What does XOR ax ax do?
xor ax, ax would do the same as mov ax, 0 , but with additional capability of setting the flag to zero and clearing carry according to the logic of xor. And xor consumes less clocks than mov does in some old architectures. mov eax,eax would take up 5 bytes in byte code where xor eax,eax would consume 2 bytes.
What flags does XOR set assembly?
the XOR (and many other arithmetic/logic operations) will set the zero flag of the status register if the result of the operation is zero.
What does sub do in assembly?
So the purpose behind the SUB instruction, like many others implemented by the CPU, is to provide a faster (execution time) and simpler way to perform operations that are most commonly performed in software, balanced with the fact that there’s a practical limit to how many instructions can be implemented.
What is XOR value?
XOR is defined as exclusive or for two integers say a and b. To find XOR, we will first find the binary representation of both a and b. Lets do this also by example. Suppose a = 7 and b = 10. So binary representation of a = 111 (see explanation above) and b = 1010 (see explanation above).
What is XOR logic gate?
What is an XOR Gate? “XOR” an abbreviation for “Exclusively-OR.” The simplest XOR gate is a two-input digital circuit that outputs a logical “1” if the two input values differ, i.e., its output is a logical “1” if either of its inputs are 1, but not at the same time (exclusively).
When we are using XOR instruction after execution What is correct?
The XOR Instruction The XOR operation sets the resultant bit to 1, if and only if the bits from the operands are different. If the bits from the operands are same (both 0 or both 1), the resultant bit is cleared to 0. XORing an operand with itself changes the operand to 0. This is used to clear a register.
What does Testl do in assembly?
In the x86 assembly language, the TEST instruction performs a bitwise AND on two operands. The flags SF , ZF , PF are modified while the result of the AND is discarded. The OF and CF flags are set to 0 , while AF flag is undefined.
What is EAX in assembly?
eax is the 32-bit, “int” size register. It was added in 1985 during the transition to 32-bit processors with the 80386 CPU. I’m in the habit of using this register size, since they also work in 32 bit mode, although I’m trying to use the longer rax registers for everything. ax is the 16-bit, “short” size register.