src: improve textEncoder encode performance with simdutf by mertcanaltin · Pull Request #61496 · nodejs/node

mertcanaltin · 2026-01-23T19:46:03Z

Benchmark CI: https://ci.nodejs.org/view/Node.js%20benchmark/job/benchmark-node-micro-benchmarks/1789/

 confidence improvement accuracy (*) (**) (***)
util/text-encoder.js op='encode' type='ascii' n=1000000 len=1024 *** 11.86 % ±1.25% ±1.66% ±2.17%
util/text-encoder.js op='encode' type='ascii' n=1000000 len=256 *** -7.82 % ±1.84% ±2.46% ±3.22%
util/text-encoder.js op='encode' type='ascii' n=1000000 len=32 * 1.26 % ±1.19% ±1.59% ±2.07%
util/text-encoder.js op='encode' type='ascii' n=1000000 len=8192 *** 146.74 % ±0.78% ±1.05% ±1.39%
util/text-encoder.js op='encode' type='one-byte-string' n=1000000 len=1024 *** 20.69 % ±0.79% ±1.05% ±1.37%
util/text-encoder.js op='encode' type='one-byte-string' n=1000000 len=256 *** 7.46 % ±0.79% ±1.05% ±1.37%
util/text-encoder.js op='encode' type='one-byte-string' n=1000000 len=32 -0.57 % ±0.91% ±1.21% ±1.58%
util/text-encoder.js op='encode' type='one-byte-string' n=1000000 len=8192 *** 182.16 % ±0.22% ±0.29% ±0.39%
util/text-encoder.js op='encode' type='two-byte-string' n=1000000 len=1024 *** 95.53 % ±1.09% ±1.47% ±1.95%
util/text-encoder.js op='encode' type='two-byte-string' n=1000000 len=256 *** 32.64 % ±0.90% ±1.20% ±1.58%
util/text-encoder.js op='encode' type='two-byte-string' n=1000000 len=32 -0.23 % ±1.04% ±1.38% ±1.80%
util/text-encoder.js op='encode' type='two-byte-string' n=1000000 len=8192 *** 299.06 % ±0.64% ±0.86% ±1.14%
util/text-encoder.js op='encodeInto' type='ascii' n=1000000 len=1024 2.14 % ±3.97% ±5.29% ±6.88%
util/text-encoder.js op='encodeInto' type='ascii' n=1000000 len=256 1.22 % ±3.31% ±4.41% ±5.75%
util/text-encoder.js op='encodeInto' type='ascii' n=1000000 len=32 *** 20.60 % ±2.77% ±3.69% ±4.80%
util/text-encoder.js op='encodeInto' type='ascii' n=1000000 len=8192 0.91 % ±3.13% ±4.16% ±5.42%
util/text-encoder.js op='encodeInto' type='one-byte-string' n=1000000 len=1024 1.21 % ±5.16% ±6.88% ±8.99%
util/text-encoder.js op='encodeInto' type='one-byte-string' n=1000000 len=256 -0.65 % ±1.12% ±1.49% ±1.94%
util/text-encoder.js op='encodeInto' type='one-byte-string' n=1000000 len=32 -0.48 % ±3.29% ±4.38% ±5.70%
util/text-encoder.js op='encodeInto' type='one-byte-string' n=1000000 len=8192 -1.57 % ±1.69% ±2.25% ±2.94%
util/text-encoder.js op='encodeInto' type='two-byte-string' n=1000000 len=1024 -0.51 % ±0.69% ±0.92% ±1.20%
util/text-encoder.js op='encodeInto' type='two-byte-string' n=1000000 len=256 -0.38 % ±0.67% ±0.89% ±1.16%
util/text-encoder.js op='encodeInto' type='two-byte-string' n=1000000 len=32 * -2.35 % ±2.05% ±2.73% ±3.55%
util/text-encoder.js op='encodeInto' type='two-byte-string' n=1000000 len=8192 * -0.32 % ±0.31% ±0.41% ±0.54%

codecov · 2026-01-23T21:03:38Z

Codecov Report

❌ Patch coverage is 63.15789% with 21 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.76%. Comparing base (ea83d32) to head (2b60e66).
⚠️ Report is 272 commits behind head on main.

Files with missing lines	Patch %	Lines
src/encoding_binding.cc	63.15%	17 Missing and 4 partials ⚠️

Additional details and impacted files

@@ Coverage Diff @@## main #61496 +/- ##
==========================================
- Coverage 89.79% 89.76% -0.04% 
==========================================
Files 673 673 Lines 203852 203901 +49 Branches 39181 39188 +7 ==========================================
- Hits 183044 183024 -20 - Misses 13143 13208 +65 - Partials 7665 7669 +4

Files with missing lines	Coverage Δ
src/encoding_binding.cc	`52.92% <63.15%> (+0.79%)`	⬆️

... and 37 files with indirect coverage changes

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

anonrig · 2026-01-30T19:58:25Z

cc @nodejs/performance please review

github-actions · 2026-01-30T20:00:47Z

The notable-changePRs with changes that should be highlighted in changelogs. label has been added by @anonrig.

Please suggest a text for the release notes if you'd like to include a more detailed summary, then proceed to update the PR description with the text or a link to the notable change suggested text comment. Otherwise, the commit will be placed in the Other Notable Changes section.

nodejs-github-bot · 2026-01-30T20:13:13Z

CI: https://ci.nodejs.org/job/node-test-pull-request/71132/

anonrig · 2026-01-30T20:21:08Z

@IlyasShabi why did you locked and limited the conversation to collaborators?

IlyasShabi · 2026-01-30T20:25:01Z

@anonrig oh! Sorry didn't know what happened, didn't mean to do it.

nodejs-github-bot · 2026-01-30T23:50:50Z

Landed in f200685

PR-URL: #61496 Refs: cloudflare/workerd#5448 Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com> Reviewed-By: Daniel Lemire <daniel@lemire.me>

Notable changes: async_hooks: * (SEMVER-MINOR) add trackPromises option to createHook() (Joyee Cheung) #61415 src: * improve textEncoder encode performance with simdutf (Mert Can Altin) #61496 stream: * (SEMVER-MINOR) add bytes() method to stream/consumers (wantaek) #60426 test_runner: * (SEMVER-MINOR) add env option to run function (Ethan Arrowood) #61367 url: * update ada to v3.4.2 and support unicode 17 (Yagiz Nizipli) #61593 PR-URL: #61635

PR-URL: #61496 Refs: cloudflare/workerd#5448 Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com> Reviewed-By: Daniel Lemire <daniel@lemire.me>

Notable changes: async_hooks: * (SEMVER-MINOR) add `trackPromises` option to `createHook()` (Joyee Cheung) #61415 net: * (SEMVER-MINOR) add `setTOS` and `getTOS` to `Socket` (Amol Yadav) #61503 src: * (SEMVER-MINOR) add initial support for ESM in embedder API (Joyee Cheung) #61548 * improve `TextEncoder` encode performance with `simdutf` (Mert Can Altin) #61496 stream: * (SEMVER-MINOR) add `bytes()` method to `node:stream/consumers` (wantaek) #60426 test_runner: * (SEMVER-MINOR) add `env` option to `run` function (Ethan Arrowood) #61367 url: * update Ada to v3.4.2 and support Unicode 17 (Yagiz Nizipli) #61593 PR-URL: #61635

aduh95 · 2026-03-09T18:17:28Z

This doesn't build when cherry-picked to v24.x-staging, and would require a manual backport if we want it on the 24.x release line

nodejs-github-bot added c++ Issues and PRs that require attention from people who are familiar with C++. needs-ci PRs that need a full CI run. labels Jan 23, 2026

mertcanaltin marked this pull request as draft January 23, 2026 19:47

mertcanaltin marked this pull request as ready for review January 30, 2026 19:20

src: improve textEncoder encode performance with simdutf
2b60e66

mertcanaltin force-pushed the mert/textencoder-encode-simdutf branch from 0c17bf1 to 2b60e66Compare January 30, 2026 19:31

anonrig approved these changes Jan 30, 2026
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anonrig added author ready PRs that have at least one approval, no pending requests for changes, and a CI started. request-ci Add this label to start a Jenkins CI on a PR. notable-change PRs with changes that should be highlighted in changelogs. labels Jan 30, 2026

anonrig requested review from jasnell, lemire and mcollina January 30, 2026 20:01

github-actionsBot removed the request-ci Add this label to start a Jenkins CI on a PR. label Jan 30, 2026

nodejs locked and limited conversation to collaborators Jan 30, 2026

nodejs unlocked this conversation Jan 30, 2026

lemire approved these changes Jan 30, 2026
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nodejs-github-bot removed the commit-queue Add this label to land a pull request using GitHub Actions. label Jan 30, 2026

nodejs-github-bot merged commit f200685 into nodejs:mainJan 30, 2026
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aduh95 pushed a commit that referenced this pull request Feb 2, 2026
src: improve textEncoder encode performance with simdutf
af0e862
PR-URL: #61496 Refs: cloudflare/workerd#5448 Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com> Reviewed-By: Daniel Lemire <daniel@lemire.me>

github-actionsBot mentioned this pull request Feb 2, 2026
2026-02-03, Version 25.6.0 (Current) #61635
Merged

aduh95 pushed a commit that referenced this pull request Feb 2, 2026
src: improve textEncoder encode performance with simdutf
e62608b
PR-URL: #61496 Refs: cloudflare/workerd#5448 Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com> Reviewed-By: Daniel Lemire <daniel@lemire.me>

ChALkeR mentioned this pull request Feb 5, 2026
src: use simdutf for one-byte string UTF-8 write in stringBytes #61696
Closed

aduh95 added the backport-requested-v24.x PRs awaiting manual backport to the v24.x-staging branch. label Mar 9, 2026

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src: improve textEncoder encode performance with simdutf - #61496

src: improve textEncoder encode performance with simdutf#61496
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