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

```asm
<stbtt__h_prefilter>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x40,%rsp
  mov    %rdi,-0x28(%rbp)
  mov    %esi,-0x2c(%rbp)
  mov    %edx,-0x30(%rbp)
  mov    %ecx,-0x34(%rbp)
  mov    %r8d,-0x38(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x8(%rbp)
  xor    %eax,%eax
  mov    -0x2c(%rbp),%eax
  sub    -0x38(%rbp),%eax
  mov    %eax,-0x14(%rbp)
  movl   $0x0,-0x20(%rbp)
  jmp    L196
L104:
  mov    -0x38(%rbp),%edx
  lea    -0x10(%rbp),%rax
  mov    $0x0,%esi
  mov    %rax,%rdi
  call   <memset@plt>
  movl   $0x0,-0x18(%rbp)
  cmpl   $0x5,-0x38(%rbp)
  je     L166
  cmpl   $0x5,-0x38(%rbp)
  ja     L92
  cmpl   $0x4,-0x38(%rbp)
  je     L209
  cmpl   $0x4,-0x38(%rbp)
  ja     L92
  cmpl   $0x2,-0x38(%rbp)
  je     L85
  cmpl   $0x3,-0x38(%rbp)
  je     L216
  jmp    L92
L85:
  movl   $0x0,-0x1c(%rbp)
  jmp    L160
L174:
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%edx
  mov    -0x1c(%rbp),%eax
  and    $0x7,%eax
  cltq
  movzbl -0x10(%rbp,%rax,1),%eax
  movzbl %al,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  add    %eax,-0x18(%rbp)
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    -0x1c(%rbp),%ecx
  mov    -0x38(%rbp),%edx
  add    %ecx,%edx
  and    $0x7,%edx
  movzbl (%rax),%eax
  mov    %edx,%edx
  mov    %al,-0x10(%rbp,%rdx,1)
  mov    -0x18(%rbp),%eax
  shr    %eax
  mov    %eax,%ecx
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    %ecx,%edx
  mov    %dl,(%rax)
  addl   $0x1,-0x1c(%rbp)
L160:
  mov    -0x1c(%rbp),%eax
  cmp    -0x14(%rbp),%eax
  jle    L174
  jmp    L99
L216:
  movl   $0x0,-0x1c(%rbp)
  jmp    L199
L138:
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%edx
  mov    -0x1c(%rbp),%eax
  and    $0x7,%eax
  cltq
  movzbl -0x10(%rbp,%rax,1),%eax
  movzbl %al,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  add    %eax,-0x18(%rbp)
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    -0x1c(%rbp),%ecx
  mov    -0x38(%rbp),%edx
  add    %ecx,%edx
  and    $0x7,%edx
  movzbl (%rax),%eax
  mov    %edx,%edx
  mov    %al,-0x10(%rbp,%rdx,1)
  mov    -0x18(%rbp),%eax
  mov    %eax,%edx
  mov    $0xaaaaaaab,%eax
  imul   %rdx,%rax
  shr    $0x20,%rax
  mov    %eax,%ecx
  shr    %ecx
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    %ecx,%edx
  mov    %dl,(%rax)
  addl   $0x1,-0x1c(%rbp)
L199:
  mov    -0x1c(%rbp),%eax
  cmp    -0x14(%rbp),%eax
  jle    L138
  jmp    L99
L209:
  movl   $0x0,-0x1c(%rbp)
  jmp    L48
L76:
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%edx
  mov    -0x1c(%rbp),%eax
  and    $0x7,%eax
  cltq
  movzbl -0x10(%rbp,%rax,1),%eax
  movzbl %al,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  add    %eax,-0x18(%rbp)
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    -0x1c(%rbp),%ecx
  mov    -0x38(%rbp),%edx
  add    %ecx,%edx
  and    $0x7,%edx
  movzbl (%rax),%eax
  mov    %edx,%edx
  mov    %al,-0x10(%rbp,%rdx,1)
  mov    -0x18(%rbp),%eax
  shr    $0x2,%eax
  mov    %eax,%ecx
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    %ecx,%edx
  mov    %dl,(%rax)
  addl   $0x1,-0x1c(%rbp)
L48:
  mov    -0x1c(%rbp),%eax
  cmp    -0x14(%rbp),%eax
  jle    L76
  jmp    L99
L166:
  movl   $0x0,-0x1c(%rbp)
  jmp    L200
L41:
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%edx
  mov    -0x1c(%rbp),%eax
  and    $0x7,%eax
  cltq
  movzbl -0x10(%rbp,%rax,1),%eax
  movzbl %al,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  add    %eax,-0x18(%rbp)
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    -0x1c(%rbp),%ecx
  mov    -0x38(%rbp),%edx
  add    %ecx,%edx
  and    $0x7,%edx
  movzbl (%rax),%eax
  mov    %edx,%edx
  mov    %al,-0x10(%rbp,%rdx,1)
  mov    -0x18(%rbp),%eax
  mov    %eax,%edx
  mov    $0xcccccccd,%eax
  imul   %rdx,%rax
  shr    $0x20,%rax
  mov    %eax,%ecx
  shr    $0x2,%ecx
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    %ecx,%edx
  mov    %dl,(%rax)
  addl   $0x1,-0x1c(%rbp)
L200:
  mov    -0x1c(%rbp),%eax
  cmp    -0x14(%rbp),%eax
  jle    L41
  jmp    L99
L92:
  movl   $0x0,-0x1c(%rbp)
  jmp    L56
L247:
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%edx
  mov    -0x1c(%rbp),%eax
  and    $0x7,%eax
  cltq
  movzbl -0x10(%rbp,%rax,1),%eax
  movzbl %al,%ecx
  mov    %edx,%eax
  sub    %ecx,%eax
  add    %eax,-0x18(%rbp)
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    -0x1c(%rbp),%ecx
  mov    -0x38(%rbp),%edx
  add    %ecx,%edx
  and    $0x7,%edx
  movzbl (%rax),%eax
  mov    %edx,%edx
  mov    %al,-0x10(%rbp,%rdx,1)
  mov    -0x18(%rbp),%eax
  mov    $0x0,%edx
  divl   -0x38(%rbp)
  mov    %eax,%ecx
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    %ecx,%edx
  mov    %dl,(%rax)
  addl   $0x1,-0x1c(%rbp)
L56:
  mov    -0x1c(%rbp),%eax
  cmp    -0x14(%rbp),%eax
  jle    L247
  nop
L99:
  jmp    L123
L198:
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  test   %al,%al
  sete   %al
  movzbl %al,%eax
  mov    %eax,%edi
  call   <assert@plt>
  mov    -0x1c(%rbp),%eax
  and    $0x7,%eax
  cltq
  movzbl -0x10(%rbp,%rax,1),%eax
  movzbl %al,%eax
  sub    %eax,-0x18(%rbp)
  mov    -0x18(%rbp),%eax
  mov    $0x0,%edx
  divl   -0x38(%rbp)
  mov    %eax,%ecx
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    %ecx,%edx
  mov    %dl,(%rax)
  addl   $0x1,-0x1c(%rbp)
L123:
  mov    -0x1c(%rbp),%eax
  cmp    -0x2c(%rbp),%eax
  jl     L198
  mov    -0x34(%rbp),%eax
  cltq
  add    %rax,-0x28(%rbp)
  addl   $0x1,-0x20(%rbp)
L196:
  mov    -0x20(%rbp),%eax
  cmp    -0x30(%rbp),%eax
  jl     L104
  nop
  mov    -0x8(%rbp),%rax
  sub    %fs:0x28,%rax
  je     L37
  call   <__stack_chk_fail@plt>
L37:
  leave
  ret
```

assistant: ```c
void stbtt__h_prefilter(unsigned char *pixels, int w, int h, int stride_in_bytes, unsigned int kernel_width) {
  unsigned char buffer[8];
  int safe_w = w - kernel_width;
  int j;
  for (j = 0; j < h; ++j) {
    int i;
    unsigned int total;
    memset(buffer, 0, kernel_width);
    total = 0;
    switch (kernel_width) {
    case 2:
      for (i = 0; i <= safe_w; ++i) {
        total += pixels[i] - buffer[i & (8 - 1)];
        buffer[(i + kernel_width) & (8 - 1)] = pixels[i];
        pixels[i] = (unsigned char)(total / 2);
      }
      break;
    case 3:
      for (i = 0; i <= safe_w; ++i) {
        total += pixels[i] - buffer[i & (8 - 1)];
        buffer[(i + kernel_width) & (8 - 1)] = pixels[i];
        pixels[i] = (unsigned char)(total / 3);
      }
      break;
    case 4:
      for (i = 0; i <= safe_w; ++i) {
        total += pixels[i] - buffer[i & (8 - 1)];
        buffer[(i + kernel_width) & (8 - 1)] = pixels[i];
        pixels[i] = (unsigned char)(total / 4);
      }
      break;
    case 5:
      for (i = 0; i <= safe_w; ++i) {
        total += pixels[i] - buffer[i & (8 - 1)];
        buffer[(i + kernel_width) & (8 - 1)] = pixels[i];
        pixels[i] = (unsigned char)(total / 5);
      }
      break;
    default:
      for (i = 0; i <= safe_w; ++i) {
        total += pixels[i] - buffer[i & (8 - 1)];
        buffer[(i + kernel_width) & (8 - 1)] = pixels[i];
        pixels[i] = (unsigned char)(total / kernel_width);
      }
      break;
    }
    for (; i < w; ++i) {
      assert(pixels[i] == 0);
      total -= buffer[i & (8 - 1)];
      pixels[i] = (unsigned char)(total / kernel_width);
    }
    pixels += stride_in_bytes;
  }
}
```