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comparison examples/erat-sieve.asm @ 57:2088fd998865

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sbc09 directry clean up
author Shinji KONO <kono@ie.u-ryukyu.ac.jp>
date Mon, 23 Jul 2018 16:07:12 +0900
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56:4fa2bdb0c457 57:2088fd998865
1 ; ERATOSTHENES SIEVE PRIMES
2 ; BYTE MAGAZINE 9/1981 BENCHMARK
3 ; Adapted by Johann Klasek, j AT klasek at
4 ; Previously implemented for a Dragon 32,
5 ; later also for a the sim6809 simulator.
6 ;
7 org $c000
8
9 FLAG EQU $5000 ; array of bytes, length SIZE
10 SIZE EQU $2000
11
12 START
13
14 lds #FLAG ; stack below flags array
15
16 ; lda #$42
17 ; jsr >$b54a ; char out Dragon Basic
18 ldb #'B
19 swi2
20
21 lda #$0a
22 pshs a
23
24 ITER ldx #FLAG ; array
25 ldu #$ffff ; filled with
26 ldd #(SIZE/2) ; words
27 CLEAR stu ,x++ ; word fill
28 decb ; byte decrement works only
29 bne CLEAR ; low byte of count is 0
30 deca
31 bne CLEAR
32
33 leau 1,u ; prime counter to 0
34 ldy #FLAG ; array
35
36 PRIMES tst ,y+ ; is prime?
37 beq NPRIME
38 leax -1,y ; prime found
39 tfr x,d
40 suba #(FLAG>>8)
41 lslb
42 rola
43 addd #3 ; prime = step
44 bra STEP
45
46 NMARK clr ,x ; mark all non-primes
47 STEP leax d,x ; step to next
48 cmpx #(FLAG+SIZE)
49 bcs NMARK
50
51 leau 1,u ; count primes
52 NPRIME cmpy #(FLAG+SIZE)
53 bcs PRIMES
54
55 ldb #'.
56 swi2 ; print
57 ; lda #$2e
58 ; jsr >$b54a ; char out Dragon Basic
59
60 dec ,s
61 bne ITER
62
63 puls a ; drop counter
64 pshs u ; store count on stack
65 ; rts
66 sync
67