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

```asm
<buf2xys>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  mov    %rdi,-0x48(%rbp)
  mov    %esi,-0x4c(%rbp)
  mov    %edx,-0x50(%rbp)
  mov    %ecx,-0x54(%rbp)
  mov    %r8d,-0x58(%rbp)
  mov    %r9,-0x60(%rbp)
  movl   $0x0,-0x2c(%rbp)
  movl   $0x0,-0x28(%rbp)
  movl   $0x0,-0x24(%rbp)
  movl   $0x1f,-0x34(%rbp)
  jmp    L78
L70:
  mov    -0x2c(%rbp),%eax
  lea    0x7(%rax),%edx
  test   %eax,%eax
  cmovs  %edx,%eax
  sar    $0x3,%eax
  movslq %eax,%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%edx
  mov    -0x2c(%rbp),%eax
  mov    %eax,%ecx
  sar    $0x1f,%ecx
  shr    $0x1d,%ecx
  add    %ecx,%eax
  and    $0x7,%eax
  sub    %ecx,%eax
  mov    %eax,%ecx
  mov    $0x7,%eax
  sub    %ecx,%eax
  mov    %eax,%ecx
  sar    %cl,%edx
  mov    %edx,%eax
  and    $0x1,%eax
  mov    %eax,-0x10(%rbp)
  addl   $0x1,-0x2c(%rbp)
  mov    -0x2c(%rbp),%eax
  lea    0x7(%rax),%edx
  test   %eax,%eax
  cmovs  %edx,%eax
  sar    $0x3,%eax
  movslq %eax,%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%edx
  mov    -0x2c(%rbp),%eax
  mov    %eax,%ecx
  sar    $0x1f,%ecx
  shr    $0x1d,%ecx
  add    %ecx,%eax
  and    $0x7,%eax
  sub    %ecx,%eax
  mov    %eax,%ecx
  mov    $0x7,%eax
  sub    %ecx,%eax
  mov    %eax,%ecx
  sar    %cl,%edx
  mov    %edx,%eax
  and    $0x1,%eax
  mov    %eax,-0xc(%rbp)
  addl   $0x1,-0x2c(%rbp)
  mov    -0x34(%rbp),%eax
  mov    -0xc(%rbp),%edx
  mov    %eax,%ecx
  shl    %cl,%edx
  mov    %edx,%eax
  or     %eax,-0x28(%rbp)
  mov    -0x34(%rbp),%eax
  mov    -0x10(%rbp),%edx
  mov    %eax,%ecx
  shl    %cl,%edx
  mov    %edx,%eax
  or     %eax,-0x24(%rbp)
  subl   $0x1,-0x34(%rbp)
L78:
  mov    $0x1f,%eax
  sub    -0x54(%rbp),%eax
  cmp    %eax,-0x34(%rbp)
  jg     L70
  movl   $0x0,-0x30(%rbp)
  jmp    L1
L50:
  mov    -0x28(%rbp),%eax
  mov    %eax,-0x20(%rbp)
  mov    -0x24(%rbp),%eax
  mov    %eax,-0x1c(%rbp)
  mov    $0x1f,%eax
  sub    -0x54(%rbp),%eax
  mov    %eax,-0x34(%rbp)
  jmp    L57
L45:
  mov    -0x2c(%rbp),%eax
  lea    0x7(%rax),%edx
  test   %eax,%eax
  cmovs  %edx,%eax
  sar    $0x3,%eax
  movslq %eax,%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%edx
  mov    -0x2c(%rbp),%eax
  mov    %eax,%ecx
  sar    $0x1f,%ecx
  shr    $0x1d,%ecx
  add    %ecx,%eax
  and    $0x7,%eax
  sub    %ecx,%eax
  mov    %eax,%ecx
  mov    $0x7,%eax
  sub    %ecx,%eax
  mov    %eax,%ecx
  sar    %cl,%edx
  mov    %edx,%eax
  and    $0x1,%eax
  mov    %eax,-0x18(%rbp)
  addl   $0x1,-0x2c(%rbp)
  mov    -0x2c(%rbp),%eax
  lea    0x7(%rax),%edx
  test   %eax,%eax
  cmovs  %edx,%eax
  sar    $0x3,%eax
  movslq %eax,%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%edx
  mov    -0x2c(%rbp),%eax
  mov    %eax,%ecx
  sar    $0x1f,%ecx
  shr    $0x1d,%ecx
  add    %ecx,%eax
  and    $0x7,%eax
  sub    %ecx,%eax
  mov    %eax,%ecx
  mov    $0x7,%eax
  sub    %ecx,%eax
  mov    %eax,%ecx
  sar    %cl,%edx
  mov    %edx,%eax
  and    $0x1,%eax
  mov    %eax,-0x14(%rbp)
  addl   $0x1,-0x2c(%rbp)
  mov    -0x34(%rbp),%eax
  mov    -0x14(%rbp),%edx
  mov    %eax,%ecx
  shl    %cl,%edx
  mov    %edx,%eax
  or     %eax,-0x20(%rbp)
  mov    -0x34(%rbp),%eax
  mov    -0x18(%rbp),%edx
  mov    %eax,%ecx
  shl    %cl,%edx
  mov    %edx,%eax
  or     %eax,-0x1c(%rbp)
  subl   $0x1,-0x34(%rbp)
L57:
  mov    -0x4c(%rbp),%eax
  mov    %eax,%edx
  shr    $0x1f,%edx
  add    %edx,%eax
  sar    %eax
  neg    %eax
  add    $0x1f,%eax
  cmp    %eax,-0x34(%rbp)
  jg     L45
  mov    -0x30(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    -0x60(%rbp),%rax
  add    %rax,%rdx
  mov    -0x20(%rbp),%eax
  mov    %eax,(%rdx)
  mov    -0x30(%rbp),%eax
  cltq
  lea    0x0(,%rax,4),%rdx
  mov    0x10(%rbp),%rax
  add    %rax,%rdx
  mov    -0x1c(%rbp),%eax
  mov    %eax,(%rdx)
  addl   $0x1,-0x30(%rbp)
L1:
  mov    -0x30(%rbp),%eax
  cmp    -0x58(%rbp),%eax
  jl     L50
  mov    -0x50(%rbp),%eax
  sub    $0x1,%eax
  mov    %eax,-0x34(%rbp)
  jmp    L71
L31:
  mov    -0x2c(%rbp),%eax
  lea    0x7(%rax),%edx
  test   %eax,%eax
  cmovs  %edx,%eax
  sar    $0x3,%eax
  movslq %eax,%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  movzbl %al,%edx
  mov    -0x2c(%rbp),%eax
  mov    %eax,%ecx
  sar    $0x1f,%ecx
  shr    $0x1d,%ecx
  add    %ecx,%eax
  and    $0x7,%eax
  sub    %ecx,%eax
  mov    %eax,%ecx
  mov    $0x7,%eax
  sub    %ecx,%eax
  mov    %eax,%ecx
  sar    %cl,%edx
  mov    %edx,%eax
  cltq
  and    $0x1,%eax
  mov    %rax,-0x8(%rbp)
  addl   $0x1,-0x2c(%rbp)
  mov    0x18(%rbp),%rax
  mov    (%rax),%rsi
  mov    -0x34(%rbp),%eax
  mov    -0x8(%rbp),%rdx
  mov    %eax,%ecx
  shl    %cl,%rdx
  mov    %rdx,%rax
  or     %rax,%rsi
  mov    %rsi,%rdx
  mov    0x18(%rbp),%rax
  mov    %rdx,(%rax)
  subl   $0x1,-0x34(%rbp)
L71:
  cmpl   $0x0,-0x34(%rbp)
  jns    L31
  nop
  nop
  pop    %rbp
  ret
```

assistant: ```c
void buf2xys(const unsigned char *const buf, const int mapbits, const int metabits, const int skip, const int n, unsigned int *x, unsigned int *y, unsigned long long *meta) {
  int i, j;
  int offbits = 0;
  unsigned int xx = 0, yy = 0;
  for (i = 31; i > 31 - skip; i--) {
    int y0 = (buf[offbits / 8] >> (7 - offbits % 8)) & 1;
    offbits++;
    int x0 = (buf[offbits / 8] >> (7 - offbits % 8)) & 1;
    offbits++;
    xx |= x0 << i;
    yy |= y0 << i;
  }
  for (j = 0; j < n; j++) {
    unsigned int xj = xx;
    unsigned int yj = yy;
    for (i = 31 - skip; i > 31 - mapbits / 2; i--) {
      int y0 = (buf[offbits / 8] >> (7 - offbits % 8)) & 1;
      offbits++;
      int x0 = (buf[offbits / 8] >> (7 - offbits % 8)) & 1;
      offbits++;
      xj |= x0 << i;
      yj |= y0 << i;
    }
    x[j] = xj;
    y[j] = yj;
  }
  for (i = metabits - 1; i >= 0; i--) {
    unsigned long long m = (buf[offbits / 8] >> (7 - offbits % 8)) & 1;
    offbits++;
    *meta |= m << i;
  }
}
```