}
+bool Expression::GuaranteedSmiResult() {
+ BinaryOperation* node = AsBinaryOperation();
+ if (node == NULL) return false;
+ Token::Value op = node->op();
+ switch (op) {
+ case Token::COMMA:
+ case Token::OR:
+ case Token::AND:
+ case Token::ADD:
+ case Token::SUB:
+ case Token::MUL:
+ case Token::DIV:
+ case Token::MOD:
+ case Token::BIT_XOR:
+ case Token::SHL:
+ return false;
+ break;
+ case Token::BIT_OR:
+ case Token::BIT_AND: {
+ Literal* left = node->left()->AsLiteral();
+ Literal* right = node->right()->AsLiteral();
+ if (left != NULL && left->handle()->IsSmi()) {
+ int value = Smi::cast(*left->handle())->value();
+ if (op == Token::BIT_OR && ((value & 0xc0000000) == 0xc0000000)) {
+ // Result of bitwise or is always a negative Smi.
+ return true;
+ }
+ if (op == Token::BIT_AND && ((value & 0xc0000000) == 0)) {
+ // Result of bitwise and is always a positive Smi.
+ return true;
+ }
+ }
+ if (right != NULL && right->handle()->IsSmi()) {
+ int value = Smi::cast(*right->handle())->value();
+ if (op == Token::BIT_OR && ((value & 0xc0000000) == 0xc0000000)) {
+ // Result of bitwise or is always a negative Smi.
+ return true;
+ }
+ if (op == Token::BIT_AND && ((value & 0xc0000000) == 0)) {
+ // Result of bitwise and is always a positive Smi.
+ return true;
+ }
+ }
+ return false;
+ break;
+ }
+ case Token::SAR:
+ case Token::SHR: {
+ Literal* right = node->right()->AsLiteral();
+ if (right != NULL && right->handle()->IsSmi()) {
+ int value = Smi::cast(*right->handle())->value();
+ if ((value & 0x1F) > 1 ||
+ (op == Token::SAR && (value & 0x1F) == 1)) {
+ return true;
+ }
+ }
+ return false;
+ break;
+ }
+ default:
+ UNREACHABLE();
+ break;
+ }
+ return false;
+}
+
// ----------------------------------------------------------------------------
// Implementation of AstVisitor
LoopConditionField::encode(flag);
}
+ // The value of the expression is guaranteed to be a smi, because the
+ // top operation is a bit operation with a mask, or a shift.
+ bool GuaranteedSmiResult();
+
// AST analysis results
// True if the expression rooted at this node can be compiled by the
Load(expr);
Result value = frame_->Pop();
ASSERT(frame_->HasNoUntaggedInt32Elements());
- ConvertInt32ResultToNumber(&value);
+ if (expr->GuaranteedSmiResult()) {
+ ConvertInt32ResultToSmi(&value);
+ } else {
+ ConvertInt32ResultToNumber(&value);
+ }
set_in_safe_int32_mode(false);
set_unsafe_bailout(NULL);
frame_->Push(&value);
}
+void CodeGenerator::ConvertInt32ResultToSmi(Result* value) {
+ ASSERT(value->is_untagged_int32());
+ if (value->is_register()) {
+ __ add(value->reg(), Operand(value->reg()));
+ } else {
+ ASSERT(value->is_constant());
+ ASSERT(value->handle()->IsSmi());
+ }
+ value->set_untagged_int32(false);
+ value->set_number_info(NumberInfo::Smi());
+}
+
+
void CodeGenerator::ConvertInt32ResultToNumber(Result* value) {
ASSERT(value->is_untagged_int32());
if (value->is_register()) {
ASSERT(value->is_constant());
}
value->set_untagged_int32(false);
+ value->set_number_info(NumberInfo::Integer32());
}
// Take the Result that is an untagged int32, and convert it to a tagged
// Smi or HeapNumber. Remove the untagged_int32 flag from the result.
void ConvertInt32ResultToNumber(Result* value);
+ void ConvertInt32ResultToSmi(Result* value);
// Track loop nesting level.
int loop_nesting() const { return loop_nesting_; }