Why does the value that DI is pointing to change when I changed the value that SI is pointing to?
push si
push [bx]
mov si, [si]
mov [bx], si
mov di, bx
pop bx
pop si
mov [si], bx
This is my code. For some reason the value that di is pointing to changes after mov[si], bx (the last line).
Does anybody know why?
Edit: Both si and di are pointing to values in the same array, which is defined as db. The value that di is pointing to becomes the value after it in the array.
assembly x86-16
asked Nov 16 '18 at 10:44
GderuGderu
368
add a comment |
push si
push [bx]
mov si, [si]
mov [bx], si
mov di, bx
pop bx
pop si
mov [si], bx
This is my code. For some reason the value that di is pointing to changes after mov[si], bx (the last line).
Does anybody know why?
Edit: Both si and di are pointing to values in the same array, which is defined as db. The value that di is pointing to becomes the value after it in the array.
assembly x86-16
asked Nov 16 '18 at 10:44
GderuGderu
368
2
Maybesianddipoint to the same memory address?
– tkausl
Nov 16 '18 at 10:46
No, they don't.
– Gderu
Nov 16 '18 at 10:48
3
You probably have a byte array but you are writing words so affecting two elements at a time.
– Jester
Nov 16 '18 at 11:12
Huh, you're right! Thanks a lot!
– Gderu
Nov 16 '18 at 11:30
add a comment |
push si
push [bx]
mov si, [si]
mov [bx], si
mov di, bx
pop bx
pop si
mov [si], bx
This is my code. For some reason the value that di is pointing to changes after mov[si], bx (the last line).
Does anybody know why?
Edit: Both si and di are pointing to values in the same array, which is defined as db. The value that di is pointing to becomes the value after it in the array.
assembly x86-16
asked Nov 16 '18 at 10:44
GderuGderu
368
push si
push [bx]
mov si, [si]
mov [bx], si
mov di, bx
pop bx
pop si
mov [si], bx
This is my code. For some reason the value that di is pointing to changes after mov[si], bx (the last line).
Does anybody know why?
Edit: Both si and di are pointing to values in the same array, which is defined as db. The value that di is pointing to becomes the value after it in the array.
assembly x86-16
assembly x86-16
asked Nov 16 '18 at 10:44
GderuGderu
368
asked Nov 16 '18 at 10:44
GderuGderu
368
edited Nov 16 '18 at 11:04
Gderu
asked Nov 16 '18 at 10:44
GderuGderu
368
asked Nov 16 '18 at 10:44
GderuGderu
368
asked Nov 16 '18 at 10:44
GderuGderu
368
368
2
Maybesianddipoint to the same memory address?
– tkausl
Nov 16 '18 at 10:46
No, they don't.
– Gderu
Nov 16 '18 at 10:48
3
You probably have a byte array but you are writing words so affecting two elements at a time.
– Jester
Nov 16 '18 at 11:12
Huh, you're right! Thanks a lot!
– Gderu
Nov 16 '18 at 11:30
add a comment |
2
Maybesianddipoint to the same memory address?
– tkausl
Nov 16 '18 at 10:46
No, they don't.
– Gderu
Nov 16 '18 at 10:48
3
You probably have a byte array but you are writing words so affecting two elements at a time.
– Jester
Nov 16 '18 at 11:12
Huh, you're right! Thanks a lot!
– Gderu
Nov 16 '18 at 11:30
2
2
Maybe
si and di point to the same memory address?– tkausl
Nov 16 '18 at 10:46
Maybe
si and di point to the same memory address?– tkausl
Nov 16 '18 at 10:46
No, they don't.
– Gderu
Nov 16 '18 at 10:48
No, they don't.
– Gderu
Nov 16 '18 at 10:48
3
3
You probably have a byte array but you are writing words so affecting two elements at a time.
– Jester
Nov 16 '18 at 11:12
You probably have a byte array but you are writing words so affecting two elements at a time.
– Jester
Nov 16 '18 at 11:12
Huh, you're right! Thanks a lot!
– Gderu
Nov 16 '18 at 11:30
Huh, you're right! Thanks a lot!
– Gderu
Nov 16 '18 at 11:30
add a comment |
1 Answer
1
active
oldest
votes
Jester was correct, I added words to an array of bytes which changed not only the specific part I was trying to change but also the parts around it.
answered Nov 16 '18 at 11:36
GderuGderu
368
1
Upvote for answering your own question! Always nice to see that.
– fuz
Nov 16 '18 at 11:57
add a comment |
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1 Answer
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oldest
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1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
Jester was correct, I added words to an array of bytes which changed not only the specific part I was trying to change but also the parts around it.
answered Nov 16 '18 at 11:36
GderuGderu
368
1
Upvote for answering your own question! Always nice to see that.
– fuz
Nov 16 '18 at 11:57
add a comment |
Jester was correct, I added words to an array of bytes which changed not only the specific part I was trying to change but also the parts around it.
answered Nov 16 '18 at 11:36
GderuGderu
368
1
Upvote for answering your own question! Always nice to see that.
– fuz
Nov 16 '18 at 11:57
add a comment |
Jester was correct, I added words to an array of bytes which changed not only the specific part I was trying to change but also the parts around it.
answered Nov 16 '18 at 11:36
GderuGderu
368
Jester was correct, I added words to an array of bytes which changed not only the specific part I was trying to change but also the parts around it.
answered Nov 16 '18 at 11:36
GderuGderu
368
answered Nov 16 '18 at 11:36
GderuGderu
368
answered Nov 16 '18 at 11:36
GderuGderu
368
answered Nov 16 '18 at 11:36
GderuGderu
368
368
1
Upvote for answering your own question! Always nice to see that.
– fuz
Nov 16 '18 at 11:57
add a comment |
1
Upvote for answering your own question! Always nice to see that.
– fuz
Nov 16 '18 at 11:57
1
1
Upvote for answering your own question! Always nice to see that.
– fuz
Nov 16 '18 at 11:57
Upvote for answering your own question! Always nice to see that.
– fuz
Nov 16 '18 at 11:57
add a comment |
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2
Maybe
sianddipoint to the same memory address?– tkausl
Nov 16 '18 at 10:46
No, they don't.
– Gderu
Nov 16 '18 at 10:48
3
You probably have a byte array but you are writing words so affecting two elements at a time.
– Jester
Nov 16 '18 at 11:12
Huh, you're right! Thanks a lot!
– Gderu
Nov 16 '18 at 11:30