AVR ASM Modulo

[Fritjof (Gast)]

Hallo, Ich suche eine Modulo Funktion in AVR ASM. Am liebsten 32bit oder 
mehr. Hat jemand von euch soetwas? Eigentlich interessiert mich der 
Genaue Rest der Division auch nicht, nur ob es einen Rest gibt. Aber wie 
kann ich das möglichst schnell herausfinden?

[perlbastel (Gast)]

Ist der Teiler konstant? Für bestimmte Zahlen gibt es ja einfache Regeln 
(letzte Ziffer für 2, Quersumme für 3 usw).

[Fritjof (Gast)]

Ne, der Teiler ist leider nicht konstant. Ich wollte halt ein paar 
Primzahlen ausbrüten ;)

[spess53 (Gast)]

Hi

http://avr-asm.tripod.com/math32x.html

Div32 -> Remainder

MfG Spess

[Fritjof (Gast)]

Hallo Spess,
ist denn eine normale Division der schnellste Weg um zu erfahren ob es 
einen Rest gibt oder nicht?

[Fritjof (Gast)]

So, ich hab jetzt die 16/16 Division aus einer Atmel Appnote erweitert 
um 40/40 rechnen zu können. Leider klappt das nicht und ich finde den 
Fehler nicht.

DIV40:
  
  clr r17
  clr r18
  clr r19
  clr r20
    ;clear remainder Low byte
  sub  r21,r21;clear remainder High byte and carry

  rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_1    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_2    ;else
d40_1:  sec      ;    set carry to be shifted into result

d40_2:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_3    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_4    ;else
d40_3:  sec      ;    set carry to be shifted into result

d40_4:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_5    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_6    ;else
d40_5:  sec      ;    set carry to be shifted into result

d40_6:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_7    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_8    ;else
d40_7:  sec      ;    set carry to be shifted into result

d40_8:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_9    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_10    ;else
d40_9:  sec      ;    set carry to be shifted into result

d40_10:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_11    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_12    ;else
d40_11:  sec      ;    set carry to be shifted into result

d40_12:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_13    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_14    ;else
d40_13:  sec      ;    set carry to be shifted into result

d40_14:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_15    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_16    ;else
d40_15:  sec      ;    set carry to be shifted into result

d40_16:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_17    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_18    ;else
d40_17:  sec      ;    set carry to be shifted into result

d40_18:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_19    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_20    ;else
d40_19:  sec      ;    set carry to be shifted into result

d40_20:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_21    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_22    ;else
d40_21:  sec      ;    set carry to be shifted into result

d40_22:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_23    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_24    ;else
d40_23:  sec      ;    set carry to be shifted into result

d40_24:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_25    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_26    ;else
d40_25:  sec      ;    set carry to be shifted into result

d40_26:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_27    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_28    ;else
d40_27:  sec      ;    set carry to be shifted into result

d40_28:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_29    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_30    ;else
d40_29:  sec      ;    set carry to be shifted into result

d40_30:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_31    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_32    ;else
d40_31:  sec      ;    set carry to be shifted into result

d40_32:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_33    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_34    ;else
d40_33:  sec      ;    set carry to be shifted into result

d40_34:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_35    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_36    ;else
d40_35:  sec      ;    set carry to be shifted into result

d40_36:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_37    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_38    ;else
d40_37:  sec      ;    set carry to be shifted into result

d40_38:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_39    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_40    ;else
d40_39:  sec      ;    set carry to be shifted into result

d40_40:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_41    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_42    ;else
d40_41:  sec      ;    set carry to be shifted into result

d40_42:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_43    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_44    ;else
d40_43:  sec      ;    set carry to be shifted into result

d40_44:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_45    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_46    ;else
d40_45:  sec      ;    set carry to be shifted into result

d40_46:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_47    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_48    ;else
d40_47:  sec      ;    set carry to be shifted into result

d40_48:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_49    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_50    ;else
d40_49:  sec      ;    set carry to be shifted into result

d40_50:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_51    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_52    ;else
d40_51:  sec      ;    set carry to be shifted into result

d40_52:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_53    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_54    ;else
d40_53:  sec      ;    set carry to be shifted into result

d40_54:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_55    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_56    ;else
d40_55:  sec      ;    set carry to be shifted into result

d40_56:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_57    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_58    ;else
d40_57:  sec      ;    set carry to be shifted into result

d40_58:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_59    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_60    ;else
d40_59:  sec      ;    set carry to be shifted into result

d40_60:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_61    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_62    ;else
d40_61:  sec      ;    set carry to be shifted into result

d40_62:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_63    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_64    ;else
d40_63:  sec      ;    set carry to be shifted into result

d40_64:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_65    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_66    ;else
d40_65:  sec      ;    set carry to be shifted into result

d40_66:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_67    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_68    ;else
d40_67:  sec      ;    set carry to be shifted into result

d40_68:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_69    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_70    ;else
d40_69:  sec      ;    set carry to be shifted into result

d40_70:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_71    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_72    ;else
d40_71:  sec      ;    set carry to be shifted into result

d40_72:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_73    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_74    ;else
d40_73:  sec      ;    set carry to be shifted into result

d40_74:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_75    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_76    ;else
d40_75:  sec      ;    set carry to be shifted into result

d40_76:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_77    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_78    ;else
d40_77:  sec      ;    set carry to be shifted into result

d40_78:rol  r22    ;shift left dividend
  rol  r23
  rol r24
  rol r25
  rol r26
  rol  r17  ;shift dividend into remainder
  rol  r18
  rol r19
  rol r20
  rol r21
  sub  r17,r27  ;remainder = remainder - divisor
  sbc  r18,r28
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21
  brcc  d40_79    ;if result negative
  add  r17,r27  ;    restore remainder
  adc  r18,r28
  adc r19,r29
  adc r20,r30
  adc r21,r31
  clc      ;    clear carry to be shifted into result
  rjmp  d40_80    ;else
d40_79:  sec      ;    set carry to be shifted into result

d40_80:
  rol r22
  rol  r23
  rol r24
  rol r25
  rol r26
  ret

[Fritjof (Gast)]

keiner weiß woran es liegt?

[spess53 (Gast)]

Hi

>keiner weiß woran es liegt?

Wahrscheinlich hast du etwas falsch gemacht. Teste mal den Anhang.

MfG Spess

[fonsana (Gast)]

Primzahlen ausbrueten auf einem 8-Bit Prozessor?
Warum will man das?

fonsana

[Axel S. (a-za-z0-9)]

Fritjof schrieb:

> keiner weiß woran es liegt?

Du erwartest doch wohl nicht ernsthaft, daß sich jemand eine komplett 
ausgerollte 40-bit Division in Assembler anschaut, um deinen Fehler zu 
finden?

Als erstes würde ich vorschlagen, den Code als Schleife zu schreiben. 
Das macht es nicht nur übersichtlicher, es reduziert auch drastisch die 
Anzahl Stellen, wo du (Tipp)Fehler machen kannst.

Wenn es dann immer noch nicht läuft, nimm ein debugbares Target (oder 
alternativ einen Simulator) und steppe das durch.


XL

[Fritjof (Gast)]

Hallo Axel,
natürlich erwarte ich nicht, dass sich jemand alles durchliest. In einem 
Forum kann man sowieso nur um Hilfe bitten.
Aber es ist doch eigentlich 40 mal das gleiche, und einen Abschnitt 
kannst du dir ja anschauen ob da ein lgischer Fehler drin ist.

[spess53 (Gast)]

Hi

>Aber es ist doch eigentlich 40 mal das gleiche, und einen Abschnitt
>kannst du dir ja anschauen ob da ein lgischer Fehler drin ist.

  ....
  sbc r19,r29
  sbc r20,r30
  sbc  r21,r21  <<<<<<<<<<<<< Fehler
  brcc  d40_63    ;if result negative
  ....

Da hatte ich dir eine etwas kürzere Variante gepostet:

Beitrag "Re: AVR ASM Modulo"

Kleiner Fehler in der Beschreibung:

r25:r24:r23:r22:r21 durch r26:r25:r24:r23:r22 ersetzen.

MfG Spess

[Fritjof (Gast)]

Ich hab das ganze schon so oft durchgelesen und das übersehen.
Kopf--->Tisch.
Vielen Dank!

[Axel S. (a-za-z0-9)]

Fritjof schrieb:

> Ich hab das ganze schon so oft durchgelesen und das übersehen.
> Kopf--->Tisch.

Mit einer Schleife wäre das nicht passiert. Bzw. eher aufgefallen. 
Loop-unrolling ist was für Compiler. Handgeschriebener Code sollte 
besser auf Lesbarkeit optimiert werden. Zumal der Gewinn durch das 
Unrolling nur wenige % betragen dürfte.


XL