user: Demonstrate the C code that generates the assembly output below:

```asm
<alcon2009_draw_rectangle>:
  endbr64
  push   %r15
  mov    %esi,%r10d
  push   %r14
  push   %r13
  mov    %ecx,%r13d
  push   %r12
  push   %rbp
  push   %rbx
  movzbl 0x48(%rsp),%r11d
  movzbl 0x50(%rsp),%ebx
  mov    %r9d,-0x18(%rsp)
  movzbl 0x40(%rsp),%r9d
  mov    %edx,-0x4(%rsp)
  mov    %r8d,-0x14(%rsp)
  cmp    0x38(%rsp),%r8d
  jg     L26
  mov    -0x14(%rsp),%r15d
  mov    -0x4(%rsp),%eax
  cmp    %eax,%r15d
  mov    %r15d,%eax
  not    %eax
  setl   %r8b
  shr    $0x1f,%eax
  and    %eax,%r8d
  lea    (%rsi,%rsi,2),%eax
  mov    %eax,-0xc(%rsp)
  mov    %r15d,%eax
  imul   %esi,%eax
  add    %ecx,%eax
  mov    -0x18(%rsp),%ecx
  lea    (%rax,%rax,2),%r12d
  mov    0x38(%rsp),%eax
  lea    0x4(%rcx),%ebp
  add    $0x1,%eax
  mov    %eax,-0x10(%rsp)
  mov    %ecx,%eax
  sub    %r13d,%eax
  lea    (%rax,%rax,2),%eax
  mov    %eax,-0x8(%rsp)
  nopw   0x0(%rax,%rax,1)
L3:
  mov    -0x8(%rsp),%eax
  mov    %r13d,%edx
  mov    %r12d,%ecx
  lea    (%r12,%rax,1),%esi
  mov    -0x18(%rsp),%eax
L105:
  test   %r8b,%r8b
  je     L68
  test   %edx,%edx
  js     L132
  cmp    %edx,%r10d
  jle    L132
  movslq %ecx,%r14
  mov    %r9b,(%rdi,%r14,1)
  mov    %r11b,0x1(%rdi,%r14,1)
  mov    %bl,0x2(%rdi,%r14,1)
L132:
  test   %eax,%eax
  js     L68
  cmp    %eax,%r10d
  jle    L68
  movslq %esi,%r14
  mov    %r9b,(%rdi,%r14,1)
  mov    %r11b,0x1(%rdi,%r14,1)
  mov    %bl,0x2(%rdi,%r14,1)
L68:
  add    $0x1,%eax
  add    $0x3,%esi
  sub    $0x3,%ecx
  sub    $0x1,%edx
  cmp    %ebp,%eax
  jne    L105
  add    $0x1,%r15d
  add    -0xc(%rsp),%r12d
  cmp    -0x10(%rsp),%r15d
  jne    L3
L26:
  mov    -0x18(%rsp),%eax
  lea    -0x3(%r13),%r12d
  add    $0x3,%eax
  cmp    %eax,%r12d
  jg     L130
  mov    %r13d,%eax
  cmp    %r10d,%r13d
  lea    (%r10,%r10,2),%r8d
  not    %eax
  setl   %bpl
  shr    $0x1f,%eax
  and    %eax,%ebp
  mov    0x38(%rsp),%eax
  imul   %r10d,%eax
  add    %r13d,%eax
  lea    -0x9(%rax,%rax,2),%r13d
  mov    -0x18(%rsp),%eax
  add    $0x4,%eax
  mov    %eax,-0x18(%rsp)
  mov    -0x14(%rsp),%eax
  sub    0x38(%rsp),%eax
  imul   %r8d,%eax
  mov    %eax,%r15d
  mov    0x38(%rsp),%eax
  mov    %r15d,-0x10(%rsp)
  mov    -0x4(%rsp),%r15d
  lea    0x4(%rax),%r10d
L106:
  mov    -0x10(%rsp),%eax
  mov    -0x14(%rsp),%edx
  mov    %r13d,%ecx
  lea    0x0(%r13,%rax,1),%esi
  mov    0x38(%rsp),%eax
L91:
  test   %bpl,%bpl
  je     L20
  test   %edx,%edx
  js     L148
  cmp    %edx,%r15d
  jle    L148
  movslq %esi,%r14
  mov    %r9b,(%rdi,%r14,1)
  mov    %r11b,0x1(%rdi,%r14,1)
  mov    %bl,0x2(%rdi,%r14,1)
L148:
  test   %eax,%eax
  js     L20
  cmp    %eax,%r15d
  jle    L20
  movslq %ecx,%r14
  mov    %r9b,(%rdi,%r14,1)
  mov    %r11b,0x1(%rdi,%r14,1)
  mov    %bl,0x2(%rdi,%r14,1)
L20:
  add    $0x1,%eax
  add    %r8d,%ecx
  sub    %r8d,%esi
  sub    $0x1,%edx
  cmp    %r10d,%eax
  jne    L91
  add    $0x1,%r12d
  add    $0x3,%r13d
  cmp    -0x18(%rsp),%r12d
  jne    L106
L130:
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void alcon2009_draw_rectangle(unsigned char *image, int width, int height, int x1, int y1, int x2, int y2, unsigned char r, unsigned char g, unsigned char b) {
  int i, w;
  for (i = y1; i <= y2; i++) {
    for (w = 0; w < 4; w++) {
      int xx1 = x1 - w;
      int xx2 = x2 + w;
      if (y1 >= 0 && y1 < height) {
        if (xx1 >= 0 && xx1 < width) {
          image[(xx1 + i * width) * 3 + 0] = r;
          image[(xx1 + i * width) * 3 + 1] = g;
          image[(xx1 + i * width) * 3 + 2] = b;
        }
        if (xx2 >= 0 && xx2 < width) {
          image[(xx2 + i * width) * 3 + 0] = r;
          image[(xx2 + i * width) * 3 + 1] = g;
          image[(xx2 + i * width) * 3 + 2] = b;
        }
      }
    }
  }
  for (i = x1 - 4 + 1; i <= x2 + 4 - 1; i++) {
    for (w = 0; w < 4; w++) {
      int yy1 = y1 - w;
      int yy2 = y2 + w;
      if (x1 >= 0 && x1 < width) {
        if (yy1 >= 0 && yy1 < height) {
          image[(i + yy1 * width) * 3 + 0] = r;
          image[(i + yy1 * width) * 3 + 1] = g;
          image[(i + yy1 * width) * 3 + 2] = b;
        }
        if (yy2 >= 0 && yy2 < height) {
          image[(i + yy2 * width) * 3 + 0] = r;
          image[(i + yy2 * width) * 3 + 1] = g;
          image[(i + yy2 * width) * 3 + 2] = b;
        }
      }
    }
  }
}
```