code-review-asm-xtensa

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. Use when this capability is needed.
metadata	{"author":"FastLED"}

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.

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Source: FastLED/FastLED — distributed by TomeVault.