user: 下面的汇编指令对应的C源代码是什么：

```asm
<internal_fiat_25519_carry>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x8,%rsp
  mov    %rdi,%rbx
  mov    %rsi,%rbp
  mov    $0x8,%esi
  mov    %ebp,%edi
  call   <_br2_load@plt>
  mov    %rax,%r12
  lea    0x8(%rbp),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,%r15
  lea    0x10(%rbp),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,%r14
  lea    0x18(%rbp),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,%r13
  lea    0x20(%rbp),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,%rcx
  mov    %r12,%rdx
  shr    $0x33,%rdx
  add    %r15,%rdx
  mov    %rdx,%rax
  shr    $0x33,%rax
  add    %r14,%rax
  mov    %rax,%r14
  shr    $0x33,%r14
  add    %r13,%r14
  mov    %r14,%r13
  shr    $0x33,%r13
  add    %rcx,%r13
  mov    %r13,%rcx
  shr    $0x33,%rcx
  lea    (%rcx,%rcx,8),%rsi
  lea    (%rcx,%rsi,2),%rsi
  movabs $0x7ffffffffffff,%rbp
  and    %rbp,%r12
  add    %r12,%rsi
  mov    %rsi,%r15
  shr    $0x33,%r15
  and    %rbp,%rdx
  add    %rdx,%r15
  mov    %r15,%r12
  shr    $0x33,%r12
  and    %rbp,%rax
  add    %rax,%r12
  and    %rbp,%rsi
  mov    $0x8,%edx
  mov    %ebx,%edi
  call   <_br2_store@plt>
  mov    %r15,%rsi
  and    %rbp,%rsi
  lea    0x8(%rbx),%edi
  mov    $0x8,%edx
  call   <_br2_store@plt>
  lea    0x10(%rbx),%edi
  mov    $0x8,%edx
  mov    %r12,%rsi
  call   <_br2_store@plt>
  mov    %r14,%rsi
  and    %rbp,%rsi
  lea    0x18(%rbx),%edi
  mov    $0x8,%edx
  call   <_br2_store@plt>
  mov    %r13,%rsi
  and    %rbp,%rsi
  lea    0x20(%rbx),%edi
  mov    $0x8,%edx
  call   <_br2_store@plt>
  add    $0x8,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void internal_fiat_25519_carry(uintptr_t out0, uintptr_t in0) {
  uintptr_t x0, x1, x2, x3, x4, x5, x6, x10, x11, x7, x8, x9, x12, x13, x14, x15, x16, x17, x18, x19, x20, x21;
  x0 = _br2_load((in0) + ((uintptr_t)0ULL), sizeof(uintptr_t));
  x1 = _br2_load((in0) + ((uintptr_t)8ULL), sizeof(uintptr_t));
  x2 = _br2_load((in0) + ((uintptr_t)16ULL), sizeof(uintptr_t));
  x3 = _br2_load((in0) + ((uintptr_t)24ULL), sizeof(uintptr_t));
  x4 = _br2_load((in0) + ((uintptr_t)32ULL), sizeof(uintptr_t));
  x5 = x0;
  x6 = ((x5) >> ((uintptr_t)51ULL)) + (x1);
  x7 = ((x6) >> ((uintptr_t)51ULL)) + (x2);
  x8 = ((x7) >> ((uintptr_t)51ULL)) + (x3);
  x9 = ((x8) >> ((uintptr_t)51ULL)) + (x4);
  x10 = ((x5) & ((uintptr_t)2251799813685247ULL)) + (((x9) >> ((uintptr_t)51ULL)) * ((uintptr_t)19ULL));
  x11 = ((x10) >> ((uintptr_t)51ULL)) + ((x6) & ((uintptr_t)2251799813685247ULL));
  x12 = (x10) & ((uintptr_t)2251799813685247ULL);
  x13 = (x11) & ((uintptr_t)2251799813685247ULL);
  x14 = ((x11) >> ((uintptr_t)51ULL)) + ((x7) & ((uintptr_t)2251799813685247ULL));
  x15 = (x8) & ((uintptr_t)2251799813685247ULL);
  x16 = (x9) & ((uintptr_t)2251799813685247ULL);
  x17 = x12;
  x18 = x13;
  x19 = x14;
  x20 = x15;
  x21 = x16;
  _br2_store((out0) + ((uintptr_t)0ULL), x17, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)8ULL), x18, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)16ULL), x19, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)24ULL), x20, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)32ULL), x21, sizeof(uintptr_t));
  return;
}
```