user: 请将以下的汇编代码转换成C语言代码：

```asm
<njColIDCT>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x18,%rsp
  mov    %rsi,%rbx
  mov    %edx,%r15d
  mov    0x80(%rdi),%r13d
  shl    $0x8,%r13d
  mov    0xc0(%rdi),%r8d
  mov    0x40(%rdi),%r9d
  mov    0x20(%rdi),%eax
  mov    0xe0(%rdi),%esi
  mov    0xa0(%rdi),%r11d
  mov    0x60(%rdi),%r10d
  mov    %r8d,%edx
  or     %r9d,%edx
  or     %eax,%edx
  or     %esi,%edx
  or     %r11d,%edx
  or     %r10d,%edx
  or     %r13d,%edx
  je     L8
  mov    (%rdi),%ebp
  shl    $0x8,%ebp
  add    $0x2000,%ebp
  lea    (%rax,%rsi,1),%edx
  imul   $0x235,%edx,%edx
  add    $0x4,%edx
  imul   $0x8e4,%eax,%eax
  add    %edx,%eax
  sar    $0x3,%eax
  imul   $0xfffff2b2,%esi,%esi
  add    %edx,%esi
  sar    $0x3,%esi
  lea    (%r11,%r10,1),%edx
  imul   $0x968,%edx,%edx
  add    $0x4,%edx
  imul   $0xfffffce1,%r11d,%r11d
  add    %edx,%r11d
  sar    $0x3,%r11d
  imul   $0xfffff04f,%r10d,%r10d
  add    %edx,%r10d
  sar    $0x3,%r10d
  lea    0x0(%r13,%rbp,1),%r12d
  sub    %r13d,%ebp
  lea    (%r8,%r9,1),%edx
  imul   $0x454,%edx,%edx
  add    $0x4,%edx
  imul   $0xfffff138,%r8d,%r8d
  add    %edx,%r8d
  sar    $0x3,%r8d
  imul   $0x620,%r9d,%r9d
  add    %edx,%r9d
  sar    $0x3,%r9d
  lea    (%rax,%r11,1),%ecx
  sub    %r11d,%eax
  lea    (%rsi,%r10,1),%edi
  mov    %edi,(%rsp)
  sub    %r10d,%esi
  lea    (%r12,%r9,1),%r13d
  sub    %r9d,%r12d
  lea    0x0(%rbp,%r8,1),%r14d
  sub    %r8d,%ebp
  lea    (%rax,%rsi,1),%edx
  imul   $0xb5,%edx,%edx
  sub    $0xffffff80,%edx
  sar    $0x8,%edx
  mov    %edx,0x4(%rsp)
  sub    %esi,%eax
  imul   $0xb5,%eax,%eax
  sub    $0xffffff80,%eax
  sar    $0x8,%eax
  mov    %eax,0x8(%rsp)
  mov    %ecx,0xc(%rsp)
  lea    (%rcx,%r13,1),%edi
  sar    $0xe,%edi
  sub    $0xffffff80,%edi
  call   <njClip@plt>
  mov    %al,(%rbx)
  movslq %r15d,%r15
  add    %r15,%rbx
  mov    0x4(%rsp),%edx
  lea    (%r14,%rdx,1),%edi
  sar    $0xe,%edi
  sub    $0xffffff80,%edi
  call   <njClip@plt>
  mov    %al,(%rbx)
  add    %r15,%rbx
  mov    0x8(%rsp),%eax
  lea    0x0(%rbp,%rax,1),%edi
  sar    $0xe,%edi
  sub    $0xffffff80,%edi
  call   <njClip@plt>
  mov    %al,(%rbx)
  add    %r15,%rbx
  mov    (%rsp),%edi
  add    %r12d,%edi
  sar    $0xe,%edi
  sub    $0xffffff80,%edi
  call   <njClip@plt>
  mov    %al,(%rbx)
  add    %r15,%rbx
  sub    (%rsp),%r12d
  sar    $0xe,%r12d
  lea    0x80(%r12),%edi
  call   <njClip@plt>
  mov    %al,(%rbx)
  add    %r15,%rbx
  sub    0x8(%rsp),%ebp
  sar    $0xe,%ebp
  lea    0x80(%rbp),%edi
  call   <njClip@plt>
  mov    %al,(%rbx)
  add    %r15,%rbx
  sub    0x4(%rsp),%r14d
  sar    $0xe,%r14d
  lea    0x80(%r14),%edi
  call   <njClip@plt>
  mov    %al,(%rbx)
  add    %r15,%rbx
  sub    0xc(%rsp),%r13d
  sar    $0xe,%r13d
  lea    0x80(%r13),%edi
  call   <njClip@plt>
  mov    %al,(%rbx)
L28:
  add    $0x18,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L8:
  mov    (%rdi),%edi
  add    $0x20,%edi
  sar    $0x6,%edi
  sub    $0xffffff80,%edi
  call   <njClip@plt>
  mov    $0x8,%edx
  movslq %r15d,%rcx
L6:
  mov    %al,(%rbx)
  add    %rcx,%rbx
  sub    $0x1,%edx
  jne    L6
  jmp    L28
```

assistant: ```c
void njColIDCT(const int *blk, unsigned char *out, int stride) {
  int x0, x1, x2, x3, x4, x5, x6, x7, x8;
  if (!((x1 = blk[8 * 4] << 8) | (x2 = blk[8 * 6]) | (x3 = blk[8 * 2]) | (x4 = blk[8 * 1]) | (x5 = blk[8 * 7]) | (x6 = blk[8 * 5]) | (x7 = blk[8 * 3]))) {
    x1 = njClip(((blk[0] + 32) >> 6) + 128);
    for (x0 = 8; x0; --x0) {
      *out = (unsigned char)x1;
      out += stride;
    }
    return;
  }
  x0 = (blk[0] << 8) + 8192;
  x8 = 565 * (x4 + x5) + 4;
  x4 = (x8 + (2841 - 565) * x4) >> 3;
  x5 = (x8 - (2841 + 565) * x5) >> 3;
  x8 = 2408 * (x6 + x7) + 4;
  x6 = (x8 - (2408 - 1609) * x6) >> 3;
  x7 = (x8 - (2408 + 1609) * x7) >> 3;
  x8 = x0 + x1;
  x0 -= x1;
  x1 = 1108 * (x3 + x2) + 4;
  x2 = (x1 - (2676 + 1108) * x2) >> 3;
  x3 = (x1 + (2676 - 1108) * x3) >> 3;
  x1 = x4 + x6;
  x4 -= x6;
  x6 = x5 + x7;
  x5 -= x7;
  x7 = x8 + x3;
  x8 -= x3;
  x3 = x0 + x2;
  x0 -= x2;
  x2 = (181 * (x4 + x5) + 128) >> 8;
  x4 = (181 * (x4 - x5) + 128) >> 8;
  *out = njClip(((x7 + x1) >> 14) + 128);
  out += stride;
  *out = njClip(((x3 + x2) >> 14) + 128);
  out += stride;
  *out = njClip(((x0 + x4) >> 14) + 128);
  out += stride;
  *out = njClip(((x8 + x6) >> 14) + 128);
  out += stride;
  *out = njClip(((x8 - x6) >> 14) + 128);
  out += stride;
  *out = njClip(((x0 - x4) >> 14) + 128);
  out += stride;
  *out = njClip(((x3 - x2) >> 14) + 128);
  out += stride;
  *out = njClip(((x7 - x1) >> 14) + 128);
}
```