Revision: 14610
Author: [email protected]
Date: Fri May 10 02:26:53 2013
Log: Verify that no-side-effects scope does not add unsafe phis and
does not change push-pop balance of the environment.
[email protected]
BUG=v8:2671
Review URL: https://chromiumcodereview.appspot.com/14696015
http://code.google.com/p/v8/source/detail?r=14610
Modified:
/branches/bleeding_edge/src/hydrogen.cc
/branches/bleeding_edge/src/hydrogen.h
=======================================
--- /branches/bleeding_edge/src/hydrogen.cc Fri May 10 01:58:58 2013
+++ /branches/bleeding_edge/src/hydrogen.cc Fri May 10 02:26:53 2013
@@ -752,6 +752,7 @@
compare->SetSuccessorAt(1, split_edge);
}
split_edge->GotoNoSimulate(split_edge_merge_block_);
+ ASSERT(builder_->SafeToAddPhiInNoSideEffectsScope());
} else {
compare->SetSuccessorAt(0, first_true_block_);
compare->SetSuccessorAt(1, first_false_block_);
@@ -769,6 +770,7 @@
split_edge_merge_block_ =
builder_->CreateBasicBlock(env->Copy());
first_true_block_->GotoNoSimulate(split_edge_merge_block_);
+ ASSERT(builder_->SafeToAddPhiInNoSideEffectsScope());
first_true_block_ = split_edge_merge_block_;
}
builder_->set_current_block(first_false_block_);
@@ -783,6 +785,7 @@
if (split_edge_merge_block_ == NULL) {
split_edge_merge_block_ = builder_->CreateBasicBlock(env->Copy());
first_false_block_->GotoNoSimulate(split_edge_merge_block_);
+ ASSERT(builder_->SafeToAddPhiInNoSideEffectsScope());
first_false_block_ = split_edge_merge_block_;
}
builder_->set_current_block(first_true_block_);
@@ -814,6 +817,7 @@
// Handle if's without any expressions, they jump directly to
the "else"
// branch.
builder_->current_block()->GotoNoSimulate(first_false_block_);
+ ASSERT(builder_->SafeToAddPhiInNoSideEffectsScope());
first_true_block_ = NULL;
}
builder_->set_current_block(first_true_block_);
@@ -876,6 +880,7 @@
ASSERT(!last_false_block->IsFinished());
last_true_block_->GotoNoSimulate(merge_block_);
last_false_block->GotoNoSimulate(merge_block_);
+ ASSERT(builder_->SafeToAddPhiInNoSideEffectsScope());
builder_->set_current_block(merge_block_);
}
}
@@ -908,6 +913,7 @@
phi_->ChangeRepresentation(Representation::Integer32());
env->Push(initial);
builder_->current_block()->GotoNoSimulate(header_block_);
+ ASSERT(builder_->SafeToAddPhiInNoSideEffectsScope());
HEnvironment* body_env = env->Copy();
HEnvironment* exit_env = env->Copy();
@@ -962,6 +968,7 @@
// Push the new increment value on the expression stack to merge into
the phi.
builder_->environment()->Push(increment_);
builder_->current_block()->GotoNoSimulate(header_block_);
+ ASSERT(builder_->SafeToAddPhiInNoSideEffectsScope());
header_block_->loop_information()->RegisterBackEdge(body_block_);
builder_->set_current_block(exit_block_);
@@ -8181,6 +8188,7 @@
access->set_position(position);
}
if_jsarray->GotoNoSimulate(join);
+ ASSERT(SafeToAddPhiInNoSideEffectsScope());
set_current_block(if_fastobject);
length = AddInstruction(new(zone())
HFixedArrayBaseLength(elements));
@@ -8207,6 +8215,7 @@
Push(access);
}
current_block()->GotoNoSimulate(join);
+ ASSERT(SafeToAddPhiInNoSideEffectsScope());
set_current_block(if_false);
}
}
=======================================
--- /branches/bleeding_edge/src/hydrogen.h Tue May 7 14:01:53 2013
+++ /branches/bleeding_edge/src/hydrogen.h Fri May 10 02:26:53 2013
@@ -934,6 +934,7 @@
: info_(info),
graph_(NULL),
current_block_(NULL),
+ no_side_effects_scope_environment_delta_(0),
no_side_effects_scope_count_(0) {}
virtual ~HGraphBuilder() {}
@@ -965,11 +966,31 @@
HReturn* AddReturn(HValue* value);
void IncrementInNoSideEffectsScope() {
+ if (no_side_effects_scope_count_ == 0) {
+ no_side_effects_scope_environment_delta_ =
+ environment()->push_count() - environment()->pop_count();
+ }
no_side_effects_scope_count_++;
}
void DecrementInNoSideEffectsScope() {
no_side_effects_scope_count_--;
+ if (no_side_effects_scope_count_ == 0) {
+ // No-side-effects scope should not change push-pop delta.
+ ASSERT_EQ(no_side_effects_scope_environment_delta_,
+ environment()->push_count() - environment()->pop_count());
+ no_side_effects_scope_environment_delta_ = 0;
+ }
+ }
+
+ bool SafeToAddPhiInNoSideEffectsScope() {
+ // Pops and pushes after a simulate are not visible in LChunkBuilder.
+ // If the number of pops is greater than the number pushes then the
+ // environment in HGraphBuilder is shorter then the corresponding
+ // environment in LChunkBuilder. This causes non-observable phis
+ // to be pushed in the environment, which breaks deoptimization.
+ return no_side_effects_scope_count_ == 0 ||
+ no_side_effects_scope_environment_delta_ >= 0;
}
protected:
@@ -1332,6 +1353,7 @@
CompilationInfo* info_;
HGraph* graph_;
HBasicBlock* current_block_;
+ int no_side_effects_scope_environment_delta_;
int no_side_effects_scope_count_;
};
--
--
v8-dev mailing list
[email protected]
http://groups.google.com/group/v8-dev
---
You received this message because you are subscribed to the Google Groups "v8-dev" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/groups/opt_out.
