   %rdi
  push   %rcx
  mov    %rdx,%rcx
  mov    $0x0,%edx
  mov    %rax,%rdi
  call   <store_move@plt>
  add    $0x10,%rsp
  mov    %rax,-0x18(%rbp)
  addl   $0x1,-0x4(%rbp)
L151:
  cmpb   $0x61,-0x7(%rbp)
  jle    L116
  cmpb   $0x31,-0x6(%rbp)
  jle    L116
  movzbl -0x6(%rbp),%eax
  sub    $0x1,%eax
  movsbl %al,%edx
  movzbl -0x7(%rbp),%eax
  sub    $0x1,%eax
  movsbl %al,%ecx
  mov    -0x20(%rbp),%rax
  mov    %ecx,%esi
  mov    %rax,%rdi
  call   <is_occupied@plt>
  cmp    $0x1,%eax
  jne    L116
  movzbl -0x6(%rbp),%eax
  sub    $0x1,%eax
  movsbl %al,%edi
  movzbl -0x7(%rbp),%eax
  sub    $0x1,%eax
  movsbl %al,%ecx
  movsbl -0x6(%rbp),%r9d
  movsbl -0x7(%rbp),%r8d
  mov    -0x28(%rbp),%rdx
  mov    -0x20(%rbp),%rsi
  mov    -0x18(%rbp),%rax
  push   %rdi
  push   %rcx
  mov    %rdx,%rcx
  mov    $0x0,%edx
  mov    %rax,%rdi
  call   <store_move@plt>
  add    $0x10,%rsp
  mov    %rax,-0x18(%rbp)
  addl   $0x1,-0x4(%rbp)
L116:
  cmpb   $0x67,-0x7(%rbp)
  jg     L32
  cmpb   $0x31,-0x6(%rbp)
  jle    L32
  movzbl -0x6(%rbp),%eax
  sub    $0x1,%eax
  movsbl %al,%edx
  movzbl -0x7(%rbp),%eax
  add    $0x1,%eax
  movsbl %al,%ecx
  mov    -0x20(%rbp),%rax
  mov    %ecx,%esi
  mov    %rax,%rdi
  call   <is_occupied@plt>
  cmp    $0x1,%eax
  jne    L32
  movzbl -0x6(%rbp),%eax
  sub    $0x1,%eax
  movsbl %al,%edi
  movzbl -0x7(%rbp),%eax
  add    $0x1,%eax
  movsbl %al,%ecx
  movsbl -0x6(%rbp),%r9d
  movsbl -0x7(%rbp),%r8d
  mov    -0x28(%rbp),%rdx
  mov    -0x20(%rbp),%rsi
  mov    -0x18(%rbp),%rax
  push   %rdi
  push   %rcx
  mov    %rdx,%rcx
  mov    $0x0,%edx
  mov    %rax,%rdi
  call   <store_move@plt>
  add    $0x10,%rsp
  mov    %rax,-0x18(%rbp)
  addl   $0x1,-0x4(%rbp)
L32:
  movzbl -0x6(%rbp),%eax
  add    $0x1,%eax
  mov    %al,-0x6(%rbp)
L156:
  cmpb   $0x38,-0x6(%rbp)
  jle    L105
  movzbl -0x7(%rbp),%eax
  add    $0x1,%eax
  mov    %al,-0x7(%rbp)
L158:
  cmpb   $0x68,-0x7(%rbp)
  jle    L37
  mov    -0x18(%rbp),%rax
  leave
  ret
```

assistant: ```c
struct node *get_pawn_moves_black(struct node *currentNode, char *board, struct node *parentNode) {
  char x, y;
  int numMoves = 0;
  for (x = 'a'; x <= 'h'; x++) {
    for (y = '1'; y <= '8'; y++) {
      char p = get_piece(board, x, y);
      if (p == 'p') {
        if ((y == '7') && (is_occupied(board, x, y - 1) == 0) && (is_occupied(board, x, y - 2) == 0)) {
          currentNode = store_move(currentNode, board, 0, parentNode, x, y, x, y - 2);
          numMoves++;
        }
        if ((y > '1') && (is_occupied(board, x, y - 1) == 0)) {
          currentNode = store_move(currentNode, board, 0, parentNode, x, y, x, y - 1);
          numMoves++;
        }
        if ((x > 'a') && (y > '1') && (is_occupied(board, x - 1, y - 1) == 1)) {
          currentNode = store_move(currentNode, board, 0, parentNode, x, y, x - 1, y - 1);
          numMoves++;
        }
        if ((x < 'h') && (y > '1') && (is_occupied(board, x + 1, y - 1) == 1)) {
          currentNode = store_move(currentNode, board, 0, parentNode, x, y, x + 1, y - 1);
          numMoves++;
        }
      }
    }
  }
  return currentNode;
}
```