def invert():
label("forth.core.INVERT")
adda(-add_cost_of_next(cost_of_invert) / 2) # 1
ld(data_stack_page, Y)
ld([data_stack_pointer], X)
ld([Y, X])
xora(0xFF) # 5
st([Y, Xpp])
ld([Y, X])
xora(0xFF)
st([Y, X]) # 9
NEXT(cost_of_invert)
def increment():
"Add one to the top of the stack (n -- n)"
label("forth.core.1+")
adda(-add_cost_of_next(cost_of_increment) / 2) # 1
ld(data_stack_page, Y)
ld([data_stack_pointer], X)
ld([Y, X])
adda(1) # 5
bne(lo(".done")) # 6
st([Y, Xpp]) # 7
ld([Y, X]) # 8
adda(1)
st([Y, X])
NEXT(cost_of_increment__two_words_written)
label(".done")
NEXT(cost_of_increment__one_word_written)
def emit_entry_page(vticks, vreturn):
"""Emit the data for NEXT and some other core routines
The first page does not have the 'restart-or-quit' trampoline at 0x00
So we can't put any Forth word in here.
"""
while pc() & 255 < 255:
nop()
assert _next.INTERPRETER_ENTER_PAGE == pc() >> 8
label("FORTH_ENTER")
C("You are now entering... Forth")
adda(_next.INBOUND_TICK_CORRECTION)
# --- Page boundary ---
align(0x100, 0x100)
st([vticks])
_next.next1(vticks)
_next.next1_reenter(vticks)
_next.next2(vticks)
_next.exit(vticks, vreturn)
_docol_exit.do_docol_rom()
_docol_exit.do_docol_ram()
def do_restore_mode():
label("forth.DO-RESTORE-MODE")
adda(-add_cost_of_reenter(cost_of_do_restore_mode) / 2)
ld(return_stack_page, Y)
ld([return_stack_pointer], X)
ld([return_stack_pointer])
adda(1)
st([return_stack_pointer])
ld([Y, X])
st([mode])
ld(0, Y)
ld(W, X)
st(lo("forth.core.EXIT"), [Y, Xpp])
st(hi("forth.core.EXIT"), [Y, Xpp]) # 12
REENTER(cost_of_do_restore_mode)
