user: Demonstrate the C code that generates the assembly output below:

```asm
<internal_fiat_secp256k1_add>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x68,%rsp
  mov    %rdi,0x8(%rsp)
  mov    %rsi,%r12
  mov    %rdx,%r13
  mov    $0x8,%esi
  mov    %r12d,%edi
  call   <_br2_load@plt>
  mov    %rax,%rbx
  lea    0x4(%r12),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,%rbp
  lea    0x8(%r12),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x18(%rsp)
  lea    0xc(%r12),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x20(%rsp)
  lea    0x10(%r12),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x28(%rsp)
  lea    0x14(%r12),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x30(%rsp)
  lea    0x18(%r12),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x38(%rsp)
  lea    0x1c(%r12),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x10(%rsp)
  mov    $0x8,%esi
  mov    %r13d,%edi
  call   <_br2_load@plt>
  mov    %rax,%r12
  lea    0x4(%r13),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,%r14
  lea    0x8(%r13),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x40(%rsp)
  lea    0xc(%r13),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x48(%rsp)
  lea    0x10(%r13),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x50(%rsp)
  lea    0x14(%r13),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,0x58(%rsp)
  lea    0x18(%r13),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,%r15
  lea    0x1c(%r13),%edi
  mov    $0x8,%esi
  call   <_br2_load@plt>
  mov    %rax,%rdx
  add    %r12,%rbx
  mov    %rbx,%rcx
  mov    %rbp,%r8
  adc    $0x0,%r8
  cmp    %r8,%rbp
  seta   %al
  movzbl %al,%eax
  add    %r14,%r8
  mov    %eax,%r14d
  adc    $0x0,%r14d
  movslq %r14d,%r14
  add    0x18(%rsp),%r14
  setb   %r13b
  movzbl %r13b,%r13d
  add    0x40(%rsp),%r14
  adc    $0x0,%r13d
  movslq %r13d,%r13
  add    0x20(%rsp),%r13
  setb   %r12b
  movzbl %r12b,%r12d
  add    0x48(%rsp),%r13
  adc    $0x0,%r12d
  movslq %r12d,%r12
  add    0x28(%rsp),%r12
  setb   %bpl
  movzbl %bpl,%ebp
  add    0x50(%rsp),%r12
  adc    $0x0,%ebp
  movslq %ebp,%rbp
  add    0x30(%rsp),%rbp
  setb   %bl
  movzbl %bl,%ebx
  add    0x58(%rsp),%rbp
  adc    $0x0,%ebx
  movslq %ebx,%rbx
  add    0x38(%rsp),%rbx
  setb   %sil
  movzbl %sil,%esi
  add    %r15,%rbx
  adc    $0x0,%esi
  movslq %esi,%rsi
  add    0x10(%rsp),%rsi
  mov    %rdx,0x18(%rsp)
  lea    (%rdx,%rsi,1),%r15
  movabs $0xffffffff000003d1,%rax
  mov    %rcx,%rdx
  lea    (%rcx,%rax,1),%r11
  movabs $0xffffffff00000002,%rcx
  add    %r8,%rcx
  mov    %rdx,0x20(%rsp)
  cmp    %r11,%rdx
  mov    %rcx,%r9
  sbb    $0x0,%r9
  lea    -0x3d0(%rax),%rax
  lea    (%r14,%rax,1),%rdi
  cmp    %rcx,%r8
  setb   %dl
  movzbl %dl,%edx
  cmp    %r9,%rcx
  adc    $0x0,%edx
  movslq %edx,%rdx
  mov    %rdi,%r10
  sub    %rdx,%r10
  lea    0x0(%r13,%rax,1),%rcx
  cmp    %rdi,%r14
  setb   %dl
  movzbl %dl,%edx
  mov    %r10,0x28(%rsp)
  cmp    %r10,%rdi
  adc    $0x0,%edx
  movslq %edx,%rdx
  mov    %rcx,%rdi
  sub    %rdx,%rdi
  mov    %rdi,%r10
  lea    (%r12,%rax,1),%rdi
  cmp    %rcx,%r13
  setb   %dl
  movzbl %dl,%edx
  mov    %r10,0x30(%rsp)
  cmp    %r10,%rcx
  adc    $0x0,%edx
  movslq %edx,%rdx
  mov    %rdi,%rcx
  sub    %rdx,%rcx
  mov    %rcx,%r10
  lea    0x0(%rbp,%rax,1),%rcx
  cmp    %rdi,%r12
  setb   %dl
  movzbl %dl,%edx
  mov    %r10,0x38(%rsp)
  cmp    %r10,%rdi
  adc    $0x0,%edx
  movslq %edx,%rdx
  mov    %rcx,%rdi
  sub    %rdx,%rdi
  lea    (%rbx,%rax,1),%rdx
  cmp    %rcx,%rbp
  setb   %r10b
  movzbl %r10b,%r10d
  cmp    %rdi,%rcx
  adc    $0x0,%r10d
  movslq %r10d,%r10
  mov    %rdx,%rcx
  sub    %r10,%rcx
  add    %r15,%rax
  cmp    %rdx,%rbx
  setb   %r10b
  movzbl %r10b,%r10d
  cmp    %rcx,%rdx
  adc    $0x0,%r10d
  movslq %r10d,%r10
  mov    %rax,%rdx
  sub    %r10,%rdx
  cmp    %rax,%r15
  setb   %r10b
  movzbl %r10b,%r10d
  cmp    %rdx,%rax
  adc    $0x0,%r10d
  movslq %r10d,%r10
  cmp    %rsi,0x10(%rsp)
  seta   %al
  movzbl %al,%eax
  cmp    %r15,0x18(%rsp)
  seta   %sil
  movzbl %sil,%esi
  add    %esi,%eax
  cltq
  cmp    %rax,%r10
  seta   %sil
  movzbl %sil,%esi
  neg    %rsi
  mov    $0xffffffff,%eax
  xor    %rsi,%rax
  and    %rsi,%r8
  and    %rax,%r9
  or     %r9,%r8
  mov    %r8,0x10(%rsp)
  and    %rsi,%r14
  mov    0x28(%rsp),%r8
  and    %rax,%r8
  or     %r8,%r14
  and    %rsi,%r13
  mov    0x30(%rsp),%r8
  and    %rax,%r8
  or     %r8,%r13
  and    %rsi,%r12
  mov    0x38(%rsp),%r8
  and    %rax,%r8
  or     %r8,%r12
  and    %rsi,%rbp
  and    %rax,%rdi
  or     %rdi,%rbp
  and    %rsi,%rbx
  and    %rax,%rcx
  or     %rcx,%rbx
  and    %rsi,%r15
  and    %rax,%rdx
  or     %rdx,%r15
  and    0x20(%rsp),%rsi
  and    %rax,%r11
  or     %r11,%rsi
  mov    $0x8,%edx
  mov    0x8(%rsp),%edi
  call   <_br2_store@plt>
  mov    0x8(%rsp),%eax
  lea    0x4(%rax),%edi
  mov    $0x8,%edx
  mov    0x10(%rsp),%rsi
  call   <_br2_store@plt>
  mov    0x8(%rsp),%eax
  lea    0x8(%rax),%edi
  mov    $0x8,%edx
  mov    %r14,%rsi
  call   <_br2_store@plt>
  mov    0x8(%rsp),%r14
  lea    0xc(%r14),%edi
  mov    $0x8,%edx
  mov    %r13,%rsi
  call   <_br2_store@plt>
  lea    0x10(%r14),%edi
  mov    $0x8,%edx
  mov    %r12,%rsi
  call   <_br2_store@plt>
  lea    0x14(%r14),%edi
  mov    $0x8,%edx
  mov    %rbp,%rsi
  call   <_br2_store@plt>
  lea    0x18(%r14),%edi
  mov    $0x8,%edx
  mov    %rbx,%rsi
  call   <_br2_store@plt>
  mov    %r14d,%edi
  add    $0x1c,%edi
  mov    $0x8,%edx
  mov    %r15,%rsi
  call   <_br2_store@plt>
  add    $0x68,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void internal_fiat_secp256k1_add(uintptr_t out0, uintptr_t in0, uintptr_t in1) {
  uintptr_t x8, x0, x17, x1, x9, x19, x2, x10, x21, x3, x11, x23, x4, x12, x25, x5, x13, x27, x6, x14, x29, x7, x15, x33, x35, x37, x39, x41, x43, x31, x45, x16, x48, x32, x49, x18, x51, x34, x52, x20, x54, x36, x55, x22, x57, x38, x58, x24, x60, x40, x61, x26, x63, x42, x64, x28, x66, x44, x67, x47, x30, x69, x46, x70, x50, x53, x56, x59, x62, x65, x68, x71, x72, x73, x74, x75, x76, x77, x78, x79;
  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((in1) + ((uintptr_t)0ULL), sizeof(uintptr_t));
  x9 = _br2_load((in1) + ((uintptr_t)4ULL), sizeof(uintptr_t));
  x10 = _br2_load((in1) + ((uintptr_t)8ULL), sizeof(uintptr_t));
  x11 = _br2_load((in1) + ((uintptr_t)12ULL), sizeof(uintptr_t));
  x12 = _br2_load((in1) + ((uintptr_t)16ULL), sizeof(uintptr_t));
  x13 = _br2_load((in1) + ((uintptr_t)20ULL), sizeof(uintptr_t));
  x14 = _br2_load((in1) + ((uintptr_t)24ULL), sizeof(uintptr_t));
  x15 = _br2_load((in1) + ((uintptr_t)28ULL), sizeof(uintptr_t));
  x16 = (x0) + (x8);
  x17 = ((x16) < (x0)) + (x1);
  x18 = (x17) + (x9);
  x19 = (((x17) < (x1)) + ((x18) < (x9))) + (x2);
  x20 = (x19) + (x10);
  x21 = (((x19) < (x2)) + ((x20) < (x10))) + (x3);
  x22 = (x21) + (x11);
  x23 = (((x21) < (x3)) + ((x22) < (x11))) + (x4);
  x24 = (x23) + (x12);
  x25 = (((x23) < (x4)) + ((x24) < (x12))) + (x5);
  x26 = (x25) + (x13);
  x27 = (((x25) < (x5)) + ((x26) < (x13))) + (x6);
  x28 = (x27) + (x14);
  x29 = (((x27) < (x6)) + ((x28) < (x14))) + (x7);
  x30 = (x29) + (x15);
  x31 = ((x29) < (x7)) + ((x30) < (x15));
  x32 = (x16) - ((uintptr_t)4294966319ULL);
  x33 = (x18) - ((uintptr_t)4294967294ULL);
  x34 = (x33) - ((x16) < (x32));
  x35 = (x20) - ((uintptr_t)4294967295ULL);
  x36 = (x35) - (((x18) < (x33)) + ((x33) < (x34)));
  x37 = (x22) - ((uintptr_t)4294967295ULL);
  x38 = (x37) - (((x20) < (x35)) + ((x35) < (x36)));
  x39 = (x24) - ((uintptr_t)4294967295ULL);
  x40 = (x39) - (((x22) < (x37)) + ((x37) < (x38)));
  x41 = (x26) - ((uintptr_t)4294967295ULL);
  x42 = (x41) - (((x24) < (x39)) + ((x39) < (x40)));
  x43 = (x28) - ((uintptr_t)4294967295ULL);
  x44 = (x43) - (((x26) < (x41)) + ((x41) < (x42)));
  x45 = (x30) - ((uintptr_t)4294967295ULL);
  x46 = (x45) - (((x28) < (x43)) + ((x43) < (x44)));
  x47 = (x31) < ((x31) - (((x30) < (x45)) + ((x45) < (x46))));
  x48 = ((uintptr_t)-1ULL) + ((x47) == ((uintptr_t)0ULL));
  x49 = (x48) ^ ((uintptr_t)4294967295ULL);
  x50 = ((x16) & (x48)) | ((x32) & (x49));
  x51 = ((uintptr_t)-1ULL) + ((x47) == ((uintptr_t)0ULL));
  x52 = (x51) ^ ((uintptr_t)4294967295ULL);
  x53 = ((x18) & (x51)) | ((x34) & (x52));
  x54 = ((uintptr_t)-1ULL) + ((x47) == ((uintptr_t)0ULL));
  x55 = (x54) ^ ((uintptr_t)4294967295ULL);
  x56 = ((x20) & (x54)) | ((x36) & (x55));
  x57 = ((uintptr_t)-1ULL) + ((x47) == ((uintptr_t)0ULL));
  x58 = (x57) ^ ((uintptr_t)4294967295ULL);
  x59 = ((x22) & (x57)) | ((x38) & (x58));
  x60 = ((uintptr_t)-1ULL) + ((x47) == ((uintptr_t)0ULL));
  x61 = (x60) ^ ((uintptr_t)4294967295ULL);
  x62 = ((x24) & (x60)) | ((x40) & (x61));
  x63 = ((uintptr_t)-1ULL) + ((x47) == ((uintptr_t)0ULL));
  x64 = (x63) ^ ((uintptr_t)4294967295ULL);
  x65 = ((x26) & (x63)) | ((x42) & (x64));
  x66 = ((uintptr_t)-1ULL) + ((x47) == ((uintptr_t)0ULL));
  x67 = (x66) ^ ((uintptr_t)4294967295ULL);
  x68 = ((x28) & (x66)) | ((x44) & (x67));
  x69 = ((uintptr_t)-1ULL) + ((x47) == ((uintptr_t)0ULL));
  x70 = (x69) ^ ((uintptr_t)4294967295ULL);
  x71 = ((x30) & (x69)) | ((x46) & (x70));
  x72 = x50;
  x73 = x53;
  x74 = x56;
  x75 = x59;
  x76 = x62;
  x77 = x65;
  x78 = x68;
  x79 = x71;
  _br2_store((out0) + ((uintptr_t)0ULL), x72, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)4ULL), x73, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)8ULL), x74, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)12ULL), x75, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)16ULL), x76, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)20ULL), x77, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)24ULL), x78, sizeof(uintptr_t));
  _br2_store((out0) + ((uintptr_t)28ULL), x79, sizeof(uintptr_t));
  return;
}
```