dump-asm

name	dump-asm
description	Generate assembly for code exercised by a benchmark and organize output into a baseline directory named after the current git branch. Use to generate assembly code that can be diff'd between branches.

Usage

/dump-asm <BenchmarkName> [<Runtimes>]

Arguments

• $ARGUMENTS - The name of the benchmark class to run (e.g., LruJustGetOrAdd, LfuJustGetOrAdd, SketchIncrement), optionally followed by a list of one or more runtimes (e.g., net48, net9.0 or net48 net9.0)

Instructions

This skill orchestrates benchmark assembly generation and organizes the output for comparison.

Parse the arguments: the first argument is the benchmark name, and the optional second argument is the list of runtimes.

Step 1: Clean artifacts

Delete the BenchmarkDotNet.Artifacts directory to ensure a clean run:

rm -rf BenchmarkDotNet.Artifacts

Step 2: Run benchmark

Invoke the /bench-fast skill with the provided benchmark name and optional runtime to generate assembly code:

/bench-fast <BenchmarkName> [<Runtimes>]

Step 3: Split assembly files

Invoke the /split-asm skill to generate individual assembly code files:

/split-asm

Step 4: Organize into baseline directory

Get the current git branch name and convert it to a valid directory name by replacing forward slashes with dashes, then append the short commit hash:

git rev-parse --abbrev-ref HEAD | tr '/' '-'
git rev-parse --short HEAD

Combine these to form the directory name: <sanitized-branch-name>-<commit-hash>.

For example, branch users/alexpeck/foo at commit abc1234 becomes users-alexpeck-foo-abc1234.

Create the baseline directory structure preserving the benchmark name and runtime hierarchy. For each benchmark and runtime combination found in BenchmarkDotNet.Artifacts/results/:

1. Extract the short benchmark name from the full benchmark path (e.g., BitFaster.Caching.Benchmarks.LruJustGetOrAdd → LruJustGetOrAdd)
2. Create the directory baseline/<sanitized-branch-name>-<commit-hash>/<benchmarkname>/<runtime>/
3. Copy all files from the corresponding BenchmarkDotNet.Artifacts/results/<full-benchmark-name>/<runtime>/ directory

The final structure should be:

baseline/
  <sanitized-branch-name>-<commit-hash>/
    <benchmarkname>/
      <runtime>/
        <MethodName>-asm.md
        <MethodName>-summary.md
        ...

For example:

baseline/
  users-alexpeck-skills-16c32c5/
    LruJustGetOrAdd/
      .NET 6.0.36 (6.0.3624.51421), X64 RyuJIT AVX2/
        FastConcurrentLru-asm.md
        FastConcurrentLru-summary.md
        ...