[compiler][rewrite] Represent scope dependencies with value blocks #32099
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This was referenced Jan 16, 2025
| @@ -3414,7 +3413,7 @@ function lowerExpressionToTemporary( | |||
| return lowerValueToTemporary(builder, value); | |||
| } | |||
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| function lowerValueToTemporary( | |||
| export function lowerValueToTemporary( | |||
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not used outside this file, remove the export?
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This is used in propagateScopeDependencies, which creates new instructions / temporaries for scope dependency blocks
| @@ -902,6 +904,7 @@ export class Environment { | |||
| this.#moduleTypes.set(REANIMATED_MODULE_NAME, reanimatedModuleType); | |||
| } | |||
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| this.parentFunction = parentFunction; | |||
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nit: splitting changes like this into a separate PR would make it easier to review and focus on the core dependency changes
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I have not processed the changes here deeply, but my first instinct is to wonder why this pass should have to change at all?
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Since we're now representing scope dependencies with value blocks + a list of Places, two things need to change:
- Promoting unnamed
Identifiers referenced by scope dependencies now requires explicitly traversing the value blocks (seethis.visitBlock(scopeBlock.dependencyInstructions, ...) - We now also need to perform some form of DCE -- after pruning passes, some instructions within
scopeBlock.dependencyInstructionsno longer correspond to real dependencies. Concretely, we need to figure out which baseIdentifiers should be excluded for promotion.
Note that this isn't an issue for codegen asReactiveScopeBlock.dependencyInstructionsalways contains non-named, non-null lvalues (which simply stores into aTemporaries: Map<Identifier, babel.t.Expression>sidemap for later inlining
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Small patch to pass aliased context values into `Object|ArrayExpression`s --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/32093). * #32099 * #32104 * #32098 * #32097 * #32096 * #32095 * #32094 * __->__ #32093
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See test fixture --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/32094). * #32099 * #32104 * #32098 * #32097 * #32096 * #32095 * __->__ #32094 * #32093
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See test fixture --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/32095). * #32099 * #32104 * #32098 * #32097 * #32096 * __->__ #32095 * #32094 * #32093
This was referenced Feb 1, 2025
mofeiZ
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Feb 14, 2025
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| getOrCreateIdentifier( | ||
| identifier: Identifier, | ||
| reactive: boolean, | ||
| ): PropertyPathNode { |
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Note that we now need to track reactivity, as we're creating new instructions to represent dependencies
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Synced offline with @josephsavona, I'm going to hold off on landing this until after:
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LoweredFunction dependencies were exclusively used for dependency extraction (in `propagateScopeDeps`). Now that we have a `propagateScopeDepsHIR` that recursively traverses into nested functions, we can delete `dependencies` and their associated synthetic `LoadLocal`/`PropertyLoad` instructions. [Internal snapshot diff](https://www.internalfb.com/phabricator/paste/view/P1716950202) for this change shows ~.2% of files changed. I [read through ~60 of the changed files](https://www.internalfb.com/phabricator/paste/view/P1733074307) - most changes are due to better outlining (due to better DCE) - a few changes in memo inference are due to changed ordering ``` // source arr.map(() => contextVar.inner); // previous instructions $0 = LoadLocal arr $1 = $0.map // Below instructions are synthetic $2 = LoadLocal contextVar $3 = $2.inner $4 = Function deps=$3 context=contextVar { ... } ``` - a few changes are effectively bugfixes (see `aliased-nested-scope-fn-expr`)
This removes special casing for `PropertyStore` mutability inference within FunctionExpressions.
(needs cleanup) - Scopes no longer store a flat list of their dependencies. Instead: - Scope terminals are effectively a `goto` for scope dependency instructions (represented as value blocks that terminate with a `goto scopeBlock` for HIR and a series of ReactiveInstructions for ReactiveIR) - Scopes themselves store `dependencies: Array<Place>`, which refer to temporaries written to by scope dependency instructions Next steps: - new pass to dedupe scope dependency instructions after all dependency and scope pruning passes, effectively 'hoisting' dependencies out - more complex dependencies (unary ops like `Boolean` or `Not`, binary ops like `!==` or logical operators)
mofeiZ
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…ns (#32096) LoweredFunction dependencies were exclusively used for dependency extraction (in `propagateScopeDeps`). Now that we have a `propagateScopeDepsHIR` that recursively traverses into nested functions, we can delete `dependencies` and their associated synthetic `LoadLocal`/`PropertyLoad` instructions. [Internal snapshot diff](https://www.internalfb.com/phabricator/paste/view/P1716950202) for this change shows ~.2% of files changed. I [read through ~60 of the changed files](https://www.internalfb.com/phabricator/paste/view/P1733074307) - most changes are due to better outlining (due to better DCE) - a few changes in memo inference are due to changed ordering ``` // source arr.map(() => contextVar.inner); // previous instructions $0 = LoadLocal arr $1 = $0.map // Below instructions are synthetic $2 = LoadLocal contextVar $3 = $2.inner $4 = Function deps=$3 context=contextVar { ... } ``` - a few changes are effectively bugfixes (see `aliased-nested-scope-fn-expr`) --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/facebook/react/pull/32096). * #32099 * #32286 * #32104 * #32098 * #32097 * __->__ #32096
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(needs cleanup)
gotofor scope dependency instructions (represented as value blocks that terminate with agoto scopeBlockfor HIR and a series of ReactiveInstructions for ReactiveIR)dependencies: Array<Place>, which refer to temporaries written to by scope dependency instructionsNext steps:
BooleanorNot, binary ops like!==or logical operators)Stack created with Sapling. Best reviewed with ReviewStack.