diff options
Diffstat (limited to 'engine/multiply_divide.asm')
| -rwxr-xr-x | engine/multiply_divide.asm | 176 |
1 files changed, 88 insertions, 88 deletions
diff --git a/engine/multiply_divide.asm b/engine/multiply_divide.asm index e55ab430..7726a2db 100755 --- a/engine/multiply_divide.asm +++ b/engine/multiply_divide.asm @@ -2,142 +2,142 @@ _Multiply: ; 37d41 (d:7d41) ld a, $8 ld b, a xor a - ld [H_DIVIDEND], a ; (aliases: H_PRODUCT, H_PASTLEADINGZEROES, H_QUOTIENT) - ld [$ff9b], a - ld [H_SAVEDNUMTOPRINT], a - ld [$ff9d], a - ld [$ff9e], a -.asm_37d4f - ld a, [H_REMAINDER] ; (aliases: H_DIVISOR, H_MULTIPLIER, H_POWEROFTEN) + ld [H_PRODUCT], a ; $ff95 + ld [H_MULTIPLYBUFFER], a ; $ff9b + ld [H_MULTIPLYBUFFER+1], a ; $ff9c + ld [H_MULTIPLYBUFFER+2], a ; $ff9d + ld [H_MULTIPLYBUFFER+3], a ; $ff9e +.multiplyLoop + ld a, [H_MULTIPLIER] ; $ff99 srl a - ld [H_REMAINDER], a ; (aliases: H_DIVISOR, H_MULTIPLIER, H_POWEROFTEN) - jr nc, .asm_37d77 - ld a, [$ff9e] + ld [H_MULTIPLIER], a ; $ff99 + jr nc, .smallMultiplier ; less than $80 +; code to possibly multiply the multiplicand by 2 and divide the multiplier by 2? + ld a, [H_MULTIPLYBUFFER+3] ld c, a - ld a, [$ff98] + ld a, [H_MULTIPLICAND+2] add c - ld [$ff9e], a - ld a, [$ff9d] + ld [H_MULTIPLYBUFFER+3], a + ld a, [H_MULTIPLYBUFFER+2] ld c, a - ld a, [$ff97] + ld a, [H_MULTIPLICAND+1] adc c - ld [$ff9d], a - ld a, [H_SAVEDNUMTOPRINT] + ld [H_MULTIPLYBUFFER+2], a + ld a, [H_MULTIPLYBUFFER+1] ; $ff9c ld c, a - ld a, [H_NUMTOPRINT] ; (aliases: H_MULTIPLICAND) + ld a, [H_MULTIPLICAND] ; $ff96 adc c - ld [H_SAVEDNUMTOPRINT], a - ld a, [$ff9b] + ld [H_MULTIPLYDBUFFER+1], a ; $ff9c + ld a, [H_MULTIPLYBUFFER] ld c, a - ld a, [H_DIVIDEND] ; (aliases: H_PRODUCT, H_PASTLEADINGZEROES, H_QUOTIENT) + ld a, [H_PRODUCT] ; $ff95 adc c - ld [$ff9b], a -.asm_37d77 + ld [H_MULTIPLYBUFFER], a +.smallMultiplier dec b - jr z, .asm_37d94 - ld a, [$ff98] + jr z, .done + ld a, [H_MULTIPLICAND] sla a - ld [$ff98], a - ld a, [$ff97] + ld [H_MULTIPLICAND+2], a + ld a, [H_MULTIPLICAND+1] rl a - ld [$ff97], a - ld a, [H_NUMTOPRINT] ; (aliases: H_MULTIPLICAND) + ld [H_MULTIPLICAND+1], a + ld a, [H_MULTIPLICAND] ; $ff96 rl a - ld [H_NUMTOPRINT], a ; (aliases: H_MULTIPLICAND) - ld a, [H_DIVIDEND] ; (aliases: H_PRODUCT, H_PASTLEADINGZEROES, H_QUOTIENT) + ld [H_MULTIPLICAND], a ; $ff96 + ld a, [H_PRODUCT] ; $ff95 rl a - ld [H_DIVIDEND], a ; (aliases: H_PRODUCT, H_PASTLEADINGZEROES, H_QUOTIENT) - jr .asm_37d4f -.asm_37d94 - ld a, [$ff9e] - ld [$ff98], a - ld a, [$ff9d] - ld [$ff97], a - ld a, [H_SAVEDNUMTOPRINT] - ld [H_NUMTOPRINT], a ; (aliases: H_MULTIPLICAND) - ld a, [$ff9b] - ld [H_DIVIDEND], a ; (aliases: H_PRODUCT, H_PASTLEADINGZEROES, H_QUOTIENT) + ld [H_PRODUCT], a ; $ff95 + jr .multiplyLoop +.done + ld a, [H_MULTIPLYBUFFER+3] + ld [H_PRODUCT+3], a + ld a, [H_MULTIPLYBUFFER+2] + ld [H_PRODUCT+2], a + ld a, [H_MULTIPLYBUFFER+1] ; $ff9c + ld [H_PRODUCT+1], a ; $ff96 + ld [H_PRODUCT], a ; $ff95 ret _Divide: ; 37da5 (d:7da5) xor a - ld [$ff9a], a - ld [$ff9b], a - ld [H_SAVEDNUMTOPRINT], a - ld [$ff9d], a - ld [$ff9e], a + ld [H_DIVIDEBUFFER], a ; ff9a + ld [H_DIVIDEBUFFER+1], a ; ff9b + ld [H_DIVIDEBUFFER+2], a ; ff9c + ld [H_DIVIDEBUFFER+3], a ; ff9d + ld [H_DIVIDEBUFFER+4], a ; ff9e ld a, $9 ld e, a .asm_37db3 - ld a, [$ff9a] + ld a, [H_DIVIDEBUFFER] ld c, a - ld a, [H_NUMTOPRINT] ; (aliases: H_MULTIPLICAND) + ld a, [H_DIVIDEND+1] ; $ff96 sub c ld d, a - ld a, [H_REMAINDER] ; (aliases: H_DIVISOR, H_MULTIPLIER, H_POWEROFTEN) + ld a, [H_DIVISOR] ; $ff99 ld c, a - ld a, [H_DIVIDEND] ; (aliases: H_PRODUCT, H_PASTLEADINGZEROES, H_QUOTIENT) + ld a, [H_DIVIDEND] ; $ff95 sbc c jr c, .asm_37dce - ld [H_DIVIDEND], a ; (aliases: H_PRODUCT, H_PASTLEADINGZEROES, H_QUOTIENT) + ld [H_DIVIDEND], a ; $ff95 ld a, d - ld [H_NUMTOPRINT], a ; (aliases: H_MULTIPLICAND) - ld a, [$ff9e] + ld [H_DIVIDEND+1], a ; $ff96 + ld a, [H_DIVIDEBUFFER+4] inc a - ld [$ff9e], a + ld [H_DIVIDEBUFFER+4], a jr .asm_37db3 .asm_37dce - ld a, b + ld a, b cp $1 - jr z, .asm_37e18 - ld a, [$ff9e] + jr z, .done + ld a, [H_DIVIDEBUFFER+4] sla a - ld [$ff9e], a - ld a, [$ff9d] + ld [H_DIVIDEBUFFER+4], a + ld a, [H_DIVIDEBUFFER+3] rl a - ld [$ff9d], a - ld a, [H_SAVEDNUMTOPRINT] + ld [H_DIVIDEBUFFER+3], a + ld a, [H_DIVIDEBUFFER+2] ; $ff9c rl a - ld [H_SAVEDNUMTOPRINT], a - ld a, [$ff9b] + ld [H_DIVIDEBUFFER+2], a ; $ff9c + ld a, [H_DIVIDEBUFFER+1] rl a - ld [$ff9b], a + ld [H_DIVIDEBUFFER+1], a dec e jr nz, .asm_37e04 ld a, $8 ld e, a - ld a, [$ff9a] - ld [H_REMAINDER], a ; (aliases: H_DIVISOR, H_MULTIPLIER, H_POWEROFTEN) + ld a, [H_DIVIDEBUFFER] + ld [H_DIVISOR], a ; $ff99 xor a - ld [$ff9a], a - ld a, [H_NUMTOPRINT] ; (aliases: H_MULTIPLICAND) - ld [H_DIVIDEND], a ; (aliases: H_PRODUCT, H_PASTLEADINGZEROES, H_QUOTIENT) - ld a, [$ff97] - ld [H_NUMTOPRINT], a ; (aliases: H_MULTIPLICAND) - ld a, [$ff98] - ld [$ff97], a + ld [H_DIVIDEBUFFER], a + ld a, [H_DIVIDEND+1] ; $ff96 + ld [H_DIVIDEND], a ; $ff95 + ld a, [H_DIVIDEND+2] + ld [H_DIVIDEND+1], a ; $ff96 + ld a, [H_DIVIDEND+3] + ld [H_DIVIDEND+2], a .asm_37e04 ld a, e cp $1 jr nz, .asm_37e0a dec b .asm_37e0a - ld a, [H_REMAINDER] ; (aliases: H_DIVISOR, H_MULTIPLIER, H_POWEROFTEN) + ld a, [H_DIVIDEND+4] ; $ff99 srl a - ld [H_REMAINDER], a ; (aliases: H_DIVISOR, H_MULTIPLIER, H_POWEROFTEN) - ld a, [$ff9a] + ld [H_REMAINDER], a ; $ff99 + ld a, [H_DIVIDEBUFFER] rr a - ld [$ff9a], a + ld [H_DIVIDEBUFFER], a jr .asm_37db3 -.asm_37e18 - ld a, [H_NUMTOPRINT] ; (aliases: H_MULTIPLICAND) - ld [H_REMAINDER], a ; (aliases: H_DIVISOR, H_MULTIPLIER, H_POWEROFTEN) - ld a, [$ff9e] - ld [$ff98], a - ld a, [$ff9d] - ld [$ff97], a - ld a, [H_SAVEDNUMTOPRINT] - ld [H_NUMTOPRINT], a ; (aliases: H_MULTIPLICAND) - ld a, [$ff9b] - ld [H_DIVIDEND], a ; (aliases: H_PRODUCT, H_PASTLEADINGZEROES, H_QUOTIENT) +.done + ld a, [H_DIVIDEND+1] ; $ff96 + ld [H_REMAINDER], a ; $ff99 + ld a, [H_DIVIDEBUFFER+4] + ld [H_QUOTIENT+3], a + ld a, [H_DIVIDEBUFFER+3] + ld [H_QUOTIENT+2], a + ld a, [H_DIVIDEBUFFER+2] ; $ff9c + ld [H_QUOTIENT+1], a ; $ff96 + ld a, [H_DIVIDEBUFFER+1] + ld [H_QUOTIENT], a ; $ff95 ret |