mirror of
https://github.com/bobbimanners/emailler.git
synced 2024-11-14 11:05:14 +00:00
171 lines
2.8 KiB
ArmAsm
171 lines
2.8 KiB
ArmAsm
.include "../inc/common.i"
|
|
|
|
;helper routines for arithmetic on 32 bit numbers
|
|
|
|
;reuse the copy_* zero page locations as pointers for 32bit addition
|
|
.importzp copy_src
|
|
.importzp copy_dest
|
|
|
|
acc32 =copy_src ;32bit accumulater (pointer)
|
|
op32 =copy_dest ;32 bit operand (pointer)
|
|
|
|
acc16 =acc32 ;16bit accumulater (value, NOT pointer)
|
|
|
|
.bss
|
|
temp_ax: .res 2
|
|
.code
|
|
;no 16bit operand as can just use AX
|
|
.exportzp acc32
|
|
.exportzp op32
|
|
.exportzp acc16
|
|
|
|
.export add_32_32
|
|
.export add_16_32
|
|
|
|
.export sub_16_16
|
|
|
|
.export cmp_32_32
|
|
.export cmp_16_16
|
|
|
|
.export mul_8_16
|
|
|
|
;compare 2 32bit numbers
|
|
;on exit, zero flag clear iff acc32==op32
|
|
cmp_32_32:
|
|
ldy #0
|
|
lda (op32),y
|
|
cmp (acc32),y
|
|
bne @exit
|
|
iny
|
|
lda (op32),y
|
|
cmp (acc32),y
|
|
bne @exit
|
|
iny
|
|
lda (op32),y
|
|
cmp (acc32),y
|
|
bne @exit
|
|
iny
|
|
lda (op32),y
|
|
cmp (acc32),y
|
|
@exit:
|
|
rts
|
|
|
|
;compare 2 16bit numbers
|
|
;on exit, zero flag clear iff acc16==AX
|
|
cmp_16_16:
|
|
cmp acc16
|
|
bne @exit
|
|
txa
|
|
cmp acc16+1
|
|
@exit:
|
|
rts
|
|
|
|
;subtract 2 16 bit numbers
|
|
;acc16=acc16-AX
|
|
sub_16_16:
|
|
stax temp_ax
|
|
sec
|
|
lda acc16
|
|
sbc temp_ax
|
|
sta acc16
|
|
lda acc16+1
|
|
sbc temp_ax+1
|
|
sta acc16+1
|
|
rts
|
|
|
|
;add a 32bit operand to the 32 bit accumulater
|
|
;acc32=acc32+op32
|
|
add_32_32:
|
|
clc
|
|
ldy #0
|
|
lda (op32),y
|
|
adc (acc32),y
|
|
sta (acc32),y
|
|
iny
|
|
lda (op32),y
|
|
adc (acc32),y
|
|
sta (acc32),y
|
|
iny
|
|
lda (op32),y
|
|
adc (acc32),y
|
|
sta (acc32),y
|
|
iny
|
|
lda (op32),y
|
|
adc (acc32),y
|
|
sta (acc32),y
|
|
|
|
rts
|
|
|
|
|
|
;add a 16bit operand to the 32 bit accumulater
|
|
;acc32=acc32+AX
|
|
add_16_32:
|
|
clc
|
|
ldy #0
|
|
adc (acc32),y
|
|
sta (acc32),y
|
|
iny
|
|
txa
|
|
adc (acc32),y
|
|
sta (acc32),y
|
|
iny
|
|
lda #0
|
|
adc (acc32),y
|
|
sta (acc32),y
|
|
iny
|
|
lda #0
|
|
adc (acc32),y
|
|
sta (acc32),y
|
|
rts
|
|
|
|
;multiply a 16 bit number by an 8 bit number
|
|
;acc16=acc16*a
|
|
mul_8_16:
|
|
tax
|
|
beq @operand_is_zero
|
|
lda acc16
|
|
sta temp_ax
|
|
lda acc16+1
|
|
sta temp_ax+1
|
|
|
|
@addition_loop:
|
|
dex
|
|
beq @done
|
|
clc
|
|
lda acc16
|
|
adc temp_ax
|
|
sta acc16
|
|
lda acc16+1
|
|
adc temp_ax+1
|
|
sta acc16+1
|
|
jmp @addition_loop
|
|
|
|
@done:
|
|
|
|
rts
|
|
@operand_is_zero:
|
|
sta acc16
|
|
sta acc16+1
|
|
rts
|
|
|
|
|
|
|
|
;-- LICENSE FOR arithmetic.s --
|
|
; The contents of this file are subject to the Mozilla Public License
|
|
; Version 1.1 (the "License"); you may not use this file except in
|
|
; compliance with the License. You may obtain a copy of the License at
|
|
; http://www.mozilla.org/MPL/
|
|
;
|
|
; Software distributed under the License is distributed on an "AS IS"
|
|
; basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
|
|
; License for the specific language governing rights and limitations
|
|
; under the License.
|
|
;
|
|
; The Original Code is ip65.
|
|
;
|
|
; The Initial Developer of the Original Code is Jonno Downes,
|
|
; jonno@jamtronix.com.
|
|
; Portions created by the Initial Developer are Copyright (C) 2009
|
|
; Jonno Downes. All Rights Reserved.
|
|
; -- LICENSE END --
|