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port(wasm): Avoid cloning symbol tables during module layout - #2293

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lapla-cogito merged 1 commit into
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lapla-cogito:wasm_symclone
Jul 30, 2026
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port(wasm): Avoid cloning symbol tables during module layout#2293
lapla-cogito merged 1 commit into
wild-linker:mainfrom
lapla-cogito:wasm_symclone

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@lapla-cogito

@lapla-cogito lapla-cogito commented Jul 29, 2026

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Borrow linking symbols and init funcs from each input File as slices instead of cloning them into WasmObjectLayoutInput and again into WasmLayout. This contributes to a slight reduction in RSS.

Benchmark 1 (116 runs): /home/lapla/wild-rg/save/0/run-with /tmp/wild-symclone/wild-before --no-fork
  measurement          mean ± σ            min … max           outliers         delta
  wall_time          43.2ms ± 2.33ms    37.5ms … 47.1ms          0 ( 0%)        0%
  peak_rss           85.6MB ±  453KB    84.3MB … 86.7MB          4 ( 3%)        0%
  cpu_cycles         38.8M  ± 21.8M     14.3M  … 83.9M           0 ( 0%)        0%
  instructions       75.7M  ± 40.7M     27.3M  …  166M           0 ( 0%)        0%
  cache_references    803K  ±  552K      262K  … 1.78M           0 ( 0%)        0%
  cache_misses        448K  ±  299K      157K  …  930K           0 ( 0%)        0%
  branch_misses       258K  ±  134K      114K  …  558K           0 ( 0%)        0%
Benchmark 2 (118 runs): /home/lapla/wild-rg/save/0/run-with /tmp/wild-symclone/wild-after --no-fork
  measurement          mean ± σ            min … max           outliers         delta
  wall_time          42.6ms ± 2.41ms    37.2ms … 49.1ms          0 ( 0%)          -  1.4% ±  1.4%
  peak_rss           83.2MB ±  421KB    81.7MB … 84.3MB          3 ( 3%)        ⚡-  2.7% ±  0.1%
  cpu_cycles         37.5M  ± 20.6M     10.6M  … 77.5M           0 ( 0%)          -  3.4% ± 14.0%
  instructions       74.6M  ± 39.2M     20.9M  …  150M           0 ( 0%)          -  1.6% ± 13.5%
  cache_references    759K  ±  527K      182K  … 1.70M           0 ( 0%)          -  5.5% ± 17.2%
  cache_misses        415K  ±  276K      125K  …  872K           0 ( 0%)          -  7.4% ± 16.4%
  branch_misses       254K  ±  129K     83.7K  …  494K           0 ( 0%)          -  1.6% ± 13.1%

Part of #1431

@davidlattimore

davidlattimore commented Jul 29, 2026

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BTW, I just tried benchmarking this and with sufficient runs and a quiet system, I saw a speedup too:

Benchmark 1 (1294 runs): /home/david/save/ripgrep-wasm/run-with /home/d/wild-builds/2026-07-30.cg1 --strip-debug --no-fork
  measurement          mean ± σ            min … max           outliers         delta
  wall_time          46.3ms ± 1.60ms    43.1ms … 81.3ms          6 ( 0%)        0%
  peak_rss           81.8MB ±  838KB    78.0MB … 85.2MB         23 ( 2%)        0%
  cpu_cycles          239M  ± 8.81M      184M  …  258M          22 ( 2%)        0%
  instructions        304M  ± 3.99M      290M  …  316M          15 ( 1%)        0%
  cache_references   10.0M  ±  163K     9.51M  … 10.6M          13 ( 1%)        0%
  cache_misses       1.39M  ± 32.1K     1.22M  … 1.48M          19 ( 1%)        0%
  branch_misses      1.07M  ± 17.4K     1.01M  … 1.13M          19 ( 1%)        0%
Benchmark 2 (1332 runs): /home/david/save/ripgrep-wasm/run-with target/cg1/wild --strip-debug --no-fork
  measurement          mean ± σ            min … max           outliers         delta
  wall_time          45.0ms ± 1.24ms    42.3ms … 51.7ms          4 ( 0%)        ⚡-  2.8% ±  0.2%
  peak_rss           79.2MB ±  870KB    76.0MB … 82.7MB         27 ( 2%)        ⚡-  3.1% ±  0.1%
  cpu_cycles          237M  ± 8.71M      203M  …  261M          23 ( 2%)          -  1.0% ±  0.3%
  instructions        303M  ± 4.04M      291M  …  315M           6 ( 0%)          -  0.3% ±  0.1%
  cache_references   9.85M  ±  160K     9.34M  … 10.4M           8 ( 1%)        ⚡-  1.9% ±  0.1%
  cache_misses       1.35M  ± 31.3K     1.24M  … 1.44M          13 ( 1%)        ⚡-  2.3% ±  0.2%
  branch_misses      1.07M  ± 17.0K     1.02M  … 1.14M          10 ( 1%)          -  0.3% ±  0.1%

@lapla-cogito
lapla-cogito merged commit 8d6cb8f into wild-linker:main Jul 30, 2026
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@lapla-cogito
lapla-cogito deleted the wasm_symclone branch July 30, 2026 00:55
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