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oziphantom
Registered: Oct 2014
Posts: 490 |
Code indenting
I've always been a strict
label code comment kinda guy but of late I've been experimenting with code readability and speed boosts. Indenting does seem to improve things
updateMovement
ldx Ents.movementPtr
- lda YXDeltas,x
cmp #$AA
bne +
ldx Ents.movementPtrBase
stx Ents.movementPtr
jmp -
+ clc
adc Ents.y
sta Ents.y
inx
lda YXDeltas,x
beq _endAdd
bmi _sub
clc
adc Ents.x
sta Ents.x
bcc _endAdd
inc Ents.xMSB
jmp _endAdd
_sub
clc
adc Ents.x
sta Ents.x
lda Ents.xMSB
adc #$ff
sta Ents.xMSB
_endAdd
inx
stx Ents.movementPtr
rts vs updateMovement
ldx Ents.movementPtr
- lda YXDeltas,x
cmp #$AA
bne +
ldx Ents.movementPtrBase
stx Ents.movementPtr
jmp -
+ clc
adc Ents.y
sta Ents.y
inx
lda YXDeltas,x
beq _endAdd
bmi _sub
clc
adc Ents.x
sta Ents.x
bcc _endAdd
inc Ents.xMSB
jmp _endAdd
_sub
clc
adc Ents.x
sta Ents.x
lda Ents.xMSB
adc #$ff
sta Ents.xMSB
_endAdd
inx
stx Ents.movementPtr
rts this kind of falls apart when you get the to the leap frog code. I.e something like
bmi C
beq B
A
A
A
bne C
A
A
jmp D
B
B
B
B
beq D
C
C
C
C
D
D
D So I was wondering if anybody else had tumbled down this rabbit hole or had other things to do to help? |
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oziphantom
Registered: Oct 2014
Posts: 490 |
Quoting SkateC64 has no tab key for a reason. :)
And the C128 does for a reason ;) The Kernal even has Tab Stops build in. |
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Skate
Registered: Jul 2003
Posts: 494 |
Quote: Quoting SkateC64 has no tab key for a reason. :)
And the C128 does for a reason ;) The Kernal even has Tab Stops build in.
We are free to use indenting for our C128 projects then, good to know.
I have a C128 but it will take a few more decades until i need that much memory and speed. ;) |
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Compyx
Registered: Jan 2005
Posts: 631 |
Quoting CruzerLooks retarded to me. I would just add some newlines to split the code into logical blocks. The only time it makes sense to indent asm code is if it's in curly brackets, e.g. because of an if-statement or for-loop.
I agree with the retarded bit. But even using brackets doesn't make sense, asm doesn't have block-level scope. And if there are assemblers that support that, those are retarded. |
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Hypnosis
Registered: Mar 2015
Posts: 36 |
I also indent my code in loops, if-end and if-else-end cases. I indent as well as I can in other cases but fail when it gets too hairy. My assembler has some syntactic sugar to help this structuring by using curly braces. They limit the lifetime of local variables but also add automatic loop and continue labels, so you can write a loop like this.
ldx #0
{
lda string,x
beq @continue
jsr CHROUT
inx
bne @loop
}
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Digger
Registered: Mar 2005
Posts: 437 |
I am also doing indenting for loops and shit, like Cruzer said.
What's interesting however is logically grouping vars and pointers like:
Ents.movementPtrBase
Ents.movementPtr
Ents.xMSB
...
etc.
How does this work in principle? |
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oziphantom
Registered: Oct 2014
Posts: 490 |
using tass and do Ents .block
movementPtrBase .byte ?
movementPtr .byte ?
xMSB .byte ?
.bend
or make a struct with it use dstruct to instance multiple copies where you want it.
Then you access it with Ents.movementPtr.
If this is a Hi/Lo word you can do HLWord .union
.word ?
.struct
lo .byte ?
hi .byte ?
.ends
.endu then make one as movementPtr .dunion HLWord if you do it inside the Ents block/struct you would then have
Ents.MovementPtr and
Ents.MovementPtr.lo and
Ents.MovementPtr.hi |
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White Flame
Registered: Sep 2002
Posts: 136 |
I tend to add just a single space at a time. I find it a lot more readable than the full tab-style examples above, since asm tends to be very column-aligned.
For loops, I indent the body including the first instruction, and de-indent the branch instruction:
ldx #$7f
: lda init,x
sta dest,x
dex
bpl :-
For if/then/else/etc branching, I just try to keep conditional areas indented, but when it goes all spaghetti that's just a guideline. |
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chatGPZ
Registered: Dec 2001
Posts: 11386 |
Quote:when it goes all spaghetti
i recommend a bit of good oil, cheese, and red wine :) |
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ChristopherJam
Registered: Aug 2004
Posts: 1409 |
I was going to stay out of this thread, as I tend not to indent asm blocks. Then I caught myself doing this last night:
for i in 1..30
{
ldx so+i
lda yv,x
ldy so+i-1
cmp yv,y
bge next
sty so+i
ldy so+i-2
cmp yv,y
bge swap1
sty so+i-1
ldy so+i-3
cmp yv,y
bge swap2
jmp abort
swap2
stx so+i-2
jmp reload
swap1
stx so+i-1
reload
ldx so+i
next
}
; 51 bytes per pair, *31 = 1550 bytes (less a bit for the first few entries)
(code may contain bugs, and is wrong for i in 1..2 and also I want to swap x & y every second iteration of the code generator so I can drop the "ldy so+i-1" on subsequent iters, but those are all by the by) |
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Cruzer
Registered: Dec 2001
Posts: 1048 |
Quoting Compyxasm doesn't have block-level scope. And if there are assemblers that support that, those are retarded. I dunno. If it's used for keeping the code organized, I beg to differ. For instance I like to keep each subroutine in braces, so I can have local labels like "loop" and "done" that would otherwise have to be either global (I remember the days of turbo-ass and having to come up with meaningless labels like "loop43") or multi-labels referenced by label+ or label-, which have the disadvantage that if you forget to add the label, it usually ends up referring to a label in another subroutine. But even when using multi-labels you avoid this if the subroutines are in different blocks, since it will just give a compile time error.
Are for-loops and other scripting retarded? Certainly if it's used for generating speedcode or data that could be generated quicker at runtime than it would take to load. But for importing gfx or generating small chunks of data or code such as setting the y-position of 8 sprites it makes a lot of sense to me. |
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