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invalid_msg:
.asciz "Invalid instruction at %X\n"
.global m68k_invalid
m68k_invalid:
lea invalid_msg(%rip), %rdi
mov %ecx, %esi
xor %rax, %rax
call printf
mov $1, %rdi
call exit
.global bcd_add
bcd_add:
xchg %rax, %rdi
mov %cl, %ch
mov %al, %ah
and $0xF, %ch
and $0xF, %ah
and $0xF0, %cl
and $0xF0, %al
add %ah, %ch
cmp $10, %ch
jb no_adjust
add $6, %ch
no_adjust:
add %ch, %al
add %al, %cl
mov $0, %ch
jc def_adjust
cmp $0xA0, %cl
jb no_adjust_h
def_adjust:
add $0x60, %cl
mov $1, %ch
no_adjust_h:
mov %rdi, %rax
ret
.global bcd_sub
bcd_sub:
xchg %rax, %rdi
mov %cl, %ch
mov %al, %ah
and $0xF, %ch
and $0xF, %ah
and $0xF0, %cl
and $0xF0, %al
sub %ah, %ch
cmp $10, %ch
jb no_adjusts
sub $6, %ch
no_adjusts:
add %ch, %cl
sub %al, %cl
mov $0, %ch
jc def_adjusts
cmp $0xA0, %cl
jb no_adjust_hs
def_adjusts:
sub $0x60, %cl
mov $1, %ch
no_adjust_hs:
mov %rdi, %rax
ret
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