In the realm of assembly language programming.
The JL instruction, which stands for Jump if Less, is a fundamental tool for controlling the flow
of execution within a program based on a specific comparison condition.
Assembly language is a low level programming language that closely corresponds to the architecture of
a computer's central processing unit CPU.
The JL instruction serves as a crucial role in the decision making process of a program, enabling it
to dynamically alter its course of action, depending on whether one value is less than another.
So here's a comprehensive breakdown of how JL instruction operates.
The first is comparison comparison.
The second is conditional assessment.
Last month.
And the third is branching.
And here in comparison, initially a comparison operation takes place between two values.
These values could be stored in registers, memory locations, or even immediate values embedded directly
in the instruction.
And here the result of the comparison dictates whether the jump occurs or not.
So should the condition less than hold true, the program execution flow will divert to a new memory
location, usually indicated by a label or memory address, and in branching, the actual branching
or jump takes place if the condition is met.
Should the condition be false?
The program proceeds with a sequential execution without any shift in its flow.
And now, as we do always, we will also develop a program for this, uh, execution here.
And now let's begin it.
So again, we will start with the defining two variables section in data section, section data, the
value one and value two The value one.
We will allocate memory for value one and initialize it with 15 value one DB 15.
And in value two we will allocate memory for value two and initialize it with 20 value two DB 20 And
after that we will also develop this write this section text.
Section text and.
Here.
We will define this.
Start here.
So move.
Value one.
So here, move the value at memory, address value one into the Al and move B move the value at memory
address value two into B al.
So value two.
And after that we will compare the values in Al and b cmp al, l and g l.
This is for jump.
If less we are now less here jump to less.
If here we are telling the assembly jump to less.
If a al is less than b l and here we will firstly define the not less label for now, not less.
So your code here for the case when value one is not less than value.
Two cmp done.
So we are telling jump to done to conclude this section and we will also write this label and also we
will write the less when this in less we will write the your code here.
Here for the case when value1 is less than value to.
And also we will write done.
And after that, I will explain all of this here.
And this is just a regular exit code.
You can also add or.
More developed as sexist quotes here.
So this is just a project for explanatory purposes.
And as we delve into the code, we start by defining this data section here.
Memory is load.
I'll allocate it for two variables Value one and value two.
The DB directive indicates that each of these variables holds a byte size value, so we initialize value
one with 15 and value two with 20.
Setting the stage for our comparisons and transitioning to the text section where executable instructions
reside.
The Start label marks the entry point to our program, as you know.
So we begin by using this move instruction to load the value residing in memory at the address pointed
to by value one into a register.
Similarly, the Move instruction transfers the value from the memory location pointed to by value two
into the B register.
Subsequently, the CMP instruction compares the value stored in A, L and b L.
If the comparison reveals that the value in L is less than the value in b, l, we proceed to the less
label.
And should the comparison result indicate that the value in L is not less than the value in b l, we
proceed to not less section.
So here we here you will generally insert your custom set of instructions to handle scenarios where
value one is not less than value.
Two.
Following this GMP done here so GMP done instruction allows us to skip directly to the done label as
we also define this bypassing this less section.
And conversely, when the comparison confirms that the value in L is indeed less than the value in b,
l, we advance to the less label.
So within this segment you will typically insert the instructions to be executed when value one is less
than value.
Two and our journey concludes at the done label here signifying signifying that the end of our program
logic and this is typically where you would include instructions for program termination or any necessary
cleanup.
So this could encompass system calls to conclude the program or to release any resources incurred during
execution.
And by meticulously examining this assembly code, we have delved into the world of conditional branching
and comparisons, the code flow branches based on the outcome of the comparison between value one and
value two.
You understanding your understanding of this branching mechanisms and comparisons will be pivotal as
you advanced in your exploration of assembly programming.
Embrace the learning process, continue practicing and venture deeper into the intricacies of assembly
programming.
So I'm waiting you in the next lecture.