shithub: pokecrystal

Info  •  Files  •  Log  •  Branches

hMultiplicand is four bytes internally, but the high byte is always 0 since allowing four-byte multiplicands could overflow hProduct.

--- a/engine/math/math.asm

+++ b/engine/math/math.asm

@@ -4,7 +4,7 @@

 	ld b, a

 	xor a

-	ldh [hProduct], a

+	ldh [hMultiplicand - 1], a

 	ldh [hMathBuffer + 1], a

 	ldh [hMathBuffer + 2], a

 	ldh [hMathBuffer + 3], a

@@ -36,7 +36,7 @@

 	ldh a, [hMathBuffer + 1]

 	ld c, a

-	ldh a, [hProduct]

+	ldh a, [hMultiplicand - 1]

 	adc c

 	ldh [hMathBuffer + 1], a

@@ -58,9 +58,9 @@

 	rla

 	ldh [hMultiplicand + 0], a

-	ldh a, [hProduct]

+	ldh a, [hMultiplicand - 1]

 	rla

-	ldh [hProduct], a

+	ldh [hMultiplicand - 1], a

 	jr .loop