Improved way to fill hub RAM with 32-bit value in reg x (preserved):
'fill hub RAM with 32-bit value in x
'N.B. x is not changed, AUGD mask long avoided
setd .xlo,x
mov .xhi,x
sets .xhi,#511
ror .xhi,#9
setq #len-1
.xhi augd #0-0
.xlo wrlong #0-0,ptra
SETS immediate could be changed for conditional AUGD.
EDIT:
Could save 4 longs in future with a new D-only AUGDR instruction:
'AUGDR does not exist yet!
setq #len-1
augdr x 'next #D = x
wrlong #0-0,ptra
@TonyB_ said:
EDIT:
Could save 4 longs in future with a new D-only AUGDR instruction:
'AUGDR does not exist yet!
setq #len-1
augdr x 'next #D = x
wrlong #0-0,ptra
I'd pondered that as well. But it's a very specific use, one that WRLONG the block copy hadn't been designed for even. Very few instructions would use such a prefix, not even RDLONG.
EDIT: Would be better to have a block filling mechanism that didn't need double prefixing like that. Ie: SETQ3 that doesn't increment the cog register pointer.
@TonyB_ said:
EDIT:
Could save 4 longs in future with a new D-only AUGDR instruction:
'AUGDR does not exist yet!
setq #len-1
augdr x 'next #D = x
wrlong #0-0,ptra
I'd pondered that as well. But it's a very specific use, one that WRLONG hadn't been designed for even. Very few instructions would use such a prefix, not even RDLONG.
EDIT: Would be better to have a block filling mechanism that didn't need double prefixing like that. Ie: SETQ3 that doesn't increment the cog register pointer.
Filling hub RAM with arbitrary values is very important. The quickest way to fill a block of cog registers currently is via hub RAM using fast block write immediate then fast block read, assuming block size is too big for hard-coding lots of 2-cycle MOVs.
I agree that it would be better to avoid AUGD entirely. Maybe use SETQ/SETQ2 with Q[31]=1 to stop reg/LUT pointer incrementing.
Wuerfel_21's original code rotates the fill register. Rotating it back costs a long, so my suggestion saves two longs overall.
@TonyB_ said:
Wuerfel_21's original code rotates the fill register. Rotating it back costs a long, so my suggestion saves two longs overall.
Oh, the span_color, I'd missed that somehow. And reading further back, it has indeed been copied from poly_color. So there is one more instruction in Wuerfel's code I hadn't counted.
Comments
Improved way to fill hub RAM with 32-bit value in reg x (preserved):
'fill hub RAM with 32-bit value in x 'N.B. x is not changed, AUGD mask long avoided setd .xlo,x mov .xhi,x sets .xhi,#511 ror .xhi,#9 setq #len-1 .xhi augd #0-0 .xlo wrlong #0-0,ptraSETS immediate could be changed for conditional AUGD.
EDIT:
Could save 4 longs in future with a new D-only AUGDR instruction:
'AUGDR does not exist yet! setq #len-1 augdr x 'next #D = x wrlong #0-0,ptraNice trick. Though only saves the mask data.
Not only that, Evan, reg containing fill value is preserved.
Also applicable to AUGS that is patched.
Wuerfel's original preservers it too - https://forums.parallax.com/discussion/comment/1517875/#Comment_1517875
Good ideas.
I'd pondered that as well. But it's a very specific use, one that WRLONG the block copy hadn't been designed for even. Very few instructions would use such a prefix, not even RDLONG.
EDIT: Would be better to have a block filling mechanism that didn't need double prefixing like that. Ie: SETQ3 that doesn't increment the cog register pointer.
Filling hub RAM with arbitrary values is very important. The quickest way to fill a block of cog registers currently is via hub RAM using fast block write immediate then fast block read, assuming block size is too big for hard-coding lots of 2-cycle MOVs.
I agree that it would be better to avoid AUGD entirely. Maybe use SETQ/SETQ2 with Q[31]=1 to stop reg/LUT pointer incrementing.
Wuerfel_21's original code rotates the fill register. Rotating it back costs a long, so my suggestion saves two longs overall.
SETQ's are single operand, plenty of opcode space for more of those instructions.
Oh, the span_color, I'd missed that somehow. And reading further back, it has indeed been copied from poly_color. So there is one more instruction in Wuerfel's code I hadn't counted.