user: What would the C source look like for the assembly code provided here:

```asm
<internal_fiat_25519_add>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x88,%rsp
  mov    %rdi,%r12
  mov    %rsi,%rbp
  mov    %rdx,%rbx
  mov    $0x8,%esi
  mov    %ebp,%edi
  call   <_br2_load@plt>
  mov    %rax,0x8(%rsp)
  lea    0x4(%rbp),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x10(%rsp)
  lea    0x8(%rbp),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x18(%rsp)
  lea    0xc(%rbp),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x20(%rsp)
  lea    0x10(%rbp),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x28(%rsp)
  lea    0x14(%rbp),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x30(%rsp)
  lea    0x18(%rbp),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x38(%rsp)
  lea    0x1c(%rbp),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x40(%rsp)
  lea    0x20(%rbp),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x48(%rsp)
  lea    0x24(%rbp),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x50(%rsp)
  mov    $0x8,%esi
  mov    %ebx,%edi
  call   <_br2_load@plt>
  mov    %rax,0x58(%rsp)
  lea    0x4(%rbx),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x60(%rsp)
  lea    0x8(%rbx),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x68(%rsp)
  lea    0xc(%rbx),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x70(%rsp)
  lea    0x10(%rbx),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,%r15
  lea    0x14(%rbx),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,%r14
  lea    0x18(%rbx),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,%r13
  lea    0x1c(%rbx),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x78(%rsp)
  lea    0x20(%rbx),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,%rbp
  lea    0x24(%rbx),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    0x10(%rsp),%rcx
  add    0x60(%rsp),%rcx
  mov    %rcx,0x10(%rsp)
  mov    0x18(%rsp),%rdx
  add    0x68(%rsp),%rdx
  mov    %rdx,0x18(%rsp)
  mov    0x20(%rsp),%rbx
  add    0x70(%rsp),%rbx
  mov    %rbx,0x20(%rsp)
  add    0x28(%rsp),%r15
  add    0x30(%rsp),%r14
  add    0x38(%rsp),%r13
  mov    0x40(%rsp),%rdi
  add    0x78(%rsp),%rdi
  mov    %rdi,0x28(%rsp)
  add    0x48(%rsp),%rbp
  mov    0x50(%rsp),%rbx
  add    %rax,%rbx
  mov    0x8(%rsp),%r8
  add    0x58(%rsp),%r8
  mov    %r8,%rsi
  mov    $0x8,%edx
  mov    %r12d,%edi
  call   <_br2_store@plt>
  lea    0x4(%r12),%edi
  mov    $0x8,%edx
  mov    0x10(%rsp),%rsi
  call   <_br2_store@plt>
  lea    0x8(%r12),%edi
  mov    $0x8,%edx
  mov    0x18(%rsp),%rsi
  call   <_br2_store@plt>
  lea    0xc(%r12),%edi
  mov    $0x8,%edx
  mov    0x20(%rsp),%rsi
  call   <_br2_store@plt>
  lea    0x10(%r12),%edi
  mov    $0x8,%edx
  mov    %r15,%rsi
  call   <_br2_store@plt>
  lea    0x14(%r12),%edi
  mov    $0x8,%edx
  mov    %r14,%rsi
  call   <_br2_store@plt>
  lea    0x18(%r12),%edi
  mov    $0x8,%edx
  mov    %r13,%rsi
  call   <_br2_store@plt>
  lea    0x1c(%r12),%edi
  mov    $0x8,%edx
  mov    0x28(%rsp),%rsi
  call   <_br2_store@plt>
  lea    0x20(%r12),%edi
  mov    $0x8,%edx
  mov    %rbp,%rsi
  call   <_br2_store@plt>
  lea    0x24(%r12),%edi
  mov    $0x8,%edx
  mov    %rbx,%rsi
  call   <_br2_store@plt>
  add    $0x88,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void internal_fiat_25519_add(uintptr_t out0, uintptr_t in0, uintptr_t in1) {
  uintptr_t x0, x10, x1, x11, x2, x12, x3, x13, x4, x14, x5, x15, x6, x16, x7, x17, x8, x18, x9, x19, x20, x21, x22, x23, x24, x25, x26, x27, x28, x29, x30, x31, x32, x33, x34, x35, x36, x37, x38, x39;
  x0 = _br2_load((in0) + ((uintptr_t)0ULL), sizeof(uintptr_t));
  x1 = _br2_load((in0) + ((uintptr_t)4ULL), sizeof(uintptr_t));
  x2 = _br2_load((in0) + ((uintptr_t)8ULL), sizeof(uintptr_t));
  x3 = _br2_load((in0) + ((uintptr_t)12ULL), sizeof(uintptr_t));
  x4 = _br2_load((in0) + ((uintptr_t)16ULL), sizeof(uintptr_t));
  x5 = _br2_load((in0) + ((uintptr_t)20ULL), sizeof(uintptr_t));
  x6 = _br2_load((in0) + ((uintptr_t)24ULL), sizeof(uintptr_t));
  x7 = _br2_load((in0) + ((uintptr_t)28ULL), sizeof(uintptr_t));
  x8 = _br2_load((in0) + ((uintptr_t)32ULL), sizeof(uintptr_t));
  x9 = _br2_load((in0) + ((uintptr_t)36ULL), sizeof(uintptr_t));
  x10 = _br2_load((in1) + ((uintptr_t)0ULL), sizeof(uintptr_t));
  x11 = _br2_load((in1) + ((uintptr_t)4ULL), sizeof(uintptr_t));
  x12 = _br2_load((in1) + ((uintptr_t)8ULL), sizeof(uintptr_t));
  x13 = _br2_load((in1) + ((uintptr_t)12ULL), sizeof(uintptr_t));
  x14 = _br2_load((in1) + ((uintptr_t)16ULL), sizeof(uintptr_t));
  x15 = _br2_load((in1) + ((uintptr_t)20ULL), sizeof(uintptr_t));
  x16 = _br2_load((in1) + ((uintptr_t)24ULL), sizeof(uintptr_t));
  x17 = _br2_load((in1) + ((uintptr_t)28ULL), sizeof(uintptr_t));
  x18 = _br2_load((in1) + ((uintptr_t)32ULL), sizeof(uintptr_t));
  x19 = _br2_load((in1) + ((uintptr_t)36ULL), sizeof(uintptr_t));
  x20 = (x0) + (x10);
  x21 = (x1) + (x11);
  x22 = (x2) + (x12);
  x23 = (x3) + (x13);
  x24 = (x4) + (x14);
  x25 = (x5) + (x15);
  x26 = (x6) + (x16);
  x27 = (x7) + (x17);
  x28 = (x8) + (x18);
  x29 = (x9) + (x19);
  x30 = x20;
  x31 = x21;
  x32 = x22;
  x33 = x23;
  x34 = x24;
  x35 = x25;
  x36 = x26;
  x37 = x27;
  x38 = x28;
  x39 = x29;
  _br2_store((out0) + ((uintptr_t)0ULL), x30, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)4ULL), x31, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)8ULL), x32, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)12ULL), x33, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)16ULL), x34, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)20ULL), x35, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)24ULL), x36, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)28ULL), x37, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)32ULL), x38, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)36ULL), x39, sizeof(uintptr_t));
  return;
}
```