user: Please show me the C implementation that matches the assembly code listed below:

```asm
<mpeg3video_idctrow>:
  endbr64
  push   %rbx
  movswl 0xc(%rdi),%r8d
  mov    %rdi,%rsi
  movswl 0x4(%rdi),%r9d
  movswl 0x2(%rdi),%eax
  mov    %r8d,%edx
  movswl 0x8(%rdi),%ebx
  movswl 0xe(%rdi),%edi
  or     %r9d,%edx
  movswl 0xa(%rsi),%r11d
  movswl 0x6(%rsi),%r10d
  or     %eax,%edx
  shl    $0xb,%ebx
  movswl (%rsi),%ecx
  or     %edi,%edx
  or     %r11d,%edx
  or     %r10d,%edx
  movswl %dx,%edx
  or     %ebx,%edx
  je     L9
  lea    (%rax,%rdi,1),%edx
  shl    $0xb,%ecx
  imul   $0x235,%edx,%edx
  sub    $0xffffff80,%ecx
  imul   $0x8e4,%eax,%eax
  imul   $0xfffff2b2,%edi,%edi
  add    %edx,%eax
  add    %edx,%edi
  lea    (%r11,%r10,1),%edx
  imul   $0x968,%edx,%edx
  imul   $0xfffffce1,%r11d,%r11d
  imul   $0xfffff04f,%r10d,%r10d
  add    %edx,%r11d
  add    %edx,%r10d
  lea    (%rbx,%rcx,1),%edx
  sub    %ebx,%ecx
  lea    (%r8,%r9,1),%ebx
  imul   $0x454,%ebx,%ebx
  imul   $0xfffff138,%r8d,%r8d
  imul   $0x620,%r9d,%r9d
  add    %ebx,%r8d
  add    %ebx,%r9d
  lea    (%rax,%r11,1),%ebx
  sub    %r11d,%eax
  movd   %ebx,%xmm8
  lea    (%rdi,%r10,1),%ebx
  sub    %r10d,%edi
  movd   %ebx,%xmm4
  lea    (%rdx,%r9,1),%ebx
  movdqa %xmm8,%xmm3
  sub    %r9d,%edx
  movd   %edx,%xmm0
  lea    (%rax,%rdi,1),%edx
  movd   %ebx,%xmm9
  sub    %edi,%eax
  imul   $0xb5,%edx,%edx
  lea    (%rcx,%r8,1),%ebx
  sub    %r8d,%ecx
  imul   $0xb5,%eax,%eax
  movd   %ebx,%xmm6
  movd   %ecx,%xmm7
  pop    %rbx
  punpckldq %xmm4,%xmm7
  punpckldq %xmm6,%xmm3
  movd   %ecx,%xmm5
  sub    $0xffffff80,%edx
  punpcklqdq %xmm7,%xmm3
  movdqa %xmm9,%xmm7
  sub    $0xffffff80,%eax
  sar    $0x8,%edx
  punpckldq %xmm9,%xmm6
  sar    $0x8,%eax
  movd   %edx,%xmm2
  movd   %eax,%xmm1
  movd   %eax,%xmm10
  punpckldq %xmm2,%xmm7
  punpckldq %xmm0,%xmm10
  punpckldq %xmm1,%xmm4
  punpckldq %xmm8,%xmm2
  punpcklqdq %xmm10,%xmm7
  punpckldq %xmm5,%xmm0
  movdqa %xmm4,%xmm1
  punpcklqdq %xmm2,%xmm1
  paddd  %xmm7,%xmm3
  punpcklqdq %xmm6,%xmm0
  psrad  $0x8,%xmm3
  psubd  %xmm1,%xmm0
  psrad  $0x8,%xmm0
  movdqa %xmm3,%xmm1
  movdqa %xmm3,%xmm2
  punpcklwd %xmm0,%xmm1
  punpckhwd %xmm0,%xmm2
  movdqa %xmm1,%xmm0
  punpcklwd %xmm2,%xmm1
  punpckhwd %xmm2,%xmm0
  punpcklwd %xmm0,%xmm1
  movups %xmm1,(%rsi)
  ret
  cs nopw 0x0(%rax,%rax,1)
L9:
  shl    $0x3,%ecx
  pop    %rbx
  movd   %ecx,%xmm0
  punpcklwd %xmm0,%xmm0
  pshufd $0x0,%xmm0,%xmm0
  movups %xmm0,(%rsi)
  ret
```

assistant: ```c
void mpeg3video_idctrow(short *blk) {
  int x0, x1, x2, x3, x4, x5, x6, x7, x8;
  if (!((x1 = blk[4] << 11) | (x2 = blk[6]) | (x3 = blk[2]) | (x4 = blk[1]) | (x5 = blk[7]) | (x6 = blk[5]) | (x7 = blk[3]))) {
    blk[0] = blk[1] = blk[2] = blk[3] = blk[4] = blk[5] = blk[6] = blk[7] = blk[0] << 3;
    return;
  }
  x0 = (blk[0] << 11) + 128;
  x8 = 565 * (x4 + x5);
  x4 = x8 + (2841 - 565) * x4;
  x5 = x8 - (2841 + 565) * x5;
  x8 = 2408 * (x6 + x7);
  x6 = x8 - (2408 - 1609) * x6;
  x7 = x8 - (2408 + 1609) * x7;
  x8 = x0 + x1;
  x0 -= x1;
  x1 = 1108 * (x3 + x2);
  x2 = x1 - (2676 + 1108) * x2;
  x3 = x1 + (2676 - 1108) * x3;
  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;
  blk[0] = (x7 + x1) >> 8;
  blk[1] = (x3 + x2) >> 8;
  blk[2] = (x0 + x4) >> 8;
  blk[3] = (x8 + x6) >> 8;
  blk[4] = (x8 - x6) >> 8;
  blk[5] = (x0 - x4) >> 8;
  blk[6] = (x3 - x2) >> 8;
  blk[7] = (x7 - x1) >> 8;
}
```