diff options
Diffstat (limited to 'heap.s')
| -rw-r--r-- | heap.s | 55 |
1 files changed, 55 insertions, 0 deletions
@@ -0,0 +1,55 @@ +; copy s-exp into big (permanent) heap +; R0 = arg1 +; big heap at 11000 +; touches R0, R1, R2 +copy: +005400 032710 BIT #1, (R0) ; test if cons or atom +005402 000001 +005404 001016 BNE is_atom ; branch if atom +; otherwise it's cons: +005406 011046 MOV @R0, -(SP) ; save car to stack +005410 016000 MOV 2(R0), R0 ; arg1 <- cdr +005412 000002 +005414 004737 JSR PC, @copy ; result <- copy(cdr) +005416 005400 +005420 010001 MOV R0, R1 ; arg2 <- result +005422 012600 MOV (SP)+, R0 ; arg1 <- car from stack +005424 010146 MOV R1, -(SP) ; save arg2 +005426 004737 JSR PC, @copy ; arg1 <- copy(car) +005430 005400 +005432 012601 MOV (SP)+, R1 ; restore arg2 +005434 004737 JSR PC, @big_cons ; allocate cons cell +005436 005600 +005440 000207 RTS PC +is_atom: +005442 013702 MOV @#11000, R2 ; get free pointer +005444 011000 +005446 010246 MOV R2, -(SP) ; save new atom start address +005450 010201 MOV R2, R1 +005452 062701 ADD #3, R1 +005454 000003 +005456 010122 MOV R1, (R2)+ ; allocate atom tag and increment free pointer +005460 011000 MOV @R0, R0 +005462 005300 DEC R0 ; get string address +005464 112022 MOVB (R0)+, (R2)+ ; copy one byte +005466 001376 BNE -4 ; if not null continue copying chars +005470 005202 INC R2 ; align free pointer +005472 042702 BIC #1, R2 +005574 000001 +005576 010237 MOV R2, @#11000 ; store new free pointer +005500 011000 +005502 012600 MOV (SP)+, R0 ; result <- address of new atom +005504 000207 RTS PC + +big_cons: +005600 013702 MOV @#11000, R2 ; get free pointer +005602 011000 +005604 010012 MOV R0, @R2 ; move arg1 to car of new cons cell +005606 010162 MOV R1, 2(R2) ; move arg2 to cdr of new cons cell +005610 000002 +005612 010200 MOV R2, R0 ; result <- new cons cell +005614 062702 ADD 4, R2 ; advance free pointer +005616 000004 +005620 010237 MOV R2, @#11000 ; store new free pointer +005622 011000 +005624 000207 RTS PC |