online compiler and debugger for c/c++

/****************************************************************************** Welcome to GDB Online. GDB online is an online compiler and debugger tool for C, C++, Python, PHP, Ruby, C#, OCaml, VB, Perl, Swift, Prolog, Javascript, Pascal, COBOL, HTML, CSS, JS Code, Compile, Run and Debug online from anywhere in world. *******************************************************************************/ #include <stdint.h> #include <iostream> #include <sstream> using namespace std; template <class T, int width = sizeof(T) << 3> struct stBitPattern { static inline constexpr T res(T x) { constexpr int hw = width >> 1; x = stBitPattern<T, hw>::res(x); x += x << hw; return x; } }; template <class T> struct stBitPattern<T, 8> { static inline constexpr T res(T x) { return x; } }; class csPop { private: template <class T> static inline constexpr T _pop8(T x) { constexpr T m1 = stBitPattern<T>::res(0x55); //binary: 0101... constexpr T m2 = stBitPattern<T>::res(0x33); //binary: 00110011.. constexpr T m4 = stBitPattern<T>::res(0x0f); //binary: 4 zeros, 4 ones ... x -= (x >> 1) & m1; //put count of each 2 bits into those 2 bits x = (x & m2) + ((x >> 2) & m2); //put count of each 4 bits into those 4 bits x = (x + (x >> 4)) & m4; //put count of each 8 bits into those 8 bits return x; } template <class T, int width = sizeof(T) << 3> struct _pop { static inline constexpr T res(T x) { const int hw = width >> 1; x = _pop<T, hw>::res(x); x += x >> hw; return x; } }; template <class T> struct _pop<T, 8> { static inline constexpr T res(T x) { x = _pop8(x); return x; } }; template<class T> static inline constexpr bool _chkIfTAvail(T *p, T *pend); public: template <class T> static inline constexpr int pop(T x) { x = _pop<T>::res(x); return (int)(x & 0x7f); } template <class T> static int pop(T *p, size_t sz); }; template<class T> constexpr bool csPop::_chkIfTAvail(T *p, T *pend) { return ((uint8_t*)pend-(uint8_t*)p) >= sizeof(T); } template <class T> int csPop::pop(T *p, size_t sz) { int res = 0; T *pend = (T*)((uint8_t*)p + sz); if (sz >= sizeof(T)) { int t = (size_t)p & (sizeof(T) - 1); sz -= t; if (t >= sizeof(uint8_t)) { res += pop(*(uint8_t*)p); p = (T*)((uint8_t*)p + 1); t -= sizeof(uint8_t); } if (t >= sizeof(uint16_t)) { res += pop(*(uint16_t*)p); p = (T*)((uint16_t*)p + 1); t -= sizeof(uint16_t); } if (t >= sizeof(uint32_t)) { res += pop(*(uint32_t*)p); p = (T*)((uint32_t*)p + 1); t -= sizeof(uint32_t); } if (t >= sizeof(uint64_t)) { res += pop(*(uint64_t*)p); p = (T*)((uint64_t*)p + 1); t -= sizeof(uint64_t); } if (_chkIfTAvail(p, pend)) { sz -= sizeof(T); res += pop(*p++); for(; _chkIfTAvail(p, pend); p++, sz-= sizeof(T)) { res += pop(*p); } } } // if (sz >= sizeof(T)) if (sz >= sizeof(uint64_t)) { res += pop(*(uint64_t*)p); p = (T*)((uint64_t*)p + 1); sz -= sizeof(uint64_t); } if (sz >= sizeof(uint32_t)) { res += pop(*(uint32_t*)p); p = (T*)((uint32_t*)p + 1); sz -= sizeof(uint32_t); } if (sz >= sizeof(uint16_t)) { res += pop(*(uint16_t*)p); p = (T*)((uint16_t*)p + 1); sz -= sizeof(uint16_t); } if (sz >= sizeof(uint8_t)) { res += pop(*(uint8_t*)p); p = (T*)((uint8_t*)p + 1); sz -= sizeof(uint8_t); } return res; } int main() { uint32_t x = 16777215; cout << "pop(" << x << ") = " << csPop::pop(x) << endl; uint32_t a[] = {x, x, x, x, 15}; uint32_t *p_end = a + sizeof(a)/sizeof(a[0]) - 1; uint32_t *p = a; stringstream ss; for(; p_end - p; p++) { ss << to_string(*p) << ", "; } ss << to_string(*p); cout << "pop({" << ss.str() << "}) = " << csPop::pop(a, sizeof(a)) << endl; return 0; }