user: 请从给定的汇编指令推导出C源代码：

```asm
<cCoreBytesRshiftCountnmfbytesfromlentolen>:
  endbr64
  mov    %esi,%r11d
  movslq %r8d,%rsi
  push   %r14
  mov    %edx,%r10d
  push   %r13
  movzbl (%r9,%rsi,1),%edx
  push   %r12
  mov    %r11d,%r12d
  neg    %r12d
  push   %rbp
  mov    %edx,%eax
  push   %rbx
  mov    %ecx,%ebx
  mov    %r12d,%ecx
  mov    0x38(%rsp),%rbp
  shr    %cl,%eax
  mov    %r11d,%ecx
  shl    %cl,%edx
  test   %r11d,%r11d
  cmovs  %eax,%edx
  lea    0x1(%r8),%eax
  cmp    %edi,%eax
  jge    L111
  cltq
  test   %ebx,%ebx
  js     L18
  test   %r11d,%r11d
  js     L120
  mov    %rbp,%r12
  sub    %rsi,%r12
  nopw   0x0(%rax,%rax,1)
L99:
  movzbl (%r9,%rax,1),%r13d
  mov    %ebx,%ecx
  mov    %r13d,%esi
  and    %r10d,%esi
  shl    %cl,%esi
  mov    %r11d,%ecx
  or     %edx,%esi
  mov    %r13d,%edx
  mov    %sil,-0x1(%r12,%rax,1)
  add    $0x1,%rax
  shl    %cl,%edx
  cmp    %eax,%edi
  jg     L99
  cmp    0x30(%rsp),%edi
  je     L112
L128:
  movslq %edi,%rax
  movzbl (%r9,%rax,1),%eax
  and    %r10d,%eax
L10:
  test   %ebx,%ebx
  js     L126
L109:
  mov    %ebx,%ecx
  shl    %cl,%eax
L154:
  sub    %r8d,%edi
  or     %edx,%eax
  movslq %edi,%rdi
  mov    %al,-0x1(%rbp,%rdi,1)
  xor    %eax,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
  nopw   0x0(%rax,%rax,1)
L120:
  mov    %rbp,%r11
  sub    %rsi,%r11
  cs nopw 0x0(%rax,%rax,1)
L83:
  movzbl (%r9,%rax,1),%r13d
  mov    %ebx,%ecx
  mov    %r13d,%esi
  and    %r10d,%esi
  shl    %cl,%esi
  mov    %r12d,%ecx
  or     %edx,%esi
  mov    %r13d,%edx
  mov    %sil,-0x1(%r11,%rax,1)
  add    $0x1,%rax
  shr    %cl,%edx
  cmp    %eax,%edi
  jg     L83
  cmp    0x30(%rsp),%edi
  jne    L128
L112:
  xor    %eax,%eax
  jmp    L109
L18:
  mov    %rbp,%r13
  mov    %ebx,%r14d
  sub    %rsi,%r13
  neg    %r14d
  test   %r11d,%r11d
  js     L41
  nopl   0x0(%rax)
L157:
  movzbl (%r9,%rax,1),%r12d
  mov    %r14d,%ecx
  mov    %r12d,%esi
  and    %r10d,%esi
  shr    %cl,%esi
  mov    %r11d,%ecx
  or     %edx,%esi
  mov    %r12d,%edx
  mov    %sil,-0x1(%r13,%rax,1)
  add    $0x1,%rax
  shl    %cl,%edx
  cmp    %eax,%edi
  jg     L157
L76:
  cmp    0x30(%rsp),%edi
  jne    L128
  xor    %eax,%eax
L126:
  neg    %ebx
  mov    %ebx,%ecx
  shr    %cl,%eax
  jmp    L154
  cs nopw 0x0(%rax,%rax,1)
L41:
  movzbl (%r9,%rax,1),%r11d
  mov    %r14d,%ecx
  mov    %r11d,%esi
  and    %r10d,%esi
  shr    %cl,%esi
  mov    %r12d,%ecx
  or     %edx,%esi
  mov    %r11d,%edx
  mov    %sil,-0x1(%r13,%rax,1)
  add    $0x1,%rax
  shr    %cl,%edx
  cmp    %eax,%edi
  jg     L41
  jmp    L76
  nopl   0x0(%rax)
L111:
  xor    %eax,%eax
  cmp    0x30(%rsp),%edi
  jne    L128
  jmp    L10
```

assistant: ```c
int cCoreBytesRshiftCountnmfbytesfromlentolen(int count, int n, int m, int f, int b, unsigned char *pFrom, int fromLen, unsigned char *pTo, int toLen) {
  int j;
  int x;
  int digit;
  ;
l1:;
  x = ((n < 0) ? ((unsigned)(pFrom[b]) >> -n) : ((unsigned)(pFrom[b]) << n));
  ;
l2:;
  for (j = (b + 1); j <= (count - 1); j += 1) {
    digit = pFrom[j];
    pTo[(j - b) - 1] = ((((f < 0) ? ((unsigned)(digit & m) >> -f) : ((unsigned)(digit & m) << f))) | x);
    x = ((n < 0) ? ((unsigned)digit >> -n) : ((unsigned)digit << n));
  }
  if (count == fromLen) {
    digit = 0;
  } else {
    digit = pFrom[count];
  }
  pTo[(count - b) - 1] = ((((f < 0) ? ((unsigned)(digit & m) >> -f) : ((unsigned)(digit & m) << f))) | x);
}
```