VM: Propagate non-nullness from instance calls.

VM: Propagate non-nullness from instance calls.

After a call to a selector that is not defined on null, we can propagate
the non-nullness of the receiver.

A redefinition is inserted after the call to ensure that only safe code
motion occurs.

Also, adjust instructions count in the inliner to account for redefinitions.

R=rmacnak@google.com, vegorov@google.com

Committed: https://github.com/dart-lang/sdk/commit/8acc787d0874708750ee9deb85095cae15fc17f2

[Florian Schneider, 2017-03-15 23:06:25]

fschneider@google.com changed reviewers:
+ rmacnak@google.com

[rmacnak, 2017-03-15 23:14:49]

lgtm

https://codereview.chromium.org/2751103003/diff/20001/runtime/vm/flow_graph_t...
File runtime/vm/flow_graph_type_propagator.cc (right):

https://codereview.chromium.org/2751103003/diff/20001/runtime/vm/flow_graph_t...
runtime/vm/flow_graph_type_propagator.cc:260: const Class& null_class =
Probably cheaper to check if the type is already non-nullable first.

https://codereview.chromium.org/2751103003/diff/20001/runtime/vm/flow_graph_t...
File runtime/vm/flow_graph_type_propagator.h (right):

https://codereview.chromium.org/2751103003/diff/20001/runtime/vm/flow_graph_t...
runtime/vm/flow_graph_type_propagator.h:42: const String& functin_name);
function

[Vyacheslav Egorov (Google), 2017-03-16 06:21:48]

vegorov@google.com changed reviewers:
+ vegorov@google.com

[Vyacheslav Egorov (Google), 2017-03-16 06:21:48]

https://codereview.chromium.org/2751103003/diff/20001/runtime/vm/flow_graph_t...
File runtime/vm/flow_graph_type_propagator.cc (right):

https://codereview.chromium.org/2751103003/diff/20001/runtime/vm/flow_graph_t...
runtime/vm/flow_graph_type_propagator.cc:330: void
FlowGraphTypePropagator::VisitBranch(BranchInstr* instr) {
Should not we also handle it here:

x == null => non-nullable type to false branch
x != null => non-nullable type to true branch

[Florian Schneider, 2017-03-17 01:12:26]

Description was changed from

==========
VM: Propagate non-nullness from instance calls.

After a call to a selector that is not defined on null, we can propagate
the non-nullness of the receiver.

A redefinition is inserted after the call to ensure that only safe code
motion occurs.
==========

to

==========
VM: Propagate non-nullness from instance calls.

After a call to a selector that is not defined on null, we can propagate
the non-nullness of the receiver.

A redefinition is inserted after the call to ensure that only safe code
motion occurs.

Also, adjust instructions count in the inliner to account for redefinitions.
==========

[Florian Schneider, 2017-03-17 01:12:40]

ptal

https://codereview.chromium.org/2751103003/diff/20001/runtime/vm/flow_graph_t...
File runtime/vm/flow_graph_type_propagator.cc (right):

https://codereview.chromium.org/2751103003/diff/20001/runtime/vm/flow_graph_t...
runtime/vm/flow_graph_type_propagator.cc:260: const Class& null_class =
On 2017/03/15 23:14:49, rmacnak wrote:
> Probably cheaper to check if the type is already non-nullable first.

Done.

https://codereview.chromium.org/2751103003/diff/20001/runtime/vm/flow_graph_t...
runtime/vm/flow_graph_type_propagator.cc:330: void
FlowGraphTypePropagator::VisitBranch(BranchInstr* instr) {
On 2017/03/16 06:21:48, Vyacheslav Egorov (Google) wrote:
> Should not we also handle it here:
> 
> x == null => non-nullable type to false branch
> x != null => non-nullable type to true branch

Yes, I was planning to do that in a separate CL.

https://codereview.chromium.org/2751103003/diff/20001/runtime/vm/flow_graph_t...
File runtime/vm/flow_graph_type_propagator.h (right):

https://codereview.chromium.org/2751103003/diff/20001/runtime/vm/flow_graph_t...
runtime/vm/flow_graph_type_propagator.h:42: const String& functin_name);
On 2017/03/15 23:14:49, rmacnak wrote:
> function

Done.

[Florian Schneider, 2017-03-20 16:41:53]

Ping

[Vyacheslav Egorov (Google), 2017-03-20 16:44:53]

lgtm

[rmacnak, 2017-03-20 17:09:16]

lgtm

[Florian Schneider, 2017-03-20 17:22:22]

Description was changed from

==========
VM: Propagate non-nullness from instance calls.

After a call to a selector that is not defined on null, we can propagate
the non-nullness of the receiver.

A redefinition is inserted after the call to ensure that only safe code
motion occurs.

Also, adjust instructions count in the inliner to account for redefinitions.
==========

to

==========
VM: Propagate non-nullness from instance calls.

After a call to a selector that is not defined on null, we can propagate
the non-nullness of the receiver.

A redefinition is inserted after the call to ensure that only safe code
motion occurs.

Also, adjust instructions count in the inliner to account for redefinitions.

R=rmacnak@google.com, vegorov@google.com

Committed:
https://github.com/dart-lang/sdk/commit/8acc787d0874708750ee9deb85095cae15fc17f2
==========

[Florian Schneider, 2017-03-20 17:22:23]

Committed patchset #3 (id:40001) manually as
8acc787d0874708750ee9deb85095cae15fc17f2 (presubmit successful).