Meaning of the instruction >>=

Hello,
I do not know what this instruction does:
temp >>= 15;

The context where I found is:

Code:

---

int my_random(int max)  {  //  Return Random Int Between 0 and max
        unsigned long temp;
          temp = (unsigned long) rand();
        temp *= (unsigned long) max;
        temp >>= 15;
        return (int) temp;
}

---

Help!

It is, technically, not an instruction, but an operator. What does a += 4 do? Do you know what >> does? If you know both of those, it should be obvious...

--
Mats

">>=" is a bitwise assignment operator.

Code:

---

temp >>= 15;

---

means right shift temp by 15 and assign it back to temp.

Quote:

---

Originally Posted by stevesmithx

">>=" is a bitwise assignment operator.

Code:

---

temp >>= 15;

---

means right shift temp by 15 and assign it back to temp.

---

Go throgh following code

Code:

---


int main(int argc, char* argv[])
{
  int tmp = 0xffff;
  printf("%d", tmp = tmp >> 15);  //tmp >>= 15 same as tmp = tmp >> 15
  return 0;

}

---

Ouput is 1

Quote:

---

Originally Posted by frodo_jedi

Hello,
I do not know what this instruction does:
temp >>= 15;

The context where I found is:

Code:

---

int my_random(int max)  {  //  Return Random Int Between 0 and max
        unsigned long temp;
          temp = (unsigned long) rand();
        temp *= (unsigned long) max;
        temp >>= 15;
        return (int) temp;
}

---

Help!

---

x=a>>n
x will be equal to a divided by 2 raised to the power n.