[codegen] Track unanalyzed assembly and include it in docs.

[jswrenn]

This is more approachable than the full llvm-mca analysis.

---

• 　  [codegen] Test and document codegen under different layouts #3085
• 　  [codegen] Make codegen tests even more stressful. #3083
• 　  [codegen] Use descriptive benchmark target fn name. #3082
• 👉 [codegen] Track unanalyzed assembly and include it in docs. #3081

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Branch

git fetch origin refs/heads/Ged67b8f5ad7d38d9f2eb40adebea8894a1a6a008 && git checkout -b pr-Ged67b8f5ad7d38d9f2eb40adebea8894a1a6a008 FETCH_HEAD

Checkout

git fetch origin refs/heads/Ged67b8f5ad7d38d9f2eb40adebea8894a1a6a008 && git checkout FETCH_HEAD

Cherry Pick

git fetch origin refs/heads/Ged67b8f5ad7d38d9f2eb40adebea8894a1a6a008 && git cherry-pick FETCH_HEAD

Pull

git pull origin refs/heads/Ged67b8f5ad7d38d9f2eb40adebea8894a1a6a008

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[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.87%. Comparing base (dbef272) to head (bdb1480).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3081   +/-   ##
=======================================
  Coverage   91.87%   91.87%           
=======================================
  Files          20       20           
  Lines        6057     6057           
=======================================
  Hits         5565     5565           
  Misses        492      492           

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[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request enhances the code generation documentation by including raw assembly code alongside the existing machine code analysis. This change provides a more direct and potentially more approachable view of the generated code. The update involves adding new benchmark files containing assembly code, modifying the rustdoc CSS to accommodate a new display column, and updating the test suite to verify the generation of both assembly and machine code analysis outputs.

Highlights

• Assembly Code Inclusion: This PR introduces the tracking and inclusion of unanalyzed assembly code in documentation, offering a more accessible alternative to full llvm-mca analysis.
• New Assembly Benchmarks: Several new assembly benchmarks have been added for various reference operations, enhancing the code generation tests.
• CSS Update: The CSS file has been modified to accommodate an additional column in the codegen tabs, improving the layout for the new assembly code display.
• Test Logic Modification: The test logic in tests/codegen.rs was modified to test both assembly and mca directives.

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Changelog

• benches/ref_from_bytes.x86-64
  • Added a new assembly benchmark for ref_from_bytes.
• benches/ref_from_bytes_with_elems.x86-64
  • Added a new assembly benchmark for ref_from_bytes_with_elems.
• benches/ref_from_prefix.x86-64
  • Added a new assembly benchmark for ref_from_prefix.
• benches/ref_from_prefix_with_elems.x86-64
  • Added a new assembly benchmark for ref_from_prefix_with_elems.
• benches/ref_from_suffix.x86-64
  • Added a new assembly benchmark for ref_from_suffix.
• benches/ref_from_suffix_with_elems.x86-64
  • Added a new assembly benchmark for ref_from_suffix_with_elems.
• benches/transmute_ref.x86-64
  • Added a new assembly benchmark for transmute_ref.
• benches/try_ref_from_bytes.x86-64
  • Added a new assembly benchmark for try_ref_from_bytes.
• benches/try_ref_from_bytes_with_elems.x86-64
  • Added a new assembly benchmark for try_ref_from_bytes_with_elems.
• benches/try_ref_from_prefix.x86-64
  • Added a new assembly benchmark for try_ref_from_prefix.
• benches/try_ref_from_prefix_with_elems.x86-64
  • Added a new assembly benchmark for try_ref_from_prefix_with_elems.
• benches/try_ref_from_suffix.x86-64
  • Added a new assembly benchmark for try_ref_from_suffix.
• benches/try_ref_from_suffix_with_elems.x86-64
  • Added a new assembly benchmark for try_ref_from_suffix_with_elems.
• benches/try_transmute_ref.x86-64
  • Added a new assembly benchmark for try_transmute_ref.
• rustdoc/style.css
  • Updated the CSS to support four columns in the codegen tabs.
• src/util/macros.rs
  • Modified the codegen_tabs macro to include assembly code from new benchmark files.
• tests/codegen.rs
  • Modified the test logic to test both assembly and mca directives.

Activity

• New assembly benchmarks were added.
• CSS was updated to accommodate the new assembly code display.
• The codegen_tabs macro was modified to include assembly code.
• Test logic was updated to test both assembly and mca directives.

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[gemini-code-assist]

Code Review

This pull request extends the codegen testing and documentation to include raw assembly output, in addition to the existing llvm-mca analysis. This is achieved by refactoring the test runner to handle different output directives (--asm and --mca) and updating the documentation macro to include a new tab for assembly.

The changes are well-structured. I have a few suggestions to improve maintainability and the developer experience when debugging test failures:

• Use a .asm extension for the generated assembly files for better clarity. This requires changes in two places and renaming the newly added files.
• Improve the panic message in the codegen tests to show the actual generated output when a mismatch is found, which will make debugging easier.