Routines
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41345: Divide Words
Divides the word in HL by the word in DE. Nothing in the game calls it.
Input
HL Dividend
DE Divisor
Output
HL Quotient
DE Remainder
Nothing in the game divides one word by another.
DivideWords 41345 PUSH BC Hold the dividend.
41346 LD B,H
41347 LD C,L
41348 PUSH AF
41349 LD HL,0 The remainder starts at zero, for sixteen bits.
41352 LD A,B
41353 LD B,16
Try the next bit of the dividend.
DivideWords_NextBit 41355 SLA C Bring that bit into the remainder.
41357 RLA
41358 ADC HL,HL
41360 SBC HL,DE See whether the divisor fits.
41362 JR C,DivideWords_1
DivideWords_0 41364 INC C The quotient gains a bit, and the next bit follows.
41365 DJNZ DivideWords_NextBit
41367 JR DivideWords_2
The divisor did not fit.
DivideWords_Restore 41369 SLA C Put the remainder back.
41371 RLA
41372 ADC HL,HL
41374 ADD HL,DE
41375 JR C,DivideWords_0 Try the next bit.
DivideWords_1 41377 DJNZ DivideWords_Restore
41379 ADD HL,DE
Nothing in the game uses this quotient.
DivideWords_2 41380 EX DE,HL Nothing in the game uses this quotient.
41381 LD H,A
41382 LD L,C
41383 POP AF Restore AF and BC from the stack.
41384 POP BC
41385 RET Return.
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