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

```asm
<unpackforblock21_64>:
  endbr64
  push   %r15
  mov    %edi,%eax
  push   %r14
  mov    %rsi,%r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    (%rsi),%rcx
  mov    (%rcx),%r13d
  mov    0x4(%rcx),%r12d
  add    $0x150,%rcx
  mov    -0x148(%rcx),%ebp
  mov    -0x144(%rcx),%ebx
  mov    %rdx,-0x8(%rsp)
  mov    -0x140(%rcx),%r11d
  mov    (%rdx),%rdx
  mov    -0x13c(%rcx),%r10d
  mov    -0x138(%rcx),%r9d
  mov    -0x134(%rcx),%r8d
  mov    -0x130(%rcx),%edi
  mov    -0x12c(%rcx),%esi
  mov    -0x128(%rcx),%r15d
  mov    %rcx,(%r14)
  mov    %r13d,%ecx
  and    $0x1fffff,%ecx
  mov    %r13d,%r14d
  add    %eax,%ecx
  mov    %ecx,(%rdx)
  mov    %r13d,%ecx
  sar    $0x15,%ecx
  and    $0x1fffff,%ecx
  add    %eax,%ecx
  mov    %ecx,0x4(%rdx)
  mov    $0x2a,%ecx
  sar    %cl,%r14d
  mov    %r14d,%ecx
  mov    %r12d,%r14d
  and    $0x1fffff,%ecx
  add    %eax,%ecx
  mov    %ecx,0x8(%rdx)
  mov    $0x3f,%ecx
  sar    %cl,%r13d
  lea    (%r12,%r12,1),%ecx
  or     %ecx,%r13d
  mov    %r12d,%ecx
  sar    $0x14,%ecx
  and    $0x1fffff,%r13d
  and    $0x1fffff,%ecx
  add    %eax,%r13d
  add    %eax,%ecx
  mov    %r13d,0xc(%rdx)
  mov    %ecx,0x10(%rdx)
  mov    $0x29,%ecx
  sar    %cl,%r14d
  mov    %r14d,%ecx
  mov    %ebp,%r14d
  and    $0x1fffff,%ecx
  add    %eax,%ecx
  mov    %ecx,0x14(%rdx)
  mov    $0x3e,%ecx
  sar    %cl,%r12d
  lea    0x0(,%rbp,4),%ecx
  or     %ecx,%r12d
  mov    %ebp,%ecx
  sar    $0x13,%ecx
  and    $0x1fffff,%r12d
  and    $0x1fffff,%ecx
  add    %eax,%r12d
  add    %eax,%ecx
  mov    %r12d,0x18(%rdx)
  mov    %ecx,0x1c(%rdx)
  mov    $0x28,%ecx
  sar    %cl,%r14d
  mov    %r14d,%ecx
  mov    %ebx,%r14d
  and    $0x1fffff,%ecx
  add    %eax,%ecx
  mov    %ecx,0x20(%rdx)
  mov    $0x3d,%ecx
  sar    %cl,%ebp
  lea    0x0(,%rbx,8),%ecx
  or     %ecx,%ebp
  mov    %ebx,%ecx
  and    $0x1fffff,%ebp
  add    %eax,%ebp
  sar    $0x12,%ecx
  and    $0x1fffff,%ecx
  mov    %ebp,0x24(%rdx)
  add    %eax,%ecx
  mov    %ecx,0x28(%rdx)
  mov    $0x27,%ecx
  sar    %cl,%r14d
  mov    %r14d,%ecx
  mov    %r11d,%r14d
  and    $0x1fffff,%ecx
  add    %eax,%ecx
  mov    %ecx,0x2c(%rdx)
  mov    $0x3c,%ecx
  sar    %cl,%ebx
  mov    %r11d,%ecx
  shl    $0x4,%ecx
  or     %ecx,%ebx
  mov    %r11d,%ecx
  sar    $0x11,%ecx
  and    $0x1fffff,%ebx
  and    $0x1fffff,%ecx
  add    %eax,%ebx
  add    %eax,%ecx
  mov    %ebx,0x30(%rdx)
  mov    %r15d,%ebx
  mov    %ecx,0x34(%rdx)
  mov    $0x26,%ecx
  sar    %cl,%r14d
  mov    %r14d,%ecx
  and    $0x1fffff,%ecx
  add    %eax,%ecx
  mov    %ecx,0x38(%rdx)
  mov    $0x3b,%ecx
  sar    %cl,%r11d
  mov    %r10d,%ecx
  shl    $0x5,%ecx
  or     %ecx,%r11d
  mov    %r10d,%ecx
  sar    $0x10,%ecx
  and    $0x1fffff,%r11d
  and    $0x1fffff,%ecx
  add    %eax,%r11d
  add    %eax,%ecx
  mov    %r11d,0x3c(%rdx)
  mov    %r10d,%r11d
  mov    %ecx,0x40(%rdx)
  mov    $0x25,%ecx
  sar    %cl,%r11d
  mov    %r11d,%ecx
  and    $0x1fffff,%ecx
  add    %eax,%ecx
  mov    %ecx,0x44(%rdx)
  mov    $0x3a,%ecx
  sar    %cl,%r10d
  mov    %r9d,%ecx
  shl    $0x6,%ecx
  or     %ecx,%r10d
  mov    %r9d,%ecx
  and    $0x1fffff,%r10d
  sar    $0xf,%ecx
  and    $0x1fffff,%ecx
  add    %eax,%r10d
  add    %eax,%ecx
  mov    %r10d,0x48(%rdx)
  mov    %r9d,%r10d
  mov    %ecx,0x4c(%rdx)
  mov    $0x24,%ecx
  sar    %cl,%r10d
  mov    %r10d,%ecx
  and    $0x1fffff,%ecx
  add    %eax,%ecx
  mov    %ecx,0x50(%rdx)
  mov    $0x39,%ecx
  sar    %cl,%r9d
  mov    %r8d,%ecx
  shl    $0x7,%ecx
  or     %ecx,%r9d
  mov    %r8d,%ecx
  sar    $0xe,%ecx
  and    $0x1fffff,%r9d
  and    $0x1fffff,%ecx
  add    %eax,%r9d
  add    %eax,%ecx
  mov    %r9d,0x54(%rdx)
  mov    %r8d,%r9d
  mov    %ecx,0x58(%rdx)
  mov    $0x23,%ecx
  sar    %cl,%r9d
  mov    %r9d,%ecx
  and    $0x1fffff,%ecx
  add    %eax,%ecx
  mov    %ecx,0x5c(%rdx)
  mov    $0x38,%ecx
  sar    %cl,%r8d
  mov    %edi,%ecx
  shl    $0x8,%ecx
  or     %ecx,%r8d
  mov    %edi,%ecx
  sar    $0xd,%ecx
  and    $0x1fffff,%r8d
  and    $0x1fffff,%ecx
  add    %eax,%r8d
  add    %eax,%ecx
  mov    %r8d,0x60(%rdx)
  mov    %edi,%r8d
  mov    %ecx,0x64(%rdx)
  mov    $0x22,%ecx
  sar    %cl,%r8d
  mov    %r8d,%ecx
  and    $0x1fffff,%ecx
  add    %eax,%ecx
  mov    %ecx,0x68(%rdx)
  mov    $0x37,%ecx
  sar    %cl,%edi
  mov    %esi,%ecx
  shl    $0x9,%ecx
  or     %ecx,%edi
  mov    %esi,%ecx
  shr    $0xb,%ebx
  sar    $0xc,%ecx
  and    $0x1fffff,%edi
  and    $0x1fffff,%ecx
  add    %eax,%edi
  add    %eax,%ecx
  mov    %edi,0x6c(%rdx)
  mov    %esi,%edi
  mov    %ecx,0x70(%rdx)
  mov    $0x21,%ecx
  sar    %cl,%edi
  mov    %edi,%ecx
  and    $0x1fffff,%ecx
  add    %eax,%ecx
  mov    %ecx,0x74(%rdx)
  mov    $0x36,%ecx
  sar    %cl,%esi
  mov    %r15d,%ecx
  shl    $0xa,%ecx
  or     %ecx,%esi
  and    $0x1fffff,%esi
  add    %eax,%esi
  add    %ebx,%eax
  mov    %eax,0x7c(%rdx)
  mov    -0x8(%rsp),%rax
  mov    %esi,0x78(%rdx)
  subq   $0xffffffffffffff80,(%rax)
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void unpackforblock21_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 = (2097151ULL);
  uint64_t w0 = pw64[0];
  uint64_t w1 = pw64[1];
  uint64_t w2 = pw64[2];
  uint64_t w3 = pw64[3];
  uint64_t w4 = pw64[4];
  uint64_t w5 = pw64[5];
  uint64_t w6 = pw64[6];
  uint64_t w7 = pw64[7];
  uint64_t w8 = pw64[8];
  uint64_t w9 = pw64[9];
  uint64_t w10 = pw64[10];
  *pw += 84;
  out[0] = base + ((w0)&mask);
  out[1] = base + ((w0 >> 21) & mask);
  out[2] = base + ((w0 >> 42) & mask);
  out[3] = base + (((w0 >> 63) | (w1 << 1)) & mask);
  out[4] = base + ((w1 >> 20) & mask);
  out[5] = base + ((w1 >> 41) & mask);
  out[6] = base + (((w1 >> 62) | (w2 << 2)) & mask);
  out[7] = base + ((w2 >> 19) & mask);
  out[8] = base + ((w2 >> 40) & mask);
  out[9] = base + (((w2 >> 61) | (w3 << 3)) & mask);
  out[10] = base + ((w3 >> 18) & mask);
  out[11] = base + ((w3 >> 39) & mask);
  out[12] = base + (((w3 >> 60) | (w4 << 4)) & mask);
  out[13] = base + ((w4 >> 17) & mask);
  out[14] = base + ((w4 >> 38) & mask);
  out[15] = base + (((w4 >> 59) | (w5 << 5)) & mask);
  out[16] = base + ((w5 >> 16) & mask);
  out[17] = base + ((w5 >> 37) & mask);
  out[18] = base + (((w5 >> 58) | (w6 << 6)) & mask);
  out[19] = base + ((w6 >> 15) & mask);
  out[20] = base + ((w6 >> 36) & mask);
  out[21] = base + (((w6 >> 57) | (w7 << 7)) & mask);
  out[22] = base + ((w7 >> 14) & mask);
  out[23] = base + ((w7 >> 35) & mask);
  out[24] = base + (((w7 >> 56) | (w8 << 8)) & mask);
  out[25] = base + ((w8 >> 13) & mask);
  out[26] = base + ((w8 >> 34) & mask);
  out[27] = base + (((w8 >> 55) | (w9 << 9)) & mask);
  out[28] = base + ((w9 >> 12) & mask);
  out[29] = base + ((w9 >> 33) & mask);
  out[30] = base + (((w9 >> 54) | (w10 << 10)) & mask);
  out[31] = base + ((w10 >> 11) & mask);
  *pout += 32;
}
```