1 line
2.1 KiB
NASM
1 line
2.1 KiB
NASM
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mcopy ccommon.macros
****************************************************************
*
* CopyString - copy a string
*
* Inputs:
* toPtr - location to copy to
* fromPtr - location to copy from
*
****************************************************************
*
CopyString start
subroutine (4:toPtr,4:fromPtr),0
short I,M
lda [fromPtr]
sta [toPtr]
tay
lb1 lda [fromPtr],Y
sta [toPtr],Y
dey
bne lb1
long I,M
return
end
****************************************************************
*
* Hash - find hash displacement
*
* Finds the displacement into an array of pointers using a
* hash function.
*
* Inputs:
* sPtr - points to string to find hash for
*
* Outputs:
* Returns the disp into the hash table
*
****************************************************************
*
Hash start
hashSize equ 876 # hash buckets - 1
sum equ 0 hash
length equ 2 length of string
subroutine (4:sPtr),4
stz sum default to bucket 0
lda [sPtr] set the length of the string
and #$00FF
sta length
ldy #1 start with char 1
lda [sPtr] if 1st char is '~', start with char 6
and #$FF00
cmp #'~'*256
bne lb1
ldy #6
lb1 lda [sPtr],Y get the value to add in
and #$3F3F
cpy length if there is only 1 char left then
bne lb2
and #$00FF and out the high byte
lb2 clc add it to the sum
adc sum
sta sum
iny next char
iny
cpy length
ble lb1
mod2 sum,#hashSize+1 return disp
asl sum
asl sum
return 2:sum
end
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