asm/runtime.scm

@@ -3,9 +3,9 @@
 ;; These need to be initialized with the runtime
 (variable scan 0)
 (variable free 0)
+(variable root 0)
 (variable old 0) 
 (variable new 0)
-(variable root 0)
 
 (push main)
 (jmp)
@@ -36,81 +36,21 @@ alloc-do-gc
 (push alloc)
 (jmp)
 
-gc-run ;; ( -- )
+gc-start ;; ( -- )
 ; Move scan & free to start of new memory
 (ref new)
 (dup)
 (set! free)
 (set! scan)
 (ref root)
-(push relocate-cons)
+(push relocate-object)
 (call)
 (push gc-loop)
 (call)
-; Flip old and new
-(ref old)
-(ref new)
-(set! old)
-(set! new)
 (return)
 
-relocate-cons ;; (o -- )
+relocate-object ;; (o -- )
-(dup)
+;; TODO
-(@)
-(push relocate-reg)
-(call)
-(push 4)
-(+)
-(@)
-(push relocate-reg)
 
-relocate-reg ;; (r -- )
-(dup)
-(push cons?)
-(call)
-(push reg-relocated)
-(if)
-(dup)
-(push eol?)
-(call)
-(not)
-(push reg-relocated)
-(if)
-(dup)
-(push broken-heart?)
-(call)
-(push copy-and-construct)
-(if)
-(dup) ;; Broken heart, copy updated address from cdr
-(push 4)
-(+)
-(@)   ;; Retrieve new address
-(dup)
-(!)   ;; Write it here
-(push reg-relocated)
-(jmp)
-copy-and-construct
-(dup) ;; Wasn't a broken heart, move car to new memory
-(@) 
-(push free)
-(!)
-(dup) ;; Push cdr to new memory
-(push 4)
-(+)
-(@)
-(push free)
-(push 4)
-(+)
-(!)
-(dup) ;; Construct the broken heart
-(push install-broken-heart)
-(call)
-(ref free) ;; Move free pointer
-(push 8)
-(+)
-(set! free)
-reg-relocated
-(drop)
-(return)
 main
 ;; TODO

reference/Makefile

@@ -1,6 +0,0 @@
-CFLAGS=-g
-
-all: gctest
-
-gctest: gc.o
-	$(CC) $(CFLAGS) -o $@ $<

reference/gc.c

@@ -1,88 +0,0 @@
-// Cheney style stop and copy garbage collector
-#include "gc.h"
-
-static cons_t *old, *new, *scanptr, *freeptr, *eom, *root;
-static cons_t *the_empty_list = NULL;
-size_t tos;
-
-void init() {
-  old = calloc(sizeof(cons_t), SIZE);
-  freeptr = old;
-  eom = old + (SIZE / 2);
-  new = eom + 1;
-  root = alloc();
-}
-
-cons_t *alloc() {
-  if (freeptr < eom) {
-    cons_t *retval = freeptr;
-    freeptr++;
-    return retval;
-  } else {
-    gc_run();
-    return alloc();
-  }
-}
-
-void gc_run() {
-  freeptr = new;
-  scanptr = new;
-  // Relocate root
-  relocate(root);
-  // Enter the main GC loop
-  gc_loop();
-  // Flip old and new;
-  cons_t *temp = old;
-  old = new;
-  new = temp;
-}
-
-void gc_loop() {
-  while (scanptr < freeptr) {
-    relocate(scanptr);
-    scanptr++;
-  }
-}
-
-void move(box_t box) {
-  if (box.type == CONS && box.cons != the_empty_list) {
-    if (box.cons->car.type == BROKEN_HEART) {
-      box.cons = box.cons->cdr.cons;
-    } else {
-      memcpy(freeptr, box.cons, sizeof(cons_t));
-      box.cons->car.type = BROKEN_HEART;
-      box.cons->cdr.cons = freeptr;
-      freeptr++;
-    }
-  }
-}
-
-void relocate(cons_t* cons) {
-  move(cons->car);
-  move(cons->cdr);
-}
-
-int main() {
-  init();
-  // Simulate running linear fibonnaci
-  root->car.type = INTEGER;
-  root->car.integer = 1;
-  root->cdr.type = CONS;
-  root->cdr.cons = alloc();
-  root->cdr.cons->car.type = INTEGER;
-  root->cdr.cons->car.integer = 0;
-  root->cdr.cons->cdr.type = CONS;
-  root->cdr.cons->cdr.cons = the_empty_list;
-  for (size_t i = 0; i < 29; i++) {
-    cons_t *cons = alloc();
-    cons->car.type = INTEGER;
-    cons->car.integer = root->car.integer + root->cdr.cons->car.integer;
-    
-    cons->cdr.type = CONS;
-    cons->cdr.cons = root;
-    root->cdr.cons = the_empty_list;
-    root = cons;
-  };
-  printf("%d\n", root->car.integer); // 832040, and we've definitely run gc a few times
-}
-

reference/gc.h

@@ -1,28 +0,0 @@
-#include <stdint.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-
-#define SIZE 8
-#define BROKEN_HEART 1
-#define CONS 2
-#define INTEGER 3
-
-typedef struct box_t {
-  char type;
-  union {
-    int integer;
-    struct cons_t* cons;
-  };
-} box_t;
-
-typedef struct cons_t {
-  box_t car;
-  box_t cdr;
-} cons_t;
-
-void init();
-cons_t *alloc();
-void gc_run();
-void gc_loop();
-void relocate(cons_t*);