57 lines
661 B
ArmAsm
57 lines
661 B
ArmAsm
.define Sri4, Sru4
|
|
.sect .text
|
|
.sect .rom
|
|
.sect .data
|
|
.sect .bss
|
|
.sect .text
|
|
|
|
! The subroutine Sri4 shifts a signed fourbyte integer to the
|
|
! right n times
|
|
! N is in register X.
|
|
! The subroutine Sru4 shifts an unsigned fourbyte integer to the
|
|
! right n times.
|
|
|
|
Sru4:
|
|
txa
|
|
tay
|
|
bne 1f
|
|
rts
|
|
1: jsr Pop
|
|
stx ARTH
|
|
sta ARTH+1
|
|
jsr Pop
|
|
stx ARTH+2
|
|
jmp 2f
|
|
Sri4:
|
|
txa
|
|
tay
|
|
bne 1f
|
|
rts
|
|
1: jsr Pop
|
|
stx ARTH
|
|
sta ARTH+1
|
|
jsr Pop
|
|
stx ARTH+2
|
|
tax
|
|
bmi 1f
|
|
2: lsr a
|
|
ror ARTH+2
|
|
ror ARTH+1
|
|
ror ARTH
|
|
dey
|
|
bne 2b
|
|
beq 4f
|
|
1: sec
|
|
ror a
|
|
ror ARTH+2
|
|
ror ARTH+1
|
|
ror ARTH
|
|
3: dey
|
|
bne 1b
|
|
4: ldx ARTH+2
|
|
jsr Push
|
|
lda ARTH+1
|
|
ldx ARTH
|
|
jmp Push
|
|
|
|
|