mirror of
https://github.com/cc65/cc65.git
synced 2024-11-18 15:05:14 +00:00
53dd513176
which included commits to RCS files with non-trunk default branches. git-svn-id: svn://svn.cc65.org/cc65/trunk@3 b7a2c559-68d2-44c3-8de9-860c34a00d81
49 lines
984 B
ArmAsm
49 lines
984 B
ArmAsm
;
|
|
; Ullrich von Bassewitz, 07.08.1998
|
|
;
|
|
; CC65 runtime: helper stuff for mod/div/mul with signed ints
|
|
;
|
|
|
|
; When negating values, we will ignore the possibility here, that one of the
|
|
; values if $8000, in which case the negate will fail.
|
|
|
|
.export popsargs, adjsres
|
|
.import negax, popax
|
|
.importzp sreg, tmp1, tmp2, ptr4
|
|
|
|
popsargs:
|
|
stx tmp1 ; Remember sign
|
|
cpx #0
|
|
bpl L1
|
|
jsr negax ; Negate accumulator
|
|
L1: sta ptr4
|
|
stx ptr4+1 ; Save right operand
|
|
|
|
jsr popax
|
|
stx tmp2 ; Remember sign
|
|
cpx #0
|
|
bpl L2
|
|
jsr negax
|
|
L2: sta sreg
|
|
stx sreg+1
|
|
|
|
; Calculate the sign of the result, that is sign(op1) * sign(op2)
|
|
|
|
lda tmp1
|
|
eor tmp2
|
|
sta tmp2 ; Save it across call
|
|
L3: rts
|
|
|
|
; Adjust the result of a mod/div/mul operation
|
|
|
|
adjsres:
|
|
|
|
; Check if we must adjust the sign
|
|
|
|
ldy tmp2
|
|
bpl L3
|
|
jmp negax ; Adjust sign
|
|
|
|
|
|
|