user: What would the C source look like for the assembly code provided here?

```asm
<ellipse>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x40,%rsp
  mov    %edi,-0x34(%rbp)
  mov    %esi,-0x38(%rbp)
  mov    %edx,-0x3c(%rbp)
  mov    %ecx,-0x40(%rbp)
  mov    -0x3c(%rbp),%eax
  sub    -0x34(%rbp),%eax
  mov    %eax,%edx
  neg    %edx
  cmovns %edx,%eax
  mov    %eax,-0x2c(%rbp)
  mov    -0x40(%rbp),%eax
  sub    -0x38(%rbp),%eax
  mov    %eax,%edx
  neg    %edx
  cmovns %edx,%eax
  mov    %eax,-0x28(%rbp)
  mov    -0x28(%rbp),%eax
  and    $0x1,%eax
  mov    %eax,-0x24(%rbp)
  mov    $0x1,%eax
  sub    -0x2c(%rbp),%eax
  imul   -0x28(%rbp),%eax
  imul   -0x28(%rbp),%eax
  shl    $0x2,%eax
  cltq
  mov    %rax,-0x20(%rbp)
  mov    -0x24(%rbp),%eax
  add    $0x1,%eax
  imul   -0x2c(%rbp),%eax
  imul   -0x2c(%rbp),%eax
  shl    $0x2,%eax
  cltq
  mov    %rax,-0x18(%rbp)
  mov    -0x20(%rbp),%rdx
  mov    -0x18(%rbp),%rax
  add    %rax,%rdx
  mov    -0x24(%rbp),%eax
  imul   -0x2c(%rbp),%eax
  imul   -0x2c(%rbp),%eax
  cltq
  add    %rdx,%rax
  mov    %rax,-0x10(%rbp)
  mov    -0x34(%rbp),%eax
  cmp    -0x3c(%rbp),%eax
  jle    L43
  mov    -0x3c(%rbp),%eax
  mov    %eax,-0x34(%rbp)
  mov    -0x2c(%rbp),%eax
  add    %eax,-0x3c(%rbp)
L43:
  mov    -0x38(%rbp),%eax
  cmp    -0x40(%rbp),%eax
  jle    L7
  mov    -0x40(%rbp),%eax
  mov    %eax,-0x38(%rbp)
L7:
  mov    -0x28(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,%edx
  shr    $0x1f,%edx
  add    %edx,%eax
  sar    %eax
  add    %eax,-0x38(%rbp)
  mov    -0x38(%rbp),%eax
  sub    -0x24(%rbp),%eax
  mov    %eax,-0x40(%rbp)
  mov    -0x2c(%rbp),%eax
  imul   %eax,%eax
  shl    $0x3,%eax
  mov    %eax,-0x2c(%rbp)
  mov    -0x28(%rbp),%eax
  imul   %eax,%eax
  shl    $0x3,%eax
  mov    %eax,-0x24(%rbp)
L35:
  mov    -0x38(%rbp),%edx
  mov    -0x3c(%rbp),%eax
  mov    %edx,%esi
  mov    %eax,%edi
  call   <setPixel@plt>
  mov    -0x38(%rbp),%edx
  mov    -0x34(%rbp),%eax
  mov    %edx,%esi
  mov    %eax,%edi
  call   <setPixel@plt>
  mov    -0x40(%rbp),%edx
  mov    -0x34(%rbp),%eax
  mov    %edx,%esi
  mov    %eax,%edi
  call   <setPixel@plt>
  mov    -0x40(%rbp),%edx
  mov    -0x3c(%rbp),%eax
  mov    %edx,%esi
  mov    %eax,%edi
  call   <setPixel@plt>
  mov    -0x10(%rbp),%rax
  add    %rax,%rax
  mov    %rax,-0x8(%rbp)
  mov    -0x8(%rbp),%rax
  cmp    -0x18(%rbp),%rax
  jg     L37
  addl   $0x1,-0x38(%rbp)
  subl   $0x1,-0x40(%rbp)
  mov    -0x2c(%rbp),%eax
  cltq
  add    %rax,-0x18(%rbp)
  mov    -0x18(%rbp),%rax
  add    %rax,-0x10(%rbp)
L37:
  mov    -0x8(%rbp),%rax
  cmp    -0x20(%rbp),%rax
  jge    L38
  mov    -0x10(%rbp),%rax
  add    %rax,%rax
  cmp    %rax,-0x18(%rbp)
  jge    L78
L38:
  addl   $0x1,-0x34(%rbp)
  subl   $0x1,-0x3c(%rbp)
  mov    -0x24(%rbp),%eax
  cltq
  add    %rax,-0x20(%rbp)
  mov    -0x20(%rbp),%rax
  add    %rax,-0x10(%rbp)
L78:
  mov    -0x34(%rbp),%eax
  cmp    -0x3c(%rbp),%eax
  jle    L35
  jmp    L71
L39:
  mov    -0x34(%rbp),%eax
  lea    -0x1(%rax),%edx
  mov    -0x38(%rbp),%eax
  mov    %eax,%esi
  mov    %edx,%edi
  call   <setPixel@plt>
  mov    -0x38(%rbp),%eax
  lea    0x1(%rax),%edx
  mov    %edx,-0x38(%rbp)
  mov    -0x3c(%rbp),%edx
  add    $0x1,%edx
  mov    %eax,%esi
  mov    %edx,%edi
  call   <setPixel@plt>
  mov    -0x34(%rbp),%eax
  lea    -0x1(%rax),%edx
  mov    -0x40(%rbp),%eax
  mov    %eax,%esi
  mov    %edx,%edi
  call   <setPixel@plt>
  mov    -0x40(%rbp),%eax
  lea    -0x1(%rax),%edx
  mov    %edx,-0x40(%rbp)
  mov    -0x3c(%rbp),%edx
  add    $0x1,%edx
  mov    %eax,%esi
  mov    %edx,%edi
  call   <setPixel@plt>
L71:
  mov    -0x38(%rbp),%eax
  sub    -0x40(%rbp),%eax
  cmp    %eax,-0x28(%rbp)
  jg     L39
  nop
  nop
  leave
  ret
```

assistant: ```c
void ellipse(int x0, int y0, int x1, int y1) {
  int a = abs(x1 - x0), b = abs(y1 - y0), b1 = b & 1;
  long dx = 4 * (1 - a) * b * b, dy = 4 * (b1 + 1) * a * a;
  long err = dx + dy + b1 * a * a, e2;
  if (x0 > x1) {
    x0 = x1;
    x1 += a;
  }
  if (y0 > y1)
    y0 = y1;
  y0 += (b + 1) / 2;
  y1 = y0 - b1;
  a *= 8 * a;
  b1 = 8 * b * b;
  do {
    setPixel(x1, y0);
    setPixel(x0, y0);
    setPixel(x0, y1);
    setPixel(x1, y1);
    e2 = 2 * err;
    if (e2 <= dy) {
      y0++;
      y1--;
      err += dy += a;
    }
    if (e2 >= dx || 2 * err > dy) {
      x0++;
      x1--;
      err += dx += b1;
    }
  } while (x0 <= x1);
  while (y0 - y1 < b) {
    setPixel(x0 - 1, y0);
    setPixel(x1 + 1, y0++);
    setPixel(x0 - 1, y1);
    setPixel(x1 + 1, y1--);
  }
}
```