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54 lines
1.5 KiB
ArmAsm
54 lines
1.5 KiB
ArmAsm
;
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; 1998-06-11, Ullrich von Bassewitz
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; 2018-05-29, Greg King
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;
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; char* __fastcall__ strpbrk (const char* str, const char* set);
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;
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.export _strpbrk
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.import popax
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.importzp ptr1, ptr2, tmp2, tmp3
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_strpbrk:
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sta ptr2 ; store set
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stx ptr2+1
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jsr popax
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stx ptr1+1 ; store str's high byte
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ldx #<$0000
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stx ptr1
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tay ; use str's low byte as index
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L1: lda (ptr1),y ; get next char from str
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beq L9 ; jump if done
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sta tmp2 ; save char
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sty tmp3 ; save index into str
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ldy #$00
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L3: lda (ptr2),y ; look at each char in set
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beq L4 ; jump if done
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cmp tmp2
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beq L6 ; break out of loops if something found
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iny
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bne L3
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; The character was not found in set. Increment the counter; and start over.
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L4: ldy tmp3 ; reload index
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iny
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bne L1
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inc ptr1+1
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bne L1 ; branch always
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; A character was found. Return its str pointer.
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L6: ldx ptr1+1
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lda tmp3 ; get .Y offset
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rts
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; None of the characters in set was found -- return NULL.
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L9: ;ldx #>$0000 ; (set by prolog)
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;lda #<$0000 ; (set by '\0' at end of str)
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rts
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