DEV Community: Maayur Dahake

SearchValues in .NET 8/9 (.NET & C#)

Maayur Dahake — Thu, 12 Nov 2026 10:30:24 +0000

Day 1/30 — SearchValues in .NET 8/9 (.NET & C#)

Spotted string parsing bottlenecks during a recent code review where repeated IndexOfAny calls were triggering excessive CPU cycles on hot paths.

• SIMD Vectorization: JIT compiler auto-vectorizes instructions to scan multiple bytes simultaneously across wide registers.
• Heap Allocation: Caching the SearchValues instance eliminates repeated array creation overhead inside tight loops.
• Memory Safety: Operating directly on ReadOnlySpan prevents unnecessary string slicing and Gen0 GC pressure.

Watch out: Always cache SearchValues as a static readonly field to avoid costly instance initialization overhead on every method call.

Have you benchmarked SIMD primitives in your ingestion pipelines yet?

DotNet #CSharp #Performance #BackendDevelopment #SoftwareEngineering

SearchValues (.NET & C#)

Maayur Dahake — Thu, 12 Nov 2026 10:22:18 +0000

Day 1/30 — SearchValues (.NET & C#)

Spotted a hot path in a code review yesterday doing repeated char lookups against standard array allocations on every request.

• Memory Profile: Creating new char arrays inside loops causes unnecessary Gen0 GC pressure.
• Instruction Set: SearchValues caches vectorized tables at startup for SIMD register execution.
• Span Boundary: Operating directly on stack-allocated spans avoids managed heap overhead.

Watch out: Always cache the instance statically; recreating it defeats the vectorization gains.

What high-frequency parser are you profiling this week?

DotNet #CSharp #Performance #BackendDevelopment #SoftwareEngineering

SearchValues in .NET 8/9 (.NET & C#)

Maayur Dahake — Thu, 12 Nov 2026 10:14:44 +0000

Day 1/30 — SearchValues in .NET 8/9 (.NET & C#)

Spotted a hot path in a string parser allocating megabytes on Gen0 just checking punctuation marks.

Before:

if (input.Contains(',') || input.Contains(';')) {
    // Triggers internal array allocations
}

After:

private static readonly SearchValues<char> S = SearchValues.Create(",;");
if (input.AsSpan().ContainsAny(S)) {
    // Executes via vectorized CPU instructions
}

Why it matters:
• SearchValues Cache: Pre-computes lookup tables once at startup to avoid repeated overhead.
• SIMD Vectorization: Processes 16 to 64 bytes per CPU cycle depending on hardware vector width.
• Zero Allocations: Operates entirely on ReadOnlySpan without boxing or heap pressure.

Watch out: Creating the SearchValues instance inside a tight loop negates all performance gains.

What is your go-to trick for reducing string parser allocations?

DotNet #CSharp #Performance #BackendDevelopment #SoftwareEngineering