mirror of https://github.com/pret/pokecrystal.git
69 lines
788 B
NASM
69 lines
788 B
NASM
AddNTimes::
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; Add bc * a to hl.
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and a
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ret z
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.loop
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add hl, bc
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dec a
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jr nz, .loop
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ret
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SimpleMultiply::
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; Return a * c.
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and a
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ret z
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push bc
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ld b, a
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xor a
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.loop
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add c
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dec b
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jr nz, .loop
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pop bc
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ret
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SimpleDivide::
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; Divide a by c. Return quotient b and remainder a.
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ld b, 0
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.loop
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inc b
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sub c
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jr nc, .loop
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dec b
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add c
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ret
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Multiply::
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; Multiply hMultiplicand (3 bytes) by hMultiplier. Result in hProduct.
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; All values are big endian.
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push hl
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push bc
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callfar _Multiply
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pop bc
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pop hl
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ret
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Divide::
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; Divide hDividend length b (max 4 bytes) by hDivisor. Result in hQuotient.
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; All values are big endian.
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push hl
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push de
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push bc
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homecall _Divide
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pop bc
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pop de
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pop hl
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ret
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SubtractSigned::
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; Return a - b, sign in carry.
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sub b
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ret nc
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cpl
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add 1
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scf
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ret
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