4995c85f28
This adds a new %_CopyDataProperties intrinsic, that reuses most of the existing machinery that we already have in place for Object.assign() and computed property names in object literals. This speeds up the general case for object spread (where the spread is not the first item in an object literal) and brings it on par with Object.assign() at least - in most cases it's significantly faster than Object.assign(). In the test case [1] referenced from the bug, the performance goes from objectSpreadLast: 3624 ms. objectAssignLast: 1938 ms. to objectSpreadLast: 646 ms. objectAssignLast: 1944 ms. which corresponds to a **5-6x performance boost**, making object spread faster than Object.assign() in general. Drive-by-fix: This refactors the Object.assign() fast-path in a way that it can be reused appropriately for object spread, and adds another new builtin SetDataProperties, which does the core of the Object.assign() work. We can teach TurboFan to inline Object.assign() based on the new SetDataProperties builtin at some later point to further optimize Object.assign(). [1]: https://gist.github.com/bmeurer/0dae4a6b0e23f43d5a22d7c91476b6c0 Bug: v8:9167 Change-Id: I57bea7a8781c4a1e8ff3d394873c3cd4c5d73834 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1587376 Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org> Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org> Auto-Submit: Benedikt Meurer <bmeurer@chromium.org> Cr-Commit-Position: refs/heads/master@{#61100} |
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| .. | ||
| regress | ||
| object-rest-basic.js | ||
| object-spread-basic.js | ||
| object-spread-ic-dontenum-transition.js | ||
| object-spread-ic-multiple-transitions.js | ||
| object-spread-ic.js | ||
| regexp-lookbehind.js | ||
| template-escapes.js | ||