Revision: 7058
Author: [email protected]
Date: Fri Mar 4 02:07:43 2011
Log: Change the translation of polymorphic stores.
They do not use subgraphs or subgraph scopes. Instead of computing a list
of single-block subgraphs and then adding all the edges afterward, build
both the blocks and edges directly.
Review URL: http://codereview.chromium.org/6615014
http://code.google.com/p/v8/source/detail?r=7058
Modified:
/branches/bleeding_edge/src/hydrogen.cc
=======================================
--- /branches/bleeding_edge/src/hydrogen.cc Thu Mar 3 05:50:16 2011
+++ /branches/bleeding_edge/src/hydrogen.cc Fri Mar 4 02:07:43 2011
@@ -3147,65 +3147,70 @@
HValue* value,
ZoneMapList* types,
Handle<String> name) {
- int number_of_types = Min(types->length(), kMaxStorePolymorphism);
- ZoneMapList maps(number_of_types);
- ZoneList<HSubgraph*> subgraphs(number_of_types);
- bool needs_generic = (types->length() > kMaxStorePolymorphism);
-
- // Build subgraphs for each of the specific maps.
- //
- // TODO(ager): We should recognize when the prototype chains for
- // different maps are identical. In that case we can avoid
- // repeatedly generating the same prototype map checks.
- for (int i = 0; i < number_of_types; ++i) {
+ int count = 0;
+ HBasicBlock* join = NULL;
+ for (int i = 0; i < types->length() && count < kMaxStorePolymorphism;
++i) {
Handle<Map> map = types->at(i);
LookupResult lookup;
if (ComputeStoredField(map, name, &lookup)) {
- HSubgraph* subgraph = CreateBranchSubgraph(environment());
- SubgraphScope scope(this, subgraph);
+ ++count;
+ if (join == NULL) {
+ AddInstruction(new HCheckNonSmi(object)); // Only needed once.
+ join = graph()->CreateBasicBlock();
+ }
+ HBasicBlock* if_true = graph()->CreateBasicBlock();
+ HBasicBlock* if_false = graph()->CreateBasicBlock();
+ HCompareMap* compare = new HCompareMap(object, map, if_true,
if_false);
+ current_block()->Finish(compare);
+
+ set_current_block(if_true);
HInstruction* instr =
BuildStoreNamedField(object, name, value, map, &lookup, false);
- Push(value);
instr->set_position(expr->position());
+ // Goto will add the HSimulate for the store.
AddInstruction(instr);
- maps.Add(map);
- subgraphs.Add(subgraph);
- } else {
- needs_generic = true;
+ if (!ast_context()->IsEffect()) Push(value);
+ current_block()->Goto(join);
+
+ set_current_block(if_false);
}
}
- // If none of the properties were named fields we generate a
- // generic store.
- if (maps.length() == 0) {
+ // Finish up. We need a generic IC if there were types we couldn't
+ // resolve statically or if we want to handle maps we've never seen.
+ if (count < types->length() || !FLAG_deoptimize_uncommon_cases) {
HInstruction* instr = BuildStoreNamedGeneric(object, name, value);
- Push(value);
instr->set_position(expr->position());
AddInstruction(instr);
- if (instr->HasSideEffects()) AddSimulate(expr->AssignmentId());
- ast_context()->ReturnValue(Pop());
- } else {
- // Build subgraph for generic store through IC.
- HSubgraph* default_graph = CreateBranchSubgraph(environment());
- { SubgraphScope scope(this, default_graph);
- if (!needs_generic && FLAG_deoptimize_uncommon_cases) {
- default_graph->exit_block()->FinishExit(new HDeoptimize());
- default_graph->set_exit_block(NULL);
- } else {
- HInstruction* instr = BuildStoreNamedGeneric(object, name, value);
- Push(value);
- instr->set_position(expr->position());
- AddInstruction(instr);
- }
+
+ if (join == NULL) {
+ // The HSimulate for the store should not see the stored value in
+ // effect contexts (it is not materialized at expr->id() in the
+ // unoptimized code).
+ if (instr->HasSideEffects()) {
+ if (ast_context()->IsEffect()) {
+ AddSimulate(expr->id());
+ } else {
+ Push(value);
+ AddSimulate(expr->id());
+ Drop(1);
+ }
+ }
+ ast_context()->ReturnValue(value);
+ } else {
+ if (!ast_context()->IsEffect()) Push(value);
+ current_block()->Goto(join);
+ join->SetJoinId(expr->id());
+ set_current_block(join);
+ if (!ast_context()->IsEffect()) ast_context()->ReturnValue(Pop());
}
- HBasicBlock* new_exit_block =
- BuildTypeSwitch(object, &maps, &subgraphs, default_graph,
expr->id());
- set_current_block(new_exit_block);
- // In an effect context, we did not materialized the value in the
- // predecessor environments so there's no need to handle it here.
- if (current_block() != NULL && !ast_context()->IsEffect()) {
- ast_context()->ReturnValue(Pop());
+ } else {
+ current_block()->FinishExit(new HDeoptimize);
+ set_current_block(join);
+ if (join != NULL) {
+ join->SetJoinId(expr->id());
+ if (!ast_context()->IsEffect()) ast_context()->ReturnValue(Pop());
}
}
}
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