Reviewers: fschneider,
Message:
Simple code review for you.
Description:
Have the flow graph builder collect definitions.
Before computing reaching definitions, the set of all definitions in a
function must be collected and they must be numbered. Have the flow
graph builder collect definitions for stack-allocated variables into a
list, and implicitly number them with their list index.
Please review this at http://codereview.chromium.org/668257
Affected files:
M src/data-flow.h
M src/data-flow.cc
Index: src/data-flow.cc
diff --git a/src/data-flow.cc b/src/data-flow.cc
index
96acb9959cfd0b58edbfa175dfaa498da9e398d6..1a0cf1a18765cf4843b14b21be4ef2225e53caa3
100644
--- a/src/data-flow.cc
+++ b/src/data-flow.cc
@@ -431,11 +431,17 @@ void FlowGraphBuilder::VisitAssignment(Assignment*
expr) {
// Left-hand side can be a variable or property (or reference error) but
// not both.
ASSERT(var == NULL || prop == NULL);
- if (prop != NULL) {
+ if (var != NULL) {
+ Visit(expr->value());
+ Slot* slot = var->slot();
+ if (slot != NULL &&
+ (slot->type() == Slot::LOCAL || slot->type() == Slot::PARAMETER)) {
+ definitions_.Add(expr);
+ }
+
+ } else if (prop != NULL) {
Visit(prop->obj());
if (!prop->key()->IsPropertyName()) Visit(prop->key());
- }
- if (var != NULL || prop != NULL) {
Visit(expr->value());
}
graph_.AppendInstruction(expr);
@@ -492,6 +498,14 @@ void
FlowGraphBuilder::VisitUnaryOperation(UnaryOperation* expr) {
void FlowGraphBuilder::VisitCountOperation(CountOperation* expr) {
Visit(expr->expression());
+ Variable* var = expr->expression()->AsVariableProxy()->AsVariable();
+ if (var != NULL) {
+ Slot* slot = var->slot();
+ if (slot != NULL &&
+ (slot->type() == Slot::LOCAL || slot->type() == Slot::PARAMETER)) {
+ definitions_.Add(expr);
+ }
+ }
graph_.AppendInstruction(expr);
}
Index: src/data-flow.h
diff --git a/src/data-flow.h b/src/data-flow.h
index
30c0336114a3bc31a6d3a78fcf1ad38b4c35b439..aec995b06a2b5685beee3773b1545d6bc0ff6a1f
100644
--- a/src/data-flow.h
+++ b/src/data-flow.h
@@ -363,7 +363,12 @@ class JoinNode: public Node {
// traversal orders as a byproduct.
class FlowGraphBuilder: public AstVisitor {
public:
- FlowGraphBuilder() : global_exit_(NULL), preorder_(4), postorder_(4) {}
+ FlowGraphBuilder()
+ : global_exit_(NULL),
+ preorder_(4),
+ postorder_(4),
+ definitions_(4) {
+ }
void Build(FunctionLiteral* lit);
@@ -384,6 +389,11 @@ class FlowGraphBuilder: public AstVisitor {
ZoneList<Node*> preorder_;
ZoneList<Node*> postorder_;
+ // The flow graph builder collects a list of definitions (assignments and
+ // count operations) to stack-allocated variables to use for reaching
+ // definitions analysis.
+ ZoneList<AstNode*> definitions_;
+
DISALLOW_COPY_AND_ASSIGN(FlowGraphBuilder);
};
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