mirror of
https://github.com/cc65/cc65.git
synced 2024-12-27 00:29:31 +00:00
53 lines
1.1 KiB
ArmAsm
53 lines
1.1 KiB
ArmAsm
;
|
|
; Ullrich von Bassewitz, 05.08.1998
|
|
; Christian Krueger, 11-Mar-2017, ímproved 65SC02 optimization
|
|
; CC65 runtime: long sub
|
|
;
|
|
|
|
;
|
|
; EAX = TOS - EAX
|
|
;
|
|
.export tossub0ax, tossubeax
|
|
.import addysp1
|
|
.importzp sp, sreg
|
|
|
|
.macpack cpu
|
|
|
|
tossub0ax:
|
|
.if (.cpu .bitand ::CPU_ISET_65SC02)
|
|
stz sreg
|
|
stz sreg+1
|
|
.else
|
|
ldy #$00
|
|
sty sreg
|
|
sty sreg+1
|
|
.endif
|
|
|
|
tossubeax:
|
|
sec
|
|
eor #$FF
|
|
.if (.cpu .bitand ::CPU_ISET_65SC02)
|
|
adc (sp) ; 65SC02 version - saves 2 cycles
|
|
ldy #1
|
|
.else
|
|
ldy #0
|
|
adc (sp),y ; lo byte
|
|
iny
|
|
.endif
|
|
pha ; Save low byte
|
|
txa
|
|
eor #$FF
|
|
adc (sp),y ; byte 1
|
|
tax
|
|
iny
|
|
lda (sp),y
|
|
sbc sreg ; byte 2
|
|
sta sreg
|
|
iny
|
|
lda (sp),y
|
|
sbc sreg+1 ; byte 3
|
|
sta sreg+1
|
|
pla ; Restore byte 0
|
|
jmp addysp1 ; Drop TOS
|
|
|