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Diffstat (limited to 'home/math.asm')
| -rw-r--r-- | home/math.asm | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/home/math.asm b/home/math.asm new file mode 100644 index 00000000..b081b540 --- /dev/null +++ b/home/math.asm @@ -0,0 +1,41 @@ +; function to do multiplication +; all values are big endian +; INPUT +; FF96-FF98 = multiplicand +; FF99 = multiplier +; OUTPUT +; FF95-FF98 = product +Multiply:: + push hl + push bc + callfar _Multiply + pop bc + pop hl + ret + +; function to do division +; all values are big endian +; INPUT +; FF95-FF98 = dividend +; FF99 = divisor +; b = number of bytes in the dividend (starting from FF95) +; OUTPUT +; FF95-FF98 = quotient +; FF99 = remainder +Divide:: + push hl + push de + push bc + ldh a, [hLoadedROMBank] + push af + ld a, BANK(_Divide) + ldh [hLoadedROMBank], a + ld [MBC1RomBank], a + call _Divide + pop af + ldh [hLoadedROMBank], a + ld [MBC1RomBank], a + pop bc + pop de + pop hl + ret |