perf(parser): force-inline read_non_decimal to fold per-digit number dispatch#23157
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…dispatch (#23157) ## Finding (F2 from assembly audit) `read_non_decimal` (numeric.rs) has a comment stating it must inline into its 3 `read_zero` call sites so the constant `kind` lets `kind.matches_number_byte(b)` reduce to one match arm. **Assembly shows plain `#[inline]` did not achieve this** — it stayed a single out-of-line symbol taking `kind` as a runtime arg, re-masking + re-comparing `kind` on every digit of a `0x`/`0o`/`0b` literal. ## Change `#[inline]` → `#[inline(always)]`. The standalone `read_non_decimal` symbol disappears; each radix call site monomorphizes on its constant kind and the per-digit dispatch folds. ##⚠️ Tradeoff — needs CodSpeed before merge The `ZER` byte-handler grows **~68 → 293 instructions** (read_zero + read_non_decimal now inline for all 3 radices). `ZER` handles *all* `0`-prefixed tokens (`0`, `0.5`, `0n`, legacy octal), so this is a static-size/icache cost on those common paths in exchange for fewer dynamic instructions per non-decimal digit. **This is only a win if CodSpeed (instruction count) confirms it net-positive** on representative input; non-decimal literals are rare in typical JS/TS, so it may be neutral-to-negative. Draft pending that signal. ## Verification - Conformance: **byte-identical** to `main` across all 31 snapshot suites (test262/babel/typescript × parser/semantic/codegen/estree/transformer/minifier/formatter). - Assembly re-checked: `read_non_decimal` standalone symbol removed; folded dispatch confirmed in `ZER`. 🤖 Generated with [Claude Code](https://claude.com/claude-code)
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### 💥 BREAKING CHANGES - 7a24911 codegen: [**BREAKING**] Borrow sourcemaps from codegen (#23422) (Boshen) - bb0ed44 transformer: [**BREAKING**] Disable styled-components transpileTemplateLiterals by default (#23171) (Boshen) ### 🚀 Features - 1490a0a linter/react: Implement react-compiler rule (#23202) (Boshen) - 6c0bdf0 transformer/react-refresh: Support `module.property.useHook()` (#23190) (Dunqing) - 47991bd semantic: Report TS1228 for invalid type predicates (#23174) (camc314) - 1d3af58 parser: Add TS2398 parameter property diagnostic (#23216) (camc314) - 44313da semantic: Add `scope_is_descendant_of` api (#22313) (camc314) - e5050c0 parser: Improve diagnostic for rest initializer (#23205) (camc314) - ec266bb transformer: Run React Compiler as a feature-gated transform pass (#23201) (Boshen) - e7374fe parser: Report error for `const` modifier on interface type parameter (#23173) (camc314) - a7c1c9b parser: Report ambient definite variable assertions (#23165) (camc314) - d169fcd parser: Report invalid class definite assertions (#23164) (camc314) - 00244d8 parser: Report definite property initializer errors (#23160) (camc314) ### 🐛 Bug Fixes - 52d0c31 transformer: Replace ambient dot defines (#23231) (camc314) - 2c28748 transformer/class: Parent generated constructors to class scope (#23222) (camc314) - 8edd234 parser: Report accessor definite assertion on token (#23203) (camc314) - de38a3f react_compiler: Keep imports referenced only by a local re-export (#23176) (Boshen) - f5721c2 codegen: Preserve parentheses around `intrinsic` type reference (#23156) (Boshen) - e89f81d parser: Don't emit TS1477 for parenthesized instantiation expression (#23147) (Boshen) - 8a04149 parser: Reject module-referencing imports/exports in a namespace body (#22829) (Boshen) ### ⚡ Performance - 2783295 parser: Table-driven operator precedence lookup (#23346) (Boshen) - 231d5de parser: Single-match member expression dispatch (#23347) (Boshen) - e89729b codegen: Accept one-shot wrap closures (#23265) (camc314) - a6c11fa parser: Force-inline read_non_decimal to fold per-digit number dispatch (#23157) (Boshen) - d74964c parser: Store class definite assertion offset (#23170) (camc314) - f0fda4d parser: Shrink-wrap cold diagnostic tails out of hot frames (#23159) (Boshen) - a082180 parser: Store definite assertion offset (#23167) (camc314) - 534f9c6 oxc: Conditionally rebuild semantic in compiler pipeline (#23153) (Boshen) - b435c6a parser: Skip checkpoint for `infer T extends U` constraint in disallow context (#23128) (Boshen) - 7464dce parser: Peek instead of checkpoint/rewind for `export default` modifier (#23124) (Boshen) - 80a9a32 parser: Fast-path single-keyword TS declarations (#23083) (Boshen) - da1a6c6 diagnostics: Migrate to allocation-optimized oxc-miette (#23094) (Boshen) - b7b08ce parser: Peek once for the static modifier disambiguation (#23079) (Boshen) - e7e07a3 parser: Fold unary dispatch into a single match (#23076) (Boshen) ### 📚 Documentation - d241add semantic: Add `AGENTS.md` test guidance for agents (#23441) (camc314) - 026f1ae parser: Add `AGENTS.md` test guidance for agents (#23440) (camc314) - 09755ac transformer: Add `AGENTS.md` test guidance for agents (#23439) (camc314) - e6bdfd4 lexer: Correct reference link for `byte_handlers!` (#23313) (Dunqing) - 65b6d7a allocator: Fix memory leaks in `Arena` examples (#23257) (overlookmotel) Co-authored-by: Boshen <1430279+Boshen@users.noreply.github.com>
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…dispatch (#23157) ## Finding (F2 from assembly audit) `read_non_decimal` (numeric.rs) has a comment stating it must inline into its 3 `read_zero` call sites so the constant `kind` lets `kind.matches_number_byte(b)` reduce to one match arm. **Assembly shows plain `#[inline]` did not achieve this** — it stayed a single out-of-line symbol taking `kind` as a runtime arg, re-masking + re-comparing `kind` on every digit of a `0x`/`0o`/`0b` literal. ## Change `#[inline]` → `#[inline(always)]`. The standalone `read_non_decimal` symbol disappears; each radix call site monomorphizes on its constant kind and the per-digit dispatch folds. ##⚠️ Tradeoff — needs CodSpeed before merge The `ZER` byte-handler grows **~68 → 293 instructions** (read_zero + read_non_decimal now inline for all 3 radices). `ZER` handles *all* `0`-prefixed tokens (`0`, `0.5`, `0n`, legacy octal), so this is a static-size/icache cost on those common paths in exchange for fewer dynamic instructions per non-decimal digit. **This is only a win if CodSpeed (instruction count) confirms it net-positive** on representative input; non-decimal literals are rare in typical JS/TS, so it may be neutral-to-negative. Draft pending that signal. ## Verification - Conformance: **byte-identical** to `main` across all 31 snapshot suites (test262/babel/typescript × parser/semantic/codegen/estree/transformer/minifier/formatter). - Assembly re-checked: `read_non_decimal` standalone symbol removed; folded dispatch confirmed in `ZER`. 🤖 Generated with [Claude Code](https://claude.com/claude-code)
camc314
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Jul 3, 2026
### 💥 BREAKING CHANGES - 7a24911 codegen: [**BREAKING**] Borrow sourcemaps from codegen (#23422) (Boshen) - bb0ed44 transformer: [**BREAKING**] Disable styled-components transpileTemplateLiterals by default (#23171) (Boshen) ### 🚀 Features - 1490a0a linter/react: Implement react-compiler rule (#23202) (Boshen) - 6c0bdf0 transformer/react-refresh: Support `module.property.useHook()` (#23190) (Dunqing) - 47991bd semantic: Report TS1228 for invalid type predicates (#23174) (camc314) - 1d3af58 parser: Add TS2398 parameter property diagnostic (#23216) (camc314) - 44313da semantic: Add `scope_is_descendant_of` api (#22313) (camc314) - e5050c0 parser: Improve diagnostic for rest initializer (#23205) (camc314) - ec266bb transformer: Run React Compiler as a feature-gated transform pass (#23201) (Boshen) - e7374fe parser: Report error for `const` modifier on interface type parameter (#23173) (camc314) - a7c1c9b parser: Report ambient definite variable assertions (#23165) (camc314) - d169fcd parser: Report invalid class definite assertions (#23164) (camc314) - 00244d8 parser: Report definite property initializer errors (#23160) (camc314) ### 🐛 Bug Fixes - 52d0c31 transformer: Replace ambient dot defines (#23231) (camc314) - 2c28748 transformer/class: Parent generated constructors to class scope (#23222) (camc314) - 8edd234 parser: Report accessor definite assertion on token (#23203) (camc314) - de38a3f react_compiler: Keep imports referenced only by a local re-export (#23176) (Boshen) - f5721c2 codegen: Preserve parentheses around `intrinsic` type reference (#23156) (Boshen) - e89f81d parser: Don't emit TS1477 for parenthesized instantiation expression (#23147) (Boshen) - 8a04149 parser: Reject module-referencing imports/exports in a namespace body (#22829) (Boshen) ### ⚡ Performance - 2783295 parser: Table-driven operator precedence lookup (#23346) (Boshen) - 231d5de parser: Single-match member expression dispatch (#23347) (Boshen) - e89729b codegen: Accept one-shot wrap closures (#23265) (camc314) - a6c11fa parser: Force-inline read_non_decimal to fold per-digit number dispatch (#23157) (Boshen) - d74964c parser: Store class definite assertion offset (#23170) (camc314) - f0fda4d parser: Shrink-wrap cold diagnostic tails out of hot frames (#23159) (Boshen) - a082180 parser: Store definite assertion offset (#23167) (camc314) - 534f9c6 oxc: Conditionally rebuild semantic in compiler pipeline (#23153) (Boshen) - b435c6a parser: Skip checkpoint for `infer T extends U` constraint in disallow context (#23128) (Boshen) - 7464dce parser: Peek instead of checkpoint/rewind for `export default` modifier (#23124) (Boshen) - 80a9a32 parser: Fast-path single-keyword TS declarations (#23083) (Boshen) - da1a6c6 diagnostics: Migrate to allocation-optimized oxc-miette (#23094) (Boshen) - b7b08ce parser: Peek once for the static modifier disambiguation (#23079) (Boshen) - e7e07a3 parser: Fold unary dispatch into a single match (#23076) (Boshen) ### 📚 Documentation - d241add semantic: Add `AGENTS.md` test guidance for agents (#23441) (camc314) - 026f1ae parser: Add `AGENTS.md` test guidance for agents (#23440) (camc314) - 09755ac transformer: Add `AGENTS.md` test guidance for agents (#23439) (camc314) - e6bdfd4 lexer: Correct reference link for `byte_handlers!` (#23313) (Dunqing) - 65b6d7a allocator: Fix memory leaks in `Arena` examples (#23257) (overlookmotel) Co-authored-by: Boshen <1430279+Boshen@users.noreply.github.com>
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Finding (F2 from assembly audit)
read_non_decimal(numeric.rs) has a comment stating it must inline into its 3read_zerocall sites so the constantkindletskind.matches_number_byte(b)reduce to one match arm. Assembly shows plain#[inline]did not achieve this — it stayed a single out-of-line symbol takingkindas a runtime arg, re-masking + re-comparingkindon every digit of a0x/0o/0bliteral.Change
#[inline]→#[inline(always)]. The standaloneread_non_decimalsymbol disappears; each radix call site monomorphizes on its constant kind and the per-digit dispatch folds.The
ZERbyte-handler grows ~68 → 293 instructions (read_zero + read_non_decimal now inline for all 3 radices).ZERhandles all0-prefixed tokens (0,0.5,0n, legacy octal), so this is a static-size/icache cost on those common paths in exchange for fewer dynamic instructions per non-decimal digit. This is only a win if CodSpeed (instruction count) confirms it net-positive on representative input; non-decimal literals are rare in typical JS/TS, so it may be neutral-to-negative. Draft pending that signal.Verification
mainacross all 31 snapshot suites (test262/babel/typescript × parser/semantic/codegen/estree/transformer/minifier/formatter).read_non_decimalstandalone symbol removed; folded dispatch confirmed inZER.🤖 Generated with Claude Code