mirror of
https://github.com/cc65/cc65.git
synced 2024-07-06 13:29:01 +00:00
c200e0ec94
they're now in common. git-svn-id: svn://svn.cc65.org/cc65/trunk@4441 b7a2c559-68d2-44c3-8de9-860c34a00d81
45 lines
1002 B
ArmAsm
45 lines
1002 B
ArmAsm
;
|
|
; Ullrich von Bassewitz, 2010-11-03
|
|
;
|
|
; CC65 runtime: 16x16 => 32 signed multiplication
|
|
;
|
|
|
|
.export imul16x16r32
|
|
.import negax, umul16x16r32m, negeax
|
|
.importzp ptr1, ptr3, tmp1
|
|
|
|
|
|
;---------------------------------------------------------------------------
|
|
; 16x16 => 32 signed multiplication routine.
|
|
;
|
|
; lhs rhs result result also in
|
|
; -------------------------------------------------------------
|
|
; ptr1 ax ax:sreg
|
|
;
|
|
; There is probably a faster way to do this.
|
|
;
|
|
|
|
imul16x16r32:
|
|
stx tmp1
|
|
cpx #0
|
|
bpl @L1
|
|
jsr negax
|
|
@L1: sta ptr3
|
|
stx ptr3+1
|
|
|
|
lda ptr1+1
|
|
eor tmp1
|
|
sta tmp1
|
|
lda ptr1
|
|
ldx ptr1+1
|
|
bpl @L2
|
|
jsr negax
|
|
sta ptr1
|
|
stx ptr1+1
|
|
@L2: jsr umul16x16r32m
|
|
ldy tmp1
|
|
bpl @L3
|
|
jmp negeax
|
|
@L3: rts
|
|
|