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base: brooke:829f46755ad73438828440a23ed082e46e7a6d8d
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brooke:main
brooke:tweak-mul
brooke:elapsed
brooke:sec
brooke:xe
brooke:fastmul2
brooke:fastmul
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compare: brooke:55d34cb388db6c8ce354e554e20fca448791ffd0
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brooke:main
brooke:tweak-mul
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Author SHA1 Message Date
Brooke Vibber
55d34cb388 Merge branch 'experiment' 2026-08-22 15:35:53 -07:00
Brooke Vibber
4b352e8f63 Merge branch 'regression' 2026-08-22 15:35:29 -07:00
Brooke Vibber
e284587edc Fix regression from merging ptr and pixel_ptr 
the XE fast-path assumed low byte of ptr never changes
to save a couple cycles
 2026-08-22 15:35:03 -07:00
Brooke Vibber
27995007c5 experiment 2026-08-22 15:25:58 -07:00
1 changed files with 25 additions and 26 deletions
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51
mandel-core.s
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@ -18,6 +18,7 @@ z_buffer_start: .res 1 ; u8: index into z_buffer
z_buffer_end: .res 1 ; u8: index into z_buffer z_buffer_end: .res 1 ; u8: index into z_buffer
iter: .res 1 ; u8: iteration count iter: .res 1 ; u8: iteration count
ptr: .res 2 ; u16 ptr: .res 2 ; u16
pixel_ptr: .res 2 ; u16
temp: .res 2 ; u16 temp: .res 2 ; u16
temp2: .res 2 ; u16 temp2: .res 2 ; u16
@ -592,7 +593,7 @@ bank_switch_table:
.macro imul8 dest, arg1, arg2, xe .macro imul8 dest, arg1, arg2, xe
.if xe .if xe
; using 64KB lookup table ; using 64KB lookup table
; 51-70 cycles ; 52-69 cycles
; clobbers x, y, dest, ptr ; clobbers x, y, dest, ptr
.scope .scope
output = dest output = dest
@ -636,9 +637,7 @@ bank_switch_table:
txa ; 2 cyc txa ; 2 cyc
adc output ; 3 cyc adc output ; 3 cyc
sta output ; 3 cyc sta output ; 3 cyc
lda #0 ; 2 cyc add_carry output + 1 ; 2-7 cyc
adc output+1 ; 3 cyc
sta output+1 ; 3 cyc
done: done:
.endscope .endscope
@ -775,8 +774,8 @@ inner_loop:
; min base mem: 81 * 4 + 22 * 2 + 10 + 6 = 384 cyc ; min base mem: 81 * 4 + 22 * 2 + 10 + 6 = 384 cyc
; max base mem: 92 * 4 + 27 * 2 + 50 + 6 = 478 cyc ; max base mem: 92 * 4 + 27 * 2 + 50 + 6 = 478 cyc
; min ext-mem: 51 * 4 + 22 * 2 + 10 + 6 = 264 cyc ; min ext-mem: 52 * 4 + 22 * 2 + 10 + 6 = 268 cyc
; max ext-mem: 70 * 4 + 27 * 2 + 50 + 6 = 390 cyc ; max ext-mem: 69 * 4 + 27 * 2 + 50 + 6 = 386 cyc
.macro imul16_impl xe .macro imul16_impl xe
.local arg1 .local arg1
.local arg2 .local arg2
@ -794,15 +793,15 @@ inner_loop:
; h1*256*(h2*256 + l2) + l1*(h2*256 + l2) ; h1*256*(h2*256 + l2) + l1*(h2*256 + l2)
; h1*h2*256*256 + h1*l2*256 + h2*l1*256 + l1*l2 ; h1*h2*256*256 + h1*l2*256 + h2*l1*256 + l1*l2
imul8 result, arg1, arg2, xe ; 81-92 or 51-70 imul8 result, arg1, arg2, xe ; 81-92 or 52-69
imul8 result + 2, arg1 + 1, arg2 + 1, xe ; 81-92 or 51-70 imul8 result + 2, arg1 + 1, arg2 + 1, xe ; 81-92 or 52-69
imul8 inter, arg1 + 1, arg2, xe ; 81-92 or 51-70 imul8 inter, arg1 + 1, arg2, xe ; 81-92 or 52-69
add16 result + 1, result + 1, inter ; 20 cyc add16 result + 1, result + 1, inter ; 20 cyc
add_carry result + 3 ; 2-7 cyc add_carry result + 3 ; 2-7 cyc
imul8 inter, arg1, arg2 + 1, xe ; 81-92 or 51-70 imul8 inter, arg1, arg2 + 1, xe ; 81-92 or 52-69
add16 result + 1, result + 1, inter ; 20 cyc add16 result + 1, result + 1, inter ; 20 cyc
add_carry result + 3 ; 2-7 cyc add_carry result + 3 ; 2-7 cyc
@ -823,8 +822,8 @@ arg2_pos:
; min base ram: 5 + 19 * 2 + 81 + 22 * 2 + 6 = 174 ; min base ram: 5 + 19 * 2 + 81 + 22 * 2 + 6 = 174
; max base ram: 23 + 19 * 2 + 92 + 27 * 2 + 6 = 213 ; max base ram: 23 + 19 * 2 + 92 + 27 * 2 + 6 = 213
; min ext ram: 5 + 19 * 2 + 51 + 22 * 2 + 6 = 144 ; min ext ram: 5 + 19 * 2 + 52 + 22 * 2 + 6 = 145
; max ext ram: 23 + 19 * 2 + 70 + 27 * 2 + 6 = 191 ; max ext ram: 23 + 19 * 2 + 69 + 27 * 2 + 6 = 190
.macro sqr16_impl xe .macro sqr16_impl xe
.scope .scope
arg = FR0 ; 16-bit arg (clobbered) arg = FR0 ; 16-bit arg (clobbered)
@ -847,7 +846,7 @@ arg2_pos:
sqr8 result + 2, arg + 1 ; 19 cyc sqr8 result + 2, arg + 1 ; 19 cyc
imul8 inter, arg + 1, arg, xe ; 81-92 / 51-70 cyc imul8 inter, arg + 1, arg, xe ; 81-92 / 52-69 cyc
add16 result + 1, result + 1, inter ; 20 cyc add16 result + 1, result + 1, inter ; 20 cyc
add_carry result + 3 ; 2-7 cyc add_carry result + 3 ; 2-7 cyc
add16 result + 1, result + 1, inter ; 20 cyc add16 result + 1, result + 1, inter ; 20 cyc
@ -1267,21 +1266,21 @@ enough:
negative: negative:
; temp1 = top half ; temp1 = top half
lda #.lobyte(framebuffer_top + stride * half_height) lda #.lobyte(framebuffer_top + stride * half_height)
sta ptr sta pixel_ptr
lda #.hibyte(framebuffer_top + stride * half_height) lda #.hibyte(framebuffer_top + stride * half_height)
sta ptr + 1 sta pixel_ptr + 1
jmp point jmp point
positive: positive:
lda #.lobyte(framebuffer_bottom) lda #.lobyte(framebuffer_bottom)
sta ptr sta pixel_ptr
lda #.hibyte(framebuffer_bottom) lda #.hibyte(framebuffer_bottom)
sta ptr + 1 sta pixel_ptr + 1
point: point:
; ptr += sy * stride ; pixel_ptr += sy * stride
; temp * 40 ; temp * 40
; = temp * 32 + temp * 8 ; = temp * 32 + temp * 8
; = (temp << 5) + (temp << 3) ; = (temp << 5) + (temp << 3)
@ -1289,10 +1288,10 @@ point:
shl16 temp shl16 temp
shl16 temp shl16 temp
shl16 temp shl16 temp
add16 ptr, ptr, temp add16 pixel_ptr, pixel_ptr, temp
shl16 temp shl16 temp
shl16 temp shl16 temp
add16 ptr, ptr, temp add16 pixel_ptr, pixel_ptr, temp
; Ok so temp1 points to the start of the line, which is 40 bytes. ; Ok so temp1 points to the start of the line, which is 40 bytes.
; Get the byte and bit offsets ; Get the byte and bit offsets
@ -1332,20 +1331,20 @@ shift_done:
draw_pixel: draw_pixel:
; read, mask, or, write ; read, mask, or, write
lda (ptr),y lda (pixel_ptr),y
and pixel_mask and pixel_mask
ora pixel_color ora pixel_color
sta (ptr),y sta (pixel_ptr),y
dex dex
beq done beq done
clc clc
lda #40 lda #40
adc ptr adc pixel_ptr
sta ptr sta pixel_ptr
lda #0 lda #0
adc ptr + 1 adc pixel_ptr + 1
sta ptr + 1 sta pixel_ptr + 1
jmp draw_pixel jmp draw_pixel
done: done: