user: 下面的汇编指令对应的C源代码是什么：

```asm
<vscan>:
  endbr64
  push   %r15
  mov    %rsi,%r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    %r9d,%ebx
  sub    $0x38,%rsp
  mov    0xa0(%rsp),%eax
  mov    %rdi,0x20(%rsp)
  mov    %rdx,(%rsp)
  sub    %r8d,%eax
  mov    %rcx,0x8(%rsp)
  mov    %eax,0x2c(%rsp)
  mov    %r8d,0x14(%rsp)
L116:
  subl   $0x1,0x88(%rsp)
  js     L61
  mov    0x14(%rsp),%r14d
  mov    %ebx,%edx
  addl   $0x1,0xb0(%rsp)
  xor    %r10d,%r10d
  mov    0xb0(%rsp),%ebp
  mov    0x90(%rsp),%ecx
  mov    0x98(%rsp),%eax
  sub    0xb8(%rsp),%edx
  sub    %r14d,%ecx
  sub    %r14d,%ebp
  mov    0x2c(%rsp),%edi
  sub    %ebx,%eax
  imul   %ecx,%edx
  imul   %ebp,%eax
  add    %edx,%eax
  add    %eax,%eax
  cltd
  idiv   %ecx
  mov    %ebx,%edx
  test   %eax,%eax
  mov    0xa8(%rsp),%eax
  setg   %r10b
  sub    0xc0(%rsp),%edx
  add    0xb8(%rsp),%r10d
  sub    %ebx,%eax
  imul   %edi,%edx
  mov    %r10d,%esi
  mov    %r10d,%r13d
  imul   %ebp,%eax
  add    %edx,%eax
  add    %eax,%eax
  cltd
  idiv   %edi
  mov    %ebp,%edi
  test   %eax,%eax
  setg   %al
  sub    %ebx,%esi
  movzbl %al,%eax
  add    0xc0(%rsp),%eax
  mov    %esi,0x10(%rsp)
  mov    %eax,0x1c(%rsp)
  mov    (%rsp),%rax
  call   *%rax
  mov    0x10(%rsp),%esi
  mov    %ebp,%edi
  lea    (%rax,%r14,1),%r12d
  mov    0x8(%rsp),%rax
  call   *%rax
  mov    0x70(%rsp),%r8d
  mov    0x20(%rsp),%rdi
  mov    %r12d,%edx
  lea    (%rax,%rbx,1),%ecx
  mov    %r15,%rsi
  call   <vcheck@plt>
  test   %rax,%rax
  jne    L103
  mov    %ebx,0xb8(%rsp)
  movl   $0x0,0x28(%rsp)
L1:
  cmp    0x1c(%rsp),%r13d
  jg     L61
  mov    0x20(%rsp),%r14
  mov    %ebx,0x10(%rsp)
  mov    %r13d,%ebx
L17:
  mov    %ebx,%r12d
  sub    0x10(%rsp),%r12d
  mov    %ebp,%edi
  mov    (%rsp),%rax
  mov    %r12d,%esi
  mov    %ebx,0xc0(%rsp)
  call   *%rax
  mov    0x14(%rsp),%edi
  mov    %r12d,%esi
  lea    (%rax,%rdi,1),%r13d
  mov    %ebp,%edi
  mov    0x8(%rsp),%rax
  call   *%rax
  mov    0x10(%rsp),%edx
  mov    0x70(%rsp),%r8d
  mov    %r15,%rsi
  mov    %r14,%rdi
  lea    (%rax,%rdx,1),%ecx
  mov    %r13d,%edx
  mov    %ecx,0x18(%rsp)
  call   <vcheck@plt>
  mov    0x18(%rsp),%ecx
  test   %rax,%rax
  jne    L77
  mov    %r12d,%esi
  mov    %ebp,%edi
  mov    (%rsp),%rax
  call   *%rax
  mov    0x14(%rsp),%edx
  mov    %r12d,%esi
  mov    %ebp,%edi
  lea    (%rax,%rdx,1),%r13d
  mov    0x8(%rsp),%rax
  call   *%rax
  mov    0x10(%rsp),%esi
  mov    0x70(%rsp),%r8d
  mov    %r13d,%edx
  mov    $0x1,%r9d
  mov    %r14,%rdi
  lea    0x1(%rbx),%r13d
  lea    (%rax,%rsi,1),%ecx
  mov    %r15,%rsi
  call   <vmark_safe@plt>
  mov    0x28(%rsp),%eax
  test   %eax,%eax
  jne    L128
  mov    0xb0(%rsp),%eax
  mov    %r13d,0x98(%rsp)
  mov    %eax,0x90(%rsp)
L43:
  mov    %r13d,%ebx
  cmp    %r13d,0x1c(%rsp)
  jge    L17
L61:
  add    $0x38,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   (%rax)
L103:
  mov    %r13d,0xb8(%rsp)
  movl   $0x1,0x28(%rsp)
  jmp    L1
  nopl   (%rax)
L77:
  push   $0x1
  mov    0x88(%rsp),%eax
  mov    %r13d,%edx
  mov    %r15,%rsi
  mov    %r14,%rdi
  push   %rax
  mov    0x88(%rsp),%r9d
  mov    0x80(%rsp),%r8d
  call   <vmark_xynb@plt>
  pop    %rdx
  pop    %rcx
  mov    0x28(%rsp),%esi
  test   %esi,%esi
  jne    L67
  mov    0xb0(%rsp),%eax
  mov    %ebx,0xb8(%rsp)
  lea    0x1(%rbx),%r13d
  mov    %ebx,0x98(%rsp)
  mov    %eax,0x90(%rsp)
  movl   $0x1,0x28(%rsp)
  jmp    L43
  nopl   0x0(%rax,%rax,1)
L128:
  sub    $0x8,%rsp
  lea    -0x1(%rbx),%r10d
  mov    %r15,%rsi
  mov    %r14,%rdi
  push   %r10
  mov    0xc8(%rsp),%eax
  push   %rax
  mov    0xc8(%rsp),%eax
  push   %rax
  push   %r10
  mov    0xd8(%rsp),%eax
  push   %rax
  mov    0xc8(%rsp),%eax
  push   %rax
  mov    0xc8(%rsp),%eax
  push   %rax
  mov    0xc8(%rsp),%eax
  push   %rax
  mov    0xc8(%rsp),%eax
  push   %rax
  mov    0xc8(%rsp),%eax
  push   %rax
  mov    0xc8(%rsp),%eax
  push   %rax
  mov    0x70(%rsp),%r9d
  mov    0x74(%rsp),%r8d
  mov    0x68(%rsp),%rcx
  mov    0x60(%rsp),%rdx
  call   <vscan>
  mov    0x110(%rsp),%eax
  add    $0x60,%rsp
  mov    %r13d,0x98(%rsp)
  mov    %eax,0x90(%rsp)
  movl   $0x0,0x28(%rsp)
  jmp    L43
  nopw   0x0(%rax,%rax,1)
L67:
  cmp    %ebx,0x1c(%rsp)
  je     L76
  lea    0x1(%rbx),%r13d
  jmp    L43
  nopw   0x0(%rax,%rax,1)
L76:
  mov    0x10(%rsp),%ebx
  jmp    L116
```

assistant: ```c
void vscan(struct grid *g, struct vision *v, int (*trans_x)(int, int), int (*trans_y)(int, int), int x0, int y0, int z0, int zminus, int zplus, int range, int xfl, int yfl, int xfh, int yfh, int prev_x, int prev_yl, int prev_yh) {
  int x, y, dyl, dyh, yl, yh;
  int b_lower = 0;
  int lower = y0;
  int range_u = range - 1;
  int xx, yy;
  if (range_u >= 0) {
    x = prev_x + 1;
    dyl = 0;
    if (2 * ((yfl - y0) * (x - x0) + (y0 - prev_yl) * (xfl - x0)) / (xfl - x0) >= 1) {
      dyl = 1;
    }
    yl = prev_yl + dyl;
    dyh = 0;
    if (2 * ((yfh - y0) * (x - x0) + (y0 - prev_yh) * (xfh - x0)) / (xfh - x0) >= 1) {
      dyh = 1;
    }
    yh = prev_yh + dyh;
    xx = x0 + trans_x(x - x0, yl - y0);
    yy = y0 + trans_y(x - x0, yl - y0);
    if (vcheck(g, v, xx, yy, z0)) {
      b_lower = 1;
      lower = yl;
    }
    for (y = yl; y <= yh; ++y) {
      xx = x0 + trans_x(x - x0, y - y0);
      yy = y0 + trans_y(x - x0, y - y0);
      if (vcheck(g, v, xx, yy, z0)) {
        vmark_xynb(g, v, xx, yy, z0, zminus, zplus, 1);
        if (b_lower) {
          if (y == yh) {
            vscan(g, v, trans_x, trans_y, x0, y0, z0, zminus, zplus, range_u, xfl, yfl, xfh, yfh, x, lower, y);
          } else {
            ;
          }
        } else {
          xfl = x;
          yfl = y;
          b_lower = 1;
          lower = y;
        }
      } else {
        xx = x0 + trans_x(x - x0, y - y0);
        yy = y0 + trans_y(x - x0, y - y0);
        vmark_safe(g, v, xx, yy, z0, 1);
        if (b_lower) {
          vscan(g, v, trans_x, trans_y, x0, y0, z0, zminus, zplus, range_u, xfl, yfl, x, y - 1, x, lower, y - 1);
          xfl = x;
          yfl = y + 1;
          b_lower = 0;
        } else {
          xfl = x;
          yfl = y + 1;
          b_lower = 0;
        }
      }
    }
  }
}
```