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inspect

Testing & Quality
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Inspect the AD pipeline IR for a Julia function at each Mooncake compilation stage.

QUICK START

How to use this skill

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  1. Open your project in Codex.
  2. Copy the prompt below and paste it into your agent.
  3. Review the proposed files and risks before you approve installation.
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I want to install this Agent Skill for this project in Codex.

Source SKILL.md: https://github.com/chalk-lab/Mooncake.jl/blob/HEAD/.claude/skills/inspect/SKILL.md

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First, summarize what it does, its dependencies, license status if identifiable, and any risks. Show the exact files you propose to add under .agents/skills/inspect/. Do not write files or run scripts until I approve.

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Inspect

Inspect IR transformations in Mooncake's AD pipeline for a given function.

Setup

using Mooncake, Mooncake.SkillUtils

Gathering user intent

Ask the user:

  1. Function and arguments — e.g. sin, 1.0 or a custom function
  2. Mode — reverse (default) or forward
  3. What to view — all stages, a specific stage, a diff between two stages, or world age info

Do not assume — ask the user to pick.

Pipeline stages

Reverse mode (default)

StageSymbolDescription
Raw IR:rawoptimised, type-inferred SSAIR from Julia's compiler
Normalised:normalizedafter Mooncake's normalisation passes
CFG blocks:cfg_blocksVector{CFGBlock} representation with stable IDs
Forward IR:fwd_irgenerated forward-pass IR
Reverse IR:rvs_irgenerated pullback IR
Optimised Forward:optimized_fwdforward pass after optimisation
Optimised Reverse:optimized_rvspullback after optimisation

Forward mode

StageSymbolDescription
Raw IR:rawoptimised, type-inferred SSAIR from Julia's compiler
Normalised:normalizedafter Mooncake's normalisation passes
CFG blocks:cfg_blocksinspection-only — forward mode does not use the CFGBlock representation internally
Dual IR:dual_irgenerated dual-number IR
Optimised:optimizedafter optimisation passes

Commands

# Full inspection
ins = inspect_ir(f, args...; mode=:reverse)  # or mode=:forward

# View stages
show_ir(ins)                          # all stages
show_stage(ins, :raw)                 # one stage

# Diffs between stages
show_diff(ins; from=:raw, to=:normalized)
show_all_diffs(ins)

# World age debugging
show_world_info(ins)

# Write everything to files
write_ir(ins, "/tmp/ir_output")

# Shorthand helpers
ins = inspect_fwd(f, args...)         # forward mode
ins = inspect_rvs(f, args...)         # reverse mode
ins = quick_inspect(f, args...)       # inspect + display immediately

# Options
inspect_ir(f, args...;
    mode       = :reverse,
    optimize   = true,
    do_inline  = true,
    debug_mode = false,
)

Presenting results

  • Run commands via Bash and present IR in fenced code blocks.
  • When showing diffs, explain what changed and why the transformation matters.
  • If errors occur, check that Mooncake is loaded and the function signature is valid.

Limitations

Inspects Mooncake's internal AD pipeline only. For allocation, world-age, or compiler-boundary debugging, see docs/src/developer_documentation/advanced_debugging.md.