user: What is the c source code of the assembly code below?

```asm
<unpackforblock8_64>:
  endbr64
  push   %rbx
  mov    (%rsi),%r9
  movd   %edi,%xmm4
  mov    %rdx,%r8
  mov    (%rdx),%rdi
  pshufd $0x0,%xmm4,%xmm0
  mov    (%r9),%ebx
  mov    0x4(%r9),%r10d
  sub    $0xffffffffffffff80,%r9
  mov    -0x78(%r9),%edx
  mov    -0x74(%r9),%eax
  mov    %r9,(%rsi)
  movzbl %bh,%esi
  movzbl %bl,%ecx
  movd   %esi,%xmm3
  mov    %ebx,%esi
  movd   %ecx,%xmm1
  sar    $0x10,%esi
  punpckldq %xmm3,%xmm1
  movzbl %sil,%ecx
  mov    %ebx,%esi
  shr    $0x18,%esi
  movd   %ecx,%xmm2
  mov    $0x20,%ecx
  movd   %esi,%xmm5
  mov    %ebx,%esi
  punpckldq %xmm5,%xmm2
  sar    %cl,%esi
  mov    $0x28,%ecx
  punpcklqdq %xmm2,%xmm1
  movzbl %sil,%esi
  paddd  %xmm0,%xmm1
  movups %xmm1,(%rdi)
  movd   %esi,%xmm1
  mov    %ebx,%esi
  sar    %cl,%esi
  mov    $0x30,%ecx
  movzbl %sil,%r9d
  mov    %ebx,%esi
  sar    %cl,%esi
  mov    $0x38,%ecx
  movd   %r9d,%xmm7
  sar    %cl,%ebx
  movzbl %sil,%esi
  punpckldq %xmm7,%xmm1
  mov    $0x20,%ecx
  movd   %ebx,%xmm6
  movd   %esi,%xmm2
  movzbl %r10b,%ebx
  mov    %r10d,%esi
  punpckldq %xmm6,%xmm2
  sar    $0x10,%esi
  punpcklqdq %xmm2,%xmm1
  paddd  %xmm0,%xmm1
  movups %xmm1,0x10(%rdi)
  movd   %ebx,%xmm1
  mov    %r10d,%ebx
  movzbl %bh,%ebx
  movd   %ebx,%xmm3
  movzbl %sil,%ebx
  mov    %r10d,%esi
  shr    $0x18,%esi
  movd   %ebx,%xmm2
  punpckldq %xmm3,%xmm1
  movd   %esi,%xmm4
  mov    %r10d,%esi
  sar    %cl,%esi
  mov    $0x28,%ecx
  punpckldq %xmm4,%xmm2
  movzbl %sil,%ebx
  mov    %r10d,%esi
  punpcklqdq %xmm2,%xmm1
  sar    %cl,%esi
  mov    $0x30,%ecx
  paddd  %xmm0,%xmm1
  movzbl %sil,%r9d
  mov    %r10d,%esi
  movups %xmm1,0x20(%rdi)
  movd   %ebx,%xmm1
  sar    %cl,%esi
  mov    $0x38,%ecx
  movd   %r9d,%xmm6
  movzbl %sil,%ebx
  sar    %cl,%r10d
  punpckldq %xmm6,%xmm1
  mov    $0x20,%ecx
  movd   %ebx,%xmm2
  movd   %r10d,%xmm5
  movzbl %dl,%ebx
  punpckldq %xmm5,%xmm2
  punpcklqdq %xmm2,%xmm1
  paddd  %xmm0,%xmm1
  movups %xmm1,0x30(%rdi)
  movd   %ebx,%xmm1
  movzbl %dh,%ebx
  movd   %ebx,%xmm3
  mov    %edx,%ebx
  sar    $0x10,%ebx
  punpckldq %xmm3,%xmm1
  movzbl %bl,%ebx
  movd   %ebx,%xmm2
  mov    %edx,%ebx
  shr    $0x18,%ebx
  movd   %ebx,%xmm7
  mov    %edx,%ebx
  punpckldq %xmm7,%xmm2
  sar    %cl,%ebx
  mov    $0x28,%ecx
  punpcklqdq %xmm2,%xmm1
  movzbl %bl,%ebx
  paddd  %xmm0,%xmm1
  movups %xmm1,0x40(%rdi)
  movd   %ebx,%xmm1
  mov    %edx,%ebx
  sar    %cl,%ebx
  mov    $0x30,%ecx
  movzbl %bl,%esi
  mov    %edx,%ebx
  sar    %cl,%ebx
  mov    $0x38,%ecx
  movd   %esi,%xmm5
  sar    %cl,%edx
  movzbl %bl,%ebx
  punpckldq %xmm5,%xmm1
  mov    $0x20,%ecx
  movd   %ebx,%xmm2
  movd   %edx,%xmm4
  movzbl %al,%edx
  movzbl %ah,%ebx
  punpckldq %xmm4,%xmm2
  movd   %ebx,%xmm3
  punpcklqdq %xmm2,%xmm1
  paddd  %xmm0,%xmm1
  movups %xmm1,0x50(%rdi)
  movd   %edx,%xmm1
  mov    %eax,%edx
  sar    $0x10,%edx
  punpckldq %xmm3,%xmm1
  movzbl %dl,%edx
  movd   %edx,%xmm2
  mov    %eax,%edx
  shr    $0x18,%edx
  movd   %edx,%xmm6
  mov    %eax,%edx
  punpckldq %xmm6,%xmm2
  sar    %cl,%edx
  mov    $0x28,%ecx
  punpcklqdq %xmm2,%xmm1
  movzbl %dl,%edx
  paddd  %xmm0,%xmm1
  movups %xmm1,0x60(%rdi)
  movd   %edx,%xmm1
  mov    %eax,%edx
  sar    %cl,%edx
  mov    $0x30,%ecx
  movzbl %dl,%edx
  movd   %edx,%xmm5
  mov    %eax,%edx
  sar    %cl,%edx
  mov    $0x38,%ecx
  punpckldq %xmm5,%xmm1
  movzbl %dl,%edx
  sar    %cl,%eax
  movd   %edx,%xmm2
  movd   %eax,%xmm7
  punpckldq %xmm7,%xmm2
  punpcklqdq %xmm2,%xmm1
  paddd  %xmm1,%xmm0
  movups %xmm0,0x70(%rdi)
  pop    %rbx
  subq   $0xffffffffffffff80,(%r8)
  ret
```

assistant: ```c
void unpackforblock8_64(const uint64_t base, const uint8_t **pw, uint64_t **pout) {
  const uint64_t *pw64 = *(const uint64_t **)pw;
  uint64_t *out = *pout;
  const uint64_t mask = (255ULL);
  uint64_t w0 = pw64[0];
  uint64_t w1 = pw64[1];
  uint64_t w2 = pw64[2];
  uint64_t w3 = pw64[3];
  *pw += 32;
  out[0] = base + ((w0)&mask);
  out[1] = base + ((w0 >> 8) & mask);
  out[2] = base + ((w0 >> 16) & mask);
  out[3] = base + ((w0 >> 24) & mask);
  out[4] = base + ((w0 >> 32) & mask);
  out[5] = base + ((w0 >> 40) & mask);
  out[6] = base + ((w0 >> 48) & mask);
  out[7] = base + (w0 >> 56);
  out[8] = base + ((w1)&mask);
  out[9] = base + ((w1 >> 8) & mask);
  out[10] = base + ((w1 >> 16) & mask);
  out[11] = base + ((w1 >> 24) & mask);
  out[12] = base + ((w1 >> 32) & mask);
  out[13] = base + ((w1 >> 40) & mask);
  out[14] = base + ((w1 >> 48) & mask);
  out[15] = base + (w1 >> 56);
  out[16] = base + ((w2)&mask);
  out[17] = base + ((w2 >> 8) & mask);
  out[18] = base + ((w2 >> 16) & mask);
  out[19] = base + ((w2 >> 24) & mask);
  out[20] = base + ((w2 >> 32) & mask);
  out[21] = base + ((w2 >> 40) & mask);
  out[22] = base + ((w2 >> 48) & mask);
  out[23] = base + (w2 >> 56);
  out[24] = base + ((w3)&mask);
  out[25] = base + ((w3 >> 8) & mask);
  out[26] = base + ((w3 >> 16) & mask);
  out[27] = base + ((w3 >> 24) & mask);
  out[28] = base + ((w3 >> 32) & mask);
  out[29] = base + ((w3 >> 40) & mask);
  out[30] = base + ((w3 >> 48) & mask);
  out[31] = base + (w3 >> 56);
  *pout += 32;
}
```