// Copyright 2006-2009 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 "bootstrapper.h"
#include "codegen-inl.h"
#include "debug.h"
#include "parser.h"
#include "register-allocator-inl.h"
#include "runtime.h"
#include "scopes.h"
namespace v8 {
namespace internal {
#define __ ACCESS_MASM(masm_)
static void EmitIdenticalObjectComparison(MacroAssembler* masm,
Label* slow,
Condition cc);
static void EmitSmiNonsmiComparison(MacroAssembler* masm,
Label* rhs_not_nan,
Label* slow,
bool strict);
static void EmitTwoNonNanDoubleComparison(MacroAssembler* masm, Condition cc);
static void EmitStrictTwoHeapObjectCompare(MacroAssembler* masm);
static void MultiplyByKnownInt(MacroAssembler* masm,
Register source,
Register destination,
int known_int);
static bool IsEasyToMultiplyBy(int x);
// -------------------------------------------------------------------------
// Platform-specific DeferredCode functions.
void DeferredCode::SaveRegisters() {
for (int i = 0; i < RegisterAllocator::kNumRegisters; i++) {
int action = registers_[i];
if (action == kPush) {
__ push(RegisterAllocator::ToRegister(i));
} else if (action != kIgnore && (action & kSyncedFlag) == 0) {
__ str(RegisterAllocator::ToRegister(i), MemOperand(fp, action));
}
}
}
void DeferredCode::RestoreRegisters() {
// Restore registers in reverse order due to the stack.
for (int i = RegisterAllocator::kNumRegisters - 1; i >= 0; i--) {
int action = registers_[i];
if (action == kPush) {
__ pop(RegisterAllocator::ToRegister(i));
} else if (action != kIgnore) {
action &= ~kSyncedFlag;
__ ldr(RegisterAllocator::ToRegister(i), MemOperand(fp, action));
}
}
}
// -------------------------------------------------------------------------
// CodeGenState implementation.
CodeGenState::CodeGenState(CodeGenerator* owner)
: owner_(owner),
typeof_state_(NOT_INSIDE_TYPEOF),
true_target_(NULL),
false_target_(NULL),
previous_(NULL) {
owner_->set_state(this);
}
CodeGenState::CodeGenState(CodeGenerator* owner,
TypeofState typeof_state,
JumpTarget* true_target,
JumpTarget* false_target)
: owner_(owner),
typeof_state_(typeof_state),
true_target_(true_target),
false_target_(false_target),
previous_(owner->state()) {
owner_->set_state(this);
}
CodeGenState::~CodeGenState() {
ASSERT(owner_->state() == this);
owner_->set_state(previous_);
}
// -------------------------------------------------------------------------
// CodeGenerator implementation
CodeGenerator::CodeGenerator(int buffer_size, Handle<Script> script,
bool is_eval)
: is_eval_(is_eval),
script_(script),
deferred_(8),
masm_(new MacroAssembler(NULL, buffer_size)),
scope_(NULL),
frame_(NULL),
allocator_(NULL),
cc_reg_(al),
state_(NULL),
function_return_is_shadowed_(false) {
}
// Calling conventions:
// fp: caller's frame pointer
// sp: stack pointer
// r1: called JS function
// cp: callee's context
void CodeGenerator::GenCode(FunctionLiteral* fun) {
ZoneList<Statement*>* body = fun->body();
// Initialize state.
ASSERT(scope_ == NULL);
scope_ = fun->scope();
ASSERT(allocator_ == NULL);
RegisterAllocator register_allocator(this);
allocator_ = ®ister_allocator;
ASSERT(frame_ == NULL);
frame_ = new VirtualFrame();
cc_reg_ = al;
{
CodeGenState state(this);
// Entry:
// Stack: receiver, arguments
// lr: return address
// fp: caller's frame pointer
// sp: stack pointer
// r1: called JS function
// cp: callee's context
allocator_->Initialize();
frame_->Enter();
// tos: code slot
#ifdef DEBUG
if (strlen(FLAG_stop_at) > 0 &&
fun->name()->IsEqualTo(CStrVector(FLAG_stop_at))) {
frame_->SpillAll();
__ stop("stop-at");
}
#endif
// Allocate space for locals and initialize them. This also checks
// for stack overflow.
frame_->AllocateStackSlots();
// Initialize the function return target after the locals are set
// up, because it needs the expected frame height from the frame.
function_return_.set_direction(JumpTarget::BIDIRECTIONAL);
function_return_is_shadowed_ = false;
VirtualFrame::SpilledScope spilled_scope;
if (scope_->num_heap_slots() > 0) {
// Allocate local context.
// Get outer context and create a new context based on it.
__ ldr(r0, frame_->Function());
frame_->EmitPush(r0);
frame_->CallRuntime(Runtime::kNewContext, 1); // r0 holds the result
#ifdef DEBUG
JumpTarget verified_true;
__ cmp(r0, Operand(cp));
verified_true.Branch(eq);
__ stop("NewContext: r0 is expected to be the same as cp");
verified_true.Bind();
#endif
// Update context local.
__ str(cp, frame_->Context());
}
// TODO(1241774): Improve this code:
// 1) only needed if we have a context
// 2) no need to recompute context ptr every single time
// 3) don't copy parameter operand code from SlotOperand!
{
Comment cmnt2(masm_, "[ copy context parameters into .context");
// Note that iteration order is relevant here! If we have the same
// parameter twice (e.g., function (x, y, x)), and that parameter
// needs to be copied into the context, it must be the last argument
// passed to the parameter that needs to be copied. This is a rare
// case so we don't check for it, instead we rely on the copying
// order: such a parameter is copied repeatedly into the same
// context location and thus the last value is what is seen inside
// the function.
for (int i = 0; i < scope_->num_parameters(); i++) {
Variable* par = scope_->parameter(i);
Slot* slot = par->slot();
if (slot != NULL && slot->type() == Slot::CONTEXT) {
ASSERT(!scope_->is_global_scope()); // no parameters in global scope
__ ldr(r1, frame_->ParameterAt(i));
// Loads r2 with context; used below in RecordWrite.
__ str(r1, SlotOperand(slot, r2));
// Load the offset into r3.
int slot_offset =
FixedArray::kHeaderSize + slot->index() * kPointerSize;
__ mov(r3, Operand(slot_offset));
__ RecordWrite(r2, r3, r1);
}
}
}
// Store the arguments object. This must happen after context
// initialization because the arguments object may be stored in the
// context.
if (scope_->arguments() != NULL) {
ASSERT(scope_->arguments_shadow() != NULL);
Comment cmnt(masm_, "[ allocate arguments object");
{ Reference shadow_ref(this, scope_->arguments_shadow());
{ Reference arguments_ref(this, scope_->arguments());
ArgumentsAccessStub stub(ArgumentsAccessStub::NEW_OBJECT);
__ ldr(r2, frame_->Function());
// The receiver is below the arguments, the return address,
// and the frame pointer on the stack.
const int kReceiverDisplacement = 2 + scope_->num_parameters();
__ add(r1, fp, Operand(kReceiverDisplacement * kPointerSize));
__ mov(r0, Operand(Smi::FromInt(scope_->num_parameters())));
frame_->Adjust(3);
__ stm(db_w, sp, r0.bit() | r1.bit() | r2.bit());
frame_->CallStub(&stub, 3);
frame_->EmitPush(r0);
arguments_ref.SetValue(NOT_CONST_INIT);
}
shadow_ref.SetValue(NOT_CONST_INIT);
}
frame_->Drop(); // Value is no longer needed.
}
// Generate code to 'execute' declarations and initialize functions
// (source elements). In case of an illegal redeclaration we need to
// handle that instead of processing the declarations.
if (scope_->HasIllegalRedeclaration()) {
Comment cmnt(masm_, "[ illegal redeclarations");
scope_->VisitIllegalRedeclaration(this);
} else {
Comment cmnt(masm_, "[ declarations");
ProcessDeclarations(scope_->declarations());
// Bail out if a stack-overflow exception occurred when processing
// declarations.
if (HasStackOverflow()) return;
}
if (FLAG_trace) {
frame_->CallRuntime(Runtime::kTraceEnter, 0);
// Ignore the return value.
}
// Compile the body of the function in a vanilla state. Don't
// bother compiling all the code if the scope has an illegal
// redeclaration.
if (!scope_->HasIllegalRedeclaration()) {
Comment cmnt(masm_, "[ function body");
#ifdef DEBUG
bool is_builtin = Bootstrapper::IsActive();
bool should_trace =
is_builtin ? FLAG_trace_builtin_calls : FLAG_trace_calls;
if (should_trace) {
frame_->CallRuntime(Runtime::kDebugTrace, 0);
// Ignore the return value.
}
#endif
VisitStatementsAndSpill(body);
}
}
// Generate the return sequence if necessary.
if (frame_ != NULL || function_return_.is_linked()) {
// exit
// r0: result
// sp: stack pointer
// fp: frame pointer
// cp: callee's context
__ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
function_return_.Bind();
if (FLAG_trace) {
// Push the return value on the stack as the parameter.
// Runtime::TraceExit returns the parameter as it is.
frame_->EmitPush(r0);
frame_->CallRuntime(Runtime::kTraceExit, 1);
}
// Tear down the frame which will restore the caller's frame pointer and
// the link register.
frame_->Exit();
__ add(sp, sp, Operand((scope_->num_parameters() + 1) * kPointerSize));
__ Jump(lr);
}
// Code generation state must be reset.
ASSERT(!has_cc());
ASSERT(state_ == NULL);
ASSERT(!function_return_is_shadowed_);
function_return_.Unuse();
DeleteFrame();
// Process any deferred code using the register allocator.
if (!HasStackOverflow()) {
ProcessDeferred();
}
allocator_ = NULL;
scope_ = NULL;
}
MemOperand CodeGenerator::SlotOperand(Slot* slot, Register tmp) {
// Currently, this assertion will fail if we try to assign to
// a constant variable that is constant because it is read-only
// (such as the variable referring to a named function expression).
// We need to implement assignments to read-only variables.
// Ideally, we should do this during AST generation (by converting
// such assignments into expression statements); however, in general
// we may not be able to make the decision until past AST generation,
// that is when the entire program is known.
ASSERT(slot != NULL);
int index = slot->index();
switch (slot->type()) {
case Slot::PARAMETER:
return frame_->ParameterAt(index);
case Slot::LOCAL:
return frame_->LocalAt(index);
case Slot::CONTEXT: {
// Follow the context chain if necessary.
ASSERT(!tmp.is(cp)); // do not overwrite context register
Register context = cp;
int chain_length = scope()->ContextChainLength(slot->var()->scope());
for (int i = 0; i < chain_length; i++) {
// Load the closure.
// (All contexts, even 'with' contexts, have a closure,
// and it is the same for all contexts inside a function.
// There is no need to go to the function context first.)
__ ldr(tmp, ContextOperand(context, Context::CLOSURE_INDEX));
// Load the function context (which is the incoming, outer context).
__ ldr(tmp, FieldMemOperand(tmp, JSFunction::kContextOffset));
context = tmp;
}
// We may have a 'with' context now. Get the function context.
// (In fact this mov may never be the needed, since the scope analysis
// may not permit a direct context access in this case and thus we are
// always at a function context. However it is safe to dereference be-
// cause the function context of a function context is itself. Before
// deleting this mov we should try to create a counter-example first,
// though...)
__ ldr(tmp, ContextOperand(context, Context::FCONTEXT_INDEX));
return ContextOperand(tmp, index);
}
default:
UNREACHABLE();
return MemOperand(r0, 0);
}
}
MemOperand CodeGenerator::ContextSlotOperandCheckExtensions(
Slot* slot,
Register tmp,
Register tmp2,
JumpTarget* slow) {
ASSERT(slot->type() == Slot::CONTEXT);
Register context = cp;
for (Scope* s = scope(); s != slot->var()->scope(); s = s->outer_scope()) {
if (s->num_heap_slots() > 0) {
if (s->calls_eval()) {
// Check that extension is NULL.
__ ldr(tmp2, ContextOperand(context, Context::EXTENSION_INDEX));
__ tst(tmp2, tmp2);
slow->Branch(ne);
}
__ ldr(tmp, ContextOperand(context, Context::CLOSURE_INDEX));
__ ldr(tmp, FieldMemOperand(tmp, JSFunction::kContextOffset));
context = tmp;
}
}
// Check that last extension is NULL.
__ ldr(tmp2, ContextOperand(context, Context::EXTENSION_INDEX));
__ tst(tmp2, tmp2);
slow->Branch(ne);
__ ldr(tmp, ContextOperand(context, Context::FCONTEXT_INDEX));
return ContextOperand(tmp, slot->index());
}
// Loads a value on TOS. If it is a boolean value, the result may have been
// (partially) translated into branches, or it may have set the condition
// code register. If force_cc is set, the value is forced to set the
// condition code register and no value is pushed. If the condition code
// register was set, has_cc() is true and cc_reg_ contains the condition to
// test for 'true'.
void CodeGenerator::LoadCondition(Expression* x,
TypeofState typeof_state,
JumpTarget* true_target,
JumpTarget* false_target,
bool force_cc) {
ASSERT(!has_cc());
int original_height = frame_->height();
{ CodeGenState new_state(this, typeof_state, true_target, false_target);
Visit(x);
// If we hit a stack overflow, we may not have actually visited
// the expression. In that case, we ensure that we have a
// valid-looking frame state because we will continue to generate
// code as we unwind the C++ stack.
//
// It's possible to have both a stack overflow and a valid frame
// state (eg, a subexpression overflowed, visiting it returned
// with a dummied frame state, and visiting this expression
// returned with a normal-looking state).
if (HasStackOverflow() &&
has_valid_frame() &&
!has_cc() &&
frame_->height() == original_height) {
true_target->Jump();
}
}
if (force_cc && frame_ != NULL && !has_cc()) {
// Convert the TOS value to a boolean in the condition code register.
ToBoolean(true_target, false_target);
}
ASSERT(!force_cc || !has_valid_frame() || has_cc());
ASSERT(!has_valid_frame() ||
(has_cc() && frame_->height() == original_height) ||
(!has_cc() && frame_->height() == original_height + 1));
}
void CodeGenerator::Load(Expression* x, TypeofState typeof_state) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
JumpTarget true_target;
JumpTarget false_target;
LoadCondition(x, typeof_state, &true_target, &false_target, false);
if (has_cc()) {
// Convert cc_reg_ into a boolean value.
JumpTarget loaded;
JumpTarget materialize_true;
materialize_true.Branch(cc_reg_);
__ LoadRoot(r0, Heap::kFalseValueRootIndex);
frame_->EmitPush(r0);
loaded.Jump();
materialize_true.Bind();
__ LoadRoot(r0, Heap::kTrueValueRootIndex);
frame_->EmitPush(r0);
loaded.Bind();
cc_reg_ = al;
}
if (true_target.is_linked() || false_target.is_linked()) {
// We have at least one condition value that has been "translated"
// into a branch, thus it needs to be loaded explicitly.
JumpTarget loaded;
if (frame_ != NULL) {
loaded.Jump(); // Don't lose the current TOS.
}
bool both = true_target.is_linked() && false_target.is_linked();
// Load "true" if necessary.
if (true_target.is_linked()) {
true_target.Bind();
__ LoadRoot(r0, Heap::kTrueValueRootIndex);
frame_->EmitPush(r0);
}
// If both "true" and "false" need to be loaded jump across the code for
// "false".
if (both) {
loaded.Jump();
}
// Load "false" if necessary.
if (false_target.is_linked()) {
false_target.Bind();
__ LoadRoot(r0, Heap::kFalseValueRootIndex);
frame_->EmitPush(r0);
}
// A value is loaded on all paths reaching this point.
loaded.Bind();
}
ASSERT(has_valid_frame());
ASSERT(!has_cc());
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::LoadGlobal() {
VirtualFrame::SpilledScope spilled_scope;
__ ldr(r0, GlobalObject());
frame_->EmitPush(r0);
}
void CodeGenerator::LoadGlobalReceiver(Register scratch) {
VirtualFrame::SpilledScope spilled_scope;
__ ldr(scratch, ContextOperand(cp, Context::GLOBAL_INDEX));
__ ldr(scratch,
FieldMemOperand(scratch, GlobalObject::kGlobalReceiverOffset));
frame_->EmitPush(scratch);
}
// TODO(1241834): Get rid of this function in favor of just using Load, now
// that we have the INSIDE_TYPEOF typeof state. => Need to handle global
// variables w/o reference errors elsewhere.
void CodeGenerator::LoadTypeofExpression(Expression* x) {
VirtualFrame::SpilledScope spilled_scope;
Variable* variable = x->AsVariableProxy()->AsVariable();
if (variable != NULL && !variable->is_this() && variable->is_global()) {
// NOTE: This is somewhat nasty. We force the compiler to load
// the variable as if through '<global>.<variable>' to make sure we
// do not get reference errors.
Slot global(variable, Slot::CONTEXT, Context::GLOBAL_INDEX);
Literal key(variable->name());
// TODO(1241834): Fetch the position from the variable instead of using
// no position.
Property property(&global, &key, RelocInfo::kNoPosition);
LoadAndSpill(&property);
} else {
LoadAndSpill(x, INSIDE_TYPEOF);
}
}
Reference::Reference(CodeGenerator* cgen, Expression* expression)
: cgen_(cgen), expression_(expression), type_(ILLEGAL) {
cgen->LoadReference(this);
}
Reference::~Reference() {
cgen_->UnloadReference(this);
}
void CodeGenerator::LoadReference(Reference* ref) {
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ LoadReference");
Expression* e = ref->expression();
Property* property = e->AsProperty();
Variable* var = e->AsVariableProxy()->AsVariable();
if (property != NULL) {
// The expression is either a property or a variable proxy that rewrites
// to a property.
LoadAndSpill(property->obj());
// We use a named reference if the key is a literal symbol, unless it is
// a string that can be legally parsed as an integer. This is because
// otherwise we will not get into the slow case code that handles [] on
// String objects.
Literal* literal = property->key()->AsLiteral();
uint32_t dummy;
if (literal != NULL &&
literal->handle()->IsSymbol() &&
!String::cast(*(literal->handle()))->AsArrayIndex(&dummy)) {
ref->set_type(Reference::NAMED);
} else {
LoadAndSpill(property->key());
ref->set_type(Reference::KEYED);
}
} else if (var != NULL) {
// The expression is a variable proxy that does not rewrite to a
// property. Global variables are treated as named property references.
if (var->is_global()) {
LoadGlobal();
ref->set_type(Reference::NAMED);
} else {
ASSERT(var->slot() != NULL);
ref->set_type(Reference::SLOT);
}
} else {
// Anything else is a runtime error.
LoadAndSpill(e);
frame_->CallRuntime(Runtime::kThrowReferenceError, 1);
}
}
void CodeGenerator::UnloadReference(Reference* ref) {
VirtualFrame::SpilledScope spilled_scope;
// Pop a reference from the stack while preserving TOS.
Comment cmnt(masm_, "[ UnloadReference");
int size = ref->size();
if (size > 0) {
frame_->EmitPop(r0);
frame_->Drop(size);
frame_->EmitPush(r0);
}
}
// ECMA-262, section 9.2, page 30: ToBoolean(). Convert the given
// register to a boolean in the condition code register. The code
// may jump to 'false_target' in case the register converts to 'false'.
void CodeGenerator::ToBoolean(JumpTarget* true_target,
JumpTarget* false_target) {
VirtualFrame::SpilledScope spilled_scope;
// Note: The generated code snippet does not change stack variables.
// Only the condition code should be set.
frame_->EmitPop(r0);
// Fast case checks
// Check if the value is 'false'.
__ LoadRoot(ip, Heap::kFalseValueRootIndex);
__ cmp(r0, ip);
false_target->Branch(eq);
// Check if the value is 'true'.
__ LoadRoot(ip, Heap::kTrueValueRootIndex);
__ cmp(r0, ip);
true_target->Branch(eq);
// Check if the value is 'undefined'.
__ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
__ cmp(r0, ip);
false_target->Branch(eq);
// Check if the value is a smi.
__ cmp(r0, Operand(Smi::FromInt(0)));
false_target->Branch(eq);
__ tst(r0, Operand(kSmiTagMask));
true_target->Branch(eq);
// Slow case: call the runtime.
frame_->EmitPush(r0);
frame_->CallRuntime(Runtime::kToBool, 1);
// Convert the result (r0) to a condition code.
__ LoadRoot(ip, Heap::kFalseValueRootIndex);
__ cmp(r0, ip);
cc_reg_ = ne;
}
void CodeGenerator::GenericBinaryOperation(Token::Value op,
OverwriteMode overwrite_mode,
int constant_rhs) {
VirtualFrame::SpilledScope spilled_scope;
// sp[0] : y
// sp[1] : x
// result : r0
// Stub is entered with a call: 'return address' is in lr.
switch (op) {
case Token::ADD: // fall through.
case Token::SUB: // fall through.
case Token::MUL:
case Token::DIV:
case Token::MOD:
case Token::BIT_OR:
case Token::BIT_AND:
case Token::BIT_XOR:
case Token::SHL:
case Token::SHR:
case Token::SAR: {
frame_->EmitPop(r0); // r0 : y
frame_->EmitPop(r1); // r1 : x
GenericBinaryOpStub stub(op, overwrite_mode, constant_rhs);
frame_->CallStub(&stub, 0);
break;
}
case Token::COMMA:
frame_->EmitPop(r0);
// simply discard left value
frame_->Drop();
break;
default:
// Other cases should have been handled before this point.
UNREACHABLE();
break;
}
}
class DeferredInlineSmiOperation: public DeferredCode {
public:
DeferredInlineSmiOperation(Token::Value op,
int value,
bool reversed,
OverwriteMode overwrite_mode)
: op_(op),
value_(value),
reversed_(reversed),
overwrite_mode_(overwrite_mode) {
set_comment("[ DeferredInlinedSmiOperation");
}
virtual void Generate();
private:
Token::Value op_;
int value_;
bool reversed_;
OverwriteMode overwrite_mode_;
};
void DeferredInlineSmiOperation::Generate() {
switch (op_) {
case Token::ADD: {
// Revert optimistic add.
if (reversed_) {
__ sub(r0, r0, Operand(Smi::FromInt(value_)));
__ mov(r1, Operand(Smi::FromInt(value_)));
} else {
__ sub(r1, r0, Operand(Smi::FromInt(value_)));
__ mov(r0, Operand(Smi::FromInt(value_)));
}
break;
}
case Token::SUB: {
// Revert optimistic sub.
if (reversed_) {
__ rsb(r0, r0, Operand(Smi::FromInt(value_)));
__ mov(r1, Operand(Smi::FromInt(value_)));
} else {
__ add(r1, r0, Operand(Smi::FromInt(value_)));
__ mov(r0, Operand(Smi::FromInt(value_)));
}
break;
}
// For these operations there is no optimistic operation that needs to be
// reverted.
case Token::MUL:
case Token::MOD:
case Token::BIT_OR:
case Token::BIT_XOR:
case Token::BIT_AND: {
if (reversed_) {
__ mov(r1, Operand(Smi::FromInt(value_)));
} else {
__ mov(r1, Operand(r0));
__ mov(r0, Operand(Smi::FromInt(value_)));
}
break;
}
case Token::SHL:
case Token::SHR:
case Token::SAR: {
if (!reversed_) {
__ mov(r1, Operand(r0));
__ mov(r0, Operand(Smi::FromInt(value_)));
} else {
UNREACHABLE(); // Should have been handled in SmiOperation.
}
break;
}
default:
// Other cases should have been handled before this point.
UNREACHABLE();
break;
}
GenericBinaryOpStub stub(op_, overwrite_mode_, value_);
__ CallStub(&stub);
}
static bool PopCountLessThanEqual2(unsigned int x) {
x &= x - 1;
return (x & (x - 1)) == 0;
}
// Returns the index of the lowest bit set.
static int BitPosition(unsigned x) {
int bit_posn = 0;
while ((x & 0xf) == 0) {
bit_posn += 4;
x >>= 4;
}
while ((x & 1) == 0) {
bit_posn++;
x >>= 1;
}
return bit_posn;
}
void CodeGenerator::SmiOperation(Token::Value op,
Handle<Object> value,
bool reversed,
OverwriteMode mode) {
VirtualFrame::SpilledScope spilled_scope;
// NOTE: This is an attempt to inline (a bit) more of the code for
// some possible smi operations (like + and -) when (at least) one
// of the operands is a literal smi. With this optimization, the
// performance of the system is increased by ~15%, and the generated
// code size is increased by ~1% (measured on a combination of
// different benchmarks).
// sp[0] : operand
int int_value = Smi::cast(*value)->value();
JumpTarget exit;
frame_->EmitPop(r0);
bool something_to_inline = true;
switch (op) {
case Token::ADD: {
DeferredCode* deferred =
new DeferredInlineSmiOperation(op, int_value, reversed, mode);
__ add(r0, r0, Operand(value), SetCC);
deferred->Branch(vs);
__ tst(r0, Operand(kSmiTagMask));
deferred->Branch(ne);
deferred->BindExit();
break;
}
case Token::SUB: {
DeferredCode* deferred =
new DeferredInlineSmiOperation(op, int_value, reversed, mode);
if (reversed) {
__ rsb(r0, r0, Operand(value), SetCC);
} else {
__ sub(r0, r0, Operand(value), SetCC);
}
deferred->Branch(vs);
__ tst(r0, Operand(kSmiTagMask));
deferred->Branch(ne);
deferred->BindExit();
break;
}
case Token::BIT_OR:
case Token::BIT_XOR:
case Token::BIT_AND: {
DeferredCode* deferred =
new DeferredInlineSmiOperation(op, int_value, reversed, mode);
__ tst(r0, Operand(kSmiTagMask));
deferred->Branch(ne);
switch (op) {
case Token::BIT_OR: __ orr(r0, r0, Operand(value)); break;
case Token::BIT_XOR: __ eor(r0, r0, Operand(value)); break;
case Token::BIT_AND: __ and_(r0, r0, Operand(value)); break;
default: UNREACHABLE();
}
deferred->BindExit();
break;
}
case Token::SHL:
case Token::SHR:
case Token::SAR: {
if (reversed) {
something_to_inline = false;
break;
}
int shift_value = int_value & 0x1f; // least significant 5 bits
DeferredCode* deferred =
new DeferredInlineSmiOperation(op, shift_value, false, mode);
__ tst(r0, Operand(kSmiTagMask));
deferred->Branch(ne);
__ mov(r2, Operand(r0, ASR, kSmiTagSize)); // remove tags
switch (op) {
case Token::SHL: {
if (shift_value != 0) {
__ mov(r2, Operand(r2, LSL, shift_value));
}
// check that the *unsigned* result fits in a smi
__ add(r3, r2, Operand(0x40000000), SetCC);
deferred->Branch(mi);
break;
}
case Token::SHR: {
// LSR by immediate 0 means shifting 32 bits.
if (shift_value != 0) {
__ mov(r2, Operand(r2, LSR, shift_value));
}
// check that the *unsigned* result fits in a smi
// neither of the two high-order bits can be set:
// - 0x80000000: high bit would be lost when smi tagging
// - 0x40000000: this number would convert to negative when
// smi tagging these two cases can only happen with shifts
// by 0 or 1 when handed a valid smi
__ and_(r3, r2, Operand(0xc0000000), SetCC);
deferred->Branch(ne);
break;
}
case Token::SAR: {
if (shift_value != 0) {
// ASR by immediate 0 means shifting 32 bits.
__ mov(r2, Operand(r2, ASR, shift_value));
}
break;
}
default: UNREACHABLE();
}
__ mov(r0, Operand(r2, LSL, kSmiTagSize));
deferred->BindExit();
break;
}
case Token::MOD: {
if (reversed || int_value < 2 || !IsPowerOf2(int_value)) {
something_to_inline = false;
break;
}
DeferredCode* deferred =
new DeferredInlineSmiOperation(op, int_value, reversed, mode);
unsigned mask = (0x80000000u | kSmiTagMask);
__ tst(r0, Operand(mask));
deferred->Branch(ne); // Go to deferred code on non-Smis and negative.
mask = (int_value << kSmiTagSize) - 1;
__ and_(r0, r0, Operand(mask));
deferred->BindExit();
break;
}
case Token::MUL: {
if (!IsEasyToMultiplyBy(int_value)) {
something_to_inline = false;
break;
}
DeferredCode* deferred =
new DeferredInlineSmiOperation(op, int_value, reversed, mode);
unsigned max_smi_that_wont_overflow = Smi::kMaxValue / int_value;
max_smi_that_wont_overflow <<= kSmiTagSize;
unsigned mask = 0x80000000u;
while ((mask & max_smi_that_wont_overflow) == 0) {
mask |= mask >> 1;
}
mask |= kSmiTagMask;
// This does a single mask that checks for a too high value in a
// conservative way and for a non-Smi. It also filters out negative
// numbers, unfortunately, but since this code is inline we prefer
// brevity to comprehensiveness.
__ tst(r0, Operand(mask));
deferred->Branch(ne);
MultiplyByKnownInt(masm_, r0, r0, int_value);
deferred->BindExit();
break;
}
default:
something_to_inline = false;
break;
}
if (!something_to_inline) {
if (!reversed) {
frame_->EmitPush(r0);
__ mov(r0, Operand(value));
frame_->EmitPush(r0);
GenericBinaryOperation(op, mode, int_value);
} else {
__ mov(ip, Operand(value));
frame_->EmitPush(ip);
frame_->EmitPush(r0);
GenericBinaryOperation(op, mode, kUnknownIntValue);
}
}
exit.Bind();
}
void CodeGenerator::Comparison(Condition cc,
Expression* left,
Expression* right,
bool strict) {
if (left != NULL) LoadAndSpill(left);
if (right != NULL) LoadAndSpill(right);
VirtualFrame::SpilledScope spilled_scope;
// sp[0] : y
// sp[1] : x
// result : cc register
// Strict only makes sense for equality comparisons.
ASSERT(!strict || cc == eq);
JumpTarget exit;
JumpTarget smi;
// Implement '>' and '<=' by reversal to obtain ECMA-262 conversion order.
if (cc == gt || cc == le) {
cc = ReverseCondition(cc);
frame_->EmitPop(r1);
frame_->EmitPop(r0);
} else {
frame_->EmitPop(r0);
frame_->EmitPop(r1);
}
__ orr(r2, r0, Operand(r1));
__ tst(r2, Operand(kSmiTagMask));
smi.Branch(eq);
// Perform non-smi comparison by stub.
// CompareStub takes arguments in r0 and r1, returns <0, >0 or 0 in r0.
// We call with 0 args because there are 0 on the stack.
CompareStub stub(cc, strict);
frame_->CallStub(&stub, 0);
__ cmp(r0, Operand(0));
exit.Jump();
// Do smi comparisons by pointer comparison.
smi.Bind();
__ cmp(r1, Operand(r0));
exit.Bind();
cc_reg_ = cc;
}
class CallFunctionStub: public CodeStub {
public:
CallFunctionStub(int argc, InLoopFlag in_loop)
: argc_(argc), in_loop_(in_loop) {}
void Generate(MacroAssembler* masm);
private:
int argc_;
InLoopFlag in_loop_;
#if defined(DEBUG)
void Print() { PrintF("CallFunctionStub (argc %d)\n", argc_); }
#endif // defined(DEBUG)
Major MajorKey() { return CallFunction; }
int MinorKey() { return argc_; }
InLoopFlag InLoop() { return in_loop_; }
};
// Call the function on the stack with the given arguments.
void CodeGenerator::CallWithArguments(ZoneList<Expression*>* args,
int position) {
VirtualFrame::SpilledScope spilled_scope;
// Push the arguments ("left-to-right") on the stack.
int arg_count = args->length();
for (int i = 0; i < arg_count; i++) {
LoadAndSpill(args->at(i));
}
// Record the position for debugging purposes.
CodeForSourcePosition(position);
// Use the shared code stub to call the function.
InLoopFlag in_loop = loop_nesting() > 0 ? IN_LOOP : NOT_IN_LOOP;
CallFunctionStub call_function(arg_count, in_loop);
frame_->CallStub(&call_function, arg_count + 1);
// Restore context and pop function from the stack.
__ ldr(cp, frame_->Context());
frame_->Drop(); // discard the TOS
}
void CodeGenerator::Branch(bool if_true, JumpTarget* target) {
VirtualFrame::SpilledScope spilled_scope;
ASSERT(has_cc());
Condition cc = if_true ? cc_reg_ : NegateCondition(cc_reg_);
target->Branch(cc);
cc_reg_ = al;
}
void CodeGenerator::CheckStack() {
VirtualFrame::SpilledScope spilled_scope;
if (FLAG_check_stack) {
Comment cmnt(masm_, "[ check stack");
__ LoadRoot(ip, Heap::kStackLimitRootIndex);
// Put the lr setup instruction in the delay slot. The 'sizeof(Instr)' is
// added to the implicit 8 byte offset that always applies to operations
// with pc and gives a return address 12 bytes down.
masm_->add(lr, pc, Operand(sizeof(Instr)));
masm_->cmp(sp, Operand(ip));
StackCheckStub stub;
// Call the stub if lower.
masm_->mov(pc,
Operand(reinterpret_cast<intptr_t>(stub.GetCode().location()),
RelocInfo::CODE_TARGET),
LeaveCC,
lo);
}
}
void CodeGenerator::VisitStatements(ZoneList<Statement*>* statements) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
for (int i = 0; frame_ != NULL && i < statements->length(); i++) {
VisitAndSpill(statements->at(i));
}
ASSERT(!has_valid_frame() || frame_->height() == original_height);
}
void CodeGenerator::VisitBlock(Block* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ Block");
CodeForStatementPosition(node);
node->break_target()->set_direction(JumpTarget::FORWARD_ONLY);
VisitStatementsAndSpill(node->statements());
if (node->break_target()->is_linked()) {
node->break_target()->Bind();
}
node->break_target()->Unuse();
ASSERT(!has_valid_frame() || frame_->height() == original_height);
}
void CodeGenerator::DeclareGlobals(Handle<FixedArray> pairs) {
VirtualFrame::SpilledScope spilled_scope;
__ mov(r0, Operand(pairs));
frame_->EmitPush(r0);
frame_->EmitPush(cp);
__ mov(r0, Operand(Smi::FromInt(is_eval() ? 1 : 0)));
frame_->EmitPush(r0);
frame_->CallRuntime(Runtime::kDeclareGlobals, 3);
// The result is discarded.
}
void CodeGenerator::VisitDeclaration(Declaration* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ Declaration");
CodeForStatementPosition(node);
Variable* var = node->proxy()->var();
ASSERT(var != NULL); // must have been resolved
Slot* slot = var->slot();
// If it was not possible to allocate the variable at compile time,
// we need to "declare" it at runtime to make sure it actually
// exists in the local context.
if (slot != NULL && slot->type() == Slot::LOOKUP) {
// Variables with a "LOOKUP" slot were introduced as non-locals
// during variable resolution and must have mode DYNAMIC.
ASSERT(var->is_dynamic());
// For now, just do a runtime call.
frame_->EmitPush(cp);
__ mov(r0, Operand(var->name()));
frame_->EmitPush(r0);
// Declaration nodes are always declared in only two modes.
ASSERT(node->mode() == Variable::VAR || node->mode() == Variable::CONST);
PropertyAttributes attr = node->mode() == Variable::VAR ? NONE : READ_ONLY;
__ mov(r0, Operand(Smi::FromInt(attr)));
frame_->EmitPush(r0);
// Push initial value, if any.
// Note: For variables we must not push an initial value (such as
// 'undefined') because we may have a (legal) redeclaration and we
// must not destroy the current value.
if (node->mode() == Variable::CONST) {
__ LoadRoot(r0, Heap::kTheHoleValueRootIndex);
frame_->EmitPush(r0);
} else if (node->fun() != NULL) {
LoadAndSpill(node->fun());
} else {
__ mov(r0, Operand(0)); // no initial value!
frame_->EmitPush(r0);
}
frame_->CallRuntime(Runtime::kDeclareContextSlot, 4);
// Ignore the return value (declarations are statements).
ASSERT(frame_->height() == original_height);
return;
}
ASSERT(!var->is_global());
// If we have a function or a constant, we need to initialize the variable.
Expression* val = NULL;
if (node->mode() == Variable::CONST) {
val = new Literal(Factory::the_hole_value());
} else {
val = node->fun(); // NULL if we don't have a function
}
if (val != NULL) {
{
// Set initial value.
Reference target(this, node->proxy());
LoadAndSpill(val);
target.SetValue(NOT_CONST_INIT);
// The reference is removed from the stack (preserving TOS) when
// it goes out of scope.
}
// Get rid of the assigned value (declarations are statements).
frame_->Drop();
}
ASSERT(frame_->height() == original_height);
}
void CodeGenerator::VisitExpressionStatement(ExpressionStatement* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ ExpressionStatement");
CodeForStatementPosition(node);
Expression* expression = node->expression();
expression->MarkAsStatement();
LoadAndSpill(expression);
frame_->Drop();
ASSERT(frame_->height() == original_height);
}
void CodeGenerator::VisitEmptyStatement(EmptyStatement* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "// EmptyStatement");
CodeForStatementPosition(node);
// nothing to do
ASSERT(frame_->height() == original_height);
}
void CodeGenerator::VisitIfStatement(IfStatement* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ IfStatement");
// Generate different code depending on which parts of the if statement
// are present or not.
bool has_then_stm = node->HasThenStatement();
bool has_else_stm = node->HasElseStatement();
CodeForStatementPosition(node);
JumpTarget exit;
if (has_then_stm && has_else_stm) {
Comment cmnt(masm_, "[ IfThenElse");
JumpTarget then;
JumpTarget else_;
// if (cond)
LoadConditionAndSpill(node->condition(), NOT_INSIDE_TYPEOF,
&then, &else_, true);
if (frame_ != NULL) {
Branch(false, &else_);
}
// then
if (frame_ != NULL || then.is_linked()) {
then.Bind();
VisitAndSpill(node->then_statement());
}
if (frame_ != NULL) {
exit.Jump();
}
// else
if (else_.is_linked()) {
else_.Bind();
VisitAndSpill(node->else_statement());
}
} else if (has_then_stm) {
Comment cmnt(masm_, "[ IfThen");
ASSERT(!has_else_stm);
JumpTarget then;
// if (cond)
LoadConditionAndSpill(node->condition(), NOT_INSIDE_TYPEOF,
&then, &exit, true);
if (frame_ != NULL) {
Branch(false, &exit);
}
// then
if (frame_ != NULL || then.is_linked()) {
then.Bind();
VisitAndSpill(node->then_statement());
}
} else if (has_else_stm) {
Comment cmnt(masm_, "[ IfElse");
ASSERT(!has_then_stm);
JumpTarget else_;
// if (!cond)
LoadConditionAndSpill(node->condition(), NOT_INSIDE_TYPEOF,
&exit, &else_, true);
if (frame_ != NULL) {
Branch(true, &exit);
}
// else
if (frame_ != NULL || else_.is_linked()) {
else_.Bind();
VisitAndSpill(node->else_statement());
}
} else {
Comment cmnt(masm_, "[ If");
ASSERT(!has_then_stm && !has_else_stm);
// if (cond)
LoadConditionAndSpill(node->condition(), NOT_INSIDE_TYPEOF,
&exit, &exit, false);
if (frame_ != NULL) {
if (has_cc()) {
cc_reg_ = al;
} else {
frame_->Drop();
}
}
}
// end
if (exit.is_linked()) {
exit.Bind();
}
ASSERT(!has_valid_frame() || frame_->height() == original_height);
}
void CodeGenerator::VisitContinueStatement(ContinueStatement* node) {
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ ContinueStatement");
CodeForStatementPosition(node);
node->target()->continue_target()->Jump();
}
void CodeGenerator::VisitBreakStatement(BreakStatement* node) {
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ BreakStatement");
CodeForStatementPosition(node);
node->target()->break_target()->Jump();
}
void CodeGenerator::VisitReturnStatement(ReturnStatement* node) {
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ ReturnStatement");
if (function_return_is_shadowed_) {
CodeForStatementPosition(node);
LoadAndSpill(node->expression());
frame_->EmitPop(r0);
function_return_.Jump();
} else {
// Load the returned value.
CodeForStatementPosition(node);
LoadAndSpill(node->expression());
// Pop the result from the frame and prepare the frame for
// returning thus making it easier to merge.
frame_->EmitPop(r0);
frame_->PrepareForReturn();
function_return_.Jump();
}
}
void CodeGenerator::VisitWithEnterStatement(WithEnterStatement* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ WithEnterStatement");
CodeForStatementPosition(node);
LoadAndSpill(node->expression());
if (node->is_catch_block()) {
frame_->CallRuntime(Runtime::kPushCatchContext, 1);
} else {
frame_->CallRuntime(Runtime::kPushContext, 1);
}
#ifdef DEBUG
JumpTarget verified_true;
__ cmp(r0, Operand(cp));
verified_true.Branch(eq);
__ stop("PushContext: r0 is expected to be the same as cp");
verified_true.Bind();
#endif
// Update context local.
__ str(cp, frame_->Context());
ASSERT(frame_->height() == original_height);
}
void CodeGenerator::VisitWithExitStatement(WithExitStatement* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ WithExitStatement");
CodeForStatementPosition(node);
// Pop context.
__ ldr(cp, ContextOperand(cp, Context::PREVIOUS_INDEX));
// Update context local.
__ str(cp, frame_->Context());
ASSERT(frame_->height() == original_height);
}
void CodeGenerator::VisitSwitchStatement(SwitchStatement* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ SwitchStatement");
CodeForStatementPosition(node);
node->break_target()->set_direction(JumpTarget::FORWARD_ONLY);
LoadAndSpill(node->tag());
JumpTarget next_test;
JumpTarget fall_through;
JumpTarget default_entry;
JumpTarget default_exit(JumpTarget::BIDIRECTIONAL);
ZoneList<CaseClause*>* cases = node->cases();
int length = cases->length();
CaseClause* default_clause = NULL;
for (int i = 0; i < length; i++) {
CaseClause* clause = cases->at(i);
if (clause->is_default()) {
// Remember the default clause and compile it at the end.
default_clause = clause;
continue;
}
Comment cmnt(masm_, "[ Case clause");
// Compile the test.
next_test.Bind();
next_test.Unuse();
// Duplicate TOS.
__ ldr(r0, frame_->Top());
frame_->EmitPush(r0);
Comparison(eq, NULL, clause->label(), true);
Branch(false, &next_test);
// Before entering the body from the test, remove the switch value from
// the stack.
frame_->Drop();
// Label the body so that fall through is enabled.
if (i > 0 && cases->at(i - 1)->is_default()) {
default_exit.Bind();
} else {
fall_through.Bind();
fall_through.Unuse();
}
VisitStatementsAndSpill(clause->statements());
// If control flow can fall through from the body, jump to the next body
// or the end of the statement.
if (frame_ != NULL) {
if (i < length - 1 && cases->at(i + 1)->is_default()) {
default_entry.Jump();
} else {
fall_through.Jump();
}
}
}
// The final "test" removes the switch value.
next_test.Bind();
frame_->Drop();
// If there is a default clause, compile it.
if (default_clause != NULL) {
Comment cmnt(masm_, "[ Default clause");
default_entry.Bind();
VisitStatementsAndSpill(default_clause->statements());
// If control flow can fall out of the default and there is a case after
// it, jup to that case's body.
if (frame_ != NULL && default_exit.is_bound()) {
default_exit.Jump();
}
}
if (fall_through.is_linked()) {
fall_through.Bind();
}
if (node->break_target()->is_linked()) {
node->break_target()->Bind();
}
node->break_target()->Unuse();
ASSERT(!has_valid_frame() || frame_->height() == original_height);
}
void CodeGenerator::VisitLoopStatement(LoopStatement* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ LoopStatement");
CodeForStatementPosition(node);
node->break_target()->set_direction(JumpTarget::FORWARD_ONLY);
// Simple condition analysis. ALWAYS_TRUE and ALWAYS_FALSE represent a
// known result for the test expression, with no side effects.
enum { ALWAYS_TRUE, ALWAYS_FALSE, DONT_KNOW } info = DONT_KNOW;
if (node->cond() == NULL) {
ASSERT(node->type() == LoopStatement::FOR_LOOP);
info = ALWAYS_TRUE;
} else {
Literal* lit = node->cond()->AsLiteral();
if (lit != NULL) {
if (lit->IsTrue()) {
info = ALWAYS_TRUE;
} else if (lit->IsFalse()) {
info = ALWAYS_FALSE;
}
}
}
switch (node->type()) {
case LoopStatement::DO_LOOP: {
JumpTarget body(JumpTarget::BIDIRECTIONAL);
// Label the top of the loop for the backward CFG edge. If the test
// is always true we can use the continue target, and if the test is
// always false there is no need.
if (info == ALWAYS_TRUE) {
node->continue_target()->set_direction(JumpTarget::BIDIRECTIONAL);
node->continue_target()->Bind();
} else if (info == ALWAYS_FALSE) {
node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
} else {
ASSERT(info == DONT_KNOW);
node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
body.Bind();
}
CheckStack(); // TODO(1222600): ignore if body contains calls.
VisitAndSpill(node->body());
// Compile the test.
if (info == ALWAYS_TRUE) {
if (has_valid_frame()) {
// If control can fall off the end of the body, jump back to the
// top.
node->continue_target()->Jump();
}
} else if (info == ALWAYS_FALSE) {
// If we have a continue in the body, we only have to bind its jump
// target.
if (node->continue_target()->is_linked()) {
node->continue_target()->Bind();
}
} else {
ASSERT(info == DONT_KNOW);
// We have to compile the test expression if it can be reached by
// control flow falling out of the body or via continue.
if (node->continue_target()->is_linked()) {
node->continue_target()->Bind();
}
if (has_valid_frame()) {
LoadConditionAndSpill(node->cond(), NOT_INSIDE_TYPEOF,
&body, node->break_target(), true);
if (has_valid_frame()) {
// A invalid frame here indicates that control did not
// fall out of the test expression.
Branch(true, &body);
}
}
}
break;
}
case LoopStatement::WHILE_LOOP: {
// If the test is never true and has no side effects there is no need
// to compile the test or body.
if (info == ALWAYS_FALSE) break;
// Label the top of the loop with the continue target for the backward
// CFG edge.
node->continue_target()->set_direction(JumpTarget::BIDIRECTIONAL);
node->continue_target()->Bind();
if (info == DONT_KNOW) {
JumpTarget body;
LoadConditionAndSpill(node->cond(), NOT_INSIDE_TYPEOF,
&body, node->break_target(), true);
if (has_valid_frame()) {
// A NULL frame indicates that control did not fall out of the
// test expression.
Branch(false, node->break_target());
}
if (has_valid_frame() || body.is_linked()) {
body.Bind();
}
}
if (has_valid_frame()) {
CheckStack(); // TODO(1222600): ignore if body contains calls.
VisitAndSpill(node->body());
// If control flow can fall out of the body, jump back to the top.
if (has_valid_frame()) {
node->continue_target()->Jump();
}
}
break;
}
case LoopStatement::FOR_LOOP: {
JumpTarget loop(JumpTarget::BIDIRECTIONAL);
if (node->init() != NULL) {
VisitAndSpill(node->init());
}
// There is no need to compile the test or body.
if (info == ALWAYS_FALSE) break;
// If there is no update statement, label the top of the loop with the
// continue target, otherwise with the loop target.
if (node->next() == NULL) {
node->continue_target()->set_direction(JumpTarget::BIDIRECTIONAL);
node->continue_target()->Bind();
} else {
node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
loop.Bind();
}
// If the test is always true, there is no need to compile it.
if (info == DONT_KNOW) {
JumpTarget body;
LoadConditionAndSpill(node->cond(), NOT_INSIDE_TYPEOF,
&body, node->break_target(), true);
if (has_valid_frame()) {
Branch(false, node->break_target());
}
if (has_valid_frame() || body.is_linked()) {
body.Bind();
}
}
if (has_valid_frame()) {
CheckStack(); // TODO(1222600): ignore if body contains calls.
VisitAndSpill(node->body());
if (node->next() == NULL) {
// If there is no update statement and control flow can fall out
// of the loop, jump directly to the continue label.
if (has_valid_frame()) {
node->continue_target()->Jump();
}
} else {
// If there is an update statement and control flow can reach it
// via falling out of the body of the loop or continuing, we
// compile the update statement.
if (node->continue_target()->is_linked()) {
node->continue_target()->Bind();
}
if (has_valid_frame()) {
// Record source position of the statement as this code which is
// after the code for the body actually belongs to the loop
// statement and not the body.
CodeForStatementPosition(node);
VisitAndSpill(node->next());
loop.Jump();
}
}
}
break;
}
}
if (node->break_target()->is_linked()) {
node->break_target()->Bind();
}
node->continue_target()->Unuse();
node->break_target()->Unuse();
ASSERT(!has_valid_frame() || frame_->height() == original_height);
}
void CodeGenerator::VisitForInStatement(ForInStatement* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ ForInStatement");
CodeForStatementPosition(node);
JumpTarget primitive;
JumpTarget jsobject;
JumpTarget fixed_array;
JumpTarget entry(JumpTarget::BIDIRECTIONAL);
JumpTarget end_del_check;
JumpTarget exit;
// Get the object to enumerate over (converted to JSObject).
LoadAndSpill(node->enumerable());
// Both SpiderMonkey and kjs ignore null and undefined in contrast
// to the specification. 12.6.4 mandates a call to ToObject.
frame_->EmitPop(r0);
__ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
__ cmp(r0, ip);
exit.Branch(eq);
__ LoadRoot(ip, Heap::kNullValueRootIndex);
__ cmp(r0, ip);
exit.Branch(eq);
// Stack layout in body:
// [iteration counter (Smi)]
// [length of array]
// [FixedArray]
// [Map or 0]
// [Object]
// Check if enumerable is already a JSObject
__ tst(r0, Operand(kSmiTagMask));
primitive.Branch(eq);
__ CompareObjectType(r0, r1, r1, FIRST_JS_OBJECT_TYPE);
jsobject.Branch(hs);
primitive.Bind();
frame_->EmitPush(r0);
Result arg_count(r0);
__ mov(r0, Operand(0));
frame_->InvokeBuiltin(Builtins::TO_OBJECT, CALL_JS, &arg_count, 1);
jsobject.Bind();
// Get the set of properties (as a FixedArray or Map).
frame_->EmitPush(r0); // duplicate the object being enumerated
frame_->EmitPush(r0);
frame_->CallRuntime(Runtime::kGetPropertyNamesFast, 1);
// If we got a Map, we can do a fast modification check.
// Otherwise, we got a FixedArray, and we have to do a slow check.
__ mov(r2, Operand(r0));
__ ldr(r1, FieldMemOperand(r2, HeapObject::kMapOffset));
__ LoadRoot(ip, Heap::kMetaMapRootIndex);
__ cmp(r1, ip);
fixed_array.Branch(ne);
// Get enum cache
__ mov(r1, Operand(r0));
__ ldr(r1, FieldMemOperand(r1, Map::kInstanceDescriptorsOffset));
__ ldr(r1, FieldMemOperand(r1, DescriptorArray::kEnumerationIndexOffset));
__ ldr(r2,
FieldMemOperand(r1, DescriptorArray::kEnumCacheBridgeCacheOffset));
frame_->EmitPush(r0); // map
frame_->EmitPush(r2); // enum cache bridge cache
__ ldr(r0, FieldMemOperand(r2, FixedArray::kLengthOffset));
__ mov(r0, Operand(r0, LSL, kSmiTagSize));
frame_->EmitPush(r0);
__ mov(r0, Operand(Smi::FromInt(0)));
frame_->EmitPush(r0);
entry.Jump();
fixed_array.Bind();
__ mov(r1, Operand(Smi::FromInt(0)));
frame_->EmitPush(r1); // insert 0 in place of Map
frame_->EmitPush(r0);
// Push the length of the array and the initial index onto the stack.
__ ldr(r0, FieldMemOperand(r0, FixedArray::kLengthOffset));
__ mov(r0, Operand(r0, LSL, kSmiTagSize));
frame_->EmitPush(r0);
__ mov(r0, Operand(Smi::FromInt(0))); // init index
frame_->EmitPush(r0);
// Condition.
entry.Bind();
// sp[0] : index
// sp[1] : array/enum cache length
// sp[2] : array or enum cache
// sp[3] : 0 or map
// sp[4] : enumerable
// Grab the current frame's height for the break and continue
// targets only after all the state is pushed on the frame.
node->break_target()->set_direction(JumpTarget::FORWARD_ONLY);
node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
__ ldr(r0, frame_->ElementAt(0)); // load the current count
__ ldr(r1, frame_->ElementAt(1)); // load the length
__ cmp(r0, Operand(r1)); // compare to the array length
node->break_target()->Branch(hs);
__ ldr(r0, frame_->ElementAt(0));
// Get the i'th entry of the array.
__ ldr(r2, frame_->ElementAt(2));
__ add(r2, r2, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
__ ldr(r3, MemOperand(r2, r0, LSL, kPointerSizeLog2 - kSmiTagSize));
// Get Map or 0.
__ ldr(r2, frame_->ElementAt(3));
// Check if this (still) matches the map of the enumerable.
// If not, we have to filter the key.
__ ldr(r1, frame_->ElementAt(4));
__ ldr(r1, FieldMemOperand(r1, HeapObject::kMapOffset));
__ cmp(r1, Operand(r2));
end_del_check.Branch(eq);
// Convert the entry to a string (or null if it isn't a property anymore).
__ ldr(r0, frame_->ElementAt(4)); // push enumerable
frame_->EmitPush(r0);
frame_->EmitPush(r3); // push entry
Result arg_count_reg(r0);
__ mov(r0, Operand(1));
frame_->InvokeBuiltin(Builtins::FILTER_KEY, CALL_JS, &arg_count_reg, 2);
__ mov(r3, Operand(r0));
// If the property has been removed while iterating, we just skip it.
__ LoadRoot(ip, Heap::kNullValueRootIndex);
__ cmp(r3, ip);
node->continue_target()->Branch(eq);
end_del_check.Bind();
// Store the entry in the 'each' expression and take another spin in the
// loop. r3: i'th entry of the enum cache (or string there of)
frame_->EmitPush(r3); // push entry
{ Reference each(this, node->each());
if (!each.is_illegal()) {
if (each.size() > 0) {
__ ldr(r0, frame_->ElementAt(each.size()));
frame_->EmitPush(r0);
}
// If the reference was to a slot we rely on the convenient property
// that it doesn't matter whether a value (eg, r3 pushed above) is
// right on top of or right underneath a zero-sized reference.
each.SetValue(NOT_CONST_INIT);
if (each.size() > 0) {
// It's safe to pop the value lying on top of the reference before
// unloading the reference itself (which preserves the top of stack,
// ie, now the topmost value of the non-zero sized reference), since
// we will discard the top of stack after unloading the reference
// anyway.
frame_->EmitPop(r0);
}
}
}
// Discard the i'th entry pushed above or else the remainder of the
// reference, whichever is currently on top of the stack.
frame_->Drop();
// Body.
CheckStack(); // TODO(1222600): ignore if body contains calls.
VisitAndSpill(node->body());
// Next. Reestablish a spilled frame in case we are coming here via
// a continue in the body.
node->continue_target()->Bind();
frame_->SpillAll();
frame_->EmitPop(r0);
__ add(r0, r0, Operand(Smi::FromInt(1)));
frame_->EmitPush(r0);
entry.Jump();
// Cleanup. No need to spill because VirtualFrame::Drop is safe for
// any frame.
node->break_target()->Bind();
frame_->Drop(5);
// Exit.
exit.Bind();
node->continue_target()->Unuse();
node->break_target()->Unuse();
ASSERT(frame_->height() == original_height);
}
void CodeGenerator::VisitTryCatch(TryCatch* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ TryCatch");
CodeForStatementPosition(node);
JumpTarget try_block;
JumpTarget exit;
try_block.Call();
// --- Catch block ---
frame_->EmitPush(r0);
// Store the caught exception in the catch variable.
{ Reference ref(this, node->catch_var());
ASSERT(ref.is_slot());
// Here we make use of the convenient property that it doesn't matter
// whether a value is immediately on top of or underneath a zero-sized
// reference.
ref.SetValue(NOT_CONST_INIT);
}
// Remove the exception from the stack.
frame_->Drop();
VisitStatementsAndSpill(node->catch_block()->statements());
if (frame_ != NULL) {
exit.Jump();
}
// --- Try block ---
try_block.Bind();
frame_->PushTryHandler(TRY_CATCH_HANDLER);
int handler_height = frame_->height();
// Shadow the labels for all escapes from the try block, including
// returns. During shadowing, the original label is hidden as the
// LabelShadow and operations on the original actually affect the
// shadowing label.
//
// We should probably try to unify the escaping labels and the return
// label.
int nof_escapes = node->escaping_targets()->length();
List<ShadowTarget*> shadows(1 + nof_escapes);
// Add the shadow target for the function return.
static const int kReturnShadowIndex = 0;
shadows.Add(new ShadowTarget(&function_return_));
bool function_return_was_shadowed = function_return_is_shadowed_;
function_return_is_shadowed_ = true;
ASSERT(shadows[kReturnShadowIndex]->other_target() == &function_return_);
// Add the remaining shadow targets.
for (int i = 0; i < nof_escapes; i++) {
shadows.Add(new ShadowTarget(node->escaping_targets()->at(i)));
}
// Generate code for the statements in the try block.
VisitStatementsAndSpill(node->try_block()->statements());
// Stop the introduced shadowing and count the number of required unlinks.
// After shadowing stops, the original labels are unshadowed and the
// LabelShadows represent the formerly shadowing labels.
bool has_unlinks = false;
for (int i = 0; i < shadows.length(); i++) {
shadows[i]->StopShadowing();
has_unlinks = has_unlinks || shadows[i]->is_linked();
}
function_return_is_shadowed_ = function_return_was_shadowed;
// Get an external reference to the handler address.
ExternalReference handler_address(Top::k_handler_address);
// If we can fall off the end of the try block, unlink from try chain.
if (has_valid_frame()) {
// The next handler address is on top of the frame. Unlink from
// the handler list and drop the rest of this handler from the
// frame.
ASSERT(StackHandlerConstants::kNextOffset == 0);
frame_->EmitPop(r1);
__ mov(r3, Operand(handler_address));
__ str(r1, MemOperand(r3));
frame_->Drop(StackHandlerConstants::kSize / kPointerSize - 1);
if (has_unlinks) {
exit.Jump();
}
}
// Generate unlink code for the (formerly) shadowing labels that have been
// jumped to. Deallocate each shadow target.
for (int i = 0; i < shadows.length(); i++) {
if (shadows[i]->is_linked()) {
// Unlink from try chain;
shadows[i]->Bind();
// Because we can be jumping here (to spilled code) from unspilled
// code, we need to reestablish a spilled frame at this block.
frame_->SpillAll();
// Reload sp from the top handler, because some statements that we
// break from (eg, for...in) may have left stuff on the stack.
__ mov(r3, Operand(handler_address));
__ ldr(sp, MemOperand(r3));
frame_->Forget(frame_->height() - handler_height);
ASSERT(StackHandlerConstants::kNextOffset == 0);
frame_->EmitPop(r1);
__ str(r1, MemOperand(r3));
frame_->Drop(StackHandlerConstants::kSize / kPointerSize - 1);
if (!function_return_is_shadowed_ && i == kReturnShadowIndex) {
frame_->PrepareForReturn();
}
shadows[i]->other_target()->Jump();
}
}
exit.Bind();
ASSERT(!has_valid_frame() || frame_->height() == original_height);
}
void CodeGenerator::VisitTryFinally(TryFinally* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ TryFinally");
CodeForStatementPosition(node);
// State: Used to keep track of reason for entering the finally
// block. Should probably be extended to hold information for
// break/continue from within the try block.
enum { FALLING, THROWING, JUMPING };
JumpTarget try_block;
JumpTarget finally_block;
try_block.Call();
frame_->EmitPush(r0); // save exception object on the stack
// In case of thrown exceptions, this is where we continue.
__ mov(r2, Operand(Smi::FromInt(THROWING)));
finally_block.Jump();
// --- Try block ---
try_block.Bind();
frame_->PushTryHandler(TRY_FINALLY_HANDLER);
int handler_height = frame_->height();
// Shadow the labels for all escapes from the try block, including
// returns. Shadowing hides the original label as the LabelShadow and
// operations on the original actually affect the shadowing label.
//
// We should probably try to unify the escaping labels and the return
// label.
int nof_escapes = node->escaping_targets()->length();
List<ShadowTarget*> shadows(1 + nof_escapes);
// Add the shadow target for the function return.
static const int kReturnShadowIndex = 0;
shadows.Add(new ShadowTarget(&function_return_));
bool function_return_was_shadowed = function_return_is_shadowed_;
function_return_is_shadowed_ = true;
ASSERT(shadows[kReturnShadowIndex]->other_target() == &function_return_);
// Add the remaining shadow targets.
for (int i = 0; i < nof_escapes; i++) {
shadows.Add(new ShadowTarget(node->escaping_targets()->at(i)));
}
// Generate code for the statements in the try block.
VisitStatementsAndSpill(node->try_block()->statements());
// Stop the introduced shadowing and count the number of required unlinks.
// After shadowing stops, the original labels are unshadowed and the
// LabelShadows represent the formerly shadowing labels.
int nof_unlinks = 0;
for (int i = 0; i < shadows.length(); i++) {
shadows[i]->StopShadowing();
if (shadows[i]->is_linked()) nof_unlinks++;
}
function_return_is_shadowed_ = function_return_was_shadowed;
// Get an external reference to the handler address.
ExternalReference handler_address(Top::k_handler_address);
// If we can fall off the end of the try block, unlink from the try
// chain and set the state on the frame to FALLING.
if (has_valid_frame()) {
// The next handler address is on top of the frame.
ASSERT(StackHandlerConstants::kNextOffset == 0);
frame_->EmitPop(r1);
__ mov(r3, Operand(handler_address));
__ str(r1, MemOperand(r3));
frame_->Drop(StackHandlerConstants::kSize / kPointerSize - 1);
// Fake a top of stack value (unneeded when FALLING) and set the
// state in r2, then jump around the unlink blocks if any.
__ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
frame_->EmitPush(r0);
__ mov(r2, Operand(Smi::FromInt(FALLING)));
if (nof_unlinks > 0) {
finally_block.Jump();
}
}
// Generate code to unlink and set the state for the (formerly)
// shadowing targets that have been jumped to.
for (int i = 0; i < shadows.length(); i++) {
if (shadows[i]->is_linked()) {
// If we have come from the shadowed return, the return value is
// in (a non-refcounted reference to) r0. We must preserve it
// until it is pushed.
//
// Because we can be jumping here (to spilled code) from
// unspilled code, we need to reestablish a spilled frame at
// this block.
shadows[i]->Bind();
frame_->SpillAll();
// Reload sp from the top handler, because some statements that
// we break from (eg, for...in) may have left stuff on the
// stack.
__ mov(r3, Operand(handler_address));
__ ldr(sp, MemOperand(r3));
frame_->Forget(frame_->height() - handler_height);
// Unlink this handler and drop it from the frame. The next
// handler address is currently on top of the frame.
ASSERT(StackHandlerConstants::kNextOffset == 0);
frame_->EmitPop(r1);
__ str(r1, MemOperand(r3));
frame_->Drop(StackHandlerConstants::kSize / kPointerSize - 1);
if (i == kReturnShadowIndex) {
// If this label shadowed the function return, materialize the
// return value on the stack.
frame_->EmitPush(r0);
} else {
// Fake TOS for targets that shadowed breaks and continues.
__ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
frame_->EmitPush(r0);
}
__ mov(r2, Operand(Smi::FromInt(JUMPING + i)));
if (--nof_unlinks > 0) {
// If this is not the last unlink block, jump around the next.
finally_block.Jump();
}
}
}
// --- Finally block ---
finally_block.Bind();
// Push the state on the stack.
frame_->EmitPush(r2);
// We keep two elements on the stack - the (possibly faked) result
// and the state - while evaluating the finally block.
//
// Generate code for the statements in the finally block.
VisitStatementsAndSpill(node->finally_block()->statements());
if (has_valid_frame()) {
// Restore state and return value or faked TOS.
frame_->EmitPop(r2);
frame_->EmitPop(r0);
}
// Generate code to jump to the right destination for all used
// formerly shadowing targets. Deallocate each shadow target.
for (int i = 0; i < shadows.length(); i++) {
if (has_valid_frame() && shadows[i]->is_bound()) {
JumpTarget* original = shadows[i]->other_target();
__ cmp(r2, Operand(Smi::FromInt(JUMPING + i)));
if (!function_return_is_shadowed_ && i == kReturnShadowIndex) {
JumpTarget skip;
skip.Branch(ne);
frame_->PrepareForReturn();
original->Jump();
skip.Bind();
} else {
original->Branch(eq);
}
}
}
if (has_valid_frame()) {
// Check if we need to rethrow the exception.
JumpTarget exit;
__ cmp(r2, Operand(Smi::FromInt(THROWING)));
exit.Branch(ne);
// Rethrow exception.
frame_->EmitPush(r0);
frame_->CallRuntime(Runtime::kReThrow, 1);
// Done.
exit.Bind();
}
ASSERT(!has_valid_frame() || frame_->height() == original_height);
}
void CodeGenerator::VisitDebuggerStatement(DebuggerStatement* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ DebuggerStatament");
CodeForStatementPosition(node);
#ifdef ENABLE_DEBUGGER_SUPPORT
frame_->CallRuntime(Runtime::kDebugBreak, 0);
#endif
// Ignore the return value.
ASSERT(frame_->height() == original_height);
}
void CodeGenerator::InstantiateBoilerplate(Handle<JSFunction> boilerplate) {
VirtualFrame::SpilledScope spilled_scope;
ASSERT(boilerplate->IsBoilerplate());
// Push the boilerplate on the stack.
__ mov(r0, Operand(boilerplate));
frame_->EmitPush(r0);
// Create a new closure.
frame_->EmitPush(cp);
frame_->CallRuntime(Runtime::kNewClosure, 2);
frame_->EmitPush(r0);
}
void CodeGenerator::VisitFunctionLiteral(FunctionLiteral* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ FunctionLiteral");
// Build the function boilerplate and instantiate it.
Handle<JSFunction> boilerplate = BuildBoilerplate(node);
// Check for stack-overflow exception.
if (HasStackOverflow()) {
ASSERT(frame_->height() == original_height);
return;
}
InstantiateBoilerplate(boilerplate);
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::VisitFunctionBoilerplateLiteral(
FunctionBoilerplateLiteral* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ FunctionBoilerplateLiteral");
InstantiateBoilerplate(node->boilerplate());
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::VisitConditional(Conditional* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ Conditional");
JumpTarget then;
JumpTarget else_;
LoadConditionAndSpill(node->condition(), NOT_INSIDE_TYPEOF,
&then, &else_, true);
if (has_valid_frame()) {
Branch(false, &else_);
}
if (has_valid_frame() || then.is_linked()) {
then.Bind();
LoadAndSpill(node->then_expression(), typeof_state());
}
if (else_.is_linked()) {
JumpTarget exit;
if (has_valid_frame()) exit.Jump();
else_.Bind();
LoadAndSpill(node->else_expression(), typeof_state());
if (exit.is_linked()) exit.Bind();
}
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::LoadFromSlot(Slot* slot, TypeofState typeof_state) {
VirtualFrame::SpilledScope spilled_scope;
if (slot->type() == Slot::LOOKUP) {
ASSERT(slot->var()->is_dynamic());
JumpTarget slow;
JumpTarget done;
// Generate fast-case code for variables that might be shadowed by
// eval-introduced variables. Eval is used a lot without
// introducing variables. In those cases, we do not want to
// perform a runtime call for all variables in the scope
// containing the eval.
if (slot->var()->mode() == Variable::DYNAMIC_GLOBAL) {
LoadFromGlobalSlotCheckExtensions(slot, typeof_state, r1, r2, &slow);
// If there was no control flow to slow, we can exit early.
if (!slow.is_linked()) {
frame_->EmitPush(r0);
return;
}
done.Jump();
} else if (slot->var()->mode() == Variable::DYNAMIC_LOCAL) {
Slot* potential_slot = slot->var()->local_if_not_shadowed()->slot();
// Only generate the fast case for locals that rewrite to slots.
// This rules out argument loads.
if (potential_slot != NULL) {
__ ldr(r0,
ContextSlotOperandCheckExtensions(potential_slot,
r1,
r2,
&slow));
if (potential_slot->var()->mode() == Variable::CONST) {
__ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
__ cmp(r0, ip);
__ LoadRoot(r0, Heap::kUndefinedValueRootIndex, eq);
}
// There is always control flow to slow from
// ContextSlotOperandCheckExtensions so we have to jump around
// it.
done.Jump();
}
}
slow.Bind();
frame_->EmitPush(cp);
__ mov(r0, Operand(slot->var()->name()));
frame_->EmitPush(r0);
if (typeof_state == INSIDE_TYPEOF) {
frame_->CallRuntime(Runtime::kLoadContextSlotNoReferenceError, 2);
} else {
frame_->CallRuntime(Runtime::kLoadContextSlot, 2);
}
done.Bind();
frame_->EmitPush(r0);
} else {
// Note: We would like to keep the assert below, but it fires because of
// some nasty code in LoadTypeofExpression() which should be removed...
// ASSERT(!slot->var()->is_dynamic());
// Special handling for locals allocated in registers.
__ ldr(r0, SlotOperand(slot, r2));
frame_->EmitPush(r0);
if (slot->var()->mode() == Variable::CONST) {
// Const slots may contain 'the hole' value (the constant hasn't been
// initialized yet) which needs to be converted into the 'undefined'
// value.
Comment cmnt(masm_, "[ Unhole const");
frame_->EmitPop(r0);
__ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
__ cmp(r0, ip);
__ LoadRoot(r0, Heap::kUndefinedValueRootIndex, eq);
frame_->EmitPush(r0);
}
}
}
void CodeGenerator::LoadFromGlobalSlotCheckExtensions(Slot* slot,
TypeofState typeof_state,
Register tmp,
Register tmp2,
JumpTarget* slow) {
// Check that no extension objects have been created by calls to
// eval from the current scope to the global scope.
Register context = cp;
Scope* s = scope();
while (s != NULL) {
if (s->num_heap_slots() > 0) {
if (s->calls_eval()) {
// Check that extension is NULL.
__ ldr(tmp2, ContextOperand(context, Context::EXTENSION_INDEX));
__ tst(tmp2, tmp2);
slow->Branch(ne);
}
// Load next context in chain.
__ ldr(tmp, ContextOperand(context, Context::CLOSURE_INDEX));
__ ldr(tmp, FieldMemOperand(tmp, JSFunction::kContextOffset));
context = tmp;
}
// If no outer scope calls eval, we do not need to check more
// context extensions.
if (!s->outer_scope_calls_eval() || s->is_eval_scope()) break;
s = s->outer_scope();
}
if (s->is_eval_scope()) {
Label next, fast;
if (!context.is(tmp)) {
__ mov(tmp, Operand(context));
}
__ bind(&next);
// Terminate at global context.
__ ldr(tmp2, FieldMemOperand(tmp, HeapObject::kMapOffset));
__ LoadRoot(ip, Heap::kGlobalContextMapRootIndex);
__ cmp(tmp2, ip);
__ b(eq, &fast);
// Check that extension is NULL.
__ ldr(tmp2, ContextOperand(tmp, Context::EXTENSION_INDEX));
__ tst(tmp2, tmp2);
slow->Branch(ne);
// Load next context in chain.
__ ldr(tmp, ContextOperand(tmp, Context::CLOSURE_INDEX));
__ ldr(tmp, FieldMemOperand(tmp, JSFunction::kContextOffset));
__ b(&next);
__ bind(&fast);
}
// All extension objects were empty and it is safe to use a global
// load IC call.
Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Initialize));
// Load the global object.
LoadGlobal();
// Setup the name register.
Result name(r2);
__ mov(r2, Operand(slot->var()->name()));
// Call IC stub.
if (typeof_state == INSIDE_TYPEOF) {
frame_->CallCodeObject(ic, RelocInfo::CODE_TARGET, &name, 0);
} else {
frame_->CallCodeObject(ic, RelocInfo::CODE_TARGET_CONTEXT, &name, 0);
}
// Drop the global object. The result is in r0.
frame_->Drop();
}
void CodeGenerator::VisitSlot(Slot* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ Slot");
LoadFromSlot(node, typeof_state());
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::VisitVariableProxy(VariableProxy* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ VariableProxy");
Variable* var = node->var();
Expression* expr = var->rewrite();
if (expr != NULL) {
Visit(expr);
} else {
ASSERT(var->is_global());
Reference ref(this, node);
ref.GetValueAndSpill(typeof_state());
}
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::VisitLiteral(Literal* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ Literal");
__ mov(r0, Operand(node->handle()));
frame_->EmitPush(r0);
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::VisitRegExpLiteral(RegExpLiteral* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ RexExp Literal");
// Retrieve the literal array and check the allocated entry.
// Load the function of this activation.
__ ldr(r1, frame_->Function());
// Load the literals array of the function.
__ ldr(r1, FieldMemOperand(r1, JSFunction::kLiteralsOffset));
// Load the literal at the ast saved index.
int literal_offset =
FixedArray::kHeaderSize + node->literal_index() * kPointerSize;
__ ldr(r2, FieldMemOperand(r1, literal_offset));
JumpTarget done;
__ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
__ cmp(r2, ip);
done.Branch(ne);
// If the entry is undefined we call the runtime system to computed
// the literal.
frame_->EmitPush(r1); // literal array (0)
__ mov(r0, Operand(Smi::FromInt(node->literal_index())));
frame_->EmitPush(r0); // literal index (1)
__ mov(r0, Operand(node->pattern())); // RegExp pattern (2)
frame_->EmitPush(r0);
__ mov(r0, Operand(node->flags())); // RegExp flags (3)
frame_->EmitPush(r0);
frame_->CallRuntime(Runtime::kMaterializeRegExpLiteral, 4);
__ mov(r2, Operand(r0));
done.Bind();
// Push the literal.
frame_->EmitPush(r2);
ASSERT(frame_->height() == original_height + 1);
}
// This deferred code stub will be used for creating the boilerplate
// by calling Runtime_CreateObjectLiteralBoilerplate.
// Each created boilerplate is stored in the JSFunction and they are
// therefore context dependent.
class DeferredObjectLiteral: public DeferredCode {
public:
explicit DeferredObjectLiteral(ObjectLiteral* node) : node_(node) {
set_comment("[ DeferredObjectLiteral");
}
virtual void Generate();
private:
ObjectLiteral* node_;
};
void DeferredObjectLiteral::Generate() {
// Argument is passed in r1.
// If the entry is undefined we call the runtime system to compute
// the literal.
// Literal array (0).
__ push(r1);
// Literal index (1).
__ mov(r0, Operand(Smi::FromInt(node_->literal_index())));
__ push(r0);
// Constant properties (2).
__ mov(r0, Operand(node_->constant_properties()));
__ push(r0);
__ CallRuntime(Runtime::kCreateObjectLiteralBoilerplate, 3);
__ mov(r2, Operand(r0));
// Result is returned in r2.
}
void CodeGenerator::VisitObjectLiteral(ObjectLiteral* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ ObjectLiteral");
DeferredObjectLiteral* deferred = new DeferredObjectLiteral(node);
// Retrieve the literal array and check the allocated entry.
// Load the function of this activation.
__ ldr(r1, frame_->Function());
// Load the literals array of the function.
__ ldr(r1, FieldMemOperand(r1, JSFunction::kLiteralsOffset));
// Load the literal at the ast saved index.
int literal_offset =
FixedArray::kHeaderSize + node->literal_index() * kPointerSize;
__ ldr(r2, FieldMemOperand(r1, literal_offset));
// Check whether we need to materialize the object literal boilerplate.
// If so, jump to the deferred code.
__ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
__ cmp(r2, Operand(ip));
deferred->Branch(eq);
deferred->BindExit();
// Push the object literal boilerplate.
frame_->EmitPush(r2);
// Clone the boilerplate object.
Runtime::FunctionId clone_function_id = Runtime::kCloneLiteralBoilerplate;
if (node->depth() == 1) {
clone_function_id = Runtime::kCloneShallowLiteralBoilerplate;
}
frame_->CallRuntime(clone_function_id, 1);
frame_->EmitPush(r0); // save the result
// r0: cloned object literal
for (int i = 0; i < node->properties()->length(); i++) {
ObjectLiteral::Property* property = node->properties()->at(i);
Literal* key = property->key();
Expression* value = property->value();
switch (property->kind()) {
case ObjectLiteral::Property::CONSTANT:
break;
case ObjectLiteral::Property::MATERIALIZED_LITERAL:
if (CompileTimeValue::IsCompileTimeValue(property->value())) break;
// else fall through
case ObjectLiteral::Property::COMPUTED: // fall through
case ObjectLiteral::Property::PROTOTYPE: {
frame_->EmitPush(r0); // dup the result
LoadAndSpill(key);
LoadAndSpill(value);
frame_->CallRuntime(Runtime::kSetProperty, 3);
// restore r0
__ ldr(r0, frame_->Top());
break;
}
case ObjectLiteral::Property::SETTER: {
frame_->EmitPush(r0);
LoadAndSpill(key);
__ mov(r0, Operand(Smi::FromInt(1)));
frame_->EmitPush(r0);
LoadAndSpill(value);
frame_->CallRuntime(Runtime::kDefineAccessor, 4);
__ ldr(r0, frame_->Top());
break;
}
case ObjectLiteral::Property::GETTER: {
frame_->EmitPush(r0);
LoadAndSpill(key);
__ mov(r0, Operand(Smi::FromInt(0)));
frame_->EmitPush(r0);
LoadAndSpill(value);
frame_->CallRuntime(Runtime::kDefineAccessor, 4);
__ ldr(r0, frame_->Top());
break;
}
}
}
ASSERT(frame_->height() == original_height + 1);
}
// This deferred code stub will be used for creating the boilerplate
// by calling Runtime_CreateArrayLiteralBoilerplate.
// Each created boilerplate is stored in the JSFunction and they are
// therefore context dependent.
class DeferredArrayLiteral: public DeferredCode {
public:
explicit DeferredArrayLiteral(ArrayLiteral* node) : node_(node) {
set_comment("[ DeferredArrayLiteral");
}
virtual void Generate();
private:
ArrayLiteral* node_;
};
void DeferredArrayLiteral::Generate() {
// Argument is passed in r1.
// If the entry is undefined we call the runtime system to computed
// the literal.
// Literal array (0).
__ push(r1);
// Literal index (1).
__ mov(r0, Operand(Smi::FromInt(node_->literal_index())));
__ push(r0);
// Constant properties (2).
__ mov(r0, Operand(node_->literals()));
__ push(r0);
__ CallRuntime(Runtime::kCreateArrayLiteralBoilerplate, 3);
__ mov(r2, Operand(r0));
// Result is returned in r2.
}
void CodeGenerator::VisitArrayLiteral(ArrayLiteral* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ ArrayLiteral");
DeferredArrayLiteral* deferred = new DeferredArrayLiteral(node);
// Retrieve the literal array and check the allocated entry.
// Load the function of this activation.
__ ldr(r1, frame_->Function());
// Load the literals array of the function.
__ ldr(r1, FieldMemOperand(r1, JSFunction::kLiteralsOffset));
// Load the literal at the ast saved index.
int literal_offset =
FixedArray::kHeaderSize + node->literal_index() * kPointerSize;
__ ldr(r2, FieldMemOperand(r1, literal_offset));
// Check whether we need to materialize the object literal boilerplate.
// If so, jump to the deferred code.
__ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
__ cmp(r2, Operand(ip));
deferred->Branch(eq);
deferred->BindExit();
// Push the object literal boilerplate.
frame_->EmitPush(r2);
// Clone the boilerplate object.
Runtime::FunctionId clone_function_id = Runtime::kCloneLiteralBoilerplate;
if (node->depth() == 1) {
clone_function_id = Runtime::kCloneShallowLiteralBoilerplate;
}
frame_->CallRuntime(clone_function_id, 1);
frame_->EmitPush(r0); // save the result
// r0: cloned object literal
// Generate code to set the elements in the array that are not
// literals.
for (int i = 0; i < node->values()->length(); i++) {
Expression* value = node->values()->at(i);
// If value is a literal the property value is already set in the
// boilerplate object.
if (value->AsLiteral() != NULL) continue;
// If value is a materialized literal the property value is already set
// in the boilerplate object if it is simple.
if (CompileTimeValue::IsCompileTimeValue(value)) continue;
// The property must be set by generated code.
LoadAndSpill(value);
frame_->EmitPop(r0);
// Fetch the object literal.
__ ldr(r1, frame_->Top());
// Get the elements array.
__ ldr(r1, FieldMemOperand(r1, JSObject::kElementsOffset));
// Write to the indexed properties array.
int offset = i * kPointerSize + FixedArray::kHeaderSize;
__ str(r0, FieldMemOperand(r1, offset));
// Update the write barrier for the array address.
__ mov(r3, Operand(offset));
__ RecordWrite(r1, r3, r2);
}
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::VisitCatchExtensionObject(CatchExtensionObject* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
// Call runtime routine to allocate the catch extension object and
// assign the exception value to the catch variable.
Comment cmnt(masm_, "[ CatchExtensionObject");
LoadAndSpill(node->key());
LoadAndSpill(node->value());
frame_->CallRuntime(Runtime::kCreateCatchExtensionObject, 2);
frame_->EmitPush(r0);
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::VisitAssignment(Assignment* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ Assignment");
CodeForStatementPosition(node);
{ Reference target(this, node->target());
if (target.is_illegal()) {
// Fool the virtual frame into thinking that we left the assignment's
// value on the frame.
__ mov(r0, Operand(Smi::FromInt(0)));
frame_->EmitPush(r0);
ASSERT(frame_->height() == original_height + 1);
return;
}
if (node->op() == Token::ASSIGN ||
node->op() == Token::INIT_VAR ||
node->op() == Token::INIT_CONST) {
LoadAndSpill(node->value());
} else {
// +=, *= and similar binary assignments.
// Get the old value of the lhs.
target.GetValueAndSpill(NOT_INSIDE_TYPEOF);
Literal* literal = node->value()->AsLiteral();
bool overwrite =
(node->value()->AsBinaryOperation() != NULL &&
node->value()->AsBinaryOperation()->ResultOverwriteAllowed());
if (literal != NULL && literal->handle()->IsSmi()) {
SmiOperation(node->binary_op(),
literal->handle(),
false,
overwrite ? OVERWRITE_RIGHT : NO_OVERWRITE);
frame_->EmitPush(r0);
} else {
LoadAndSpill(node->value());
GenericBinaryOperation(node->binary_op(),
overwrite ? OVERWRITE_RIGHT : NO_OVERWRITE);
frame_->EmitPush(r0);
}
}
Variable* var = node->target()->AsVariableProxy()->AsVariable();
if (var != NULL &&
(var->mode() == Variable::CONST) &&
node->op() != Token::INIT_VAR && node->op() != Token::INIT_CONST) {
// Assignment ignored - leave the value on the stack.
} else {
CodeForSourcePosition(node->position());
if (node->op() == Token::INIT_CONST) {
// Dynamic constant initializations must use the function context
// and initialize the actual constant declared. Dynamic variable
// initializations are simply assignments and use SetValue.
target.SetValue(CONST_INIT);
} else {
target.SetValue(NOT_CONST_INIT);
}
}
}
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::VisitThrow(Throw* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ Throw");
LoadAndSpill(node->exception());
CodeForSourcePosition(node->position());
frame_->CallRuntime(Runtime::kThrow, 1);
frame_->EmitPush(r0);
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::VisitProperty(Property* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ Property");
{ Reference property(this, node);
property.GetValueAndSpill(typeof_state());
}
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::VisitCall(Call* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ Call");
ZoneList<Expression*>* args = node->arguments();
CodeForStatementPosition(node);
// Standard function call.
// Check if the function is a variable or a property.
Expression* function = node->expression();
Variable* var = function->AsVariableProxy()->AsVariable();
Property* property = function->AsProperty();
// ------------------------------------------------------------------------
// Fast-case: Use inline caching.
// ---
// According to ECMA-262, section 11.2.3, page 44, the function to call
// must be resolved after the arguments have been evaluated. The IC code
// automatically handles this by loading the arguments before the function
// is resolved in cache misses (this also holds for megamorphic calls).
// ------------------------------------------------------------------------
if (var != NULL && !var->is_this() && var->is_global()) {
// ----------------------------------
// JavaScript example: 'foo(1, 2, 3)' // foo is global
// ----------------------------------
// Push the name of the function and the receiver onto the stack.
__ mov(r0, Operand(var->name()));
frame_->EmitPush(r0);
// Pass the global object as the receiver and let the IC stub
// patch the stack to use the global proxy as 'this' in the
// invoked function.
LoadGlobal();
// Load the arguments.
int arg_count = args->length();
for (int i = 0; i < arg_count; i++) {
LoadAndSpill(args->at(i));
}
// Setup the receiver register and call the IC initialization code.
InLoopFlag in_loop = loop_nesting() > 0 ? IN_LOOP : NOT_IN_LOOP;
Handle<Code> stub = ComputeCallInitialize(arg_count, in_loop);
CodeForSourcePosition(node->position());
frame_->CallCodeObject(stub, RelocInfo::CODE_TARGET_CONTEXT,
arg_count + 1);
__ ldr(cp, frame_->Context());
// Remove the function from the stack.
frame_->Drop();
frame_->EmitPush(r0);
} else if (var != NULL && var->slot() != NULL &&
var->slot()->type() == Slot::LOOKUP) {
// ----------------------------------
// JavaScript example: 'with (obj) foo(1, 2, 3)' // foo is in obj
// ----------------------------------
// Load the function
frame_->EmitPush(cp);
__ mov(r0, Operand(var->name()));
frame_->EmitPush(r0);
frame_->CallRuntime(Runtime::kLoadContextSlot, 2);
// r0: slot value; r1: receiver
// Load the receiver.
frame_->EmitPush(r0); // function
frame_->EmitPush(r1); // receiver
// Call the function.
CallWithArguments(args, node->position());
frame_->EmitPush(r0);
} else if (property != NULL) {
// Check if the key is a literal string.
Literal* literal = property->key()->AsLiteral();
if (literal != NULL && literal->handle()->IsSymbol()) {
// ------------------------------------------------------------------
// JavaScript example: 'object.foo(1, 2, 3)' or 'map["key"](1, 2, 3)'
// ------------------------------------------------------------------
// Push the name of the function and the receiver onto the stack.
__ mov(r0, Operand(literal->handle()));
frame_->EmitPush(r0);
LoadAndSpill(property->obj());
// Load the arguments.
int arg_count = args->length();
for (int i = 0; i < arg_count; i++) {
LoadAndSpill(args->at(i));
}
// Set the receiver register and call the IC initialization code.
InLoopFlag in_loop = loop_nesting() > 0 ? IN_LOOP : NOT_IN_LOOP;
Handle<Code> stub = ComputeCallInitialize(arg_count, in_loop);
CodeForSourcePosition(node->position());
frame_->CallCodeObject(stub, RelocInfo::CODE_TARGET, arg_count + 1);
__ ldr(cp, frame_->Context());
// Remove the function from the stack.
frame_->Drop();
frame_->EmitPush(r0); // push after get rid of function from the stack
} else {
// -------------------------------------------
// JavaScript example: 'array[index](1, 2, 3)'
// -------------------------------------------
// Load the function to call from the property through a reference.
Reference ref(this, property);
ref.GetValueAndSpill(NOT_INSIDE_TYPEOF); // receiver
// Pass receiver to called function.
if (property->is_synthetic()) {
LoadGlobalReceiver(r0);
} else {
__ ldr(r0, frame_->ElementAt(ref.size()));
frame_->EmitPush(r0);
}
// Call the function.
CallWithArguments(args, node->position());
frame_->EmitPush(r0);
}
} else {
// ----------------------------------
// JavaScript example: 'foo(1, 2, 3)' // foo is not global
// ----------------------------------
// Load the function.
LoadAndSpill(function);
// Pass the global proxy as the receiver.
LoadGlobalReceiver(r0);
// Call the function.
CallWithArguments(args, node->position());
frame_->EmitPush(r0);
}
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::VisitCallEval(CallEval* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ CallEval");
// In a call to eval, we first call %ResolvePossiblyDirectEval to resolve
// the function we need to call and the receiver of the call.
// Then we call the resolved function using the given arguments.
ZoneList<Expression*>* args = node->arguments();
Expression* function = node->expression();
CodeForStatementPosition(node);
// Prepare stack for call to resolved function.
LoadAndSpill(function);
__ LoadRoot(r2, Heap::kUndefinedValueRootIndex);
frame_->EmitPush(r2); // Slot for receiver
int arg_count = args->length();
for (int i = 0; i < arg_count; i++) {
LoadAndSpill(args->at(i));
}
// Prepare stack for call to ResolvePossiblyDirectEval.
__ ldr(r1, MemOperand(sp, arg_count * kPointerSize + kPointerSize));
frame_->EmitPush(r1);
if (arg_count > 0) {
__ ldr(r1, MemOperand(sp, arg_count * kPointerSize));
frame_->EmitPush(r1);
} else {
frame_->EmitPush(r2);
}
// Resolve the call.
frame_->CallRuntime(Runtime::kResolvePossiblyDirectEval, 2);
// Touch up stack with the right values for the function and the receiver.
__ ldr(r1, FieldMemOperand(r0, FixedArray::kHeaderSize));
__ str(r1, MemOperand(sp, (arg_count + 1) * kPointerSize));
__ ldr(r1, FieldMemOperand(r0, FixedArray::kHeaderSize + kPointerSize));
__ str(r1, MemOperand(sp, arg_count * kPointerSize));
// Call the function.
CodeForSourcePosition(node->position());
InLoopFlag in_loop = loop_nesting() > 0 ? IN_LOOP : NOT_IN_LOOP;
CallFunctionStub call_function(arg_count, in_loop);
frame_->CallStub(&call_function, arg_count + 1);
__ ldr(cp, frame_->Context());
// Remove the function from the stack.
frame_->Drop();
frame_->EmitPush(r0);
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::VisitCallNew(CallNew* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ CallNew");
CodeForStatementPosition(node);
// According to ECMA-262, section 11.2.2, page 44, the function
// expression in new calls must be evaluated before the
// arguments. This is different from ordinary calls, where the
// actual function to call is resolved after the arguments have been
// evaluated.
// Compute function to call and use the global object as the
// receiver. There is no need to use the global proxy here because
// it will always be replaced with a newly allocated object.
LoadAndSpill(node->expression());
LoadGlobal();
// Push the arguments ("left-to-right") on the stack.
ZoneList<Expression*>* args = node->arguments();
int arg_count = args->length();
for (int i = 0; i < arg_count; i++) {
LoadAndSpill(args->at(i));
}
// r0: the number of arguments.
Result num_args(r0);
__ mov(r0, Operand(arg_count));
// Load the function into r1 as per calling convention.
Result function(r1);
__ ldr(r1, frame_->ElementAt(arg_count + 1));
// Call the construct call builtin that handles allocation and
// constructor invocation.
CodeForSourcePosition(node->position());
Handle<Code> ic(Builtins::builtin(Builtins::JSConstructCall));
frame_->CallCodeObject(ic,
RelocInfo::CONSTRUCT_CALL,
&num_args,
&function,
arg_count + 1);
// Discard old TOS value and push r0 on the stack (same as Pop(), push(r0)).
__ str(r0, frame_->Top());
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::GenerateClassOf(ZoneList<Expression*>* args) {
VirtualFrame::SpilledScope spilled_scope;
ASSERT(args->length() == 1);
JumpTarget leave, null, function, non_function_constructor;
// Load the object into r0.
LoadAndSpill(args->at(0));
frame_->EmitPop(r0);
// If the object is a smi, we return null.
__ tst(r0, Operand(kSmiTagMask));
null.Branch(eq);
// Check that the object is a JS object but take special care of JS
// functions to make sure they have 'Function' as their class.
__ CompareObjectType(r0, r0, r1, FIRST_JS_OBJECT_TYPE);
null.Branch(lt);
// As long as JS_FUNCTION_TYPE is the last instance type and it is
// right after LAST_JS_OBJECT_TYPE, we can avoid checking for
// LAST_JS_OBJECT_TYPE.
ASSERT(LAST_TYPE == JS_FUNCTION_TYPE);
ASSERT(JS_FUNCTION_TYPE == LAST_JS_OBJECT_TYPE + 1);
__ cmp(r1, Operand(JS_FUNCTION_TYPE));
function.Branch(eq);
// Check if the constructor in the map is a function.
__ ldr(r0, FieldMemOperand(r0, Map::kConstructorOffset));
__ CompareObjectType(r0, r1, r1, JS_FUNCTION_TYPE);
non_function_constructor.Branch(ne);
// The r0 register now contains the constructor function. Grab the
// instance class name from there.
__ ldr(r0, FieldMemOperand(r0, JSFunction::kSharedFunctionInfoOffset));
__ ldr(r0, FieldMemOperand(r0, SharedFunctionInfo::kInstanceClassNameOffset));
frame_->EmitPush(r0);
leave.Jump();
// Functions have class 'Function'.
function.Bind();
__ mov(r0, Operand(Factory::function_class_symbol()));
frame_->EmitPush(r0);
leave.Jump();
// Objects with a non-function constructor have class 'Object'.
non_function_constructor.Bind();
__ mov(r0, Operand(Factory::Object_symbol()));
frame_->EmitPush(r0);
leave.Jump();
// Non-JS objects have class null.
null.Bind();
__ LoadRoot(r0, Heap::kNullValueRootIndex);
frame_->EmitPush(r0);
// All done.
leave.Bind();
}
void CodeGenerator::GenerateValueOf(ZoneList<Expression*>* args) {
VirtualFrame::SpilledScope spilled_scope;
ASSERT(args->length() == 1);
JumpTarget leave;
LoadAndSpill(args->at(0));
frame_->EmitPop(r0); // r0 contains object.
// if (object->IsSmi()) return the object.
__ tst(r0, Operand(kSmiTagMask));
leave.Branch(eq);
// It is a heap object - get map. If (!object->IsJSValue()) return the object.
__ CompareObjectType(r0, r1, r1, JS_VALUE_TYPE);
leave.Branch(ne);
// Load the value.
__ ldr(r0, FieldMemOperand(r0, JSValue::kValueOffset));
leave.Bind();
frame_->EmitPush(r0);
}
void CodeGenerator::GenerateSetValueOf(ZoneList<Expression*>* args) {
VirtualFrame::SpilledScope spilled_scope;
ASSERT(args->length() == 2);
JumpTarget leave;
LoadAndSpill(args->at(0)); // Load the object.
LoadAndSpill(args->at(1)); // Load the value.
frame_->EmitPop(r0); // r0 contains value
frame_->EmitPop(r1); // r1 contains object
// if (object->IsSmi()) return object.
__ tst(r1, Operand(kSmiTagMask));
leave.Branch(eq);
// It is a heap object - get map. If (!object->IsJSValue()) return the object.
__ CompareObjectType(r1, r2, r2, JS_VALUE_TYPE);
leave.Branch(ne);
// Store the value.
__ str(r0, FieldMemOperand(r1, JSValue::kValueOffset));
// Update the write barrier.
__ mov(r2, Operand(JSValue::kValueOffset - kHeapObjectTag));
__ RecordWrite(r1, r2, r3);
// Leave.
leave.Bind();
frame_->EmitPush(r0);
}
void CodeGenerator::GenerateIsSmi(ZoneList<Expression*>* args) {
VirtualFrame::SpilledScope spilled_scope;
ASSERT(args->length() == 1);
LoadAndSpill(args->at(0));
frame_->EmitPop(r0);
__ tst(r0, Operand(kSmiTagMask));
cc_reg_ = eq;
}
void CodeGenerator::GenerateLog(ZoneList<Expression*>* args) {
VirtualFrame::SpilledScope spilled_scope;
// See comment in CodeGenerator::GenerateLog in codegen-ia32.cc.
ASSERT_EQ(args->length(), 3);
#ifdef ENABLE_LOGGING_AND_PROFILING
if (ShouldGenerateLog(args->at(0))) {
LoadAndSpill(args->at(1));
LoadAndSpill(args->at(2));
__ CallRuntime(Runtime::kLog, 2);
}
#endif
__ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
frame_->EmitPush(r0);
}
void CodeGenerator::GenerateIsNonNegativeSmi(ZoneList<Expression*>* args) {
VirtualFrame::SpilledScope spilled_scope;
ASSERT(args->length() == 1);
LoadAndSpill(args->at(0));
frame_->EmitPop(r0);
__ tst(r0, Operand(kSmiTagMask | 0x80000000u));
cc_reg_ = eq;
}
// This should generate code that performs a charCodeAt() call or returns
// undefined in order to trigger the slow case, Runtime_StringCharCodeAt.
// It is not yet implemented on ARM, so it always goes to the slow case.
void CodeGenerator::GenerateFastCharCodeAt(ZoneList<Expression*>* args) {
VirtualFrame::SpilledScope spilled_scope;
ASSERT(args->length() == 2);
__ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
frame_->EmitPush(r0);
}
void CodeGenerator::GenerateIsArray(ZoneList<Expression*>* args) {
VirtualFrame::SpilledScope spilled_scope;
ASSERT(args->length() == 1);
LoadAndSpill(args->at(0));
JumpTarget answer;
// We need the CC bits to come out as not_equal in the case where the
// object is a smi. This can't be done with the usual test opcode so
// we use XOR to get the right CC bits.
frame_->EmitPop(r0);
__ and_(r1, r0, Operand(kSmiTagMask));
__ eor(r1, r1, Operand(kSmiTagMask), SetCC);
answer.Branch(ne);
// It is a heap object - get the map. Check if the object is a JS array.
__ CompareObjectType(r0, r1, r1, JS_ARRAY_TYPE);
answer.Bind();
cc_reg_ = eq;
}
void CodeGenerator::GenerateIsConstructCall(ZoneList<Expression*>* args) {
VirtualFrame::SpilledScope spilled_scope;
ASSERT(args->length() == 0);
// Get the frame pointer for the calling frame.
__ ldr(r2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
// Skip the arguments adaptor frame if it exists.
Label check_frame_marker;
__ ldr(r1, MemOperand(r2, StandardFrameConstants::kContextOffset));
__ cmp(r1, Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
__ b(ne, &check_frame_marker);
__ ldr(r2, MemOperand(r2, StandardFrameConstants::kCallerFPOffset));
// Check the marker in the calling frame.
__ bind(&check_frame_marker);
__ ldr(r1, MemOperand(r2, StandardFrameConstants::kMarkerOffset));
__ cmp(r1, Operand(Smi::FromInt(StackFrame::CONSTRUCT)));
cc_reg_ = eq;
}
void CodeGenerator::GenerateArgumentsLength(ZoneList<Expression*>* args) {
VirtualFrame::SpilledScope spilled_scope;
ASSERT(args->length() == 0);
// Seed the result with the formal parameters count, which will be used
// in case no arguments adaptor frame is found below the current frame.
__ mov(r0, Operand(Smi::FromInt(scope_->num_parameters())));
// Call the shared stub to get to the arguments.length.
ArgumentsAccessStub stub(ArgumentsAccessStub::READ_LENGTH);
frame_->CallStub(&stub, 0);
frame_->EmitPush(r0);
}
void CodeGenerator::GenerateArgumentsAccess(ZoneList<Expression*>* args) {
VirtualFrame::SpilledScope spilled_scope;
ASSERT(args->length() == 1);
// Satisfy contract with ArgumentsAccessStub:
// Load the key into r1 and the formal parameters count into r0.
LoadAndSpill(args->at(0));
frame_->EmitPop(r1);
__ mov(r0, Operand(Smi::FromInt(scope_->num_parameters())));
// Call the shared stub to get to arguments[key].
ArgumentsAccessStub stub(ArgumentsAccessStub::READ_ELEMENT);
frame_->CallStub(&stub, 0);
frame_->EmitPush(r0);
}
void CodeGenerator::GenerateRandomPositiveSmi(ZoneList<Expression*>* args) {
VirtualFrame::SpilledScope spilled_scope;
ASSERT(args->length() == 0);
__ Call(ExternalReference::random_positive_smi_function().address(),
RelocInfo::RUNTIME_ENTRY);
frame_->EmitPush(r0);
}
void CodeGenerator::GenerateFastMathOp(MathOp op, ZoneList<Expression*>* args) {
VirtualFrame::SpilledScope spilled_scope;
LoadAndSpill(args->at(0));
switch (op) {
case SIN:
frame_->CallRuntime(Runtime::kMath_sin, 1);
break;
case COS:
frame_->CallRuntime(Runtime::kMath_cos, 1);
break;
}
frame_->EmitPush(r0);
}
void CodeGenerator::GenerateObjectEquals(ZoneList<Expression*>* args) {
VirtualFrame::SpilledScope spilled_scope;
ASSERT(args->length() == 2);
// Load the two objects into registers and perform the comparison.
LoadAndSpill(args->at(0));
LoadAndSpill(args->at(1));
frame_->EmitPop(r0);
frame_->EmitPop(r1);
__ cmp(r0, Operand(r1));
cc_reg_ = eq;
}
void CodeGenerator::VisitCallRuntime(CallRuntime* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
if (CheckForInlineRuntimeCall(node)) {
ASSERT((has_cc() && frame_->height() == original_height) ||
(!has_cc() && frame_->height() == original_height + 1));
return;
}
ZoneList<Expression*>* args = node->arguments();
Comment cmnt(masm_, "[ CallRuntime");
Runtime::Function* function = node->function();
if (function == NULL) {
// Prepare stack for calling JS runtime function.
__ mov(r0, Operand(node->name()));
frame_->EmitPush(r0);
// Push the builtins object found in the current global object.
__ ldr(r1, GlobalObject());
__ ldr(r0, FieldMemOperand(r1, GlobalObject::kBuiltinsOffset));
frame_->EmitPush(r0);
}
// Push the arguments ("left-to-right").
int arg_count = args->length();
for (int i = 0; i < arg_count; i++) {
LoadAndSpill(args->at(i));
}
if (function == NULL) {
// Call the JS runtime function.
InLoopFlag in_loop = loop_nesting() > 0 ? IN_LOOP : NOT_IN_LOOP;
Handle<Code> stub = ComputeCallInitialize(arg_count, in_loop);
frame_->CallCodeObject(stub, RelocInfo::CODE_TARGET, arg_count + 1);
__ ldr(cp, frame_->Context());
frame_->Drop();
frame_->EmitPush(r0);
} else {
// Call the C runtime function.
frame_->CallRuntime(function, arg_count);
frame_->EmitPush(r0);
}
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::VisitUnaryOperation(UnaryOperation* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ UnaryOperation");
Token::Value op = node->op();
if (op == Token::NOT) {
LoadConditionAndSpill(node->expression(),
NOT_INSIDE_TYPEOF,
false_target(),
true_target(),
true);
// LoadCondition may (and usually does) leave a test and branch to
// be emitted by the caller. In that case, negate the condition.
if (has_cc()) cc_reg_ = NegateCondition(cc_reg_);
} else if (op == Token::DELETE) {
Property* property = node->expression()->AsProperty();
Variable* variable = node->expression()->AsVariableProxy()->AsVariable();
if (property != NULL) {
LoadAndSpill(property->obj());
LoadAndSpill(property->key());
Result arg_count(r0);
__ mov(r0, Operand(1)); // not counting receiver
frame_->InvokeBuiltin(Builtins::DELETE, CALL_JS, &arg_count, 2);
} else if (variable != NULL) {
Slot* slot = variable->slot();
if (variable->is_global()) {
LoadGlobal();
__ mov(r0, Operand(variable->name()));
frame_->EmitPush(r0);
Result arg_count(r0);
__ mov(r0, Operand(1)); // not counting receiver
frame_->InvokeBuiltin(Builtins::DELETE, CALL_JS, &arg_count, 2);
} else if (slot != NULL && slot->type() == Slot::LOOKUP) {
// lookup the context holding the named variable
frame_->EmitPush(cp);
__ mov(r0, Operand(variable->name()));
frame_->EmitPush(r0);
frame_->CallRuntime(Runtime::kLookupContext, 2);
// r0: context
frame_->EmitPush(r0);
__ mov(r0, Operand(variable->name()));
frame_->EmitPush(r0);
Result arg_count(r0);
__ mov(r0, Operand(1)); // not counting receiver
frame_->InvokeBuiltin(Builtins::DELETE, CALL_JS, &arg_count, 2);
} else {
// Default: Result of deleting non-global, not dynamically
// introduced variables is false.
__ LoadRoot(r0, Heap::kFalseValueRootIndex);
}
} else {
// Default: Result of deleting expressions is true.
LoadAndSpill(node->expression()); // may have side-effects
frame_->Drop();
__ LoadRoot(r0, Heap::kTrueValueRootIndex);
}
frame_->EmitPush(r0);
} else if (op == Token::TYPEOF) {
// Special case for loading the typeof expression; see comment on
// LoadTypeofExpression().
LoadTypeofExpression(node->expression());
frame_->CallRuntime(Runtime::kTypeof, 1);
frame_->EmitPush(r0); // r0 has result
} else {
LoadAndSpill(node->expression());
frame_->EmitPop(r0);
switch (op) {
case Token::NOT:
case Token::DELETE:
case Token::TYPEOF:
UNREACHABLE(); // handled above
break;
case Token::SUB: {
bool overwrite =
(node->expression()->AsBinaryOperation() != NULL &&
node->expression()->AsBinaryOperation()->ResultOverwriteAllowed());
UnarySubStub stub(overwrite);
frame_->CallStub(&stub, 0);
break;
}
case Token::BIT_NOT: {
// smi check
JumpTarget smi_label;
JumpTarget continue_label;
__ tst(r0, Operand(kSmiTagMask));
smi_label.Branch(eq);
frame_->EmitPush(r0);
Result arg_count(r0);
__ mov(r0, Operand(0)); // not counting receiver
frame_->InvokeBuiltin(Builtins::BIT_NOT, CALL_JS, &arg_count, 1);
continue_label.Jump();
smi_label.Bind();
__ mvn(r0, Operand(r0));
__ bic(r0, r0, Operand(kSmiTagMask)); // bit-clear inverted smi-tag
continue_label.Bind();
break;
}
case Token::VOID:
// since the stack top is cached in r0, popping and then
// pushing a value can be done by just writing to r0.
__ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
break;
case Token::ADD: {
// Smi check.
JumpTarget continue_label;
__ tst(r0, Operand(kSmiTagMask));
continue_label.Branch(eq);
frame_->EmitPush(r0);
Result arg_count(r0);
__ mov(r0, Operand(0)); // not counting receiver
frame_->InvokeBuiltin(Builtins::TO_NUMBER, CALL_JS, &arg_count, 1);
continue_label.Bind();
break;
}
default:
UNREACHABLE();
}
frame_->EmitPush(r0); // r0 has result
}
ASSERT(!has_valid_frame() ||
(has_cc() && frame_->height() == original_height) ||
(!has_cc() && frame_->height() == original_height + 1));
}
void CodeGenerator::VisitCountOperation(CountOperation* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ CountOperation");
bool is_postfix = node->is_postfix();
bool is_increment = node->op() == Token::INC;
Variable* var = node->expression()->AsVariableProxy()->AsVariable();
bool is_const = (var != NULL && var->mode() == Variable::CONST);
// Postfix: Make room for the result.
if (is_postfix) {
__ mov(r0, Operand(0));
frame_->EmitPush(r0);
}
{ Reference target(this, node->expression());
if (target.is_illegal()) {
// Spoof the virtual frame to have the expected height (one higher
// than on entry).
if (!is_postfix) {
__ mov(r0, Operand(Smi::FromInt(0)));
frame_->EmitPush(r0);
}
ASSERT(frame_->height() == original_height + 1);
return;
}
target.GetValueAndSpill(NOT_INSIDE_TYPEOF);
frame_->EmitPop(r0);
JumpTarget slow;
JumpTarget exit;
// Load the value (1) into register r1.
__ mov(r1, Operand(Smi::FromInt(1)));
// Check for smi operand.
__ tst(r0, Operand(kSmiTagMask));
slow.Branch(ne);
// Postfix: Store the old value as the result.
if (is_postfix) {
__ str(r0, frame_->ElementAt(target.size()));
}
// Perform optimistic increment/decrement.
if (is_increment) {
__ add(r0, r0, Operand(r1), SetCC);
} else {
__ sub(r0, r0, Operand(r1), SetCC);
}
// If the increment/decrement didn't overflow, we're done.
exit.Branch(vc);
// Revert optimistic increment/decrement.
if (is_increment) {
__ sub(r0, r0, Operand(r1));
} else {
__ add(r0, r0, Operand(r1));
}
// Slow case: Convert to number.
slow.Bind();
{
// Convert the operand to a number.
frame_->EmitPush(r0);
Result arg_count(r0);
__ mov(r0, Operand(0));
frame_->InvokeBuiltin(Builtins::TO_NUMBER, CALL_JS, &arg_count, 1);
}
if (is_postfix) {
// Postfix: store to result (on the stack).
__ str(r0, frame_->ElementAt(target.size()));
}
// Compute the new value.
__ mov(r1, Operand(Smi::FromInt(1)));
frame_->EmitPush(r0);
frame_->EmitPush(r1);
if (is_increment) {
frame_->CallRuntime(Runtime::kNumberAdd, 2);
} else {
frame_->CallRuntime(Runtime::kNumberSub, 2);
}
// Store the new value in the target if not const.
exit.Bind();
frame_->EmitPush(r0);
if (!is_const) target.SetValue(NOT_CONST_INIT);
}
// Postfix: Discard the new value and use the old.
if (is_postfix) frame_->EmitPop(r0);
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::VisitBinaryOperation(BinaryOperation* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ BinaryOperation");
Token::Value op = node->op();
// According to ECMA-262 section 11.11, page 58, the binary logical
// operators must yield the result of one of the two expressions
// before any ToBoolean() conversions. This means that the value
// produced by a && or || operator is not necessarily a boolean.
// NOTE: If the left hand side produces a materialized value (not in
// the CC register), we force the right hand side to do the
// same. This is necessary because we may have to branch to the exit
// after evaluating the left hand side (due to the shortcut
// semantics), but the compiler must (statically) know if the result
// of compiling the binary operation is materialized or not.
if (op == Token::AND) {
JumpTarget is_true;
LoadConditionAndSpill(node->left(),
NOT_INSIDE_TYPEOF,
&is_true,
false_target(),
false);
if (has_valid_frame() && !has_cc()) {
// The left-hand side result is on top of the virtual frame.
JumpTarget pop_and_continue;
JumpTarget exit;
__ ldr(r0, frame_->Top()); // Duplicate the stack top.
frame_->EmitPush(r0);
// Avoid popping the result if it converts to 'false' using the
// standard ToBoolean() conversion as described in ECMA-262,
// section 9.2, page 30.
ToBoolean(&pop_and_continue, &exit);
Branch(false, &exit);
// Pop the result of evaluating the first part.
pop_and_continue.Bind();
frame_->EmitPop(r0);
// Evaluate right side expression.
is_true.Bind();
LoadAndSpill(node->right());
// Exit (always with a materialized value).
exit.Bind();
} else if (has_cc() || is_true.is_linked()) {
// The left-hand side is either (a) partially compiled to
// control flow with a final branch left to emit or (b) fully
// compiled to control flow and possibly true.
if (has_cc()) {
Branch(false, false_target());
}
is_true.Bind();
LoadConditionAndSpill(node->right(),
NOT_INSIDE_TYPEOF,
true_target(),
false_target(),
false);
} else {
// Nothing to do.
ASSERT(!has_valid_frame() && !has_cc() && !is_true.is_linked());
}
} else if (op == Token::OR) {
JumpTarget is_false;
LoadConditionAndSpill(node->left(),
NOT_INSIDE_TYPEOF,
true_target(),
&is_false,
false);
if (has_valid_frame() && !has_cc()) {
// The left-hand side result is on top of the virtual frame.
JumpTarget pop_and_continue;
JumpTarget exit;
__ ldr(r0, frame_->Top());
frame_->EmitPush(r0);
// Avoid popping the result if it converts to 'true' using the
// standard ToBoolean() conversion as described in ECMA-262,
// section 9.2, page 30.
ToBoolean(&exit, &pop_and_continue);
Branch(true, &exit);
// Pop the result of evaluating the first part.
pop_and_continue.Bind();
frame_->EmitPop(r0);
// Evaluate right side expression.
is_false.Bind();
LoadAndSpill(node->right());
// Exit (always with a materialized value).
exit.Bind();
} else if (has_cc() || is_false.is_linked()) {
// The left-hand side is either (a) partially compiled to
// control flow with a final branch left to emit or (b) fully
// compiled to control flow and possibly false.
if (has_cc()) {
Branch(true, true_target());
}
is_false.Bind();
LoadConditionAndSpill(node->right(),
NOT_INSIDE_TYPEOF,
true_target(),
false_target(),
false);
} else {
// Nothing to do.
ASSERT(!has_valid_frame() && !has_cc() && !is_false.is_linked());
}
} else {
// Optimize for the case where (at least) one of the expressions
// is a literal small integer.
Literal* lliteral = node->left()->AsLiteral();
Literal* rliteral = node->right()->AsLiteral();
// NOTE: The code below assumes that the slow cases (calls to runtime)
// never return a constant/immutable object.
bool overwrite_left =
(node->left()->AsBinaryOperation() != NULL &&
node->left()->AsBinaryOperation()->ResultOverwriteAllowed());
bool overwrite_right =
(node->right()->AsBinaryOperation() != NULL &&
node->right()->AsBinaryOperation()->ResultOverwriteAllowed());
if (rliteral != NULL && rliteral->handle()->IsSmi()) {
LoadAndSpill(node->left());
SmiOperation(node->op(),
rliteral->handle(),
false,
overwrite_right ? OVERWRITE_RIGHT : NO_OVERWRITE);
} else if (lliteral != NULL && lliteral->handle()->IsSmi()) {
LoadAndSpill(node->right());
SmiOperation(node->op(),
lliteral->handle(),
true,
overwrite_left ? OVERWRITE_LEFT : NO_OVERWRITE);
} else {
OverwriteMode overwrite_mode = NO_OVERWRITE;
if (overwrite_left) {
overwrite_mode = OVERWRITE_LEFT;
} else if (overwrite_right) {
overwrite_mode = OVERWRITE_RIGHT;
}
LoadAndSpill(node->left());
LoadAndSpill(node->right());
GenericBinaryOperation(node->op(), overwrite_mode);
}
frame_->EmitPush(r0);
}
ASSERT(!has_valid_frame() ||
(has_cc() && frame_->height() == original_height) ||
(!has_cc() && frame_->height() == original_height + 1));
}
void CodeGenerator::VisitThisFunction(ThisFunction* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
__ ldr(r0, frame_->Function());
frame_->EmitPush(r0);
ASSERT(frame_->height() == original_height + 1);
}
void CodeGenerator::VisitCompareOperation(CompareOperation* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ CompareOperation");
// Get the expressions from the node.
Expression* left = node->left();
Expression* right = node->right();
Token::Value op = node->op();
// To make null checks efficient, we check if either left or right is the
// literal 'null'. If so, we optimize the code by inlining a null check
// instead of calling the (very) general runtime routine for checking
// equality.
if (op == Token::EQ || op == Token::EQ_STRICT) {
bool left_is_null =
left->AsLiteral() != NULL && left->AsLiteral()->IsNull();
bool right_is_null =
right->AsLiteral() != NULL && right->AsLiteral()->IsNull();
// The 'null' value can only be equal to 'null' or 'undefined'.
if (left_is_null || right_is_null) {
LoadAndSpill(left_is_null ? right : left);
frame_->EmitPop(r0);
__ LoadRoot(ip, Heap::kNullValueRootIndex);
__ cmp(r0, ip);
// The 'null' value is only equal to 'undefined' if using non-strict
// comparisons.
if (op != Token::EQ_STRICT) {
true_target()->Branch(eq);
__ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
__ cmp(r0, Operand(ip));
true_target()->Branch(eq);
__ tst(r0, Operand(kSmiTagMask));
false_target()->Branch(eq);
// It can be an undetectable object.
__ ldr(r0, FieldMemOperand(r0, HeapObject::kMapOffset));
__ ldrb(r0, FieldMemOperand(r0, Map::kBitFieldOffset));
__ and_(r0, r0, Operand(1 << Map::kIsUndetectable));
__ cmp(r0, Operand(1 << Map::kIsUndetectable));
}
cc_reg_ = eq;
ASSERT(has_cc() && frame_->height() == original_height);
return;
}
}
// To make typeof testing for natives implemented in JavaScript really
// efficient, we generate special code for expressions of the form:
// 'typeof <expression> == <string>'.
UnaryOperation* operation = left->AsUnaryOperation();
if ((op == Token::EQ || op == Token::EQ_STRICT) &&
(operation != NULL && operation->op() == Token::TYPEOF) &&
(right->AsLiteral() != NULL &&
right->AsLiteral()->handle()->IsString())) {
Handle<String> check(String::cast(*right->AsLiteral()->handle()));
// Load the operand, move it to register r1.
LoadTypeofExpression(operation->expression());
frame_->EmitPop(r1);
if (check->Equals(Heap::number_symbol())) {
__ tst(r1, Operand(kSmiTagMask));
true_target()->Branch(eq);
__ ldr(r1, FieldMemOperand(r1, HeapObject::kMapOffset));
__ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
__ cmp(r1, ip);
cc_reg_ = eq;
} else if (check->Equals(Heap::string_symbol())) {
__ tst(r1, Operand(kSmiTagMask));
false_target()->Branch(eq);
__ ldr(r1, FieldMemOperand(r1, HeapObject::kMapOffset));
// It can be an undetectable string object.
__ ldrb(r2, FieldMemOperand(r1, Map::kBitFieldOffset));
__ and_(r2, r2, Operand(1 << Map::kIsUndetectable));
__ cmp(r2, Operand(1 << Map::kIsUndetectable));
false_target()->Branch(eq);
__ ldrb(r2, FieldMemOperand(r1, Map::kInstanceTypeOffset));
__ cmp(r2, Operand(FIRST_NONSTRING_TYPE));
cc_reg_ = lt;
} else if (check->Equals(Heap::boolean_symbol())) {
__ LoadRoot(ip, Heap::kTrueValueRootIndex);
__ cmp(r1, ip);
true_target()->Branch(eq);
__ LoadRoot(ip, Heap::kFalseValueRootIndex);
__ cmp(r1, ip);
cc_reg_ = eq;
} else if (check->Equals(Heap::undefined_symbol())) {
__ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
__ cmp(r1, ip);
true_target()->Branch(eq);
__ tst(r1, Operand(kSmiTagMask));
false_target()->Branch(eq);
// It can be an undetectable object.
__ ldr(r1, FieldMemOperand(r1, HeapObject::kMapOffset));
__ ldrb(r2, FieldMemOperand(r1, Map::kBitFieldOffset));
__ and_(r2, r2, Operand(1 << Map::kIsUndetectable));
__ cmp(r2, Operand(1 << Map::kIsUndetectable));
cc_reg_ = eq;
} else if (check->Equals(Heap::function_symbol())) {
__ tst(r1, Operand(kSmiTagMask));
false_target()->Branch(eq);
__ CompareObjectType(r1, r1, r1, JS_FUNCTION_TYPE);
cc_reg_ = eq;
} else if (check->Equals(Heap::object_symbol())) {
__ tst(r1, Operand(kSmiTagMask));
false_target()->Branch(eq);
__ ldr(r2, FieldMemOperand(r1, HeapObject::kMapOffset));
__ LoadRoot(ip, Heap::kNullValueRootIndex);
__ cmp(r1, ip);
true_target()->Branch(eq);
// It can be an undetectable object.
__ ldrb(r1, FieldMemOperand(r2, Map::kBitFieldOffset));
__ and_(r1, r1, Operand(1 << Map::kIsUndetectable));
__ cmp(r1, Operand(1 << Map::kIsUndetectable));
false_target()->Branch(eq);
__ ldrb(r2, FieldMemOperand(r2, Map::kInstanceTypeOffset));
__ cmp(r2, Operand(FIRST_JS_OBJECT_TYPE));
false_target()->Branch(lt);
__ cmp(r2, Operand(LAST_JS_OBJECT_TYPE));
cc_reg_ = le;
} else {
// Uncommon case: typeof testing against a string literal that is
// never returned from the typeof operator.
false_target()->Jump();
}
ASSERT(!has_valid_frame() ||
(has_cc() && frame_->height() == original_height));
return;
}
switch (op) {
case Token::EQ:
Comparison(eq, left, right, false);
break;
case Token::LT:
Comparison(lt, left, right);
break;
case Token::GT:
Comparison(gt, left, right);
break;
case Token::LTE:
Comparison(le, left, right);
break;
case Token::GTE:
Comparison(ge, left, right);
break;
case Token::EQ_STRICT:
Comparison(eq, left, right, true);
break;
case Token::IN: {
LoadAndSpill(left);
LoadAndSpill(right);
Result arg_count(r0);
__ mov(r0, Operand(1)); // not counting receiver
frame_->InvokeBuiltin(Builtins::IN, CALL_JS, &arg_count, 2);
frame_->EmitPush(r0);
break;
}
case Token::INSTANCEOF: {
LoadAndSpill(left);
LoadAndSpill(right);
InstanceofStub stub;
frame_->CallStub(&stub, 2);
// At this point if instanceof succeeded then r0 == 0.
__ tst(r0, Operand(r0));
cc_reg_ = eq;
break;
}
default:
UNREACHABLE();
}
ASSERT((has_cc() && frame_->height() == original_height) ||
(!has_cc() && frame_->height() == original_height + 1));
}
#ifdef DEBUG
bool CodeGenerator::HasValidEntryRegisters() { return true; }
#endif
#undef __
#define __ ACCESS_MASM(masm)
Handle<String> Reference::GetName() {
ASSERT(type_ == NAMED);
Property* property = expression_->AsProperty();
if (property == NULL) {
// Global variable reference treated as a named property reference.
VariableProxy* proxy = expression_->AsVariableProxy();
ASSERT(proxy->AsVariable() != NULL);
ASSERT(proxy->AsVariable()->is_global());
return proxy->name();
} else {
Literal* raw_name = property->key()->AsLiteral();
ASSERT(raw_name != NULL);
return Handle<String>(String::cast(*raw_name->handle()));
}
}
void Reference::GetValue(TypeofState typeof_state) {
ASSERT(cgen_->HasValidEntryRegisters());
ASSERT(!is_illegal());
ASSERT(!cgen_->has_cc());
MacroAssembler* masm = cgen_->masm();
Property* property = expression_->AsProperty();
if (property != NULL) {
cgen_->CodeForSourcePosition(property->position());
}
switch (type_) {
case SLOT: {
Comment cmnt(masm, "[ Load from Slot");
Slot* slot = expression_->AsVariableProxy()->AsVariable()->slot();
ASSERT(slot != NULL);
cgen_->LoadFromSlot(slot, typeof_state);
break;
}
case NAMED: {
// TODO(1241834): Make sure that this it is safe to ignore the
// distinction between expressions in a typeof and not in a typeof. If
// there is a chance that reference errors can be thrown below, we
// must distinguish between the two kinds of loads (typeof expression
// loads must not throw a reference error).
VirtualFrame* frame = cgen_->frame();
Comment cmnt(masm, "[ Load from named Property");
Handle<String> name(GetName());
Variable* var = expression_->AsVariableProxy()->AsVariable();
Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Initialize));
// Setup the name register.
Result name_reg(r2);
__ mov(r2, Operand(name));
ASSERT(var == NULL || var->is_global());
RelocInfo::Mode rmode = (var == NULL)
? RelocInfo::CODE_TARGET
: RelocInfo::CODE_TARGET_CONTEXT;
frame->CallCodeObject(ic, rmode, &name_reg, 0);
frame->EmitPush(r0);
break;
}
case KEYED: {
// TODO(1241834): Make sure that this it is safe to ignore the
// distinction between expressions in a typeof and not in a typeof.
// TODO(181): Implement inlined version of array indexing once
// loop nesting is properly tracked on ARM.
VirtualFrame* frame = cgen_->frame();
Comment cmnt(masm, "[ Load from keyed Property");
ASSERT(property != NULL);
Handle<Code> ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize));
Variable* var = expression_->AsVariableProxy()->AsVariable();
ASSERT(var == NULL || var->is_global());
RelocInfo::Mode rmode = (var == NULL)
? RelocInfo::CODE_TARGET
: RelocInfo::CODE_TARGET_CONTEXT;
frame->CallCodeObject(ic, rmode, 0);
frame->EmitPush(r0);
break;
}
default:
UNREACHABLE();
}
}
void Reference::SetValue(InitState init_state) {
ASSERT(!is_illegal());
ASSERT(!cgen_->has_cc());
MacroAssembler* masm = cgen_->masm();
VirtualFrame* frame = cgen_->frame();
Property* property = expression_->AsProperty();
if (property != NULL) {
cgen_->CodeForSourcePosition(property->position());
}
switch (type_) {
case SLOT: {
Comment cmnt(masm, "[ Store to Slot");
Slot* slot = expression_->AsVariableProxy()->AsVariable()->slot();
ASSERT(slot != NULL);
if (slot->type() == Slot::LOOKUP) {
ASSERT(slot->var()->is_dynamic());
// For now, just do a runtime call.
frame->EmitPush(cp);
__ mov(r0, Operand(slot->var()->name()));
frame->EmitPush(r0);
if (init_state == CONST_INIT) {
// Same as the case for a normal store, but ignores attribute
// (e.g. READ_ONLY) of context slot so that we can initialize
// const properties (introduced via eval("const foo = (some
// expr);")). Also, uses the current function context instead of
// the top context.
//
// Note that we must declare the foo upon entry of eval(), via a
// context slot declaration, but we cannot initialize it at the
// same time, because the const declaration may be at the end of
// the eval code (sigh...) and the const variable may have been
// used before (where its value is 'undefined'). Thus, we can only
// do the initialization when we actually encounter the expression
// and when the expression operands are defined and valid, and
// thus we need the split into 2 operations: declaration of the
// context slot followed by initialization.
frame->CallRuntime(Runtime::kInitializeConstContextSlot, 3);
} else {
frame->CallRuntime(Runtime::kStoreContextSlot, 3);
}
// Storing a variable must keep the (new) value on the expression
// stack. This is necessary for compiling assignment expressions.
frame->EmitPush(r0);
} else {
ASSERT(!slot->var()->is_dynamic());
JumpTarget exit;
if (init_state == CONST_INIT) {
ASSERT(slot->var()->mode() == Variable::CONST);
// Only the first const initialization must be executed (the slot
// still contains 'the hole' value). When the assignment is
// executed, the code is identical to a normal store (see below).
Comment cmnt(masm, "[ Init const");
__ ldr(r2, cgen_->SlotOperand(slot, r2));
__ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
__ cmp(r2, ip);
exit.Branch(ne);
}
// We must execute the store. Storing a variable must keep the
// (new) value on the stack. This is necessary for compiling
// assignment expressions.
//
// Note: We will reach here even with slot->var()->mode() ==
// Variable::CONST because of const declarations which will
// initialize consts to 'the hole' value and by doing so, end up
// calling this code. r2 may be loaded with context; used below in
// RecordWrite.
frame->EmitPop(r0);
__ str(r0, cgen_->SlotOperand(slot, r2));
frame->EmitPush(r0);
if (slot->type() == Slot::CONTEXT) {
// Skip write barrier if the written value is a smi.
__ tst(r0, Operand(kSmiTagMask));
exit.Branch(eq);
// r2 is loaded with context when calling SlotOperand above.
int offset = FixedArray::kHeaderSize + slot->index() * kPointerSize;
__ mov(r3, Operand(offset));
__ RecordWrite(r2, r3, r1);
}
// If we definitely did not jump over the assignment, we do not need
// to bind the exit label. Doing so can defeat peephole
// optimization.
if (init_state == CONST_INIT || slot->type() == Slot::CONTEXT) {
exit.Bind();
}
}
break;
}
case NAMED: {
Comment cmnt(masm, "[ Store to named Property");
// Call the appropriate IC code.
Handle<Code> ic(Builtins::builtin(Builtins::StoreIC_Initialize));
Handle<String> name(GetName());
Result value(r0);
frame->EmitPop(r0);
// Setup the name register.
Result property_name(r2);
__ mov(r2, Operand(name));
frame->CallCodeObject(ic,
RelocInfo::CODE_TARGET,
&value,
&property_name,
0);
frame->EmitPush(r0);
break;
}
case KEYED: {
Comment cmnt(masm, "[ Store to keyed Property");
Property* property = expression_->AsProperty();
ASSERT(property != NULL);
cgen_->CodeForSourcePosition(property->position());
// Call IC code.
Handle<Code> ic(Builtins::builtin(Builtins::KeyedStoreIC_Initialize));
// TODO(1222589): Make the IC grab the values from the stack.
Result value(r0);
frame->EmitPop(r0); // value
frame->CallCodeObject(ic, RelocInfo::CODE_TARGET, &value, 0);
frame->EmitPush(r0);
break;
}
default:
UNREACHABLE();
}
}
// Count leading zeros in a 32 bit word. On ARM5 and later it uses the clz
// instruction. On pre-ARM5 hardware this routine gives the wrong answer for 0
// (31 instead of 32).
static void CountLeadingZeros(
MacroAssembler* masm,
Register source,
Register scratch,
Register zeros) {
#ifdef __ARM_ARCH_5__
__ clz(zeros, source); // This instruction is only supported after ARM5.
#else
__ mov(zeros, Operand(0));
__ mov(scratch, source);
// Top 16.
__ tst(scratch, Operand(0xffff0000));
__ add(zeros, zeros, Operand(16), LeaveCC, eq);
__ mov(scratch, Operand(scratch, LSL, 16), LeaveCC, eq);
// Top 8.
__ tst(scratch, Operand(0xff000000));
__ add(zeros, zeros, Operand(8), LeaveCC, eq);
__ mov(scratch, Operand(scratch, LSL, 8), LeaveCC, eq);
// Top 4.
__ tst(scratch, Operand(0xf0000000));
__ add(zeros, zeros, Operand(4), LeaveCC, eq);
__ mov(scratch, Operand(scratch, LSL, 4), LeaveCC, eq);
// Top 2.
__ tst(scratch, Operand(0xc0000000));
__ add(zeros, zeros, Operand(2), LeaveCC, eq);
__ mov(scratch, Operand(scratch, LSL, 2), LeaveCC, eq);
// Top bit.
__ tst(scratch, Operand(0x80000000u));
__ add(zeros, zeros, Operand(1), LeaveCC, eq);
#endif
}
// Takes a Smi and converts to an IEEE 64 bit floating point value in two
// registers. The format is 1 sign bit, 11 exponent bits (biased 1023) and
// 52 fraction bits (20 in the first word, 32 in the second). Zeros is a
// scratch register. Destroys the source register. No GC occurs during this
// stub so you don't have to set up the frame.
class ConvertToDoubleStub : public CodeStub {
public:
ConvertToDoubleStub(Register result_reg_1,
Register result_reg_2,
Register source_reg,
Register scratch_reg)
: result1_(result_reg_1),
result2_(result_reg_2),
source_(source_reg),
zeros_(scratch_reg) { }
private:
Register result1_;
Register result2_;
Register source_;
Register zeros_;
// Minor key encoding in 16 bits.
class ModeBits: public BitField<OverwriteMode, 0, 2> {};
class OpBits: public BitField<Token::Value, 2, 14> {};
Major MajorKey() { return ConvertToDouble; }
int MinorKey() {
// Encode the parameters in a unique 16 bit value.
return result1_.code() +
(result2_.code() << 4) +
(source_.code() << 8) +
(zeros_.code() << 12);
}
void Generate(MacroAssembler* masm);
const char* GetName() { return "ConvertToDoubleStub"; }
#ifdef DEBUG
void Print() { PrintF("ConvertToDoubleStub\n"); }
#endif
};
void ConvertToDoubleStub::Generate(MacroAssembler* masm) {
#ifndef BIG_ENDIAN_FLOATING_POINT
Register exponent = result1_;
Register mantissa = result2_;
#else
Register exponent = result2_;
Register mantissa = result1_;
#endif
Label not_special;
// Convert from Smi to integer.
__ mov(source_, Operand(source_, ASR, kSmiTagSize));
// Move sign bit from source to destination. This works because the sign bit
// in the exponent word of the double has the same position and polarity as
// the 2's complement sign bit in a Smi.
ASSERT(HeapNumber::kSignMask == 0x80000000u);
__ and_(exponent, source_, Operand(HeapNumber::kSignMask), SetCC);
// Subtract from 0 if source was negative.
__ rsb(source_, source_, Operand(0), LeaveCC, ne);
__ cmp(source_, Operand(1));
__ b(gt, ¬_special);
// We have -1, 0 or 1, which we treat specially.
__ cmp(source_, Operand(0));
// For 1 or -1 we need to or in the 0 exponent (biased to 1023).
static const uint32_t exponent_word_for_1 =
HeapNumber::kExponentBias << HeapNumber::kExponentShift;
__ orr(exponent, exponent, Operand(exponent_word_for_1), LeaveCC, ne);
// 1, 0 and -1 all have 0 for the second word.
__ mov(mantissa, Operand(0));
__ Ret();
__ bind(¬_special);
// Count leading zeros. Uses result2 for a scratch register on pre-ARM5.
// Gets the wrong answer for 0, but we already checked for that case above.
CountLeadingZeros(masm, source_, mantissa, zeros_);
// Compute exponent and or it into the exponent register.
// We use result2 as a scratch register here.
__ rsb(mantissa, zeros_, Operand(31 + HeapNumber::kExponentBias));
__ orr(exponent,
exponent,
Operand(mantissa, LSL, HeapNumber::kExponentShift));
// Shift up the source chopping the top bit off.
__ add(zeros_, zeros_, Operand(1));
// This wouldn't work for 1.0 or -1.0 as the shift would be 32 which means 0.
__ mov(source_, Operand(source_, LSL, zeros_));
// Compute lower part of fraction (last 12 bits).
__ mov(mantissa, Operand(source_, LSL, HeapNumber::kMantissaBitsInTopWord));
// And the top (top 20 bits).
__ orr(exponent,
exponent,
Operand(source_, LSR, 32 - HeapNumber::kMantissaBitsInTopWord));
__ Ret();
}
// This stub can convert a signed int32 to a heap number (double). It does
// not work for int32s that are in Smi range! No GC occurs during this stub
// so you don't have to set up the frame.
class WriteInt32ToHeapNumberStub : public CodeStub {
public:
WriteInt32ToHeapNumberStub(Register the_int,
Register the_heap_number,
Register scratch)
: the_int_(the_int),
the_heap_number_(the_heap_number),
scratch_(scratch) { }
private:
Register the_int_;
Register the_heap_number_;
Register scratch_;
// Minor key encoding in 16 bits.
class ModeBits: public BitField<OverwriteMode, 0, 2> {};
class OpBits: public BitField<Token::Value, 2, 14> {};
Major MajorKey() { return WriteInt32ToHeapNumber; }
int MinorKey() {
// Encode the parameters in a unique 16 bit value.
return the_int_.code() +
(the_heap_number_.code() << 4) +
(scratch_.code() << 8);
}
void Generate(MacroAssembler* masm);
const char* GetName() { return "WriteInt32ToHeapNumberStub"; }
#ifdef DEBUG
void Print() { PrintF("WriteInt32ToHeapNumberStub\n"); }
#endif
};
// See comment for class.
void WriteInt32ToHeapNumberStub::Generate(MacroAssembler *masm) {
Label max_negative_int;
// the_int_ has the answer which is a signed int32 but not a Smi.
// We test for the special value that has a different exponent. This test
// has the neat side effect of setting the flags according to the sign.
ASSERT(HeapNumber::kSignMask == 0x80000000u);
__ cmp(the_int_, Operand(0x80000000u));
__ b(eq, &max_negative_int);
// Set up the correct exponent in scratch_. All non-Smi int32s have the same.
// A non-Smi integer is 1.xxx * 2^30 so the exponent is 30 (biased).
uint32_t non_smi_exponent =
(HeapNumber::kExponentBias + 30) << HeapNumber::kExponentShift;
__ mov(scratch_, Operand(non_smi_exponent));
// Set the sign bit in scratch_ if the value was negative.
__ orr(scratch_, scratch_, Operand(HeapNumber::kSignMask), LeaveCC, cs);
// Subtract from 0 if the value was negative.
__ rsb(the_int_, the_int_, Operand(0), LeaveCC, cs);
// We should be masking the implict first digit of the mantissa away here,
// but it just ends up combining harmlessly with the last digit of the
// exponent that happens to be 1. The sign bit is 0 so we shift 10 to get
// the most significant 1 to hit the last bit of the 12 bit sign and exponent.
ASSERT(((1 << HeapNumber::kExponentShift) & non_smi_exponent) != 0);
const int shift_distance = HeapNumber::kNonMantissaBitsInTopWord - 2;
__ orr(scratch_, scratch_, Operand(the_int_, LSR, shift_distance));
__ str(scratch_, FieldMemOperand(the_heap_number_,
HeapNumber::kExponentOffset));
__ mov(scratch_, Operand(the_int_, LSL, 32 - shift_distance));
__ str(scratch_, FieldMemOperand(the_heap_number_,
HeapNumber::kMantissaOffset));
__ Ret();
__ bind(&max_negative_int);
// The max negative int32 is stored as a positive number in the mantissa of
// a double because it uses a sign bit instead of using two's complement.
// The actual mantissa bits stored are all 0 because the implicit most
// significant 1 bit is not stored.
non_smi_exponent += 1 << HeapNumber::kExponentShift;
__ mov(ip, Operand(HeapNumber::kSignMask | non_smi_exponent));
__ str(ip, FieldMemOperand(the_heap_number_, HeapNumber::kExponentOffset));
__ mov(ip, Operand(0));
__ str(ip, FieldMemOperand(the_heap_number_, HeapNumber::kMantissaOffset));
__ Ret();
}
// Handle the case where the lhs and rhs are the same object.
// Equality is almost reflexive (everything but NaN), so this is a test
// for "identity and not NaN".
static void EmitIdenticalObjectComparison(MacroAssembler* masm,
Label* slow,
Condition cc) {
Label not_identical;
__ cmp(r0, Operand(r1));
__ b(ne, ¬_identical);
Register exp_mask_reg = r5;
__ mov(exp_mask_reg, Operand(HeapNumber::kExponentMask));
// Test for NaN. Sadly, we can't just compare to Factory::nan_value(),
// so we do the second best thing - test it ourselves.
Label heap_number, return_equal;
// They are both equal and they are not both Smis so both of them are not
// Smis. If it's not a heap number, then return equal.
if (cc == lt || cc == gt) {
__ CompareObjectType(r0, r4, r4, FIRST_JS_OBJECT_TYPE);
__ b(ge, slow);
} else {
__ CompareObjectType(r0, r4, r4, HEAP_NUMBER_TYPE);
__ b(eq, &heap_number);
// Comparing JS objects with <=, >= is complicated.
if (cc != eq) {
__ cmp(r4, Operand(FIRST_JS_OBJECT_TYPE));
__ b(ge, slow);
}
}
__ bind(&return_equal);
if (cc == lt) {
__ mov(r0, Operand(GREATER)); // Things aren't less than themselves.
} else if (cc == gt) {
__ mov(r0, Operand(LESS)); // Things aren't greater than themselves.
} else {
__ mov(r0, Operand(0)); // Things are <=, >=, ==, === themselves.
}
__ mov(pc, Operand(lr)); // Return.
// For less and greater we don't have to check for NaN since the result of
// x < x is false regardless. For the others here is some code to check
// for NaN.
if (cc != lt && cc != gt) {
__ bind(&heap_number);
// It is a heap number, so return non-equal if it's NaN and equal if it's
// not NaN.
// The representation of NaN values has all exponent bits (52..62) set,
// and not all mantissa bits (0..51) clear.
// Read top bits of double representation (second word of value).
__ ldr(r2, FieldMemOperand(r0, HeapNumber::kExponentOffset));
// Test that exponent bits are all set.
__ and_(r3, r2, Operand(exp_mask_reg));
__ cmp(r3, Operand(exp_mask_reg));
__ b(ne, &return_equal);
// Shift out flag and all exponent bits, retaining only mantissa.
__ mov(r2, Operand(r2, LSL, HeapNumber::kNonMantissaBitsInTopWord));
// Or with all low-bits of mantissa.
__ ldr(r3, FieldMemOperand(r0, HeapNumber::kMantissaOffset));
__ orr(r0, r3, Operand(r2), SetCC);
// For equal we already have the right value in r0: Return zero (equal)
// if all bits in mantissa are zero (it's an Infinity) and non-zero if not
// (it's a NaN). For <= and >= we need to load r0 with the failing value
// if it's a NaN.
if (cc != eq) {
// All-zero means Infinity means equal.
__ mov(pc, Operand(lr), LeaveCC, eq); // Return equal
if (cc == le) {
__ mov(r0, Operand(GREATER)); // NaN <= NaN should fail.
} else {
__ mov(r0, Operand(LESS)); // NaN >= NaN should fail.
}
}
__ mov(pc, Operand(lr)); // Return.
}
// No fall through here.
__ bind(¬_identical);
}
// See comment at call site.
static void EmitSmiNonsmiComparison(MacroAssembler* masm,
Label* rhs_not_nan,
Label* slow,
bool strict) {
Label lhs_is_smi;
__ tst(r0, Operand(kSmiTagMask));
__ b(eq, &lhs_is_smi);
// Rhs is a Smi. Check whether the non-smi is a heap number.
__ CompareObjectType(r0, r4, r4, HEAP_NUMBER_TYPE);
if (strict) {
// If lhs was not a number and rhs was a Smi then strict equality cannot
// succeed. Return non-equal (r0 is already not zero)
__ mov(pc, Operand(lr), LeaveCC, ne); // Return.
} else {
// Smi compared non-strictly with a non-Smi non-heap-number. Call
// the runtime.
__ b(ne, slow);
}
// Rhs is a smi, lhs is a number.
__ push(lr);
__ mov(r7, Operand(r1));
ConvertToDoubleStub stub1(r3, r2, r7, r6);
__ Call(stub1.GetCode(), RelocInfo::CODE_TARGET);
// r3 and r2 are rhs as double.
__ ldr(r1, FieldMemOperand(r0, HeapNumber::kValueOffset + kPointerSize));
__ ldr(r0, FieldMemOperand(r0, HeapNumber::kValueOffset));
// We now have both loaded as doubles but we can skip the lhs nan check
// since it's a Smi.
__ pop(lr);
__ jmp(rhs_not_nan);
__ bind(&lhs_is_smi);
// Lhs is a Smi. Check whether the non-smi is a heap number.
__ CompareObjectType(r1, r4, r4, HEAP_NUMBER_TYPE);
if (strict) {
// If lhs was not a number and rhs was a Smi then strict equality cannot
// succeed. Return non-equal.
__ mov(r0, Operand(1), LeaveCC, ne); // Non-zero indicates not equal.
__ mov(pc, Operand(lr), LeaveCC, ne); // Return.
} else {
// Smi compared non-strictly with a non-Smi non-heap-number. Call
// the runtime.
__ b(ne, slow);
}
// Lhs is a smi, rhs is a number.
// r0 is Smi and r1 is heap number.
__ push(lr);
__ ldr(r2, FieldMemOperand(r1, HeapNumber::kValueOffset));
__ ldr(r3, FieldMemOperand(r1, HeapNumber::kValueOffset + kPointerSize));
__ mov(r7, Operand(r0));
ConvertToDoubleStub stub2(r1, r0, r7, r6);
__ Call(stub2.GetCode(), RelocInfo::CODE_TARGET);
__ pop(lr);
// Fall through to both_loaded_as_doubles.
}
void EmitNanCheck(MacroAssembler* masm, Label* rhs_not_nan, Condition cc) {
bool exp_first = (HeapNumber::kExponentOffset == HeapNumber::kValueOffset);
Register lhs_exponent = exp_first ? r0 : r1;
Register rhs_exponent = exp_first ? r2 : r3;
Register lhs_mantissa = exp_first ? r1 : r0;
Register rhs_mantissa = exp_first ? r3 : r2;
Label one_is_nan, neither_is_nan;
Register exp_mask_reg = r5;
__ mov(exp_mask_reg, Operand(HeapNumber::kExponentMask));
__ and_(r4, rhs_exponent, Operand(exp_mask_reg));
__ cmp(r4, Operand(exp_mask_reg));
__ b(ne, rhs_not_nan);
__ mov(r4,
Operand(rhs_exponent, LSL, HeapNumber::kNonMantissaBitsInTopWord),
SetCC);
__ b(ne, &one_is_nan);
__ cmp(rhs_mantissa, Operand(0));
__ b(ne, &one_is_nan);
__ bind(rhs_not_nan);
__ mov(exp_mask_reg, Operand(HeapNumber::kExponentMask));
__ and_(r4, lhs_exponent, Operand(exp_mask_reg));
__ cmp(r4, Operand(exp_mask_reg));
__ b(ne, &neither_is_nan);
__ mov(r4,
Operand(lhs_exponent, LSL, HeapNumber::kNonMantissaBitsInTopWord),
SetCC);
__ b(ne, &one_is_nan);
__ cmp(lhs_mantissa, Operand(0));
__ b(eq, &neither_is_nan);
__ bind(&one_is_nan);
// NaN comparisons always fail.
// Load whatever we need in r0 to make the comparison fail.
if (cc == lt || cc == le) {
__ mov(r0, Operand(GREATER));
} else {
__ mov(r0, Operand(LESS));
}
__ mov(pc, Operand(lr)); // Return.
__ bind(&neither_is_nan);
}
// See comment at call site.
static void EmitTwoNonNanDoubleComparison(MacroAssembler* masm, Condition cc) {
bool exp_first = (HeapNumber::kExponentOffset == HeapNumber::kValueOffset);
Register lhs_exponent = exp_first ? r0 : r1;
Register rhs_exponent = exp_first ? r2 : r3;
Register lhs_mantissa = exp_first ? r1 : r0;
Register rhs_mantissa = exp_first ? r3 : r2;
// r0, r1, r2, r3 have the two doubles. Neither is a NaN.
if (cc == eq) {
// Doubles are not equal unless they have the same bit pattern.
// Exception: 0 and -0.
__ cmp(lhs_mantissa, Operand(rhs_mantissa));
__ orr(r0, lhs_mantissa, Operand(rhs_mantissa), LeaveCC, ne);
// Return non-zero if the numbers are unequal.
__ mov(pc, Operand(lr), LeaveCC, ne);
__ sub(r0, lhs_exponent, Operand(rhs_exponent), SetCC);
// If exponents are equal then return 0.
__ mov(pc, Operand(lr), LeaveCC, eq);
// Exponents are unequal. The only way we can return that the numbers
// are equal is if one is -0 and the other is 0. We already dealt
// with the case where both are -0 or both are 0.
// We start by seeing if the mantissas (that are equal) or the bottom
// 31 bits of the rhs exponent are non-zero. If so we return not
// equal.
__ orr(r4, rhs_mantissa, Operand(rhs_exponent, LSL, kSmiTagSize), SetCC);
__ mov(r0, Operand(r4), LeaveCC, ne);
__ mov(pc, Operand(lr), LeaveCC, ne); // Return conditionally.
// Now they are equal if and only if the lhs exponent is zero in its
// low 31 bits.
__ mov(r0, Operand(lhs_exponent, LSL, kSmiTagSize));
__ mov(pc, Operand(lr));
} else {
// Call a native function to do a comparison between two non-NaNs.
// Call C routine that may not cause GC or other trouble.
__ mov(r5, Operand(ExternalReference::compare_doubles()));
__ Jump(r5); // Tail call.
}
}
// See comment at call site.
static void EmitStrictTwoHeapObjectCompare(MacroAssembler* masm) {
// If either operand is a JSObject or an oddball value, then they are
// not equal since their pointers are different.
// There is no test for undetectability in strict equality.
ASSERT(LAST_TYPE == JS_FUNCTION_TYPE);
Label first_non_object;
// Get the type of the first operand into r2 and compare it with
// FIRST_JS_OBJECT_TYPE.
__ CompareObjectType(r0, r2, r2, FIRST_JS_OBJECT_TYPE);
__ b(lt, &first_non_object);
// Return non-zero (r0 is not zero)
Label return_not_equal;
__ bind(&return_not_equal);
__ mov(pc, Operand(lr)); // Return.
__ bind(&first_non_object);
// Check for oddballs: true, false, null, undefined.
__ cmp(r2, Operand(ODDBALL_TYPE));
__ b(eq, &return_not_equal);
__ CompareObjectType(r1, r3, r3, FIRST_JS_OBJECT_TYPE);
__ b(ge, &return_not_equal);
// Check for oddballs: true, false, null, undefined.
__ cmp(r3, Operand(ODDBALL_TYPE));
__ b(eq, &return_not_equal);
}
// See comment at call site.
static void EmitCheckForTwoHeapNumbers(MacroAssembler* masm,
Label* both_loaded_as_doubles,
Label* not_heap_numbers,
Label* slow) {
__ CompareObjectType(r0, r2, r2, HEAP_NUMBER_TYPE);
__ b(ne, not_heap_numbers);
__ CompareObjectType(r1, r3, r3, HEAP_NUMBER_TYPE);
__ b(ne, slow); // First was a heap number, second wasn't. Go slow case.
// Both are heap numbers. Load them up then jump to the code we have
// for that.
__ ldr(r2, FieldMemOperand(r1, HeapNumber::kValueOffset));
__ ldr(r3, FieldMemOperand(r1, HeapNumber::kValueOffset + kPointerSize));
__ ldr(r1, FieldMemOperand(r0, HeapNumber::kValueOffset + kPointerSize));
__ ldr(r0, FieldMemOperand(r0, HeapNumber::kValueOffset));
__ jmp(both_loaded_as_doubles);
}
// Fast negative check for symbol-to-symbol equality.
static void EmitCheckForSymbols(MacroAssembler* masm, Label* slow) {
// r2 is object type of r0.
__ tst(r2, Operand(kIsNotStringMask));
__ b(ne, slow);
__ tst(r2, Operand(kIsSymbolMask));
__ b(eq, slow);
__ CompareObjectType(r1, r3, r3, FIRST_NONSTRING_TYPE);
__ b(ge, slow);
__ tst(r3, Operand(kIsSymbolMask));
__ b(eq, slow);
// Both are symbols. We already checked they weren't the same pointer
// so they are not equal.
__ mov(r0, Operand(1)); // Non-zero indicates not equal.
__ mov(pc, Operand(lr)); // Return.
}
// On entry r0 and r1 are the things to be compared. On exit r0 is 0,
// positive or negative to indicate the result of the comparison.
void CompareStub::Generate(MacroAssembler* masm) {
Label slow; // Call builtin.
Label not_smis, both_loaded_as_doubles, rhs_not_nan;
// NOTICE! This code is only reached after a smi-fast-case check, so
// it is certain that at least one operand isn't a smi.
// Handle the case where the objects are identical. Either returns the answer
// or goes to slow. Only falls through if the objects were not identical.
EmitIdenticalObjectComparison(masm, &slow, cc_);
// If either is a Smi (we know that not both are), then they can only
// be strictly equal if the other is a HeapNumber.
ASSERT_EQ(0, kSmiTag);
ASSERT_EQ(0, Smi::FromInt(0));
__ and_(r2, r0, Operand(r1));
__ tst(r2, Operand(kSmiTagMask));
__ b(ne, ¬_smis);
// One operand is a smi. EmitSmiNonsmiComparison generates code that can:
// 1) Return the answer.
// 2) Go to slow.
// 3) Fall through to both_loaded_as_doubles.
// 4) Jump to rhs_not_nan.
// In cases 3 and 4 we have found out we were dealing with a number-number
// comparison and the numbers have been loaded into r0, r1, r2, r3 as doubles.
EmitSmiNonsmiComparison(masm, &rhs_not_nan, &slow, strict_);
__ bind(&both_loaded_as_doubles);
// r0, r1, r2, r3 are the double representations of the left hand side
// and the right hand side.
// Checks for NaN in the doubles we have loaded. Can return the answer or
// fall through if neither is a NaN. Also binds rhs_not_nan.
EmitNanCheck(masm, &rhs_not_nan, cc_);
// Compares two doubles in r0, r1, r2, r3 that are not NaNs. Returns the
// answer. Never falls through.
EmitTwoNonNanDoubleComparison(masm, cc_);
__ bind(¬_smis);
// At this point we know we are dealing with two different objects,
// and neither of them is a Smi. The objects are in r0 and r1.
if (strict_) {
// This returns non-equal for some object types, or falls through if it
// was not lucky.
EmitStrictTwoHeapObjectCompare(masm);
}
Label check_for_symbols;
// Check for heap-number-heap-number comparison. Can jump to slow case,
// or load both doubles into r0, r1, r2, r3 and jump to the code that handles
// that case. If the inputs are not doubles then jumps to check_for_symbols.
// In this case r2 will contain the type of r0.
EmitCheckForTwoHeapNumbers(masm,
&both_loaded_as_doubles,
&check_for_symbols,
&slow);
__ bind(&check_for_symbols);
if (cc_ == eq) {
// Either jumps to slow or returns the answer. Assumes that r2 is the type
// of r0 on entry.
EmitCheckForSymbols(masm, &slow);
}
__ bind(&slow);
__ push(lr);
__ push(r1);
__ push(r0);
// Figure out which native to call and setup the arguments.
Builtins::JavaScript native;
int arg_count = 1; // Not counting receiver.
if (cc_ == eq) {
native = strict_ ? Builtins::STRICT_EQUALS : Builtins::EQUALS;
} else {
native = Builtins::COMPARE;
int ncr; // NaN compare result
if (cc_ == lt || cc_ == le) {
ncr = GREATER;
} else {
ASSERT(cc_ == gt || cc_ == ge); // remaining cases
ncr = LESS;
}
arg_count++;
__ mov(r0, Operand(Smi::FromInt(ncr)));
__ push(r0);
}
// Call the native; it returns -1 (less), 0 (equal), or 1 (greater)
// tagged as a small integer.
__ mov(r0, Operand(arg_count));
__ InvokeBuiltin(native, CALL_JS);
__ cmp(r0, Operand(0));
__ pop(pc);
}
// Allocates a heap number or jumps to the label if the young space is full and
// a scavenge is needed.
static void AllocateHeapNumber(
MacroAssembler* masm,
Label* need_gc, // Jump here if young space is full.
Register result, // The tagged address of the new heap number.
Register scratch1, // A scratch register.
Register scratch2) { // Another scratch register.
// Allocate an object in the heap for the heap number and tag it as a heap
// object.
__ AllocateObjectInNewSpace(HeapNumber::kSize / kPointerSize,
result,
scratch1,
scratch2,
need_gc,
TAG_OBJECT);
// Get heap number map and store it in the allocated object.
__ LoadRoot(scratch1, Heap::kHeapNumberMapRootIndex);
__ str(scratch1, FieldMemOperand(result, HeapObject::kMapOffset));
}
// We fall into this code if the operands were Smis, but the result was
// not (eg. overflow). We branch into this code (to the not_smi label) if
// the operands were not both Smi. The operands are in r0 and r1. In order
// to call the C-implemented binary fp operation routines we need to end up
// with the double precision floating point operands in r0 and r1 (for the
// value in r1) and r2 and r3 (for the value in r0).
static void HandleBinaryOpSlowCases(MacroAssembler* masm,
Label* not_smi,
const Builtins::JavaScript& builtin,
Token::Value operation,
OverwriteMode mode) {
Label slow, slow_pop_2_first, do_the_call;
Label r0_is_smi, r1_is_smi, finished_loading_r0, finished_loading_r1;
// Smi-smi case (overflow).
// Since both are Smis there is no heap number to overwrite, so allocate.
// The new heap number is in r5. r6 and r7 are scratch.
AllocateHeapNumber(masm, &slow, r5, r6, r7);
// Write Smi from r0 to r3 and r2 in double format. r6 is scratch.
__ mov(r7, Operand(r0));
ConvertToDoubleStub stub1(r3, r2, r7, r6);
__ push(lr);
__ Call(stub1.GetCode(), RelocInfo::CODE_TARGET);
// Write Smi from r1 to r1 and r0 in double format. r6 is scratch.
__ mov(r7, Operand(r1));
ConvertToDoubleStub stub2(r1, r0, r7, r6);
__ Call(stub2.GetCode(), RelocInfo::CODE_TARGET);
__ pop(lr);
__ jmp(&do_the_call); // Tail call. No return.
// We jump to here if something goes wrong (one param is not a number of any
// sort or new-space allocation fails).
__ bind(&slow);
__ push(r1);
__ push(r0);
__ mov(r0, Operand(1)); // Set number of arguments.
__ InvokeBuiltin(builtin, JUMP_JS); // Tail call. No return.
// We branch here if at least one of r0 and r1 is not a Smi.
__ bind(not_smi);
if (mode == NO_OVERWRITE) {
// In the case where there is no chance of an overwritable float we may as
// well do the allocation immediately while r0 and r1 are untouched.
AllocateHeapNumber(masm, &slow, r5, r6, r7);
}
// Move r0 to a double in r2-r3.
__ tst(r0, Operand(kSmiTagMask));
__ b(eq, &r0_is_smi); // It's a Smi so don't check it's a heap number.
__ CompareObjectType(r0, r4, r4, HEAP_NUMBER_TYPE);
__ b(ne, &slow);
if (mode == OVERWRITE_RIGHT) {
__ mov(r5, Operand(r0)); // Overwrite this heap number.
}
// Calling convention says that second double is in r2 and r3.
__ ldr(r2, FieldMemOperand(r0, HeapNumber::kValueOffset));
__ ldr(r3, FieldMemOperand(r0, HeapNumber::kValueOffset + 4));
__ jmp(&finished_loading_r0);
__ bind(&r0_is_smi);
if (mode == OVERWRITE_RIGHT) {
// We can't overwrite a Smi so get address of new heap number into r5.
AllocateHeapNumber(masm, &slow, r5, r6, r7);
}
// Write Smi from r0 to r3 and r2 in double format.
__ mov(r7, Operand(r0));
ConvertToDoubleStub stub3(r3, r2, r7, r6);
__ push(lr);
__ Call(stub3.GetCode(), RelocInfo::CODE_TARGET);
__ pop(lr);
__ bind(&finished_loading_r0);
// Move r1 to a double in r0-r1.
__ tst(r1, Operand(kSmiTagMask));
__ b(eq, &r1_is_smi); // It's a Smi so don't check it's a heap number.
__ CompareObjectType(r1, r4, r4, HEAP_NUMBER_TYPE);
__ b(ne, &slow);
if (mode == OVERWRITE_LEFT) {
__ mov(r5, Operand(r1)); // Overwrite this heap number.
}
// Calling convention says that first double is in r0 and r1.
__ ldr(r0, FieldMemOperand(r1, HeapNumber::kValueOffset));
__ ldr(r1, FieldMemOperand(r1, HeapNumber::kValueOffset + 4));
__ jmp(&finished_loading_r1);
__ bind(&r1_is_smi);
if (mode == OVERWRITE_LEFT) {
// We can't overwrite a Smi so get address of new heap number into r5.
AllocateHeapNumber(masm, &slow, r5, r6, r7);
}
// Write Smi from r1 to r1 and r0 in double format.
__ mov(r7, Operand(r1));
ConvertToDoubleStub stub4(r1, r0, r7, r6);
__ push(lr);
__ Call(stub4.GetCode(), RelocInfo::CODE_TARGET);
__ pop(lr);
__ bind(&finished_loading_r1);
__ bind(&do_the_call);
// r0: Left value (least significant part of mantissa).
// r1: Left value (sign, exponent, top of mantissa).
// r2: Right value (least significant part of mantissa).
// r3: Right value (sign, exponent, top of mantissa).
// r5: Address of heap number for result.
__ push(lr); // For later.
__ push(r5); // Address of heap number that is answer.
// Call C routine that may not cause GC or other trouble.
__ mov(r5, Operand(ExternalReference::double_fp_operation(operation)));
__ Call(r5);
// Store answer in the overwritable heap number.
__ pop(r4);
#if !defined(USE_ARM_EABI)
// Double returned in fp coprocessor register 0 and 1, encoded as register
// cr8. Offsets must be divisible by 4 for coprocessor so we need to
// substract the tag from r4.
__ sub(r5, r4, Operand(kHeapObjectTag));
__ stc(p1, cr8, MemOperand(r5, HeapNumber::kValueOffset));
#else
// Double returned in registers 0 and 1.
__ str(r0, FieldMemOperand(r4, HeapNumber::kValueOffset));
__ str(r1, FieldMemOperand(r4, HeapNumber::kValueOffset + 4));
#endif
__ mov(r0, Operand(r4));
// And we are done.
__ pop(pc);
}
// Tries to get a signed int32 out of a double precision floating point heap
// number. Rounds towards 0. Fastest for doubles that are in the ranges
// -0x7fffffff to -0x40000000 or 0x40000000 to 0x7fffffff. This corresponds
// almost to the range of signed int32 values that are not Smis. Jumps to the
// label 'slow' if the double isn't in the range -0x80000000.0 to 0x80000000.0
// (excluding the endpoints).
static void GetInt32(MacroAssembler* masm,
Register source,
Register dest,
Register scratch,
Register scratch2,
Label* slow) {
Label right_exponent, done;
// Get exponent word.
__ ldr(scratch, FieldMemOperand(source, HeapNumber::kExponentOffset));
// Get exponent alone in scratch2.
__ and_(scratch2, scratch, Operand(HeapNumber::kExponentMask));
// Load dest with zero. We use this either for the final shift or
// for the answer.
__ mov(dest, Operand(0));
// Check whether the exponent matches a 32 bit signed int that is not a Smi.
// A non-Smi integer is 1.xxx * 2^30 so the exponent is 30 (biased). This is
// the exponent that we are fastest at and also the highest exponent we can
// handle here.
const uint32_t non_smi_exponent =
(HeapNumber::kExponentBias + 30) << HeapNumber::kExponentShift;
__ cmp(scratch2, Operand(non_smi_exponent));
// If we have a match of the int32-but-not-Smi exponent then skip some logic.
__ b(eq, &right_exponent);
// If the exponent is higher than that then go to slow case. This catches
// numbers that don't fit in a signed int32, infinities and NaNs.
__ b(gt, slow);
// We know the exponent is smaller than 30 (biased). If it is less than
// 0 (biased) then the number is smaller in magnitude than 1.0 * 2^0, ie
// it rounds to zero.
const uint32_t zero_exponent =
(HeapNumber::kExponentBias + 0) << HeapNumber::kExponentShift;
__ sub(scratch2, scratch2, Operand(zero_exponent), SetCC);
// Dest already has a Smi zero.
__ b(lt, &done);
// We have a shifted exponent between 0 and 30 in scratch2.
__ mov(dest, Operand(scratch2, LSR, HeapNumber::kExponentShift));
// We now have the exponent in dest. Subtract from 30 to get
// how much to shift down.
__ rsb(dest, dest, Operand(30));
__ bind(&right_exponent);
// Get the top bits of the mantissa.
__ and_(scratch2, scratch, Operand(HeapNumber::kMantissaMask));
// Put back the implicit 1.
__ orr(scratch2, scratch2, Operand(1 << HeapNumber::kExponentShift));
// Shift up the mantissa bits to take up the space the exponent used to take.
// We just orred in the implicit bit so that took care of one and we want to
// leave the sign bit 0 so we subtract 2 bits from the shift distance.
const int shift_distance = HeapNumber::kNonMantissaBitsInTopWord - 2;
__ mov(scratch2, Operand(scratch2, LSL, shift_distance));
// Put sign in zero flag.
__ tst(scratch, Operand(HeapNumber::kSignMask));
// Get the second half of the double. For some exponents we don't actually
// need this because the bits get shifted out again, but it's probably slower
// to test than just to do it.
__ ldr(scratch, FieldMemOperand(source, HeapNumber::kMantissaOffset));
// Shift down 22 bits to get the last 10 bits.
__ orr(scratch, scratch2, Operand(scratch, LSR, 32 - shift_distance));
// Move down according to the exponent.
__ mov(dest, Operand(scratch, LSR, dest));
// Fix sign if sign bit was set.
__ rsb(dest, dest, Operand(0), LeaveCC, ne);
__ bind(&done);
}
// For bitwise ops where the inputs are not both Smis we here try to determine
// whether both inputs are either Smis or at least heap numbers that can be
// represented by a 32 bit signed value. We truncate towards zero as required
// by the ES spec. If this is the case we do the bitwise op and see if the
// result is a Smi. If so, great, otherwise we try to find a heap number to
// write the answer into (either by allocating or by overwriting).
// On entry the operands are in r0 and r1. On exit the answer is in r0.
void GenericBinaryOpStub::HandleNonSmiBitwiseOp(MacroAssembler* masm) {
Label slow, result_not_a_smi;
Label r0_is_smi, r1_is_smi;
Label done_checking_r0, done_checking_r1;
__ tst(r1, Operand(kSmiTagMask));
__ b(eq, &r1_is_smi); // It's a Smi so don't check it's a heap number.
__ CompareObjectType(r1, r4, r4, HEAP_NUMBER_TYPE);
__ b(ne, &slow);
GetInt32(masm, r1, r3, r4, r5, &slow);
__ jmp(&done_checking_r1);
__ bind(&r1_is_smi);
__ mov(r3, Operand(r1, ASR, 1));
__ bind(&done_checking_r1);
__ tst(r0, Operand(kSmiTagMask));
__ b(eq, &r0_is_smi); // It's a Smi so don't check it's a heap number.
__ CompareObjectType(r0, r4, r4, HEAP_NUMBER_TYPE);
__ b(ne, &slow);
GetInt32(masm, r0, r2, r4, r5, &slow);
__ jmp(&done_checking_r0);
__ bind(&r0_is_smi);
__ mov(r2, Operand(r0, ASR, 1));
__ bind(&done_checking_r0);
// r0 and r1: Original operands (Smi or heap numbers).
// r2 and r3: Signed int32 operands.
switch (op_) {
case Token::BIT_OR: __ orr(r2, r2, Operand(r3)); break;
case Token::BIT_XOR: __ eor(r2, r2, Operand(r3)); break;
case Token::BIT_AND: __ and_(r2, r2, Operand(r3)); break;
case Token::SAR:
// Use only the 5 least significant bits of the shift count.
__ and_(r2, r2, Operand(0x1f));
__ mov(r2, Operand(r3, ASR, r2));
break;
case Token::SHR:
// Use only the 5 least significant bits of the shift count.
__ and_(r2, r2, Operand(0x1f));
__ mov(r2, Operand(r3, LSR, r2), SetCC);
// SHR is special because it is required to produce a positive answer.
// The code below for writing into heap numbers isn't capable of writing
// the register as an unsigned int so we go to slow case if we hit this
// case.
__ b(mi, &slow);
break;
case Token::SHL:
// Use only the 5 least significant bits of the shift count.
__ and_(r2, r2, Operand(0x1f));
__ mov(r2, Operand(r3, LSL, r2));
break;
default: UNREACHABLE();
}
// check that the *signed* result fits in a smi
__ add(r3, r2, Operand(0x40000000), SetCC);
__ b(mi, &result_not_a_smi);
__ mov(r0, Operand(r2, LSL, kSmiTagSize));
__ Ret();
Label have_to_allocate, got_a_heap_number;
__ bind(&result_not_a_smi);
switch (mode_) {
case OVERWRITE_RIGHT: {
__ tst(r0, Operand(kSmiTagMask));
__ b(eq, &have_to_allocate);
__ mov(r5, Operand(r0));
break;
}
case OVERWRITE_LEFT: {
__ tst(r1, Operand(kSmiTagMask));
__ b(eq, &have_to_allocate);
__ mov(r5, Operand(r1));
break;
}
case NO_OVERWRITE: {
// Get a new heap number in r5. r6 and r7 are scratch.
AllocateHeapNumber(masm, &slow, r5, r6, r7);
}
default: break;
}
__ bind(&got_a_heap_number);
// r2: Answer as signed int32.
// r5: Heap number to write answer into.
// Nothing can go wrong now, so move the heap number to r0, which is the
// result.
__ mov(r0, Operand(r5));
// Tail call that writes the int32 in r2 to the heap number in r0, using
// r3 as scratch. r0 is preserved and returned.
WriteInt32ToHeapNumberStub stub(r2, r0, r3);
__ Jump(stub.GetCode(), RelocInfo::CODE_TARGET);
if (mode_ != NO_OVERWRITE) {
__ bind(&have_to_allocate);
// Get a new heap number in r5. r6 and r7 are scratch.
AllocateHeapNumber(masm, &slow, r5, r6, r7);
__ jmp(&got_a_heap_number);
}
// If all else failed then we go to the runtime system.
__ bind(&slow);
__ push(r1); // restore stack
__ push(r0);
__ mov(r0, Operand(1)); // 1 argument (not counting receiver).
switch (op_) {
case Token::BIT_OR:
__ InvokeBuiltin(Builtins::BIT_OR, JUMP_JS);
break;
case Token::BIT_AND:
__ InvokeBuiltin(Builtins::BIT_AND, JUMP_JS);
break;
case Token::BIT_XOR:
__ InvokeBuiltin(Builtins::BIT_XOR, JUMP_JS);
break;
case Token::SAR:
__ InvokeBuiltin(Builtins::SAR, JUMP_JS);
break;
case Token::SHR:
__ InvokeBuiltin(Builtins::SHR, JUMP_JS);
break;
case Token::SHL:
__ InvokeBuiltin(Builtins::SHL, JUMP_JS);
break;
default:
UNREACHABLE();
}
}
// Can we multiply by x with max two shifts and an add.
// This answers yes to all integers from 2 to 10.
static bool IsEasyToMultiplyBy(int x) {
if (x < 2) return false; // Avoid special cases.
if (x > (Smi::kMaxValue + 1) >> 2) return false; // Almost always overflows.
if (IsPowerOf2(x)) return true; // Simple shift.
if (PopCountLessThanEqual2(x)) return true; // Shift and add and shift.
if (IsPowerOf2(x + 1)) return true; // Patterns like 11111.
return false;
}
// Can multiply by anything that IsEasyToMultiplyBy returns true for.
// Source and destination may be the same register. This routine does
// not set carry and overflow the way a mul instruction would.
static void MultiplyByKnownInt(MacroAssembler* masm,
Register source,
Register destination,
int known_int) {
if (IsPowerOf2(known_int)) {
__ mov(destination, Operand(source, LSL, BitPosition(known_int)));
} else if (PopCountLessThanEqual2(known_int)) {
int first_bit = BitPosition(known_int);
int second_bit = BitPosition(known_int ^ (1 << first_bit));
__ add(destination, source, Operand(source, LSL, second_bit - first_bit));
if (first_bit != 0) {
__ mov(destination, Operand(destination, LSL, first_bit));
}
} else {
ASSERT(IsPowerOf2(known_int + 1)); // Patterns like 1111.
int the_bit = BitPosition(known_int + 1);
__ rsb(destination, source, Operand(source, LSL, the_bit));
}
}
// This function (as opposed to MultiplyByKnownInt) takes the known int in a
// a register for the cases where it doesn't know a good trick, and may deliver
// a result that needs shifting.
static void MultiplyByKnownInt2(
MacroAssembler* masm,
Register result,
Register source,
Register known_int_register, // Smi tagged.
int known_int,
int* required_shift) { // Including Smi tag shift
switch (known_int) {
case 3:
__ add(result, source, Operand(source, LSL, 1));
*required_shift = 1;
break;
case 5:
__ add(result, source, Operand(source, LSL, 2));
*required_shift = 1;
break;
case 6:
__ add(result, source, Operand(source, LSL, 1));
*required_shift = 2;
break;
case 7:
__ rsb(result, source, Operand(source, LSL, 3));
*required_shift = 1;
break;
case 9:
__ add(result, source, Operand(source, LSL, 3));
*required_shift = 1;
break;
case 10:
__ add(result, source, Operand(source, LSL, 2));
*required_shift = 2;
break;
default:
ASSERT(!IsPowerOf2(known_int)); // That would be very inefficient.
__ mul(result, source, known_int_register);
*required_shift = 0;
}
}
void GenericBinaryOpStub::Generate(MacroAssembler* masm) {
// r1 : x
// r0 : y
// result : r0
// All ops need to know whether we are dealing with two Smis. Set up r2 to
// tell us that.
__ orr(r2, r1, Operand(r0)); // r2 = x | y;
switch (op_) {
case Token::ADD: {
Label not_smi;
// Fast path.
ASSERT(kSmiTag == 0); // Adjust code below.
__ tst(r2, Operand(kSmiTagMask));
__ b(ne, ¬_smi);
__ add(r0, r1, Operand(r0), SetCC); // Add y optimistically.
// Return if no overflow.
__ Ret(vc);
__ sub(r0, r0, Operand(r1)); // Revert optimistic add.
HandleBinaryOpSlowCases(masm,
¬_smi,
Builtins::ADD,
Token::ADD,
mode_);
break;
}
case Token::SUB: {
Label not_smi;
// Fast path.
ASSERT(kSmiTag == 0); // Adjust code below.
__ tst(r2, Operand(kSmiTagMask));
__ b(ne, ¬_smi);
__ sub(r0, r1, Operand(r0), SetCC); // Subtract y optimistically.
// Return if no overflow.
__ Ret(vc);
__ sub(r0, r1, Operand(r0)); // Revert optimistic subtract.
HandleBinaryOpSlowCases(masm,
¬_smi,
Builtins::SUB,
Token::SUB,
mode_);
break;
}
case Token::MUL: {
Label not_smi, slow;
ASSERT(kSmiTag == 0); // adjust code below
__ tst(r2, Operand(kSmiTagMask));
__ b(ne, ¬_smi);
// Remove tag from one operand (but keep sign), so that result is Smi.
__ mov(ip, Operand(r0, ASR, kSmiTagSize));
// Do multiplication
__ smull(r3, r2, r1, ip); // r3 = lower 32 bits of ip*r1.
// Go slow on overflows (overflow bit is not set).
__ mov(ip, Operand(r3, ASR, 31));
__ cmp(ip, Operand(r2)); // no overflow if higher 33 bits are identical
__ b(ne, &slow);
// Go slow on zero result to handle -0.
__ tst(r3, Operand(r3));
__ mov(r0, Operand(r3), LeaveCC, ne);
__ Ret(ne);
// We need -0 if we were multiplying a negative number with 0 to get 0.
// We know one of them was zero.
__ add(r2, r0, Operand(r1), SetCC);
__ mov(r0, Operand(Smi::FromInt(0)), LeaveCC, pl);
__ Ret(pl); // Return Smi 0 if the non-zero one was positive.
// Slow case. We fall through here if we multiplied a negative number
// with 0, because that would mean we should produce -0.
__ bind(&slow);
HandleBinaryOpSlowCases(masm,
¬_smi,
Builtins::MUL,
Token::MUL,
mode_);
break;
}
case Token::DIV:
case Token::MOD: {
Label not_smi;
if (specialized_on_rhs_) {
Label smi_is_unsuitable;
__ BranchOnNotSmi(r1, ¬_smi);
if (IsPowerOf2(constant_rhs_)) {
if (op_ == Token::MOD) {
__ and_(r0,
r1,
Operand(0x80000000u | ((constant_rhs_ << kSmiTagSize) - 1)),
SetCC);
// We now have the answer, but if the input was negative we also
// have the sign bit. Our work is done if the result is
// positive or zero:
__ Ret(pl);
// A mod of a negative left hand side must return a negative number.
// Unfortunately if the answer is 0 then we must return -0. And we
// already optimistically trashed r0 so we may need to restore it.
__ eor(r0, r0, Operand(0x80000000u), SetCC);
// Next two instructions are conditional on the answer being -0.
__ mov(r0, Operand(Smi::FromInt(constant_rhs_)), LeaveCC, eq);
__ b(eq, &smi_is_unsuitable);
// We need to subtract the dividend. Eg. -3 % 4 == -3.
__ sub(r0, r0, Operand(Smi::FromInt(constant_rhs_)));
} else {
ASSERT(op_ == Token::DIV);
__ tst(r1,
Operand(0x80000000u | ((constant_rhs_ << kSmiTagSize) - 1)));
__ b(ne, &smi_is_unsuitable); // Go slow on negative or remainder.
int shift = 0;
int d = constant_rhs_;
while ((d & 1) == 0) {
d >>= 1;
shift++;
}
__ mov(r0, Operand(r1, LSR, shift));
__ bic(r0, r0, Operand(kSmiTagMask));
}
} else {
// Not a power of 2.
__ tst(r1, Operand(0x80000000u));
__ b(ne, &smi_is_unsuitable);
// Find a fixed point reciprocal of the divisor so we can divide by
// multiplying.
double divisor = 1.0 / constant_rhs_;
int shift = 32;
double scale = 4294967296.0; // 1 << 32.
uint32_t mul;
// Maximise the precision of the fixed point reciprocal.
while (true) {
mul = static_cast<uint32_t>(scale * divisor);
if (mul >= 0x7fffffff) break;
scale *= 2.0;
shift++;
}
mul++;
__ mov(r2, Operand(mul));
__ umull(r3, r2, r2, r1);
__ mov(r2, Operand(r2, LSR, shift - 31));
// r2 is r1 / rhs. r2 is not Smi tagged.
// r0 is still the known rhs. r0 is Smi tagged.
// r1 is still the unkown lhs. r1 is Smi tagged.
int required_r4_shift = 0; // Including the Smi tag shift of 1.
// r4 = r2 * r0.
MultiplyByKnownInt2(masm,
r4,
r2,
r0,
constant_rhs_,
&required_r4_shift);
// r4 << required_r4_shift is now the Smi tagged rhs * (r1 / rhs).
if (op_ == Token::DIV) {
__ sub(r3, r1, Operand(r4, LSL, required_r4_shift), SetCC);
__ b(ne, &smi_is_unsuitable); // There was a remainder.
__ mov(r0, Operand(r2, LSL, kSmiTagSize));
} else {
ASSERT(op_ == Token::MOD);
__ sub(r0, r1, Operand(r4, LSL, required_r4_shift));
}
}
__ Ret();
__ bind(&smi_is_unsuitable);
} else {
__ jmp(¬_smi);
}
HandleBinaryOpSlowCases(masm,
¬_smi,
op_ == Token::MOD ? Builtins::MOD : Builtins::DIV,
op_,
mode_);
break;
}
case Token::BIT_OR:
case Token::BIT_AND:
case Token::BIT_XOR:
case Token::SAR:
case Token::SHR:
case Token::SHL: {
Label slow;
ASSERT(kSmiTag == 0); // adjust code below
__ tst(r2, Operand(kSmiTagMask));
__ b(ne, &slow);
switch (op_) {
case Token::BIT_OR: __ orr(r0, r0, Operand(r1)); break;
case Token::BIT_AND: __ and_(r0, r0, Operand(r1)); break;
case Token::BIT_XOR: __ eor(r0, r0, Operand(r1)); break;
case Token::SAR:
// Remove tags from right operand.
__ mov(r2, Operand(r0, ASR, kSmiTagSize)); // y
// Use only the 5 least significant bits of the shift count.
__ and_(r2, r2, Operand(0x1f));
__ mov(r0, Operand(r1, ASR, r2));
// Smi tag result.
__ bic(r0, r0, Operand(kSmiTagMask));
break;
case Token::SHR:
// Remove tags from operands. We can't do this on a 31 bit number
// because then the 0s get shifted into bit 30 instead of bit 31.
__ mov(r3, Operand(r1, ASR, kSmiTagSize)); // x
__ mov(r2, Operand(r0, ASR, kSmiTagSize)); // y
// Use only the 5 least significant bits of the shift count.
__ and_(r2, r2, Operand(0x1f));
__ mov(r3, Operand(r3, LSR, r2));
// Unsigned shift is not allowed to produce a negative number, so
// check the sign bit and the sign bit after Smi tagging.
__ tst(r3, Operand(0xc0000000));
__ b(ne, &slow);
// Smi tag result.
__ mov(r0, Operand(r3, LSL, kSmiTagSize));
break;
case Token::SHL:
// Remove tags from operands.
__ mov(r3, Operand(r1, ASR, kSmiTagSize)); // x
__ mov(r2, Operand(r0, ASR, kSmiTagSize)); // y
// Use only the 5 least significant bits of the shift count.
__ and_(r2, r2, Operand(0x1f));
__ mov(r3, Operand(r3, LSL, r2));
// Check that the signed result fits in a Smi.
__ add(r2, r3, Operand(0x40000000), SetCC);
__ b(mi, &slow);
__ mov(r0, Operand(r3, LSL, kSmiTagSize));
break;
default: UNREACHABLE();
}
__ Ret();
__ bind(&slow);
HandleNonSmiBitwiseOp(masm);
break;
}
default: UNREACHABLE();
}
// This code should be unreachable.
__ stop("Unreachable");
}
void StackCheckStub::Generate(MacroAssembler* masm) {
// Do tail-call to runtime routine. Runtime routines expect at least one
// argument, so give it a Smi.
__ mov(r0, Operand(Smi::FromInt(0)));
__ push(r0);
__ TailCallRuntime(ExternalReference(Runtime::kStackGuard), 1);
__ StubReturn(1);
}
void UnarySubStub::Generate(MacroAssembler* masm) {
Label undo;
Label slow;
Label not_smi;
// Enter runtime system if the value is not a smi.
__ tst(r0, Operand(kSmiTagMask));
__ b(ne, ¬_smi);
// Enter runtime system if the value of the expression is zero
// to make sure that we switch between 0 and -0.
__ cmp(r0, Operand(0));
__ b(eq, &slow);
// The value of the expression is a smi that is not zero. Try
// optimistic subtraction '0 - value'.
__ rsb(r1, r0, Operand(0), SetCC);
__ b(vs, &slow);
__ mov(r0, Operand(r1)); // Set r0 to result.
__ StubReturn(1);
// Enter runtime system.
__ bind(&slow);
__ push(r0);
__ mov(r0, Operand(0)); // Set number of arguments.
__ InvokeBuiltin(Builtins::UNARY_MINUS, JUMP_JS);
__ bind(¬_smi);
__ CompareObjectType(r0, r1, r1, HEAP_NUMBER_TYPE);
__ b(ne, &slow);
// r0 is a heap number. Get a new heap number in r1.
if (overwrite_) {
__ ldr(r2, FieldMemOperand(r0, HeapNumber::kExponentOffset));
__ eor(r2, r2, Operand(HeapNumber::kSignMask)); // Flip sign.
__ str(r2, FieldMemOperand(r0, HeapNumber::kExponentOffset));
} else {
AllocateHeapNumber(masm, &slow, r1, r2, r3);
__ ldr(r3, FieldMemOperand(r0, HeapNumber::kMantissaOffset));
__ ldr(r2, FieldMemOperand(r0, HeapNumber::kExponentOffset));
__ str(r3, FieldMemOperand(r1, HeapNumber::kMantissaOffset));
__ eor(r2, r2, Operand(HeapNumber::kSignMask)); // Flip sign.
__ str(r2, FieldMemOperand(r1, HeapNumber::kExponentOffset));
__ mov(r0, Operand(r1));
}
__ StubReturn(1);
}
void CEntryStub::GenerateThrowTOS(MacroAssembler* masm) {
// r0 holds the exception.
// Adjust this code if not the case.
ASSERT(StackHandlerConstants::kSize == 4 * kPointerSize);
// Drop the sp to the top of the handler.
__ mov(r3, Operand(ExternalReference(Top::k_handler_address)));
__ ldr(sp, MemOperand(r3));
// Restore the next handler and frame pointer, discard handler state.
ASSERT(StackHandlerConstants::kNextOffset == 0);
__ pop(r2);
__ str(r2, MemOperand(r3));
ASSERT(StackHandlerConstants::kFPOffset == 2 * kPointerSize);
__ ldm(ia_w, sp, r3.bit() | fp.bit()); // r3: discarded state.
// Before returning we restore the context from the frame pointer if
// not NULL. The frame pointer is NULL in the exception handler of a
// JS entry frame.
__ cmp(fp, Operand(0));
// Set cp to NULL if fp is NULL.
__ mov(cp, Operand(0), LeaveCC, eq);
// Restore cp otherwise.
__ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset), ne);
#ifdef DEBUG
if (FLAG_debug_code) {
__ mov(lr, Operand(pc));
}
#endif
ASSERT(StackHandlerConstants::kPCOffset == 3 * kPointerSize);
__ pop(pc);
}
void CEntryStub::GenerateThrowUncatchable(MacroAssembler* masm,
UncatchableExceptionType type) {
// Adjust this code if not the case.
ASSERT(StackHandlerConstants::kSize == 4 * kPointerSize);
// Drop sp to the top stack handler.
__ mov(r3, Operand(ExternalReference(Top::k_handler_address)));
__ ldr(sp, MemOperand(r3));
// Unwind the handlers until the ENTRY handler is found.
Label loop, done;
__ bind(&loop);
// Load the type of the current stack handler.
const int kStateOffset = StackHandlerConstants::kStateOffset;
__ ldr(r2, MemOperand(sp, kStateOffset));
__ cmp(r2, Operand(StackHandler::ENTRY));
__ b(eq, &done);
// Fetch the next handler in the list.
const int kNextOffset = StackHandlerConstants::kNextOffset;
__ ldr(sp, MemOperand(sp, kNextOffset));
__ jmp(&loop);
__ bind(&done);
// Set the top handler address to next handler past the current ENTRY handler.
ASSERT(StackHandlerConstants::kNextOffset == 0);
__ pop(r2);
__ str(r2, MemOperand(r3));
if (type == OUT_OF_MEMORY) {
// Set external caught exception to false.
ExternalReference external_caught(Top::k_external_caught_exception_address);
__ mov(r0, Operand(false));
__ mov(r2, Operand(external_caught));
__ str(r0, MemOperand(r2));
// Set pending exception and r0 to out of memory exception.
Failure* out_of_memory = Failure::OutOfMemoryException();
__ mov(r0, Operand(reinterpret_cast<int32_t>(out_of_memory)));
__ mov(r2, Operand(ExternalReference(Top::k_pending_exception_address)));
__ str(r0, MemOperand(r2));
}
// Stack layout at this point. See also StackHandlerConstants.
// sp -> state (ENTRY)
// fp
// lr
// Discard handler state (r2 is not used) and restore frame pointer.
ASSERT(StackHandlerConstants::kFPOffset == 2 * kPointerSize);
__ ldm(ia_w, sp, r2.bit() | fp.bit()); // r2: discarded state.
// Before returning we restore the context from the frame pointer if
// not NULL. The frame pointer is NULL in the exception handler of a
// JS entry frame.
__ cmp(fp, Operand(0));
// Set cp to NULL if fp is NULL.
__ mov(cp, Operand(0), LeaveCC, eq);
// Restore cp otherwise.
__ ldr(cp, MemOperand(fp, StandardFrameConstants::kContextOffset), ne);
#ifdef DEBUG
if (FLAG_debug_code) {
__ mov(lr, Operand(pc));
}
#endif
ASSERT(StackHandlerConstants::kPCOffset == 3 * kPointerSize);
__ pop(pc);
}
void CEntryStub::GenerateCore(MacroAssembler* masm,
Label* throw_normal_exception,
Label* throw_termination_exception,
Label* throw_out_of_memory_exception,
StackFrame::Type frame_type,
bool do_gc,
bool always_allocate) {
// r0: result parameter for PerformGC, if any
// r4: number of arguments including receiver (C callee-saved)
// r5: pointer to builtin function (C callee-saved)
// r6: pointer to the first argument (C callee-saved)
if (do_gc) {
// Passing r0.
ExternalReference gc_reference = ExternalReference::perform_gc_function();
__ Call(gc_reference.address(), RelocInfo::RUNTIME_ENTRY);
}
ExternalReference scope_depth =
ExternalReference::heap_always_allocate_scope_depth();
if (always_allocate) {
__ mov(r0, Operand(scope_depth));
__ ldr(r1, MemOperand(r0));
__ add(r1, r1, Operand(1));
__ str(r1, MemOperand(r0));
}
// Call C built-in.
// r0 = argc, r1 = argv
__ mov(r0, Operand(r4));
__ mov(r1, Operand(r6));
// TODO(1242173): To let the GC traverse the return address of the exit
// frames, we need to know where the return address is. Right now,
// we push it on the stack to be able to find it again, but we never
// restore from it in case of changes, which makes it impossible to
// support moving the C entry code stub. This should be fixed, but currently
// this is OK because the CEntryStub gets generated so early in the V8 boot
// sequence that it is not moving ever.
masm->add(lr, pc, Operand(4)); // compute return address: (pc + 8) + 4
masm->push(lr);
masm->Jump(r5);
if (always_allocate) {
// It's okay to clobber r2 and r3 here. Don't mess with r0 and r1
// though (contain the result).
__ mov(r2, Operand(scope_depth));
__ ldr(r3, MemOperand(r2));
__ sub(r3, r3, Operand(1));
__ str(r3, MemOperand(r2));
}
// check for failure result
Label failure_returned;
ASSERT(((kFailureTag + 1) & kFailureTagMask) == 0);
// Lower 2 bits of r2 are 0 iff r0 has failure tag.
__ add(r2, r0, Operand(1));
__ tst(r2, Operand(kFailureTagMask));
__ b(eq, &failure_returned);
// Exit C frame and return.
// r0:r1: result
// sp: stack pointer
// fp: frame pointer
__ LeaveExitFrame(frame_type);
// check if we should retry or throw exception
Label retry;
__ bind(&failure_returned);
ASSERT(Failure::RETRY_AFTER_GC == 0);
__ tst(r0, Operand(((1 << kFailureTypeTagSize) - 1) << kFailureTagSize));
__ b(eq, &retry);
// Special handling of out of memory exceptions.
Failure* out_of_memory = Failure::OutOfMemoryException();
__ cmp(r0, Operand(reinterpret_cast<int32_t>(out_of_memory)));
__ b(eq, throw_out_of_memory_exception);
// Retrieve the pending exception and clear the variable.
__ mov(ip, Operand(ExternalReference::the_hole_value_location()));
__ ldr(r3, MemOperand(ip));
__ mov(ip, Operand(ExternalReference(Top::k_pending_exception_address)));
__ ldr(r0, MemOperand(ip));
__ str(r3, MemOperand(ip));
// Special handling of termination exceptions which are uncatchable
// by javascript code.
__ cmp(r0, Operand(Factory::termination_exception()));
__ b(eq, throw_termination_exception);
// Handle normal exception.
__ jmp(throw_normal_exception);
__ bind(&retry); // pass last failure (r0) as parameter (r0) when retrying
}
void CEntryStub::GenerateBody(MacroAssembler* masm, bool is_debug_break) {
// Called from JavaScript; parameters are on stack as if calling JS function
// r0: number of arguments including receiver
// r1: pointer to builtin function
// fp: frame pointer (restored after C call)
// sp: stack pointer (restored as callee's sp after C call)
// cp: current context (C callee-saved)
// NOTE: Invocations of builtins may return failure objects
// instead of a proper result. The builtin entry handles
// this by performing a garbage collection and retrying the
// builtin once.
StackFrame::Type frame_type = is_debug_break
? StackFrame::EXIT_DEBUG
: StackFrame::EXIT;
// Enter the exit frame that transitions from JavaScript to C++.
__ EnterExitFrame(frame_type);
// r4: number of arguments (C callee-saved)
// r5: pointer to builtin function (C callee-saved)
// r6: pointer to first argument (C callee-saved)
Label throw_normal_exception;
Label throw_termination_exception;
Label throw_out_of_memory_exception;
// Call into the runtime system.
GenerateCore(masm,
&throw_normal_exception,
&throw_termination_exception,
&throw_out_of_memory_exception,
frame_type,
false,
false);
// Do space-specific GC and retry runtime call.
GenerateCore(masm,
&throw_normal_exception,
&throw_termination_exception,
&throw_out_of_memory_exception,
frame_type,
true,
false);
// Do full GC and retry runtime call one final time.
Failure* failure = Failure::InternalError();
__ mov(r0, Operand(reinterpret_cast<int32_t>(failure)));
GenerateCore(masm,
&throw_normal_exception,
&throw_termination_exception,
&throw_out_of_memory_exception,
frame_type,
true,
true);
__ bind(&throw_out_of_memory_exception);
GenerateThrowUncatchable(masm, OUT_OF_MEMORY);
__ bind(&throw_termination_exception);
GenerateThrowUncatchable(masm, TERMINATION);
__ bind(&throw_normal_exception);
GenerateThrowTOS(masm);
}
void JSEntryStub::GenerateBody(MacroAssembler* masm, bool is_construct) {
// r0: code entry
// r1: function
// r2: receiver
// r3: argc
// [sp+0]: argv
Label invoke, exit;
// Called from C, so do not pop argc and args on exit (preserve sp)
// No need to save register-passed args
// Save callee-saved registers (incl. cp and fp), sp, and lr
__ stm(db_w, sp, kCalleeSaved | lr.bit());
// Get address of argv, see stm above.
// r0: code entry
// r1: function
// r2: receiver
// r3: argc
__ add(r4, sp, Operand((kNumCalleeSaved + 1)*kPointerSize));
__ ldr(r4, MemOperand(r4)); // argv
// Push a frame with special values setup to mark it as an entry frame.
// r0: code entry
// r1: function
// r2: receiver
// r3: argc
// r4: argv
__ mov(r8, Operand(-1)); // Push a bad frame pointer to fail if it is used.
int marker = is_construct ? StackFrame::ENTRY_CONSTRUCT : StackFrame::ENTRY;
__ mov(r7, Operand(Smi::FromInt(marker)));
__ mov(r6, Operand(Smi::FromInt(marker)));
__ mov(r5, Operand(ExternalReference(Top::k_c_entry_fp_address)));
__ ldr(r5, MemOperand(r5));
__ stm(db_w, sp, r5.bit() | r6.bit() | r7.bit() | r8.bit());
// Setup frame pointer for the frame to be pushed.
__ add(fp, sp, Operand(-EntryFrameConstants::kCallerFPOffset));
// Call a faked try-block that does the invoke.
__ bl(&invoke);
// Caught exception: Store result (exception) in the pending
// exception field in the JSEnv and return a failure sentinel.
// Coming in here the fp will be invalid because the PushTryHandler below
// sets it to 0 to signal the existence of the JSEntry frame.
__ mov(ip, Operand(ExternalReference(Top::k_pending_exception_address)));
__ str(r0, MemOperand(ip));
__ mov(r0, Operand(reinterpret_cast<int32_t>(Failure::Exception())));
__ b(&exit);
// Invoke: Link this frame into the handler chain.
__ bind(&invoke);
// Must preserve r0-r4, r5-r7 are available.
__ PushTryHandler(IN_JS_ENTRY, JS_ENTRY_HANDLER);
// If an exception not caught by another handler occurs, this handler
// returns control to the code after the bl(&invoke) above, which
// restores all kCalleeSaved registers (including cp and fp) to their
// saved values before returning a failure to C.
// Clear any pending exceptions.
__ mov(ip, Operand(ExternalReference::the_hole_value_location()));
__ ldr(r5, MemOperand(ip));
__ mov(ip, Operand(ExternalReference(Top::k_pending_exception_address)));
__ str(r5, MemOperand(ip));
// Invoke the function by calling through JS entry trampoline builtin.
// Notice that we cannot store a reference to the trampoline code directly in
// this stub, because runtime stubs are not traversed when doing GC.
// Expected registers by Builtins::JSEntryTrampoline
// r0: code entry
// r1: function
// r2: receiver
// r3: argc
// r4: argv
if (is_construct) {
ExternalReference construct_entry(Builtins::JSConstructEntryTrampoline);
__ mov(ip, Operand(construct_entry));
} else {
ExternalReference entry(Builtins::JSEntryTrampoline);
__ mov(ip, Operand(entry));
}
__ ldr(ip, MemOperand(ip)); // deref address
// Branch and link to JSEntryTrampoline. We don't use the double underscore
// macro for the add instruction because we don't want the coverage tool
// inserting instructions here after we read the pc.
__ mov(lr, Operand(pc));
masm->add(pc, ip, Operand(Code::kHeaderSize - kHeapObjectTag));
// Unlink this frame from the handler chain. When reading the
// address of the next handler, there is no need to use the address
// displacement since the current stack pointer (sp) points directly
// to the stack handler.
__ ldr(r3, MemOperand(sp, StackHandlerConstants::kNextOffset));
__ mov(ip, Operand(ExternalReference(Top::k_handler_address)));
__ str(r3, MemOperand(ip));
// No need to restore registers
__ add(sp, sp, Operand(StackHandlerConstants::kSize));
__ bind(&exit); // r0 holds result
// Restore the top frame descriptors from the stack.
__ pop(r3);
__ mov(ip, Operand(ExternalReference(Top::k_c_entry_fp_address)));
__ str(r3, MemOperand(ip));
// Reset the stack to the callee saved registers.
__ add(sp, sp, Operand(-EntryFrameConstants::kCallerFPOffset));
// Restore callee-saved registers and return.
#ifdef DEBUG
if (FLAG_debug_code) {
__ mov(lr, Operand(pc));
}
#endif
__ ldm(ia_w, sp, kCalleeSaved | pc.bit());
}
// This stub performs an instanceof, calling the builtin function if
// necessary. Uses r1 for the object, r0 for the function that it may
// be an instance of (these are fetched from the stack).
void InstanceofStub::Generate(MacroAssembler* masm) {
// Get the object - slow case for smis (we may need to throw an exception
// depending on the rhs).
Label slow, loop, is_instance, is_not_instance;
__ ldr(r0, MemOperand(sp, 1 * kPointerSize));
__ BranchOnSmi(r0, &slow);
// Check that the left hand is a JS object and put map in r3.
__ CompareObjectType(r0, r3, r2, FIRST_JS_OBJECT_TYPE);
__ b(lt, &slow);
__ cmp(r2, Operand(LAST_JS_OBJECT_TYPE));
__ b(gt, &slow);
// Get the prototype of the function (r4 is result, r2 is scratch).
__ ldr(r1, MemOperand(sp, 0 * kPointerSize));
__ TryGetFunctionPrototype(r1, r4, r2, &slow);
// Check that the function prototype is a JS object.
__ BranchOnSmi(r4, &slow);
__ CompareObjectType(r4, r5, r5, FIRST_JS_OBJECT_TYPE);
__ b(lt, &slow);
__ cmp(r5, Operand(LAST_JS_OBJECT_TYPE));
__ b(gt, &slow);
// Register mapping: r3 is object map and r4 is function prototype.
// Get prototype of object into r2.
__ ldr(r2, FieldMemOperand(r3, Map::kPrototypeOffset));
// Loop through the prototype chain looking for the function prototype.
__ bind(&loop);
__ cmp(r2, Operand(r4));
__ b(eq, &is_instance);
__ LoadRoot(ip, Heap::kNullValueRootIndex);
__ cmp(r2, ip);
__ b(eq, &is_not_instance);
__ ldr(r2, FieldMemOperand(r2, HeapObject::kMapOffset));
__ ldr(r2, FieldMemOperand(r2, Map::kPrototypeOffset));
__ jmp(&loop);
__ bind(&is_instance);
__ mov(r0, Operand(Smi::FromInt(0)));
__ pop();
__ pop();
__ mov(pc, Operand(lr)); // Return.
__ bind(&is_not_instance);
__ mov(r0, Operand(Smi::FromInt(1)));
__ pop();
__ pop();
__ mov(pc, Operand(lr)); // Return.
// Slow-case. Tail call builtin.
__ bind(&slow);
__ mov(r0, Operand(1)); // Arg count without receiver.
__ InvokeBuiltin(Builtins::INSTANCE_OF, JUMP_JS);
}
void ArgumentsAccessStub::GenerateReadLength(MacroAssembler* masm) {
// Check if the calling frame is an arguments adaptor frame.
Label adaptor;
__ ldr(r2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
__ ldr(r3, MemOperand(r2, StandardFrameConstants::kContextOffset));
__ cmp(r3, Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
__ b(eq, &adaptor);
// Nothing to do: The formal number of parameters has already been
// passed in register r0 by calling function. Just return it.
__ Jump(lr);
// Arguments adaptor case: Read the arguments length from the
// adaptor frame and return it.
__ bind(&adaptor);
__ ldr(r0, MemOperand(r2, ArgumentsAdaptorFrameConstants::kLengthOffset));
__ Jump(lr);
}
void ArgumentsAccessStub::GenerateReadElement(MacroAssembler* masm) {
// The displacement is the offset of the last parameter (if any)
// relative to the frame pointer.
static const int kDisplacement =
StandardFrameConstants::kCallerSPOffset - kPointerSize;
// Check that the key is a smi.
Label slow;
__ BranchOnNotSmi(r1, &slow);
// Check if the calling frame is an arguments adaptor frame.
Label adaptor;
__ ldr(r2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
__ ldr(r3, MemOperand(r2, StandardFrameConstants::kContextOffset));
__ cmp(r3, Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
__ b(eq, &adaptor);
// Check index against formal parameters count limit passed in
// through register eax. Use unsigned comparison to get negative
// check for free.
__ cmp(r1, r0);
__ b(cs, &slow);
// Read the argument from the stack and return it.
__ sub(r3, r0, r1);
__ add(r3, fp, Operand(r3, LSL, kPointerSizeLog2 - kSmiTagSize));
__ ldr(r0, MemOperand(r3, kDisplacement));
__ Jump(lr);
// Arguments adaptor case: Check index against actual arguments
// limit found in the arguments adaptor frame. Use unsigned
// comparison to get negative check for free.
__ bind(&adaptor);
__ ldr(r0, MemOperand(r2, ArgumentsAdaptorFrameConstants::kLengthOffset));
__ cmp(r1, r0);
__ b(cs, &slow);
// Read the argument from the adaptor frame and return it.
__ sub(r3, r0, r1);
__ add(r3, r2, Operand(r3, LSL, kPointerSizeLog2 - kSmiTagSize));
__ ldr(r0, MemOperand(r3, kDisplacement));
__ Jump(lr);
// Slow-case: Handle non-smi or out-of-bounds access to arguments
// by calling the runtime system.
__ bind(&slow);
__ push(r1);
__ TailCallRuntime(ExternalReference(Runtime::kGetArgumentsProperty), 1);
}
void ArgumentsAccessStub::GenerateNewObject(MacroAssembler* masm) {
// Check if the calling frame is an arguments adaptor frame.
Label runtime;
__ ldr(r2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
__ ldr(r3, MemOperand(r2, StandardFrameConstants::kContextOffset));
__ cmp(r3, Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
__ b(ne, &runtime);
// Patch the arguments.length and the parameters pointer.
__ ldr(r0, MemOperand(r2, ArgumentsAdaptorFrameConstants::kLengthOffset));
__ str(r0, MemOperand(sp, 0 * kPointerSize));
__ add(r3, r2, Operand(r0, LSL, kPointerSizeLog2 - kSmiTagSize));
__ add(r3, r3, Operand(StandardFrameConstants::kCallerSPOffset));
__ str(r3, MemOperand(sp, 1 * kPointerSize));
// Do the runtime call to allocate the arguments object.
__ bind(&runtime);
__ TailCallRuntime(ExternalReference(Runtime::kNewArgumentsFast), 3);
}
void CallFunctionStub::Generate(MacroAssembler* masm) {
Label slow;
// Get the function to call from the stack.
// function, receiver [, arguments]
__ ldr(r1, MemOperand(sp, (argc_ + 1) * kPointerSize));
// Check that the function is really a JavaScript function.
// r1: pushed function (to be verified)
__ BranchOnSmi(r1, &slow);
// Get the map of the function object.
__ CompareObjectType(r1, r2, r2, JS_FUNCTION_TYPE);
__ b(ne, &slow);
// Fast-case: Invoke the function now.
// r1: pushed function
ParameterCount actual(argc_);
__ InvokeFunction(r1, actual, JUMP_FUNCTION);
// Slow-case: Non-function called.
__ bind(&slow);
__ mov(r0, Operand(argc_)); // Setup the number of arguments.
__ mov(r2, Operand(0));
__ GetBuiltinEntry(r3, Builtins::CALL_NON_FUNCTION);
__ Jump(Handle<Code>(Builtins::builtin(Builtins::ArgumentsAdaptorTrampoline)),
RelocInfo::CODE_TARGET);
}
int CompareStub::MinorKey() {
// Encode the two parameters in a unique 16 bit value.
ASSERT(static_cast<unsigned>(cc_) >> 28 < (1 << 15));
return (static_cast<unsigned>(cc_) >> 27) | (strict_ ? 1 : 0);
}
#undef __
} } // namespace v8::internal