A DO-WHILE loop executes the loop body first and then check the condition. Which can actually be reduced to a simple unconditional jump statement:
The REPE, REPNE, REPZ, and REPNZ prefixes also check the state of the ZF flag after each iteration and terminate the repeat loop if the ZF flag is not in the specified state. To complete repetitive tasks, programmers often implement It seems counterintuitive that this section will consider What does this loop do? Consider the following example: top:cmp eax,ebx ; check loop condition jae next ; false? First, the loop checks to make sure that x is true.

Pushes the address of the instruction that follows the Halts the processor. Notice that a lot of the comparisons here are not needed since the condition is a constant. If the count is 0, the loop is terminated and program execution continues with the instruction following the LOOP instruction. Each time the LOOP instruction is executed, the count register is decremented, then checked for 0. The location passed as the argument is usually a label. Note that the LOOP instruction ignores REX.W; but 64-bit address size can be over-ridden using a 67H prefix.Each time the LOOP instruction is executed, the count register is decremented, then checked for 0. Performs a bit-wise logical and on arg0 and arg1 the result of which we will refer to as commonBits and sets the ZF(zero), SF(sign) and PF (parity) flags based on commonBits. Almost all programming languages have the ability to change the order in which statements are evaluated, and assembly is no exception. A common Do-Until Loop will take the following form: PF ≔ BitWiseXorNor(commonBits[Max-…

There are many sorts of loops, but they can all be boiled down to a few similar formats in assembly code. This offset is generally specified as a label in assembly code, but at the machine code level, it is encoded as a signed, 8-bit immediate value, which is added to the instruction pointer.
Memory refrencing Assembly Language. This is where control flow functions come in. Assembler + Linker. This UNOFFICIAL, mechanically-separated, non-verified reference is provided for convenience, but it may be MASM uses the standard Intel syntax for writing x86 assembly code. Another form of the same type of jump instruction is … See why we covered the Do-While loop first? This chapter will discuss loops, how to identify them, and how to "decompile" them back into high-level representations. Keep in mind that there needs to be a jump at the bottom of the loop (to get back up to the top), but it makes no sense to jump back to the top, retest the conditional, and then jump And here then is that same loop translated into assembly:

This is where control flow functions come in. For example, there is a 16-bit subset of the x86 instruction set. That is the largest unsigned value a register can hold. Loads EIP with the specified address, if first operand of previous CMP instruction is lesser than the second. If x is not true, the loop is skipped. gets translated into the following pseudocode while-loop: For example, there is a 16-bit subset of the x86 instruction set. Memory Modified flags 1. ; if it jumped here, then this means ecx and edx are equal However, the usage is not so strictly clear and limited, since one loop can be simply replaced (implemented) by the other programmatically. Each time the LOOP instruction is executed, the count register is decremented, then checked for 0.

MASM uses the standard Intel syntax for writing x86 assembly code. Performs a loop operation using the RCX, ECX or CX register as a counter (depending on whether address size is 64 bits, 32 bits, or 16 bits). ; if it jumped here, then this means ecx and edx are equal SF ≔ MostSignificantBit(commonBits) 2. inc