arr[i+1] = arr[i+1] >> 1 | arr[i] << 31

static void SHR(uintptr_t* Value, const size_t n)
{
     uintptr_t carry = 0;
     for (int i = n - 1; i >= 0; i--)
     {
         uintptr_t new_carry = (Value[i] & 1) != 0? (uintptr_t)1 << ((sizeof(uintptr_t) * 
8) - 1): 0x00;
         Value[i] = Value[i] >> 1 | carry;
		carry = new_carry;
     }
}

static void SHR_asm(uintptr_t* Value, size_t n)
{
	Value += n - 1;
	asm volatile (R"asm(
		pushf
		mov	%%rsi, %%rdi
		clc
		std
Shift%=:
		lodsq
		rcr		%%rax
		stosq
		loop Shift%=
		popf
)asm"
}

#include <stdio.h>
#include <intrin.h>

static void Add(uintptr_t* Source, uintptr_t* Dest, size_t n)
{
	unsigned char Carry = 0;
	for (size_t i = 0; i < n; i++)
	{
#ifdef __x86_64__
		Carry = _addcarry_u64(Carry, Source[i], *Dest, Dest);
#else
		Carry = _addcarry_u32(Carry, Source[i], *Dest, Dest);
#endif
		Dest++;
	}
	while (Carry != 0)
	{
#ifdef __x86_64__
		Carry = _addcarry_u64(Carry, 0, *Dest, Dest);
#else
		Carry = _addcarry_u32(Carry, 0, *Dest, Dest);
#endif
		Dest++;
	}
}

int main()
{
   uintptr_t a[] = { -1, -1, -1, -1, 0 };
   uintptr_t b[] = { 1, 0, 0, 0, 0 };
   Add(b, a, 4);
   printf("%x %x %x %x %x\n", a[0], a[1], a[2], a[3], a[4]);
}