This CL inlines the following builtins into TurboFan
- %MapIteratorPrototype%.next
- %SetIteratorPrototype%.next
following the design that we are using for Array iteration already
(different instance types for the different kinds of iterators). Details
can be found in the relevant design document at:
https://docs.google.com/document/d/13z1fvRVpe_oEroplXEEX0a3WK94fhXorHjcOMsDmR-8
The key to great performance here is to ensure that the inlined code
allows escape analysis and scalar replacement of aggregates to remove
the allocations for the iterator itself as well as the iterator results
and potential key/value arrays in the simple case of a for-of loop (and
by extension also in other constructs that reduce to for-of loops
internally), i.e.:
const s = new Set;
// ... do something with s
for (const x of s) {
// ...
}
Here the for-of loop shouldn't perform any allocations of helper
objects.
Drive-by-fix: Replace the ExistsJSMapWithness in JSBuiltinReducer with a more
general HasInstanceTypeWitness, similar to what's in JSCallReducer. Also
migrate the {Map,Set}.prototype.size getter inlining to the
JSBuiltinReducer, so that everything is in a single place.
R=jgruber@chromium.org
Bug: v8:6344, v8:6571, chromium:740122
Change-Id: I09cb506fe26ed3e10d7dcb2f95ec4415e639582d
Reviewed-on: https://chromium-review.googlesource.com/570159
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46655}
This is the next step towards faster Map and Set iteration. It
introduces the appropriate instance types for Map and Set
iterators (following the pattern for Array iterators) and migrates
the following builtins to the CodeStubAssembler:
- Set.prototype.entries
- Set.prototype.values
- Map.prototype.entries
- Map.prototype.keys
- Map.prototype.values
- %SetIteratorPrototype%.next
- %MapIteratorPrototype%.next
This already provides a significant performance boost for regular
for-of iteration of Sets and Maps, by a factor of 5-10 depending
on the input. The final step will be to inline some fast-paths
into TurboFan.
Drive-by-fix: Remove obsolete %IsJSSetIterator and %IsJSMapIterator
intrinsics and runtime functions.
TBR=jgruber@chromium.org
Bug: v8:6344, v8:6571, chromium:740122
Change-Id: I3ab0ee49e2afe8d4295707a5ecbd51adda621918
Reviewed-on: https://chromium-review.googlesource.com/563626
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46497}
ES2015 Object.prototype.toString semantics were enabled in version 4.9,
which has been in stable Chrome for nearly two weeks at this point.
R=littledan@chromium.org
Review URL: https://codereview.chromium.org/1784033002
Cr-Commit-Position: refs/heads/master@{#34732}
