user: 请从给定的汇编指令推导出C源代码：

```asm
<flipBoard>:
  endbr64
  push   %r15
  mov    $0x57,%eax
  push   %r14
  mov    %rdi,%r14
  push   %r13
  movsbl %cl,%r13d
  push   %r12
  movsbl %dl,%r12d
  sub    $0x61,%r13d
  push   %rbp
  sub    $0x61,%r12d
  mov    %r13d,%edx
  mov    $0x42,%ebp
  push   %rbx
  mov    %esi,%ebx
  mov    %r12d,%esi
  sub    $0x38,%rsp
  cmp    $0x42,%r8b
  mov    %rdi,0x10(%rsp)
  mov    %ebx,%edi
  cmove  %eax,%ebp
  mov    0x70(%rsp),%r15d
  mov    %r9d,0x8(%rsp)
  mov    %r8b,0x4(%rsp)
  call   <positionInBounds@plt>
  movzbl 0x4(%rsp),%r11d
  mov    0x8(%rsp),%r9d
  mov    %eax,%ecx
  movslq %r12d,%rax
  lea    (%rax,%rax,2),%rdx
  lea    (%rax,%rdx,4),%rax
  lea    (%r14,%rax,2),%rdx
  movslq %r13d,%rax
  cmpb   $0x55,(%rdx,%rax,1)
  je     L2
L28:
  add    $0x38,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   (%rax)
L2:
  add    %r9d,%r12d
  mov    0x10(%rsp),%rdi
  add    %r15d,%r13d
  movslq %r12d,%rax
  lea    (%rax,%rax,2),%rdx
  lea    (%rax,%rdx,4),%rax
  lea    (%rdi,%rax,2),%rdx
  movslq %r13d,%rax
  cmp    %bpl,(%rdx,%rax,1)
  jne    L28
  lea    (%r9,%r12,1),%ebp
  lea    (%r15,%r13,1),%r14d
  cmp    $0x1,%ecx
  jne    L28
  movslq %r9d,%rsi
  mov    %r9d,0x4(%rsp)
  lea    (%rsi,%rsi,2),%rax
  mov    %rsi,0x18(%rsp)
  lea    (%rsi,%rax,4),%rax
  mov    %r12d,0x28(%rsp)
  lea    (%rax,%rax,1),%rdi
  movslq %r15d,%rax
  mov    %r13d,0x2c(%rsp)
  mov    %ebp,%r13d
  add    %rdi,%rax
  mov    %rdi,0x20(%rsp)
  mov    %rax,0x8(%rsp)
  movslq %ebp,%rax
  mov    %r11d,%ebp
  lea    (%rax,%rax,2),%rcx
  lea    (%rax,%rcx,4),%rcx
  movslq %r14d,%rax
  lea    (%rax,%rcx,2),%rcx
  add    0x10(%rsp),%rcx
  mov    %rcx,%r12
  nopl   0x0(%rax,%rax,1)
L46:
  mov    %r14d,%edx
  mov    %r13d,%esi
  mov    %ebx,%edi
  call   <positionInBounds@plt>
  movzbl (%r12),%edx
  cmp    %bpl,%dl
  je     L59
  cmp    $0x55,%dl
  je     L28
  add    0x4(%rsp),%r13d
  add    %r15d,%r14d
  add    0x8(%rsp),%r12
  cmp    $0x1,%eax
  je     L46
  jmp    L28
  nop
L59:
  movslq %r13d,%rcx
  mov    %ebp,%r11d
  mov    0x10(%rsp),%rbx
  mov    %r15d,%eax
  mov    %rcx,%rbp
  sub    0x18(%rsp),%rcx
  neg    %eax
  mov    0x28(%rsp),%r12d
  lea    (%rcx,%rcx,2),%rsi
  mov    0x2c(%rsp),%r13d
  mov    0x4(%rsp),%r9d
  cltq
  lea    (%rcx,%rsi,4),%rsi
  mov    %r14d,%ecx
  sub    0x20(%rsp),%rax
  sub    %r15d,%ecx
  movslq %ecx,%rcx
  lea    (%rcx,%rsi,2),%rcx
  add    %rcx,%rbx
  cs nopw 0x0(%rax,%rax,1)
L58:
  sub    %r9d,%ebp
  mov    %r11b,(%rbx)
  sub    %r15d,%r14d
  add    %rax,%rbx
  cmp    %ebp,%r12d
  jne    L58
  cmp    %r14d,%r13d
  jne    L58
  add    $0x38,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void flipBoard(char board[][26], int n, char row, char col, char colour, int deltaRow, int deltaCol) {
  int rowNum = row - 'a';
  int colNum = col - 'a';
  bool q;
  char anticolour = 'B';
  if (colour == 'B')
    anticolour = 'W';
  bool judge = positionInBounds(n, rowNum, colNum);
  if (board[rowNum][colNum] == 'U') {
    rowNum = rowNum + deltaRow;
    colNum = colNum + deltaCol;
    if (board[rowNum][colNum] == anticolour) {
      rowNum = rowNum + deltaRow;
      colNum = colNum + deltaCol;
      for (; judge == true; rowNum = rowNum + deltaRow, colNum = colNum + deltaCol) {
        judge = positionInBounds(n, rowNum, colNum);
        if (judge == false)
          q = false;
        if (board[rowNum][colNum] == colour) {
          q = true;
          judge = false;
          do {
            rowNum = rowNum - deltaRow;
            colNum = colNum - deltaCol;
            board[rowNum][colNum] = colour;
          } while (rowNum != row - 'a' + deltaRow || colNum != col - 'a' + deltaCol);
        } else if (board[rowNum][colNum] == 'U') {
          q = false;
          judge = false;
        }
      }
    } else
      q = false;
  } else
    q = false;
}
```