factor/vm/stack.c

342 lines
6.8 KiB
C

#include "factor.h"
void reset_datastack(void)
{
ds = ds_bot - CELLS;
}
void reset_retainstack(void)
{
rs = rs_bot - CELLS;
}
void reset_callstack(void)
{
cs = cs_bot - CELLS;
}
void fix_stacks(void)
{
if(STACK_UNDERFLOW(ds,stack_chain->data_region))
reset_datastack();
if(STACK_OVERFLOW(ds,stack_chain->data_region))
reset_datastack();
if(STACK_UNDERFLOW(rs,stack_chain->retain_region))
reset_retainstack();
if(STACK_OVERFLOW(rs,stack_chain->retain_region))
reset_retainstack();
if(STACK_UNDERFLOW(cs,stack_chain->call_region))
reset_callstack();
if(STACK_OVERFLOW(cs,stack_chain->call_region))
reset_callstack();
}
/* called before entry into foreign C code. Note that ds, rs and cs might
be stored in registers, so callbacks must save and restore the correct values */
void save_stacks(void)
{
stack_chain->data = ds;
stack_chain->retain = rs;
stack_chain->call = cs;
}
/* called on entry into a compiled callback */
void nest_stacks(void)
{
STACKS *new_stacks = safe_malloc(sizeof(STACKS));
/* note that these register values are not necessarily valid stack
pointers. they are merely saved non-volatile registers, and are
restored in unnest_stacks(). consider this scenario:
- factor code calls C function
- C function saves ds/cs registers (since they're non-volatile)
- C function clobbers them
- C function calls Factor callback
- Factor callback returns
- C function restores registers
- C function returns to Factor code */
new_stacks->data_save = ds;
new_stacks->retain_save = rs;
new_stacks->call_save = cs;
new_stacks->cards_offset = cards_offset;
new_stacks->callframe = callframe;
new_stacks->callframe_scan = callframe_scan;
new_stacks->callframe_end = callframe_end;
new_stacks->catch_save = userenv[CATCHSTACK_ENV];
new_stacks->data_region = alloc_bounded_block(ds_size);
new_stacks->retain_region = alloc_bounded_block(rs_size);
new_stacks->call_region = alloc_bounded_block(cs_size);
new_stacks->next = stack_chain;
stack_chain = new_stacks;
callframe = F;
callframe_scan = callframe_end = 0;
reset_datastack();
reset_retainstack();
reset_callstack();
update_cards_offset();
}
/* called when leaving a compiled callback */
void unnest_stacks(void)
{
STACKS *old_stacks = stack_chain;
dealloc_bounded_block(stack_chain->data_region);
dealloc_bounded_block(stack_chain->retain_region);
dealloc_bounded_block(stack_chain->call_region);
ds = old_stacks->data_save;
rs = old_stacks->retain_save;
cs = old_stacks->call_save;
cards_offset = old_stacks->cards_offset;
callframe = old_stacks->callframe;
callframe_scan = old_stacks->callframe_scan;
callframe_end = old_stacks->callframe_end;
userenv[CATCHSTACK_ENV] = old_stacks->catch_save;
stack_chain = old_stacks->next;
free(old_stacks);
}
/* called on startup */
void init_stacks(CELL ds_size_, CELL rs_size_, CELL cs_size_)
{
ds_size = ds_size_;
rs_size = rs_size_;
cs_size = cs_size_;
stack_chain = NULL;
nest_stacks();
}
void primitive_drop(void)
{
dpop();
}
void primitive_2drop(void)
{
ds -= 2 * CELLS;
}
void primitive_3drop(void)
{
ds -= 3 * CELLS;
}
void primitive_dup(void)
{
dpush(dpeek());
}
void primitive_2dup(void)
{
CELL top = dpeek();
CELL next = get(ds - CELLS);
ds += CELLS * 2;
put(ds - CELLS,next);
put(ds,top);
}
void primitive_3dup(void)
{
CELL c1 = dpeek();
CELL c2 = get(ds - CELLS);
CELL c3 = get(ds - CELLS * 2);
ds += CELLS * 3;
put (ds,c1);
put (ds - CELLS,c2);
put (ds - CELLS * 2,c3);
}
void primitive_rot(void)
{
CELL c1 = dpeek();
CELL c2 = get(ds - CELLS);
CELL c3 = get(ds - CELLS * 2);
put(ds,c3);
put(ds - CELLS,c1);
put(ds - CELLS * 2,c2);
}
void primitive__rot(void)
{
CELL c1 = dpeek();
CELL c2 = get(ds - CELLS);
CELL c3 = get(ds - CELLS * 2);
put(ds,c2);
put(ds - CELLS,c3);
put(ds - CELLS * 2,c1);
}
void primitive_dupd(void)
{
CELL top = dpeek();
CELL next = get(ds - CELLS);
put(ds,next);
put(ds - CELLS,next);
dpush(top);
}
void primitive_swapd(void)
{
CELL top = get(ds - CELLS);
CELL next = get(ds - CELLS * 2);
put(ds - CELLS,next);
put(ds - CELLS * 2,top);
}
void primitive_nip(void)
{
CELL top = dpop();
drepl(top);
}
void primitive_2nip(void)
{
CELL top = dpeek();
ds -= CELLS * 2;
drepl(top);
}
void primitive_tuck(void)
{
CELL top = dpeek();
CELL next = get(ds - CELLS);
put(ds,next);
put(ds - CELLS,top);
dpush(top);
}
void primitive_over(void)
{
dpush(get(ds - CELLS));
}
void primitive_pick(void)
{
dpush(get(ds - CELLS * 2));
}
void primitive_swap(void)
{
CELL top = dpeek();
CELL next = get(ds - CELLS);
put(ds,next);
put(ds - CELLS,top);
}
void primitive_to_r(void)
{
rpush(dpop());
}
void primitive_from_r(void)
{
dpush(rpop());
}
F_VECTOR* stack_to_vector(CELL bottom, CELL top)
{
CELL depth = (top - bottom + CELLS) / CELLS;
F_VECTOR *v = vector(depth);
F_ARRAY *a = untag_array_fast(v->array);
memcpy(a + 1,(void*)bottom,depth * CELLS);
v->top = tag_fixnum(depth);
return v;
}
void primitive_datastack(void)
{
maybe_gc(0);
dpush(tag_object(stack_to_vector(ds_bot,ds)));
}
void primitive_retainstack(void)
{
maybe_gc(0);
dpush(tag_object(stack_to_vector(rs_bot,rs)));
}
void primitive_callstack(void)
{
maybe_gc(0);
CELL depth = (cs - cs_bot + CELLS) / CELLS - 3;
F_VECTOR *v = vector(depth);
F_ARRAY *a = untag_array_fast(v->array);
CELL i;
CELL ptr = cs_bot;
for(i = 0; i < depth; i += 3, ptr += 3 * CELLS)
{
CELL quot = get(ptr);
CELL untagged = UNTAG(quot);
CELL position = UNAREF(untagged,get(ptr + CELLS));
CELL end = UNAREF(untagged,get(ptr + CELLS * 2));
put(AREF(a,i),quot);
put(AREF(a,i + 1),tag_fixnum(position));
put(AREF(a,i + 2),tag_fixnum(end));
}
v->top = tag_fixnum(depth);
dpush(tag_object(v));
}
/* returns pointer to top of stack */
CELL vector_to_stack(F_VECTOR* vector, CELL bottom)
{
CELL start = bottom;
CELL len = untag_fixnum_fast(vector->top) * CELLS;
memcpy((void*)start,untag_array_fast(vector->array) + 1,len);
return start + len - CELLS;
}
void primitive_set_datastack(void)
{
ds = vector_to_stack(untag_vector(dpop()),ds_bot);
}
void primitive_set_retainstack(void)
{
rs = vector_to_stack(untag_vector(dpop()),rs_bot);
}
void primitive_set_callstack(void)
{
F_VECTOR *v = untag_vector(dpop());
F_ARRAY *a = untag_array_fast(v->array);
CELL depth = untag_fixnum_fast(v->top);
depth -= (depth % 3);
CELL i, ptr;
for(i = 0, ptr = cs_bot; i < depth; i += 3, ptr += 3 * CELLS)
{
CELL quot = get(AREF(a,i));
type_check(QUOTATION_TYPE,quot);
F_ARRAY *untagged = (F_ARRAY*)UNTAG(quot);
CELL length = array_capacity(untagged);
F_FIXNUM position = to_fixnum(get(AREF(a,i + 1)));
F_FIXNUM end = to_fixnum(get(AREF(a,i + 2)));
if(end < 0) end = 0;
if(end > length) end = length;
if(position < 0) position = 0;
if(position > end) position = end;
put(ptr,quot);
put(ptr + CELLS,AREF(untagged,position));
put(ptr + CELLS * 2,AREF(untagged,end));
}
cs = cs_bot + depth * CELLS - CELLS;
}