JIT

raw.cpp

#include <windows.h>
#include <stdio.h>
#include <string.h>

unsigned char testf[] = {
    0x8b, 0x44, 0x24, 0x04, // mov eax, [esp+4]
    0x03, 0x44, 0x24, 0x08, // add eax, [esp+8]
    0xc3 // ret
};

int main() {
    auto page = VirtualAlloc(nullptr, sizeof(testf), MEM_COMMIT, PAGE_EXECUTE_READWRITE);
    memcpy(page, testf, sizeof(testf));
    auto test = reinterpret_cast<int(*)(int, int)>(page);
    printf("test(2, 3): %d\n", test(2, 3));
    VirtualFree(page, 0, MEM_RELEASE);
}

xbyak.cpp

#include <stdio.h>
#include "xbyak/xbyak.h"

struct TestFunc : public Xbyak::CodeGenerator {
    TestFunc() {
        mov(eax, ptr[esp+4]);
        add(eax, ptr[esp+8]);
        ret();
    }
};

int main() {
    TestFunc testf;
    auto test = reinterpret_cast<int(*)(int, int)>(
        const_cast<Xbyak::uint8 *>(testf.getCode()));
    printf("test(2, 3): %d\n", test(2, 3));
}