Avoid allocating unnecessary result locations for some instructions.

Avoid allocating unnecessary result locations for some instructions.

If the result of an instruction is not needed, we don't need to
assign a result location. I fixed StoreStatic and StoreVMField.

For calls, it does not hurt since all registers are blocked anyway.
Other instructions that don't have side effects usually don't occur
in an effect context and should be removed by a separate pass before
entering the register allocator.

Committed: http://code.google.com/p/dart/source/detail?r=12111

[Kevin Millikin (Google), 2012-09-10 12:28:01]

LGTM.

https://chromiumcodereview.appspot.com/10918144/diff/1/runtime/vm/intermediat...
File runtime/vm/intermediate_language_ia32.cc (right):

https://chromiumcodereview.appspot.com/10918144/diff/1/runtime/vm/intermediat...
runtime/vm/intermediate_language_ia32.cc:1036: locs->set_out(is_used()
This should be:

locs->set_out(is_used()
                  ? Location::SameAsFirstInput()
                  : Location::NoLocation());

or:

locs->set_out(is_used() ? Location::SameAsFirstInput()
                        : Location::NoLocation());

or:

locs->set_out(
    is_used() ? Location::SameAsFirstInput() : Location::NoLocation());

[Florian Schneider, 2012-09-10 13:05:40]

https://chromiumcodereview.appspot.com/10918144/diff/1/runtime/vm/intermediat...
File runtime/vm/intermediate_language_ia32.cc (right):

https://chromiumcodereview.appspot.com/10918144/diff/1/runtime/vm/intermediat...
runtime/vm/intermediate_language_ia32.cc:1036: locs->set_out(is_used()
On 2012/09/10 12:28:02, kmillikin wrote:
> This should be:
> 
> locs->set_out(is_used()
>                   ? Location::SameAsFirstInput()
>                   : Location::NoLocation());
> 
> or:
> 
> locs->set_out(is_used() ? Location::SameAsFirstInput()
>                         : Location::NoLocation());
> 
> or:
> 
> locs->set_out(
>     is_used() ? Location::SameAsFirstInput() : Location::NoLocation());
> 

Done.