Author: [email protected]
Date: Thu May 14 00:12:58 2009
New Revision: 1942
Modified:
branches/bleeding_edge/src/hashmap.cc
branches/bleeding_edge/src/objects.cc
branches/bleeding_edge/src/scopes.cc
branches/bleeding_edge/src/scopes.h
branches/bleeding_edge/src/utils.h
Log:
Optimize the scope creation code by lazily allocating the hash maps
for dynamic variables (only do it for the scopes that need them).
Review URL: http://codereview.chromium.org/113393
Modified: branches/bleeding_edge/src/hashmap.cc
==============================================================================
--- branches/bleeding_edge/src/hashmap.cc (original)
+++ branches/bleeding_edge/src/hashmap.cc Thu May 14 00:12:58 2009
@@ -31,13 +31,6 @@
namespace v8 { namespace internal {
-
-static inline bool IsPowerOf2(uint32_t x) {
- ASSERT(x != 0);
- return (x & (x - 1)) == 0;
-}
-
-
Allocator HashMap::DefaultAllocator;
Modified: branches/bleeding_edge/src/objects.cc
==============================================================================
--- branches/bleeding_edge/src/objects.cc (original)
+++ branches/bleeding_edge/src/objects.cc Thu May 14 00:12:58 2009
@@ -3437,8 +3437,8 @@
void
SeqTwoByteString::SeqTwoByteStringReadBlockIntoBuffer(ReadBlockBuffer* rbb,
- unsigned* offset_ptr,
- unsigned max_chars) {
+ unsigned*
offset_ptr,
+ unsigned
max_chars) {
unsigned chars_read = 0;
unsigned offset = *offset_ptr;
while (chars_read < max_chars) {
Modified: branches/bleeding_edge/src/scopes.cc
==============================================================================
--- branches/bleeding_edge/src/scopes.cc (original)
+++ branches/bleeding_edge/src/scopes.cc Thu May 14 00:12:58 2009
@@ -112,9 +112,7 @@
locals_(false),
temps_(0),
params_(0),
- dynamics_(false),
- dynamics_local_(false),
- dynamics_global_(false),
+ dynamics_(NULL),
unresolved_(0),
decls_(0) {
}
@@ -125,9 +123,9 @@
inner_scopes_(4),
type_(type),
scope_name_(Factory::empty_symbol()),
- locals_(),
temps_(4),
params_(4),
+ dynamics_(NULL),
unresolved_(16),
decls_(4),
receiver_(NULL),
@@ -477,9 +475,11 @@
PrintMap(&printer, n1, &locals_);
Indent(n1, "// dynamic vars\n");
- PrintMap(&printer, n1, &dynamics_);
- PrintMap(&printer, n1, &dynamics_local_);
- PrintMap(&printer, n1, &dynamics_global_);
+ if (dynamics_ != NULL) {
+ PrintMap(&printer, n1, dynamics_->GetMap(Variable::DYNAMIC));
+ PrintMap(&printer, n1, dynamics_->GetMap(Variable::DYNAMIC_LOCAL));
+ PrintMap(&printer, n1, dynamics_->GetMap(Variable::DYNAMIC_GLOBAL));
+ }
// Print inner scopes (disable by providing negative n).
if (n >= 0) {
@@ -495,23 +495,8 @@
Variable* Scope::NonLocal(Handle<String> name, Variable::Mode mode) {
- // Space optimization: reuse existing non-local with the same name
- // and mode.
- LocalsMap* map = NULL;
- switch (mode) {
- case Variable::DYNAMIC:
- map = &dynamics_;
- break;
- case Variable::DYNAMIC_LOCAL:
- map = &dynamics_local_;
- break;
- case Variable::DYNAMIC_GLOBAL:
- map = &dynamics_global_;
- break;
- default:
- UNREACHABLE();
- break;
- }
+ if (dynamics_ == NULL) dynamics_ = new DynamicScopePart();
+ LocalsMap* map = dynamics_->GetMap(mode);
Variable* var = map->Lookup(name);
if (var == NULL) {
// Declare a new non-local.
Modified: branches/bleeding_edge/src/scopes.h
==============================================================================
--- branches/bleeding_edge/src/scopes.h (original)
+++ branches/bleeding_edge/src/scopes.h Thu May 14 00:12:58 2009
@@ -35,7 +35,6 @@
// A hash map to support fast local variable declaration and lookup.
-
class LocalsMap: public HashMap {
public:
LocalsMap();
@@ -53,6 +52,23 @@
};
+// The dynamic scope part holds hash maps for the variables that will
+// be looked up dynamically from within eval and with scopes. The objects
+// are allocated on-demand from Scope::NonLocal to avoid wasting memory
+// and setup time for scopes that don't need them.
+class DynamicScopePart : public ZoneObject {
+ public:
+ LocalsMap* GetMap(Variable::Mode mode) {
+ int index = mode - Variable::DYNAMIC;
+ ASSERT(index >= 0 && index < 3);
+ return &maps_[index];
+ }
+
+ private:
+ LocalsMap maps_[3];
+};
+
+
// Global invariants after AST construction: Each reference (i.e.
identifier)
// to a JavaScript variable (including global properties) is represented
by a
// VariableProxy node. Immediately after AST construction and before
variable
@@ -278,9 +294,7 @@
// parameter list in source order
ZoneList<Variable*> params_;
// variables that must be looked up dynamically
- LocalsMap dynamics_;
- LocalsMap dynamics_local_;
- LocalsMap dynamics_global_;
+ DynamicScopePart* dynamics_;
// unresolved variables referred to from this scope
ZoneList<VariableProxy*> unresolved_;
// declarations
Modified: branches/bleeding_edge/src/utils.h
==============================================================================
--- branches/bleeding_edge/src/utils.h (original)
+++ branches/bleeding_edge/src/utils.h Thu May 14 00:12:58 2009
@@ -42,8 +42,6 @@
}
-
-
// The C++ standard leaves the semantics of '>>' undefined for
// negative signed operands. Most implementations do the right thing,
// though.
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