factor/vm/dispatch.cpp

212 lines
4.8 KiB
C++
Executable File

#include "master.hpp"
namespace factor
{
cell megamorphic_cache_hits;
cell megamorphic_cache_misses;
static cell search_lookup_alist(cell table, cell klass)
{
array *pairs = untag<array>(table);
fixnum index = array_capacity(pairs) - 1;
while(index >= 0)
{
array *pair = untag<array>(array_nth(pairs,index));
if(array_nth(pair,0) == klass)
return array_nth(pair,1);
else
index--;
}
return F;
}
static cell search_lookup_hash(cell table, cell klass, cell hashcode)
{
array *buckets = untag<array>(table);
cell bucket = array_nth(buckets,hashcode & (array_capacity(buckets) - 1));
if(tagged<object>(bucket).type_p(WORD_TYPE) || bucket == F)
return bucket;
else
return search_lookup_alist(bucket,klass);
}
static cell nth_superclass(tuple_layout *layout, fixnum echelon)
{
cell *ptr = (cell *)(layout + 1);
return ptr[echelon * 2];
}
static cell nth_hashcode(tuple_layout *layout, fixnum echelon)
{
cell *ptr = (cell *)(layout + 1);
return ptr[echelon * 2 + 1];
}
static cell lookup_tuple_method(cell obj, cell methods)
{
tuple_layout *layout = untag<tuple_layout>(untag<tuple>(obj)->layout);
array *echelons = untag<array>(methods);
fixnum echelon = untag_fixnum(layout->echelon);
fixnum max_echelon = array_capacity(echelons) - 1;
if(echelon > max_echelon) echelon = max_echelon;
while(echelon >= 0)
{
cell echelon_methods = array_nth(echelons,echelon);
if(tagged<object>(echelon_methods).type_p(WORD_TYPE))
return echelon_methods;
else if(echelon_methods != F)
{
cell klass = nth_superclass(layout,echelon);
cell hashcode = untag_fixnum(nth_hashcode(layout,echelon));
cell result = search_lookup_hash(echelon_methods,klass,hashcode);
if(result != F)
return result;
}
echelon--;
}
critical_error("Cannot find tuple method",methods);
return F;
}
static cell lookup_hi_tag_method(cell obj, cell methods)
{
array *hi_tag_methods = untag<array>(methods);
cell tag = untag<object>(obj)->h.hi_tag() - HEADER_TYPE;
#ifdef FACTOR_DEBUG
assert(tag < TYPE_COUNT - HEADER_TYPE);
#endif
return array_nth(hi_tag_methods,tag);
}
static cell lookup_hairy_method(cell obj, cell methods)
{
cell method = array_nth(untag<array>(methods),TAG(obj));
if(tagged<object>(method).type_p(WORD_TYPE))
return method;
else
{
switch(TAG(obj))
{
case TUPLE_TYPE:
return lookup_tuple_method(obj,method);
break;
case OBJECT_TYPE:
return lookup_hi_tag_method(obj,method);
break;
default:
critical_error("Bad methods array",methods);
return 0;
}
}
}
cell lookup_method(cell obj, cell methods)
{
cell tag = TAG(obj);
if(tag == TUPLE_TYPE || tag == OBJECT_TYPE)
return lookup_hairy_method(obj,methods);
else
return array_nth(untag<array>(methods),TAG(obj));
}
PRIMITIVE(lookup_method)
{
cell methods = dpop();
cell obj = dpop();
dpush(lookup_method(obj,methods));
}
cell object_class(cell obj)
{
switch(TAG(obj))
{
case TUPLE_TYPE:
return untag<tuple>(obj)->layout;
case OBJECT_TYPE:
return untag<object>(obj)->h.value;
default:
return tag_fixnum(TAG(obj));
}
}
static cell method_cache_hashcode(cell klass, array *array)
{
cell capacity = (array_capacity(array) >> 1) - 1;
return ((klass >> TAG_BITS) & capacity) << 1;
}
static void update_method_cache(cell cache, cell klass, cell method)
{
array *cache_elements = untag<array>(cache);
cell hashcode = method_cache_hashcode(klass,cache_elements);
set_array_nth(cache_elements,hashcode,klass);
set_array_nth(cache_elements,hashcode + 1,method);
}
PRIMITIVE(mega_cache_miss)
{
megamorphic_cache_misses++;
cell cache = dpop();
fixnum index = untag_fixnum(dpop());
cell methods = dpop();
cell object = ((cell *)ds)[-index];
cell klass = object_class(object);
cell method = lookup_method(object,methods);
update_method_cache(cache,klass,method);
dpush(method);
}
PRIMITIVE(reset_dispatch_stats)
{
megamorphic_cache_hits = megamorphic_cache_misses = 0;
}
PRIMITIVE(dispatch_stats)
{
growable_array stats;
stats.add(allot_cell(megamorphic_cache_hits));
stats.add(allot_cell(megamorphic_cache_misses));
stats.trim();
dpush(stats.elements.value());
}
void quotation_jit::emit_mega_cache_lookup(cell methods_, fixnum index, cell cache_)
{
gc_root<array> methods(methods_);
gc_root<array> cache(cache_);
/* Generate machine code to determine the object's class. */
emit_class_lookup(index,PIC_HI_TAG_TUPLE);
/* Do a cache lookup. */
emit_with(userenv[MEGA_LOOKUP],cache.value());
/* If we end up here, the cache missed. */
emit(userenv[JIT_PROLOG]);
/* Push index, method table and cache on the stack. */
push(methods.value());
push(tag_fixnum(index));
push(cache.value());
word_call(userenv[MEGA_MISS_WORD]);
/* Now the new method has been stored into the cache, and its on
the stack. */
emit(userenv[JIT_EPILOG]);
emit(userenv[JIT_EXECUTE_JUMP]);
}
}