05_16_09_runtime_dispatch

Advanced Runtime Dispatch System

Status: ⏸️ NOT STARTED Priority: CRITICAL (Critical Path) Dependencies: TAREA 0-8 (All variant implementations) Estimated Effort: 3-4 weeks

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🎯 Purpose

Runtime dispatch provides the highest-level optimization layer: - Template-based dispatch: Compile-time optimization - Function pointer optimization: Minimize virtual call overhead - JIT compilation: Generate code at runtime - Profile-guided optimization: Learn from usage patterns

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📋 Planned Features

1. Template-Based Dispatch

template<typename VariantType>
class StaticDispatcher {
public:
    bool process(const float* input, float* output, size_t numSamples) {
        // No virtual call overhead
        return variant_.process(input, output, numSamples);
    }

private:
    VariantType variant_;
};

2. Function Pointer Cache

class OptimizedDispatcher : public VariantDispatcher {
public:
    bool process(const float* input, float* output, size_t numSamples) override {
        // Cached function pointer (no virtual lookup)
        return cachedProcessFunc_(input, output, numSamples);
    }

private:
    ProcessFunc cachedProcessFunc_;
    void updateCache() {
        cachedProcessFunc_ = activeVariant_->getProcessFunc();
    }
};

3. JIT Compilation (LLVM)

class JITVariant : public IVariant {
public:
    bool process(const float* input, float* output, size_t numSamples) override {
        // Generate specialized code at runtime
        if (!jitCompiled_) {
            compileForCurrentCPU();
        }
        return jittedFunc_(input, output, numSamples);
    }

private:
    void compileForCurrentCPU();
    ProcessFunc jittedFunc_;
    bool jitCompiled_ = false;
};

4. Profile-Guided Optimization

class AdaptiveDispatcher : public VariantDispatcher {
public:
    void profileAndOptimize() {
        // Analyze usage patterns
        auto stats = collectStats();

        // Optimize hot paths
        if (stats.mostFrequentBufferSize == 512) {
            // Compile specialized 512-sample variant
            optimizeFor512Samples();
        }
    }
};

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📊 Dispatch Overhead Targets

Dispatch Method	Overhead	Flexibility
Virtual Call	~2ns	High
Function Pointer	~1ns	Medium
Template	~0ns	Low (compile-time)
JIT	~0ns (after compile)	High

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🛠️ Implementation Plan

Week 1-2: Template Dispatch - Template-based static dispatch - Compile-time variant selection - Zero-overhead abstractions

Week 3: Function Pointer Optimization - Cached function pointers - Inline dispatch - Branch prediction hints

Week 4: JIT (Experimental) - LLVM integration research - Simple JIT proof-of-concept - Performance evaluation

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Status: ⏸️ Requires all variants complete Priority: CRITICAL - Final optimization layer