Adapt compile time constants and integrate with Kevin's CL 10302007 (Remove temporaries using expli…

Fix bugs in expression temp allocation, Kevin's CL 10302007 (Remove temporaries using explicit names) and merge with other temp.
Committed: https://code.google.com/p/dart/source/detail?r=7472

[hausner, 2012-05-09 20:52:08]

LGTM but this whole business with the per-function temporary variable becomes
more and more difficult to understand.

https://chromiumcodereview.appspot.com/10389041/diff/3004/runtime/vm/parser.cc
File runtime/vm/parser.cc (right):

https://chromiumcodereview.appspot.com/10389041/diff/3004/runtime/vm/parser.c...
runtime/vm/parser.cc:700: if (parsed_function->has_expression_temp_var()) {
This if statement is true iff the previous one was true, I think. Can this be
simplified to one if?

https://chromiumcodereview.appspot.com/10389041/diff/3004/runtime/vm/parser.c...
runtime/vm/parser.cc:5970: if ((binary_op == Token::kAND) || (binary_op ==
Token::kOR)) {
I thought you wanted to do constant folding in the compiler, i.e. replace the
binary op node with a literal true or false if both sides are compile time
constant boolean expressions.

[srdjan, 2012-05-09 21:25:45]

Thanks!

https://chromiumcodereview.appspot.com/10389041/diff/3004/runtime/vm/parser.cc
File runtime/vm/parser.cc (right):

https://chromiumcodereview.appspot.com/10389041/diff/3004/runtime/vm/parser.c...
runtime/vm/parser.cc:700: if (parsed_function->has_expression_temp_var()) {
On 2012/05/09 20:52:08, hausner wrote:
> This if statement is true iff the previous one was true, I think. Can this be
> simplified to one if?

Yes, but it can be true even if the previous one was false.

https://chromiumcodereview.appspot.com/10389041/diff/3004/runtime/vm/parser.c...
runtime/vm/parser.cc:5970: if ((binary_op == Token::kAND) || (binary_op ==
Token::kOR)) {
On 2012/05/09 20:52:08, hausner wrote:
> I thought you wanted to do constant folding in the compiler, i.e. replace the
> binary op node with a literal true or false if both sides are compile time
> constant boolean expressions.

It turns out that constant folding is not needed. It will be done by the
optimizing compiler later.