1
00:00:00,310 --> 00:00:01,990
And now that's it.

2
00:00:02,110 --> 00:00:05,600
We have completed our program and it's running, as you can see.

3
00:00:05,650 --> 00:00:09,820
We just have some like, uh, three typos here.

4
00:00:10,210 --> 00:00:16,190
As you can see here in line 7109 and 135.

5
00:00:16,210 --> 00:00:21,120
So in order already fix that and just the regular typos here like a.

6
00:00:22,490 --> 00:00:28,730
Are as all Thai here, like the 1 or 2 keyword typos I fixed it with here.

7
00:00:28,730 --> 00:00:29,570
Now it's fixed.

8
00:00:29,570 --> 00:00:30,950
As you can see, it's running.

9
00:00:30,980 --> 00:00:33,230
I also, uh, the.

10
00:00:34,360 --> 00:00:36,070
Publish the fixed one here.

11
00:00:36,070 --> 00:00:37,410
That is not a big deal.

12
00:00:37,420 --> 00:00:44,650
Now, in this lecture, what you're going to learn is you will learn all of the registers and the.

13
00:00:45,650 --> 00:00:50,210
I will explain all of the things that we did in this code here.

14
00:00:50,210 --> 00:00:55,100
And as you can see, it's almost 150 lines of code.

15
00:00:55,280 --> 00:00:56,300
So.

16
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Now let's start from the assembly.

17
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The start from the increment here because we already explained the previously code.

18
00:01:10,820 --> 00:01:13,010
Here before the increment.

19
00:01:14,790 --> 00:01:16,710
So here we have increment, right?

20
00:01:16,710 --> 00:01:17,490
So.

21
00:01:18,680 --> 00:01:21,860
We are using the as a first assembly here.

22
00:01:21,860 --> 00:01:24,740
We are using the this instruction here.

23
00:01:24,740 --> 00:01:30,650
This instruction moves the value stored in the memory location referred as number one into the Rax register

24
00:01:30,650 --> 00:01:35,270
and it's loading the value of number one into the register for manipulation.

25
00:01:35,270 --> 00:01:41,150
And I see here this is the instruction here.

26
00:01:41,180 --> 00:01:48,380
This increments the value in the rax register by one, and in this case it's incrementing the value

27
00:01:48,380 --> 00:01:50,450
of number one by one.

28
00:01:50,450 --> 00:01:56,060
Here, as you can see here, it was 1 to 8 and now it's 129.

29
00:01:56,060 --> 00:01:56,630
Right.

30
00:01:56,720 --> 00:02:04,250
And here we also have move result i rax this is this instruction moves the value in the rax register

31
00:02:04,250 --> 00:02:11,690
which now holds the incremented value to the memory location pointed to by result i and it stores the

32
00:02:11,690 --> 00:02:13,940
result of increment operation.

33
00:02:14,120 --> 00:02:17,750
And here we are displaying the results in this case.

34
00:02:17,870 --> 00:02:18,720
So.

35
00:02:19,760 --> 00:02:26,330
The RDA register is loaded with the memory address of the format string fmt integer.

36
00:02:26,330 --> 00:02:32,510
So this string will be used in the printf function to format the output.

37
00:02:32,630 --> 00:02:38,090
And we also have the RSI and C here in C.

38
00:02:38,480 --> 00:02:43,940
So this RSI register is loaded with the memory address of the message string in C here.

39
00:02:43,940 --> 00:02:50,600
So this message will be used in the printf function to provide context for the displayed result.

40
00:02:50,600 --> 00:02:52,640
I want to also here.

41
00:03:00,510 --> 00:03:01,530
As you can see, it's tradition.

42
00:03:01,530 --> 00:03:02,700
Number one, incremented.

43
00:03:03,630 --> 00:03:08,840
And also we have move the result.

44
00:03:08,880 --> 00:03:14,970
I hear the RDX register is loaded with the value stored in the memory location pointed to by result

45
00:03:15,000 --> 00:03:15,180
I.

46
00:03:15,210 --> 00:03:22,140
So this value represents the result of the incremented operation increment operation and we have the

47
00:03:22,140 --> 00:03:31,440
move rax and this instruction sets the value of Rax register to zero and it prepares Rax to be used

48
00:03:31,440 --> 00:03:36,750
as the return value when the printf function call is complete.

49
00:03:36,750 --> 00:03:42,420
And this instruction calls the printf function to display the formatted message and the arguments for

50
00:03:42,420 --> 00:03:48,870
the printed functions are loaded into the RTI, RSI and RDX registers.

51
00:03:48,870 --> 00:03:52,710
And we also have the incrementing here.

52
00:03:52,710 --> 00:03:58,980
So similar to before, this instruction moves the value stored in memory location reference by number

53
00:03:58,980 --> 00:04:05,470
one into the Rax register and it's loading the value of number one into the register for manipulation.

54
00:04:05,470 --> 00:04:10,630
And we have the D a C here.

55
00:04:11,760 --> 00:04:18,390
So the the the instruction decrements the value in the rax register by one.

56
00:04:18,390 --> 00:04:23,220
And in this case it's decrementing the value of number one.

57
00:04:23,670 --> 00:04:30,510
And we lastly, we have the result i rax mov result i rax this instruction moves the value in the rax

58
00:04:30,510 --> 00:04:38,070
register register which now holds the decremented value to the memory location pointed to by result

59
00:04:38,100 --> 00:04:42,570
i and it stores the IT stores the result of the decrement operation.

60
00:04:42,570 --> 00:04:45,600
And now we have the displaying the result.

61
00:04:45,720 --> 00:04:46,410
So.

62
00:04:47,310 --> 00:04:55,260
This is basically almost the same as the previous incrementing operation here.

63
00:04:56,830 --> 00:05:01,300
And yeah, the code goes same and same here.

64
00:05:01,300 --> 00:05:06,460
Just changing three registers, instructions and variables.

65
00:05:06,460 --> 00:05:08,440
But the code structure is almost the same.

66
00:05:08,440 --> 00:05:13,330
But here we have the in the display result divide.

67
00:05:13,330 --> 00:05:23,380
And now here we in the shifting code side of the code, we have something interesting here which I will

68
00:05:23,380 --> 00:05:25,840
explain that here.

69
00:05:25,840 --> 00:05:33,070
But we have SA and as a register and sal, we should have somewhere here.

70
00:05:34,330 --> 00:05:35,080
Not division.

71
00:05:37,730 --> 00:05:38,320
Sal.

72
00:05:39,770 --> 00:05:40,550
So.

73
00:05:41,940 --> 00:05:50,640
This instruction moves the value stored in the memory location referenced by a number one into the Rax

74
00:05:50,640 --> 00:05:55,140
register, and it's loading the value of number one into the register for manipulation.

75
00:05:55,140 --> 00:05:58,440
And here we have Sal rax two.

76
00:05:58,470 --> 00:06:09,750
The Sal instruction, also known as c h l this which is meaning the show shift logical shift logical

77
00:06:09,750 --> 00:06:16,770
left shifts the bits of the rax register to the left by two positions, effectively multiplying the

78
00:06:16,770 --> 00:06:19,080
value by two.

79
00:06:19,500 --> 00:06:22,230
And we have the move here.

80
00:06:22,260 --> 00:06:28,890
This instruction moves the value in the tax register which now holds the shifted value to the memory

81
00:06:28,890 --> 00:06:35,610
location pointed to by result I and it stores the result of the left shift operation.

82
00:06:36,900 --> 00:06:41,930
And we us what we have here, we are displaying the result with as we always do.

83
00:06:41,940 --> 00:06:44,280
This is the opposite, opposite for this.

84
00:06:44,310 --> 00:06:44,940
Here we are.

85
00:06:44,940 --> 00:06:49,320
Instead of using Sal, we are using a here.

86
00:06:50,530 --> 00:06:51,280
And.

87
00:06:56,250 --> 00:06:59,880
Yeah, that's it with our program explanation here.

88
00:07:01,750 --> 00:07:05,830
And in next lecture, we will also run this program here.

89
00:07:06,340 --> 00:07:08,080
Explain it, uh, deeper.

90
00:07:08,080 --> 00:07:10,390
And we will analyze this program as well.

91
00:07:11,190 --> 00:07:17,430
And before the closing, stopping this lecture, I want to explain the.

92
00:07:18,510 --> 00:07:19,470
Registers as well.

93
00:07:19,470 --> 00:07:23,430
Again, because we need to repeat it until we.

94
00:07:24,710 --> 00:07:25,610
Know it better.

95
00:07:25,610 --> 00:07:29,090
And I will start with R.D. here.

96
00:07:29,090 --> 00:07:35,000
So this is a general purpose registers often used to hold the address of the format string to be used

97
00:07:35,000 --> 00:07:37,010
with the printf function.

98
00:07:37,010 --> 00:07:41,420
And it is one one of the arguments passed to the functions.

99
00:07:41,420 --> 00:07:42,980
And we also have RSI.

100
00:07:43,280 --> 00:07:47,420
This is a general purpose register also used for holding arguments to function.

101
00:07:47,420 --> 00:07:54,140
And in the code it's utilized to hold the values of numbers or messages that need to be displayed.

102
00:07:54,140 --> 00:07:55,900
And we also have RDX.

103
00:07:55,910 --> 00:08:01,700
This is the general purpose registers as well, often used to hold additional arguments to functions

104
00:08:01,700 --> 00:08:08,330
and in the code it is used to store values such as the result of arithmetic operations before they are

105
00:08:08,330 --> 00:08:09,080
displayed.

106
00:08:09,080 --> 00:08:12,240
And we also have the r BP.

107
00:08:12,260 --> 00:08:17,060
We use that somewhere here r BP here.

108
00:08:18,220 --> 00:08:18,920
Let me find.

109
00:08:18,940 --> 00:08:19,390
Yeah.

110
00:08:19,960 --> 00:08:20,740
RVP.

111
00:08:22,100 --> 00:08:24,450
This is a stack pointer register.

112
00:08:24,470 --> 00:08:31,100
This is points to the top of the stack and it is adjusted to allocate and deallocate memory for local

113
00:08:31,100 --> 00:08:32,960
variables and function calls.

114
00:08:33,880 --> 00:08:43,450
And we have the rags, RTI, RSI, RDX, Rbx and RSP are part of the x86 64 calling convention and are

115
00:08:43,450 --> 00:08:48,910
used to pass arguments and manage function calls between the caller and Callie.

116
00:08:49,330 --> 00:08:59,020
And we also have in C and D, a C Here we use the incrementing and decrementing operations.

117
00:09:01,890 --> 00:09:03,450
Uh, it should be somewhere here.

118
00:09:03,720 --> 00:09:04,240
I see.

119
00:09:04,280 --> 00:09:10,800
And I see here these instructions, uh, for incrementing and decrementing a register or memory location

120
00:09:10,800 --> 00:09:12,600
by one, respectively.

121
00:09:12,600 --> 00:09:16,680
So they are used to perform simple arithmetic operations quickly.

122
00:09:17,040 --> 00:09:22,380
We have the add and sub here.

123
00:09:23,440 --> 00:09:30,130
This instruction that adds a value to a register or memory location, and it is used for addition parents

124
00:09:30,130 --> 00:09:31,060
and for sub.

125
00:09:31,060 --> 00:09:37,270
Here is this instruction that subtracts a value from a register or memory location and it is used for

126
00:09:37,270 --> 00:09:49,180
subtraction operations and we also have s a L and s r a s a r here, which should be somewhere.

127
00:09:50,700 --> 00:09:54,360
Here's are s a are here and.

128
00:09:55,280 --> 00:09:55,850
Sal.

129
00:09:57,320 --> 00:10:03,350
So these are the shift arithmetic left and shift arithmetic right instructions are used for shifting

130
00:10:03,350 --> 00:10:08,720
the bits of registers or memory location to the left or right, and they can be used for multiplication

131
00:10:08,720 --> 00:10:12,050
and division by powers of two respectively.

132
00:10:12,050 --> 00:10:20,840
And we also have here I'm u l you should see somewhere here instruction use.

133
00:10:20,840 --> 00:10:24,440
This instruction is used for sine multiplication of two values.

134
00:10:24,440 --> 00:10:32,060
It is often used with two operands and the result is stored in the destination operand.

135
00:10:32,670 --> 00:10:34,190
And we have it here.

136
00:10:34,200 --> 00:10:39,660
This is this instruction used for sign division and it divides the contents of the accumulator by the

137
00:10:39,660 --> 00:10:46,980
specified operand and stores, the quotient in the accumulator and the remainder in the specified register.

138
00:10:46,980 --> 00:10:48,840
And we have the printf.

139
00:10:48,870 --> 00:10:52,710
This is a function from the C library used for formatted output.

140
00:10:52,710 --> 00:10:57,840
And in the code it's called with arguments stored in registers and displays the formatted message to

141
00:10:57,840 --> 00:10:58,680
the console.