Revision: 6189
Author: [email protected]
Date: Wed Jan 5 23:38:19 2011
Log: Fix an bug in deoptimization after polymorphic calls in effect
contexts.
For polymorphic calls (also loads and stores) we construct a type switch
graph that has a basic block merging all the variants. There is an
environment simulation before the goto at the end of all the predecessor
blocks. This simulation is used to define the environment on entry to the
successor block, and captures the return value of the call. In effect
contexts, this value should not be present in the environment.
The fix is to use the AST context to decide whether to have this value in
the join node's environment at all.
BUG=1014
Review URL: http://codereview.chromium.org/6065014
http://code.google.com/p/v8/source/detail?r=6189
Modified:
/branches/bleeding_edge/src/hydrogen.cc
=======================================
--- /branches/bleeding_edge/src/hydrogen.cc Wed Jan 5 03:17:37 2011
+++ /branches/bleeding_edge/src/hydrogen.cc Wed Jan 5 23:38:19 2011
@@ -3103,8 +3103,15 @@
// this basic block the current basic block.
HBasicBlock* join_block = graph_->CreateBasicBlock();
for (int i = 0; i < subgraphs->length(); ++i) {
- if (subgraphs->at(i)->HasExit()) {
- subgraphs->at(i)->exit_block()->Goto(join_block);
+ HSubgraph* subgraph = subgraphs->at(i);
+ if (subgraph->HasExit()) {
+ // In an effect context the value of the type switch is not needed.
+ // There is no need to merge it at the join block only to discard it.
+ HBasicBlock* subgraph_exit = subgraph->exit_block();
+ if (ast_context()->IsEffect()) {
+ subgraph_exit->last_environment()->Drop(1);
+ }
+ subgraph_exit->Goto(join_block);
}
}
@@ -3242,7 +3249,8 @@
Push(value);
instr->set_position(expr->position());
AddInstruction(instr);
- if (instr->HasSideEffects()) AddSimulate(expr->id());
+ if (instr->HasSideEffects()) AddSimulate(expr->AssignmentId());
+ ast_context()->ReturnValue(Pop());
} else {
// Build subgraph for generic store through IC.
{
@@ -3260,11 +3268,14 @@
}
HBasicBlock* new_exit_block =
- BuildTypeSwitch(&maps, &subgraphs, object, expr->AssignmentId());
+ BuildTypeSwitch(&maps, &subgraphs, object, expr->id());
subgraph()->set_exit_block(new_exit_block);
- }
-
- if (subgraph()->HasExit()) ast_context()->ReturnValue(Pop());
+ // In an effect context, we did not materialized the value in the
+ // predecessor environments so there's no need to handle it here.
+ if (subgraph()->HasExit() && !ast_context()->IsEffect()) {
+ ast_context()->ReturnValue(Pop());
+ }
+ }
}
@@ -3548,8 +3559,7 @@
if (maps.length() == 0) {
HInstruction* instr = BuildLoadNamedGeneric(object, expr);
instr->set_position(expr->position());
- PushAndAdd(instr);
- if (instr->HasSideEffects()) AddSimulate(expr->id());
+ ast_context()->ReturnInstruction(instr, expr->id());
} else {
// Build subgraph for generic load through IC.
{
@@ -3568,9 +3578,12 @@
HBasicBlock* new_exit_block =
BuildTypeSwitch(&maps, &subgraphs, object, expr->id());
subgraph()->set_exit_block(new_exit_block);
- }
-
- if (subgraph()->HasExit()) ast_context()->ReturnValue(Pop());
+ // In an effect context, we did not materialized the value in the
+ // predecessor environments so there's no need to handle it here.
+ if (subgraph()->HasExit() && !ast_context()->IsEffect()) {
+ ast_context()->ReturnValue(Pop());
+ }
+ }
}
@@ -3856,7 +3869,11 @@
HBasicBlock* new_exit_block =
BuildTypeSwitch(&maps, &subgraphs, receiver, expr->id());
subgraph()->set_exit_block(new_exit_block);
- if (new_exit_block != NULL) ast_context()->ReturnValue(Pop());
+ // In an effect context, we did not materialized the value in the
+ // predecessor environments so there's no need to handle it here.
+ if (new_exit_block != NULL && !ast_context()->IsEffect()) {
+ ast_context()->ReturnValue(Pop());
+ }
}
}
--
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