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

```asm
<vo_draw_alpha_rgb15>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r12
  push   %rbx
  mov    %edi,-0x24(%rbp)
  mov    %esi,-0x28(%rbp)
  mov    %rdx,-0x30(%rbp)
  mov    %rcx,-0x38(%rbp)
  mov    %r8d,-0x3c(%rbp)
  mov    %r9,-0x48(%rbp)
  movl   $0x0,-0x14(%rbp)
  jmp    L31
L19:
  mov    -0x48(%rbp),%r12
  mov    $0x0,%ebx
  jmp    L15
L36:
  movslq %ebx,%rdx
  mov    -0x38(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  test   %al,%al
  je     L24
  movslq %ebx,%rax
  add    %rax,%rax
  add    %r12,%rax
  movzwl (%rax),%eax
  and    $0x1f,%eax
  mov    %al,-0x17(%rbp)
  movslq %ebx,%rax
  add    %rax,%rax
  add    %r12,%rax
  movzwl (%rax),%eax
  shr    $0x5,%ax
  and    $0x1f,%eax
  mov    %al,-0x16(%rbp)
  movslq %ebx,%rax
  add    %rax,%rax
  add    %r12,%rax
  movzwl (%rax),%eax
  shr    $0xa,%ax
  and    $0x1f,%eax
  mov    %al,-0x15(%rbp)
  movzbl -0x17(%rbp),%edx
  movslq %ebx,%rcx
  mov    -0x38(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  imul   %edx,%eax
  sar    $0x5,%eax
  mov    %eax,%ecx
  movslq %ebx,%rdx
  mov    -0x30(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  add    %ecx,%eax
  sar    $0x3,%eax
  mov    %al,-0x17(%rbp)
  movzbl -0x16(%rbp),%edx
  movslq %ebx,%rcx
  mov    -0x38(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  imul   %edx,%eax
  sar    $0x5,%eax
  mov    %eax,%ecx
  movslq %ebx,%rdx
  mov    -0x30(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  add    %ecx,%eax
  sar    $0x3,%eax
  mov    %al,-0x16(%rbp)
  movzbl -0x15(%rbp),%edx
  movslq %ebx,%rcx
  mov    -0x38(%rbp),%rax
  add    %rcx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  imul   %edx,%eax
  sar    $0x5,%eax
  mov    %eax,%ecx
  movslq %ebx,%rdx
  mov    -0x30(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%eax
  add    %ecx,%eax
  sar    $0x3,%eax
  mov    %al,-0x15(%rbp)
  movzbl -0x15(%rbp),%eax
  shl    $0xa,%eax
  mov    %eax,%edx
  movzbl -0x16(%rbp),%eax
  shl    $0x5,%eax
  or     %eax,%edx
  movzbl -0x17(%rbp),%eax
  or     %eax,%edx
  movslq %ebx,%rax
  add    %rax,%rax
  add    %r12,%rax
  mov    %dx,(%rax)
L24:
  add    $0x1,%ebx
L15:
  cmp    -0x24(%rbp),%ebx
  jl     L36
  mov    -0x3c(%rbp),%eax
  cltq
  add    %rax,-0x30(%rbp)
  mov    -0x3c(%rbp),%eax
  cltq
  add    %rax,-0x38(%rbp)
  mov    0x10(%rbp),%eax
  cltq
  add    %rax,-0x48(%rbp)
  addl   $0x1,-0x14(%rbp)
L31:
  mov    -0x14(%rbp),%eax
  cmp    -0x28(%rbp),%eax
  jl     L19
  nop
  pop    %rbx
  pop    %r12
  pop    %rbp
  ret
```

assistant: ```c
void vo_draw_alpha_rgb15(int w, int h, unsigned char *src, unsigned char *srca, int srcstride, unsigned char *dstbase, int dststride) {
  int y;
  for (y = 0; y < h; y++) {
    register unsigned short *dst = (unsigned short *)dstbase;
    register int x;
    for (x = 0; x < w; x++) {
      if (srca[x]) {
        unsigned char r = dst[x] & 0x1F;
        unsigned char g = (dst[x] >> 5) & 0x1F;
        unsigned char b = (dst[x] >> 10) & 0x1F;
        r = (((r * srca[x]) >> 5) + src[x]) >> 3;
        g = (((g * srca[x]) >> 5) + src[x]) >> 3;
        b = (((b * srca[x]) >> 5) + src[x]) >> 3;
        dst[x] = (b << 10) | (g << 5) | r;
      }
    }
    src += srcstride;
    srca += srcstride;
    dstbase += dststride;
  }
  return;
}
```