ZI
Zig Performance
Performance optimization patterns for Zig programs
Details
Language / Topic
ZigCategory
Performance
Rules
balanced
- Use `std.mem.Allocator` with an `std.heap.ArenaAllocator` for request-scoped or phase-scoped allocations to amortize allocation overhead.
- Prefer stack allocation for small, fixed-size buffers (`var buf: [256]u8 = undefined;`) over heap allocation to avoid allocator overhead.
- Use `@Vector` types for SIMD operations on fixed-width numeric arrays — Zig maps vector operations to hardware SIMD instructions automatically.
- Use `std.heap.GeneralPurposeAllocator` in debug builds for leak and use-after-free detection and `std.heap.c_allocator` in release for performance.
- Enable `ReleaseFast` or `ReleaseSafe` build modes in production — `Debug` mode disables optimizations and adds safety checks that are too slow for benchmarks.
- Use `@prefetch` for pointer arrays where sequential access patterns are known to improve cache line utilization in tight loops.
- Avoid allocating inside hot loops — pre-allocate buffers before the loop and pass them as slices to functions that process data in-place.