Added mulAbyHL

FSHa.asm

@@ -12,7 +12,6 @@ Setup:
  LD HL, 0
  CALL fshvarfill
 
-
 Input:
  LD   C, $00
  CALL fshcmdfill

includes/Math.asm

@@ -28,6 +28,7 @@ cpBCDE:
   sbc hl, de
  pop hl
  ret
+
 ;; mulAbyB
 ;; Multiplys AxB
 ;; Inputs:
@@ -45,50 +46,30 @@ mulAbyBLoop:
  pop bc
  ret
 
-;; mul8By8 [Maths]
-;;  Performs an unsigned multiplication of H and E
+;; mulAbyHL
+;; Multiplys AxHL
 ;; Inputs:
-;;  H: Multiplier
-;;  E: Multiplicand
+;;  A: Multiplier
+;;  HL: Multiplicand
 ;; Outputs:
-;;  HL: Product of H and E.
-mul8By8:
+;;  HL: Product of A and HL.
+mulAbyHL:
+ push bc
  push de
-  ld l, 0
-  ld d, l
-
-  sla h
-  jr nc, $ + 3
-  ld l, e
-
-  add hl, hl
-  jr nc, $ + 3
+  ld de, 0
+  ex de, hl
+  cp 0
+  jr z, mulAbyHLEnd
+  ld b, a
+mulAbyHLLoop:
   add hl, de
-  add hl, hl
-  jr nc, $ + 3
-  add hl, de
-  add hl, hl
-  jr nc, $ + 3
-  add hl, de
-  add hl, hl
-  jr nc, $ + 3
-  add hl, de
-  add hl, hl
-  jr nc, $ + 3
-  add hl, de
-  add hl, hl
-  jr nc, $ + 3
-  add hl, de
-  add hl, hl
-  jr nc, $ + 3
-  add hl, hl
-  jr nc, $ + 3
-  add hl, de
-  add hl, de
-
+  djnz mulAbyHLLoop
+mulAbyHLEnd:
  pop de
+ pop bc
  ret
 
+
 ;; mul32By8 [Maths]
 ;;  Performs an unsigned multiplication of DEHL and A.
 ;; Outputs: