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if_literal and lookup

This commit is contained in:
Simon Forman 2019-11-09 18:39:39 -08:00
parent 7a821a4eaf
commit 8405d3f863
1 changed files with 23 additions and 18 deletions
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41
thun/compiler.markII.pl
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@ -54,29 +54,21 @@ Mark II
]),[
% TermAddr has the address of the term record.
% Now TERM has the term's record data and TermAddr has the address of the term.
mov(EXPR_addr, TEMP0),
mov(EXPR_addr, TEMP0)
% EXPR_addr now holds the address of the next cell of the expression list.
% if_literal(TERM, PUSH),
asr_imm(TEMP0, TERM, 30), % get just the two tag bits.
and_imm(TEMP0, TEMP0, 2), % mask the two tag bits.
sub_imm(TEMP0, TEMP0, 2), % if this is a symbol result is zero.
ne_offset(PUSH),
],⟐([
if_literal(TERM, PUSH, TEMP0),
% if it is a symbol the rest of it is the pointer to the machine code.
% lookup(TERM), % Jump to command.
mov_imm_with_shift(TEMP0, 0x3fff), % TEMP0 = 0x3fffffff
ior_imm(TEMP0, TEMP0, 0xffff),
and(TEMP0, TEMP0, TERM),
do(TEMP0),
lookup(TERM, TEMP0) % Jump to command.
]),[
% going into push we have the term
label(PUSH)],
label(PUSH)
% push2(TOS, TEMP1, SP), % stack = TERM, stack
⟐(incr(SP)),
],⟐(
incr(SP)
),[
% SP points to the future home of the new stack cell.
[sub(TOS, TermAddr, SP), % TOS := &temp - sp
sub(TOS, TermAddr, SP), % TOS := &temp - sp
% Er, what if it's negative?
hi_offset(Bar0),
and_imm(TOS, TOS, 0x7fff), % Mask off high bits so
@ -162,6 +154,19 @@ language.
⟐(incr(SP)) --> [sub_imm(SP, SP, 4)]. % SP -= 1 (word, not byte).
⟐(if_literal(TERM, Push, TEMP)) -->
[asr_imm(TEMP, TERM, 30), % get just the two tag bits.
and_imm(TEMP, TEMP, 2), % mask the two tag bits.
sub_imm(TEMP, TEMP, 2), % if this is a symbol result is zero.
ne_offset(Push)].
⟐(lookup(TERM, TEMP)) -->
% if it is a symbol the rest of it is the pointer to the machine code.
[mov_imm_with_shift(TEMP, 0x3fff), % TEMP = 0x3fffffff
ior_imm(TEMP, TEMP, 0xffff),
and(TEMP, TEMP, TERM),
do(TEMP)]. % Jump to command.
do :-
compile_program(Binary),