Review Xtensa assembly code for ESP32 platforms. Checks for critical errors in inline assembly, ABI compliance, and optimization opportunities. Use after modifying ESP32 assembly or inline asm code.
Install with the open skills CLI (global, non-interactive — available in every Claude Code session):
npx skills add FastLED/FastLED --skill "code-review-asm-xtensa" -g -a claude-code -yOr manually — copy the SKILL.md below into:
~/.claude/skills/code-review-asm-xtensa-fastled-2/SKILL.md---
name: code-review-asm-xtensa
description: Review Xtensa assembly code for ESP32 platforms. Checks for critical errors in inline assembly, ABI compliance, and optimization opportunities. Use after modifying ESP32 assembly or inline asm code.
disable-model-invocation: true
context: fork
agent: code_review_asm_xtensa-agent
---
Perform comprehensive manual review of Xtensa assembly code in FastLED ESP32 platforms for correctness, ABI compliance, safety, and performance.
## What Gets Checked
### Critical Errors (Must Fix)
- **E001**: Invalid `movi` for 32-bit addresses
- **E002**: Wrong return instruction in interrupts
- **E003**: Missing `memw` memory barriers for MMIO writes
- **E004**: Windowed ABI used in interrupt handlers
- **E005**: Unaligned memory access
- **E006**: Missing `IRAM_ATTR` on interrupt handlers
- **E007**: Mixed ABI usage in same function
### Performance Warnings
- **W001-W005**: Load-use hazards, loop overhead, nesting depth, register pressure, dependency chains
### Optimization Opportunities
- **O001-O004**: Array indexing, conditional moves, loop unrolling, code density
Search for Xtensa assembly code in git changes (inline asm and .S files) and perform deep analysis.
Use when completing tasks, implementing major features, or before merging to verify work meets requirements
Use when implementing any feature or bugfix, before writing implementation code
Use when about to claim work is complete, fixed, or passing, before committing or creating PRs - requires running verification commands and confirming output before making any success claims; evidence before assertions always