user: 提供的汇编代码用C语言表示会是什么样子:

```asm
<lookup_mono_lightbg>:
  endbr64
  mov    %esi,%edx
  mov    %ecx,%esi
  test   %edx,%edx
  jle    L46
  lea    -0x1(%rdx),%eax
  cmp    $0xe,%eax
  jbe    L69
  mov    %edx,%ecx
  pxor   %xmm0,%xmm0
  pxor   %xmm4,%xmm4
  mov    %rdi,%rax
  shr    $0x4,%ecx
  pxor   %xmm3,%xmm3
  sub    $0x1,%ecx
  shl    $0x4,%rcx
  lea    0x10(%rdi,%rcx,1),%rcx
  nopl   0x0(%rax)
L173:
  movdqu (%rax),%xmm1
  add    $0x10,%rax
  movdqa %xmm1,%xmm2
  punpckhbw %xmm4,%xmm1
  punpcklbw %xmm4,%xmm2
  movdqa %xmm2,%xmm5
  punpckhwd %xmm3,%xmm2
  punpcklwd %xmm3,%xmm5
  paddd  %xmm5,%xmm0
  paddd  %xmm2,%xmm0
  movdqa %xmm1,%xmm2
  punpckhwd %xmm3,%xmm1
  punpcklwd %xmm3,%xmm2
  paddd  %xmm2,%xmm0
  paddd  %xmm1,%xmm0
  cmp    %rcx,%rax
  jne    L173
  movdqa %xmm0,%xmm1
  mov    %edx,%ecx
  psrldq $0x8,%xmm1
  and    $0xfffffff0,%ecx
  paddd  %xmm1,%xmm0
  movdqa %xmm0,%xmm1
  psrldq $0x4,%xmm1
  paddd  %xmm1,%xmm0
  movd   %xmm0,%eax
  test   $0xf,%dl
  je     L106
L189:
  movslq %ecx,%r8
  movzbl (%rdi,%r8,1),%r8d
  add    %r8d,%eax
  lea    0x1(%rcx),%r8d
  cmp    %r8d,%edx
  jle    L106
  movslq %r8d,%r8
  movzbl (%rdi,%r8,1),%r8d
  add    %r8d,%eax
  lea    0x2(%rcx),%r8d
  cmp    %r8d,%edx
  jle    L106
  movslq %r8d,%r8
  movzbl (%rdi,%r8,1),%r8d
  add    %r8d,%eax
  lea    0x3(%rcx),%r8d
  cmp    %r8d,%edx
  jle    L106
  movslq %r8d,%r8
  movzbl (%rdi,%r8,1),%r8d
  add    %r8d,%eax
  lea    0x4(%rcx),%r8d
  cmp    %r8d,%edx
  jle    L106
  movslq %r8d,%r8
  movzbl (%rdi,%r8,1),%r8d
  add    %r8d,%eax
  lea    0x5(%rcx),%r8d
  cmp    %r8d,%edx
  jle    L106
  movslq %r8d,%r8
  movzbl (%rdi,%r8,1),%r8d
  add    %r8d,%eax
  lea    0x6(%rcx),%r8d
  cmp    %r8d,%edx
  jle    L106
  movslq %r8d,%r8
  movzbl (%rdi,%r8,1),%r8d
  add    %r8d,%eax
  lea    0x7(%rcx),%r8d
  cmp    %r8d,%edx
  jle    L106
  movslq %r8d,%r8
  movzbl (%rdi,%r8,1),%r8d
  add    %r8d,%eax
  lea    0x8(%rcx),%r8d
  cmp    %r8d,%edx
  jle    L106
  movslq %r8d,%r8
  movzbl (%rdi,%r8,1),%r8d
  add    %r8d,%eax
  lea    0x9(%rcx),%r8d
  cmp    %r8d,%edx
  jle    L106
  movslq %r8d,%r8
  movzbl (%rdi,%r8,1),%r8d
  add    %r8d,%eax
  lea    0xa(%rcx),%r8d
  cmp    %r8d,%edx
  jle    L106
  movslq %r8d,%r8
  movzbl (%rdi,%r8,1),%r8d
  add    %r8d,%eax
  lea    0xb(%rcx),%r8d
  cmp    %r8d,%edx
  jle    L106
  movslq %r8d,%r8
  movzbl (%rdi,%r8,1),%r8d
  add    %r8d,%eax
  lea    0xc(%rcx),%r8d
  cmp    %r8d,%edx
  jle    L106
  movslq %r8d,%r8
  movzbl (%rdi,%r8,1),%r8d
  add    %r8d,%eax
  lea    0xd(%rcx),%r8d
  cmp    %r8d,%edx
  jle    L106
  movslq %r8d,%r8
  add    $0xe,%ecx
  movzbl (%rdi,%r8,1),%r8d
  add    %r8d,%eax
  cmp    %ecx,%edx
  jle    L106
  movslq %ecx,%rcx
  movzbl (%rdi,%rcx,1),%edx
  add    %edx,%eax
L106:
  shl    $0x7,%esi
  cmp    %eax,%esi
  setg   %al
  movzbl %al,%eax
  ret
  nopl   0x0(%rax)
L46:
  xor    %eax,%eax
  shl    $0x7,%esi
  cmp    %eax,%esi
  setg   %al
  movzbl %al,%eax
  ret
L69:
  xor    %eax,%eax
  xor    %ecx,%ecx
  jmp    L189
```

assistant: ```c
int lookup_mono_lightbg(unsigned char const *const pixel, int const depth, unsigned char const *const palette, int const ncolor, unsigned short *const cachetable) {
  int n;
  int distant;
  distant = 0;
  for (n = 0; n < depth; ++n) {
    distant += pixel[n];
  }
  return distant < 128 * ncolor ? 1 : 0;
}
```