Test Types Instead Of Dispatch Profile Code

(From TestTypesInsteadOfDispatch)

Before we jump to any conclusions about the results of this code, we need Sunir to come verify that it is a fair test.

It isn't. I'll have to carve out some time to demonstrate what I mean, but that isn't likely to happen while I have a deadline next week ;) --ss

---

In dispatch.cpp:

#include
#include
class Timeable {
public:
clock_t run() {
clock_t start = ::clock();
for (int i = 0; i < 5000000; i++)
reallyRun(); // (Template pattern)
clock_t end = ::clock();
return end - start;
}
virtual void reallyRun() = 0;
};
class NormalDispatchTimer: public Timeable {
public:
class NormalClass {
public:
virtual void run() = 0;
};
// It would probably work with just one derived class, but just in case...
class FirstNormalClass: public NormalClass {
public:
void run() { /* */ }
};
class SecondNormalClass: public NormalClass {
public:
void run() { /* */ }
};
void reallyRun() {
first.run();
second.run();
}
private:
FirstNormalClass first;
SecondNormalClass second;
};
class ManualDispatchTimer: public Timeable {
public:
void reallyRun() {
runOn(&first);
runOn(&second);
}
class ManualClass {
public:
enum TYPE {
FirstType,
SecondType,
};
unsigned char type;
};
class FirstManualClass: public ManualClass {
public:
FirstManualClass(): type(FirstType) { }
unsigned char type;
int someData;
};
class SecondManualClass: public ManualClass {
public:
SecondManualClass(): type(SecondType) { }
unsigned char type;
int someOtherData;
};
inline void runOn(ManualClass* mcp) {
int x;
if (ManualClass::FirstType == mcp->type)
x = ((FirstManualClass*)mcp)->someData;
else if (ManualClass::SecondType == mcp->type)
x = ((SecondManualClass*)mcp)->someOtherData;
}
private:
FirstManualClass first;
SecondManualClass second;
};
int main() {
std::cout
<< "Normal: "
<< NormalDispatchTimer().run()
<< std::endl
<< "Manual: "
<< ManualDispatchTimer().run()
<< std::endl;
}


---

In the Makefile:

default: plain optimized
./plain
./optimized
plain: *.cpp
g++ $< -o plain
optimized: *.cpp
g++ -O3 $< -o optimized