user: 下面的汇编指令对应的C源代码是什么：

```asm
<drawCircle>:
  endbr64
  push   %r15
  mov    %ecx,%r8d
  mov    %edx,%eax
  mov    %esi,%r15d
  push   %r14
  neg    %eax
  mov    %esi,%r14d
  add    %edx,%esi
  push   %r13
  mov    %edx,%ecx
  mov    %edx,%r13d
  add    %eax,%eax
  push   %r12
  mov    $0x1,%r12d
  movswl %si,%esi
  push   %rbp
  sub    %edx,%r12d
  mov    %edi,%ebp
  movswl %di,%edi
  push   %rbx
  movswl %r8w,%ebx
  mov    %ebx,%edx
  sub    $0x28,%rsp
  mov    %ecx,0x10(%rsp)
  mov    %edi,0xc(%rsp)
  mov    %ax,0x1e(%rsp)
  call   <drawPixel@plt>
  mov    %r14d,%esi
  mov    0xc(%rsp),%edi
  mov    %ebx,%edx
  sub    %r13d,%esi
  movswl %si,%esi
  call   <drawPixel@plt>
  lea    0x0(%r13,%rbp,1),%edi
  movswl %r14w,%esi
  mov    %ebx,%edx
  movswl %di,%edi
  mov    %esi,0xc(%rsp)
  mov    %ebp,%r14d
  sub    %r13d,%ebp
  call   <drawPixel@plt>
  mov    0xc(%rsp),%esi
  movswl %bp,%edi
  mov    %ebx,%edx
  call   <drawPixel@plt>
  test   %r13w,%r13w
  mov    0x10(%rsp),%ecx
  jle    L9
  xor    %ebp,%ebp
L15:
  mov    %ecx,%r13d
  test   %r12w,%r12w
  js     L14
  addw   $0x2,0x1e(%rsp)
  movzwl 0x1e(%rsp),%eax
  lea    -0x1(%rcx),%r13d
  mov    %r13d,%ecx
  add    %eax,%r12d
L14:
  add    $0x1,%ebp
  lea    (%r15,%r13,1),%esi
  mov    %ebx,%edx
  mov    %ecx,0x18(%rsp)
  lea    (%r14,%rbp,1),%r9d
  movswl %si,%esi
  lea    0x1(%r12,%rbp,2),%r12d
  movswl %r9w,%r9d
  mov    %esi,0xc(%rsp)
  mov    %r9d,%edi
  mov    %r9d,0x14(%rsp)
  call   <drawPixel@plt>
  mov    %r14d,%r8d
  mov    0xc(%rsp),%esi
  mov    %ebx,%edx
  sub    %ebp,%r8d
  movswl %r8w,%r8d
  mov    %r8d,%edi
  mov    %r8d,0x10(%rsp)
  call   <drawPixel@plt>
  mov    %r15d,%esi
  mov    0x14(%rsp),%edi
  mov    %ebx,%edx
  sub    %r13d,%esi
  movswl %si,%esi
  mov    %esi,0xc(%rsp)
  call   <drawPixel@plt>
  mov    0xc(%rsp),%esi
  mov    0x10(%rsp),%edi
  mov    %ebx,%edx
  call   <drawPixel@plt>
  lea    (%r14,%r13,1),%r8d
  lea    (%r15,%rbp,1),%esi
  mov    %ebx,%edx
  movswl %r8w,%r8d
  movswl %si,%esi
  mov    %r8d,%edi
  mov    %r8d,0x10(%rsp)
  mov    %esi,0xc(%rsp)
  call   <drawPixel@plt>
  mov    %r14d,%eax
  mov    0xc(%rsp),%esi
  mov    %ebx,%edx
  sub    %r13d,%eax
  movswl %ax,%r13d
  mov    %r13d,%edi
  call   <drawPixel@plt>
  mov    %r15d,%esi
  mov    0x10(%rsp),%edi
  mov    %ebx,%edx
  sub    %ebp,%esi
  movswl %si,%esi
  mov    %esi,0xc(%rsp)
  call   <drawPixel@plt>
  mov    0xc(%rsp),%esi
  mov    %ebx,%edx
  mov    %r13d,%edi
  call   <drawPixel@plt>
  mov    0x18(%rsp),%ecx
  cmp    %bp,%cx
  jg     L15
L9:
  add    $0x28,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void drawCircle(short x0, short y0, short r, short color) {
  short f = 1 - r;
  short ddF_x = 1;
  short ddF_y = -2 * r;
  short x = 0;
  short y = r;
  drawPixel(x0, y0 + r, color);
  drawPixel(x0, y0 - r, color);
  drawPixel(x0 + r, y0, color);
  drawPixel(x0 - r, y0, color);
  while (x < y) {
    if (f >= 0) {
      y--;
      ddF_y += 2;
      f += ddF_y;
    }
    x++;
    ddF_x += 2;
    f += ddF_x;
    drawPixel(x0 + x, y0 + y, color);
    drawPixel(x0 - x, y0 + y, color);
    drawPixel(x0 + x, y0 - y, color);
    drawPixel(x0 - x, y0 - y, color);
    drawPixel(x0 + y, y0 + x, color);
    drawPixel(x0 - y, y0 + x, color);
    drawPixel(x0 + y, y0 - x, color);
    drawPixel(x0 - y, y0 - x, color);
  }
}
```