v8/src/variables.cc
kasperl@chromium.org f66ea38c0b Allocate arguments object on-demand instead of at function entry.
This allows Function.prototype.apply to not allocate the objects 
and copy the arguments directly from the stack.
Review URL: http://codereview.chromium.org/147075

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2256 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2009-06-24 08:01:38 +00:00

164 lines
4.6 KiB
C++

// Copyright 2006-2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "v8.h"
#include "ast.h"
#include "scopes.h"
#include "variables.h"
namespace v8 {
namespace internal {
// ----------------------------------------------------------------------------
// Implementation UseCount.
UseCount::UseCount()
: nreads_(0),
nwrites_(0) {
}
void UseCount::RecordRead(int weight) {
ASSERT(weight > 0);
nreads_ += weight;
// We must have a positive nreads_ here. Handle
// any kind of overflow by setting nreads_ to
// some large-ish value.
if (nreads_ <= 0) nreads_ = 1000000;
ASSERT(is_read() & is_used());
}
void UseCount::RecordWrite(int weight) {
ASSERT(weight > 0);
nwrites_ += weight;
// We must have a positive nwrites_ here. Handle
// any kind of overflow by setting nwrites_ to
// some large-ish value.
if (nwrites_ <= 0) nwrites_ = 1000000;
ASSERT(is_written() && is_used());
}
void UseCount::RecordAccess(int weight) {
RecordRead(weight);
RecordWrite(weight);
}
void UseCount::RecordUses(UseCount* uses) {
if (uses->nreads() > 0) RecordRead(uses->nreads());
if (uses->nwrites() > 0) RecordWrite(uses->nwrites());
}
#ifdef DEBUG
void UseCount::Print() {
// PrintF("r = %d, w = %d", nreads_, nwrites_);
PrintF("%du = %dr + %dw", nuses(), nreads(), nwrites());
}
#endif
// ----------------------------------------------------------------------------
// Implementation SmiAnalysis.
const char* SmiAnalysis::Type2String(SmiAnalysis* type) {
switch (type->kind_) {
case UNKNOWN:
return "UNKNOWN";
case LIKELY_SMI:
return "LIKELY_SMI";
default:
UNREACHABLE();
}
return "UNREACHABLE";
}
// ----------------------------------------------------------------------------
// Implementation Variable.
const char* Variable::Mode2String(Mode mode) {
switch (mode) {
case VAR: return "VAR";
case CONST: return "CONST";
case DYNAMIC: return "DYNAMIC";
case DYNAMIC_GLOBAL: return "DYNAMIC_GLOBAL";
case DYNAMIC_LOCAL: return "DYNAMIC_LOCAL";
case INTERNAL: return "INTERNAL";
case TEMPORARY: return "TEMPORARY";
}
UNREACHABLE();
return NULL;
}
Property* Variable::AsProperty() {
return rewrite_ == NULL ? NULL : rewrite_->AsProperty();
}
Variable* Variable::AsVariable() {
return rewrite_ == NULL || rewrite_->AsSlot() != NULL ? this : NULL;
}
Slot* Variable::slot() const {
return rewrite_ != NULL ? rewrite_->AsSlot() : NULL;
}
Variable::Variable(Scope* scope,
Handle<String> name,
Mode mode,
bool is_valid_LHS,
Kind kind)
: scope_(scope),
name_(name),
mode_(mode),
is_valid_LHS_(is_valid_LHS),
kind_(kind),
local_if_not_shadowed_(NULL),
is_accessed_from_inner_scope_(false),
rewrite_(NULL) {
// names must be canonicalized for fast equality checks
ASSERT(name->IsSymbol());
}
bool Variable::is_global() const {
// Temporaries are never global, they must always be allocated in the
// activation frame.
return mode_ != TEMPORARY && scope_ != NULL && scope_->is_global_scope();
}
} } // namespace v8::internal