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b85679eaf3
Right now all type literal usages will perform a runtime call which is
rather slow.
Flutter happens to use type literals such as `return T;` in hot code
which causes this to show up in the profile.
This CL adds fast paths for type parameter type literals if
the type parameter value (i.e. entry of TAV corresponding to T):
* is `null`: return `dynamic`
* is a non-FutureOr [Type] with compatible nullability: return value
* is [FunctionType] with compatible nullability: return value
otherwise fall back to runtime call.
It makes simple type literal uses 10x+ faster - the kinds that Flutter
is using.
Issue https://github.com/dart-lang/sdk/issues/48757
TEST=vm/dart{,_2}/instantiate_type_literal_test
Change-Id: I1139d6689aedbc68321f47ee6c9946a3323fbf6e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/241968
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
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| observatory | ||
| observatory_2 | ||
| platform | ||
| tests | ||
| third_party | ||
| tools | ||
| vm | ||
| .clang-tidy | ||
| .gitignore | ||
| BUILD.gn | ||
| codereview.settings | ||
| configs.gni | ||
| CPPLINT.cfg | ||
| OWNERS | ||
| PRESUBMIT.py | ||
| runtime_args.gni | ||