perf: localize SIMD to profitable scan paths - #235
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SIMD setup dominates short scans, and whole-module `-msimd128` also changes scalar hot paths. This keeps short and unrelated scans scalar, then uses SIMD for long line comments and templates. Non-SIMD builds remain byte-identical to v3. Long line-comment scans improve 9-65%, and long templates improve 66.8% against the SHA-identical scalar control on Node 18 arm64. The complete 3.06 MB sample corpus shows no aggregate regression across Node 18-26. Two isolated-process runs each produced a 0.94% equal-version geomean improvement. The SIMD build is 563 bytes smaller than #231.
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August 10, 2026 18:40
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SIMD setup dominates short scans, and whole-module
-msimd128also changes scalar hot paths. This keeps short and unrelated scans scalar, then uses SIMD for long line comments and templates. Non-SIMD builds remain byte-identical to v3.Long line-comment scans improve 9-65%, and long templates improve 66.8% against the SHA-identical scalar control on Node 18 arm64. The complete 3.06 MB sample corpus shows no aggregate regression across Node 18-26. Two isolated-process runs each produced a 0.94% equal-version geomean improvement. The SIMD build is 563 bytes smaller than #231.