paracodex-cuda-hip-step2

name	paracodex-cuda-hip-step2
description	ParaCodex prompt for cuda to hip step2 (optimization) step.

Performance Tuning - CUDA to HIP Migration

Directory: {kernel_dir}/
Files: {file_listing}
Profile: {profile_log_path} Reference: {kernel_dir}/hip_migration_plan.md

Context

Migrated from CUDA → HIP. Target hardware is AMD GPU (CDNA/RDNA).

Workflow

1. Verify Baseline Correctness

cd {kernel_dir}
{clean_cmd_str}
timeout 300 {correctness_run_cmd} > current_output.txt 2>&1
diff baseline_output.txt current_output.txt

2. Analyze Performance Profile

1. Read profile (rocprof output).
2. Compare with CUDA/Baseline.

3. Create Optimization Plan

MANDATORY: Create optimization_plan.md in {kernel_dir} using template in references/output.md.

Fill Analysis:

• Block Size: Multiple of 64? (AMD Wavefront)
• Registers: VGPR usage high?
• LDS: Bank conflicts?

4. Execute Optimization Plan

Reference: references/examples.md.

• 4A. Tune Block Size: Try 256, 128, 64. Avoid 32 (too small on CDNA where wavefront=64). 256 is safe for both CDNA (wavefront=64) and RDNA (wavefront=32). Always use warpSize — not __AMDGCN_WAVEFRONT_SIZE (removed in ROCm 7.x).
• 4B. Registers: Move uniform data to SGPRs.
• 4C. Memory: Coalescing.

5. Verify & Profile (Iterative)

{clean_cmd_str}
{build_cmd_str}
timeout 300 {run_cmd_str} > optimized_output.txt 2>&1
diff baseline_output.txt optimized_output.txt
{profile_cmd_str} > {profile_log_path}_optimized 2>&1

Rules

• NO GIT COMMANDS
• DO NOT READ/WRITE OUTSIDE THE WORKING DIRECTORY
• ALWAYS CLEAN BEFORE BUILD
• PRESERVE CORRECTNESS - diff against baseline.
• VERIFY PERFORMANCE GAIN - revert if slower.