Update number info for count operations.

If the input of a ++ or -- operation is a smi, the
result is an Integer32. Otherwise it is a number.

Review URL: http://codereview.chromium.org/1075004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4177 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
fschneider@chromium.org 2010-03-18 10:01:53 +00:00
parent 494ba3a4c8
commit c5ce8e47ef

View File

@ -6884,8 +6884,8 @@ void CodeGenerator::VisitCountOperation(CountOperation* node) {
ASSERT(old_value.is_valid());
__ mov(old_value.reg(), new_value.reg());
// The old value that is return for postfix operations has the
// same type as the input value we got from the frame.
// The return value for postfix operations is the
// same as the input, and has the same number info.
old_value.set_number_info(new_value.number_info());
}
@ -6952,8 +6952,13 @@ void CodeGenerator::VisitCountOperation(CountOperation* node) {
}
deferred->BindExit();
// The result of ++ or -- is always a number.
new_value.set_number_info(NumberInfo::Number());
// The result of ++ or -- is an Integer32 if the
// input is a smi. Otherwise it is a number.
if (new_value.is_smi()) {
new_value.set_number_info(NumberInfo::Integer32());
} else {
new_value.set_number_info(NumberInfo::Number());
}
// Postfix: store the old value in the allocated slot under the
// reference.