VM: Improve single-target polymorphic calls.

VM: Improve single-target polymorphic calls.

Use the existing class-id check for dense ranges in more places.
Previously we would fall back to megamorphic lookup with >4 cids,
even though we can check cid ranges up to word-size efficiently.

Next step is to generalize the dense class id checks to multiple
word-sizes.

BUG=
R=vegorov@google.com

Committed: https://github.com/dart-lang/sdk/commit/f6c19ee595ca9495c8b9520259b1cb55b2e152a6

[Florian Schneider, 2016-04-01 00:22:56]

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

[Vyacheslav Egorov (Google), 2016-04-01 10:53:59]

lgtm

https://codereview.chromium.org/1847293002/diff/20001/runtime/vm/jit_optimize...
File runtime/vm/jit_optimizer.cc (right):

https://codereview.chromium.org/1847293002/diff/20001/runtime/vm/jit_optimize...
runtime/vm/jit_optimizer.cc:2671: static bool IsDenseCidRange(const ICData&
unary_checks) {
I am a bit concerned that we have two functions that do the same (they are even
called slightly differently): see CheckClassInstr::IsDenseSwitch.

[Florian Schneider, 2016-04-01 15:58:44]

https://codereview.chromium.org/1847293002/diff/20001/runtime/vm/jit_optimize...
File runtime/vm/jit_optimizer.cc (right):

https://codereview.chromium.org/1847293002/diff/20001/runtime/vm/jit_optimize...
runtime/vm/jit_optimizer.cc:2671: static bool IsDenseCidRange(const ICData&
unary_checks) {
On 2016/04/01 10:53:59, Vyacheslav Egorov (Google) wrote:
> I am a bit concerned that we have two functions that do the same (they are
even
> called slightly differently): see CheckClassInstr::IsDenseSwitch.

Changed to use a single function CheckClassInstr::IsDenseCidRange.

[Florian Schneider, 2016-04-01 16:59:29]

Description was changed from

==========
VM: Improve single-target polymorphic calls.

Use the existing class-id check for dense ranges in more places.
Previously we would fall back to megamorphic lookup with >4 cids,
even though we can check cid ranges up to word-size efficiently.

Next step is to generalize the dense class id checks to multiple
word-sizes.

BUG=
==========

to

==========
VM: Improve single-target polymorphic calls.

Use the existing class-id check for dense ranges in more places.
Previously we would fall back to megamorphic lookup with >4 cids,
even though we can check cid ranges up to word-size efficiently.

Next step is to generalize the dense class id checks to multiple
word-sizes.

BUG=
R=vegorov@google.com

Committed:
https://github.com/dart-lang/sdk/commit/f6c19ee595ca9495c8b9520259b1cb55b2e152a6
==========

[Florian Schneider, 2016-04-01 16:59:31]

Committed patchset #3 (id:40001) manually as
f6c19ee595ca9495c8b9520259b1cb55b2e152a6 (presubmit successful).

[srdjan, 2016-04-01 18:11:29]

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

[srdjan, 2016-04-01 18:11:30]

DBC

https://codereview.chromium.org/1847293002/diff/40001/runtime/vm/intermediate...
File runtime/vm/intermediate_language.cc (right):

https://codereview.chromium.org/1847293002/diff/40001/runtime/vm/intermediate...
runtime/vm/intermediate_language.cc:235: bool
CheckClassInstr::IsDenseCidRange(const ICData& unary_checks) {
Assert that 'unary_checks' are unary.

https://codereview.chromium.org/1847293002/diff/40001/runtime/vm/intermediate...
runtime/vm/intermediate_language.cc:236: if
(unary_checks.GetReceiverClassIdAt(0) == kSmiCid) return false;
You may want to allow Smi checks since they have to be done anyway before
extracting cid?

[Florian Schneider, 2016-04-03 04:39:52]

https://codereview.chromium.org/1847293002/diff/40001/runtime/vm/intermediate...
File runtime/vm/intermediate_language.cc (right):

https://codereview.chromium.org/1847293002/diff/40001/runtime/vm/intermediate...
runtime/vm/intermediate_language.cc:235: bool
CheckClassInstr::IsDenseCidRange(const ICData& unary_checks) {
On 2016/04/01 18:11:29, srdjan wrote:
> Assert that 'unary_checks' are unary.

Done.

https://codereview.chromium.org/1847293002/diff/40001/runtime/vm/intermediate...
runtime/vm/intermediate_language.cc:236: if
(unary_checks.GetReceiverClassIdAt(0) == kSmiCid) return false;
On 2016/04/01 18:11:29, srdjan wrote:
> You may want to allow Smi checks since they have to be done anyway before
> extracting cid?

I'll add a TODO for now.