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34dee0319c
v8/src/arm/codegen-arm.cc
kmillikin@chromium.org 34dee0319c Remove the typeof state threaded through the code generator. It was 
used to signal that an expression was the immediate subexpression of
typeof, or (?) in the arm of a conditional expression itself in the
typeof state.

It was inconsistently consulted.  It was not used for property loads,
but only for slot loads.  This means that we matched the Webkit JSC
(not Spidermonkey) behavior for:

typeof(true ? x : y)  // throws ReferenceError

and we matched the SpiderMonkey behavior (not JSC) for:

with ({}) { typeof(true ? x : y) }  // ==> "undefined"

Now we are expected to match the JSC behavior in all cases.

Review URL: http://codereview.chromium.org/362004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3212 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2009-11-04 13:56:41 +00:00

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// 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),
true_target_(NULL),
false_target_(NULL),
previous_(NULL) {
owner_->set_state(this);
}
CodeGenState::CodeGenState(CodeGenerator* owner,
JumpTarget* true_target,
JumpTarget* false_target)
: owner_(owner),
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) {
// Record the position for debugging purposes.
CodeForFunctionPosition(fun);
ZoneList<Statement*>* body = fun->body();
// Initialize state.
ASSERT(scope_ == NULL);
scope_ = fun->scope();
ASSERT(allocator_ == NULL);
RegisterAllocator register_allocator(this);
allocator_ = &register_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 (has_valid_frame() || function_return_.is_linked()) {
if (!function_return_.is_linked()) {
CodeForReturnPosition(fun);
}
// 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);
}
// Add a label for checking the size of the code used for returning.
Label check_exit_codesize;
masm_->bind(&check_exit_codesize);
// Tear down the frame which will restore the caller's frame pointer and
// the link register.
frame_->Exit();
// Here we use masm_-> instead of the __ macro to avoid the code coverage
// tool from instrumenting as we rely on the code size here.
int32_t sp_delta = (scope_->num_parameters() + 1) * kPointerSize;
masm_->add(sp, sp, Operand(sp_delta));
masm_->Jump(lr);
// Check that the size of the code used for returning matches what is
// expected by the debugger. The add instruction above is an addressing
// mode 1 instruction where there are restrictions on which immediate values
// can be encoded in the instruction and which immediate values requires
// use of an additional instruction for moving the immediate to a temporary
// register.
#ifdef DEBUG
int expected_return_sequence_length = kJSReturnSequenceLength;
if (!masm_->ImmediateFitsAddrMode1Instruction(sp_delta)) {
// Additional mov instruction generated.
expected_return_sequence_length++;
}
ASSERT_EQ(expected_return_sequence_length,
masm_->InstructionsGeneratedSince(&check_exit_codesize));
#endif
}
// 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,
JumpTarget* true_target,
JumpTarget* false_target,
bool force_cc) {
ASSERT(!has_cc());
int original_height = frame_->height();
{ CodeGenState new_state(this, 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* expr) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
JumpTarget true_target;
JumpTarget false_target;
LoadCondition(expr, &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);
}
void CodeGenerator::LoadTypeofExpression(Expression* expr) {
// Special handling of identifiers as subexpressions of typeof.
VirtualFrame::SpilledScope spilled_scope;
Variable* variable = expr->AsVariableProxy()->AsVariable();
if (variable != NULL && !variable->is_this() && variable->is_global()) {
// For a global variable we build the property reference
// <global>.<variable> and perform a (regular non-contextual) property
// load 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);
Reference ref(this, &property);
ref.GetValueAndSpill();
} else if (variable != NULL && variable->slot() != NULL) {
// For a variable that rewrites to a slot, we signal it is the immediate
// subexpression of a typeof.
LoadFromSlot(variable->slot(), INSIDE_TYPEOF);
frame_->SpillAll();
} else {
// Anything else can be handled normally.
LoadAndSpill(expr);
}
}
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;
}
// 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;
Comment cmnt(masm_, "[ check stack");
__ LoadRoot(ip, Heap::kStackLimitRootIndex);
// Put the lr setup instruction in the delay slot. kInstrSize 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(Assembler::kInstrSize));
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;
frame_->EmitPush(cp);
__ mov(r0, Operand(pairs));
frame_->EmitPush(r0);
__ 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");
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(), &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(), &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(), &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(), &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");
CodeForStatementPosition(node);
LoadAndSpill(node->expression());
if (function_return_is_shadowed_) {
frame_->EmitPop(r0);
function_return_.Jump();
} else {
// 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::VisitDoWhileStatement(DoWhileStatement* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ DoWhileStatement");
CodeForStatementPosition(node);
node->break_target()->set_direction(JumpTarget::FORWARD_ONLY);
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.
ConditionAnalysis info = AnalyzeCondition(node->cond());
switch (info) {
case ALWAYS_TRUE:
node->continue_target()->set_direction(JumpTarget::BIDIRECTIONAL);
node->continue_target()->Bind();
break;
case ALWAYS_FALSE:
node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
break;
case DONT_KNOW:
node->continue_target()->set_direction(JumpTarget::FORWARD_ONLY);
body.Bind();
break;
}
CheckStack(); // TODO(1222600): ignore if body contains calls.
VisitAndSpill(node->body());
// Compile the test.
switch (info) {
case ALWAYS_TRUE:
// If control can fall off the end of the body, jump back to the
// top.
if (has_valid_frame()) {
node->continue_target()->Jump();
}
break;
case 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();
}
break;
case 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(), &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;
}
if (node->break_target()->is_linked()) {
node->break_target()->Bind();
}
ASSERT(!has_valid_frame() || frame_->height() == original_height);
}
void CodeGenerator::VisitWhileStatement(WhileStatement* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ WhileStatement");
CodeForStatementPosition(node);
// If the test is never true and has no side effects there is no need
// to compile the test or body.
ConditionAnalysis info = AnalyzeCondition(node->cond());
if (info == ALWAYS_FALSE) return;
node->break_target()->set_direction(JumpTarget::FORWARD_ONLY);
// 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(), &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();
}
}
if (node->break_target()->is_linked()) {
node->break_target()->Bind();
}
ASSERT(!has_valid_frame() || frame_->height() == original_height);
}
void CodeGenerator::VisitForStatement(ForStatement* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ ForStatement");
CodeForStatementPosition(node);
if (node->init() != NULL) {
VisitAndSpill(node->init());
}
// If the test is never true there is no need to compile the test or
// body.
ConditionAnalysis info = AnalyzeCondition(node->cond());
if (info == ALWAYS_FALSE) return;
node->break_target()->set_direction(JumpTarget::FORWARD_ONLY);
// If there is no update statement, label the top of the loop with the
// continue target, otherwise with the loop target.
JumpTarget loop(JumpTarget::BIDIRECTIONAL);
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(), &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();
}
}
}
if (node->break_target()->is_linked()) {
node->break_target()->Bind();
}
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::VisitTryCatchStatement(TryCatchStatement* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ TryCatchStatement");
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::VisitTryFinallyStatement(TryFinallyStatement* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ TryFinallyStatement");
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());
// Create a new closure.
frame_->EmitPush(cp);
__ mov(r0, Operand(boilerplate));
frame_->EmitPush(r0);
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(), &then, &else_, true);
if (has_valid_frame()) {
Branch(false, &else_);
}
if (has_valid_frame() || then.is_linked()) {
then.Bind();
LoadAndSpill(node->then_expression());
}
if (else_.is_linked()) {
JumpTarget exit;
if (has_valid_frame()) exit.Jump();
else_.Bind();
LoadAndSpill(node->else_expression());
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 {
// 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, NOT_INSIDE_TYPEOF);
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();
}
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");
{ 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();
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();
}
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");
Expression* function = node->expression();
ZoneList<Expression*>* args = node->arguments();
// Standard function call.
// Check if the function is a variable or a property.
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_possibly_eval()) {
// ----------------------------------
// JavaScript example: 'eval(arg)' // eval is not known to be shadowed
// ----------------------------------
// 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.
// 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);
} else 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(); // 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::VisitCallNew(CallNew* node) {
#ifdef DEBUG
int original_height = frame_->height();
#endif
VirtualFrame::SpilledScope spilled_scope;
Comment cmnt(masm_, "[ CallNew");
// 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(),
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();
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(),
&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(),
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(),
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(),
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() {
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, NOT_INSIDE_TYPEOF);
break;
}
case NAMED: {
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(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 CAN_USE_ARMV5_INSTRUCTIONS
__ 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, &not_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(&not_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, &not_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(&not_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, &not_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(&not_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.
__ AllocateInNewSpace(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.
__ AlignStack(0);
// Call C routine that may not cause GC or other trouble.
__ mov(r5, Operand(ExternalReference::double_fp_operation(operation)));
__ Call(r5);
__ pop(r4); // Address of heap number.
__ cmp(r4, Operand(Smi::FromInt(0)));
__ pop(r4, eq); // Conditional pop instruction to get rid of alignment push.
// Store answer in the overwritable heap number.
#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, &not_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,
&not_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, &not_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,
&not_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, &not_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,
&not_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, &not_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(&not_smi);
}
HandleBinaryOpSlowCases(masm,
&not_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, 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, &not_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(&not_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);
}
int CEntryStub::MinorKey() {
ASSERT(result_size_ <= 2);
// Result returned in r0 or r0+r1 by default.
return 0;
}
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,
ExitFrame::Mode mode,
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(mode);
// 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.
ExitFrame::Mode mode = is_debug_break
? ExitFrame::MODE_DEBUG
: ExitFrame::MODE_NORMAL;
// Enter the exit frame that transitions from JavaScript to C++.
__ EnterExitFrame(mode);
// 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,
mode,
false,
false);
// Do space-specific GC and retry runtime call.
GenerateCore(masm,
&throw_normal_exception,
&throw_termination_exception,
&throw_out_of_memory_exception,
mode,
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,
mode,
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, 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, 1);
}
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
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