#include <string>
#include "log.h"
#include <fenv.h>
+#include <vector>
+#include <cmath>
+#include <cassert> // it's going to be ok
+#include <set>
-#define PARANOID_DIGIT_T int8_t // we could theoretically replace this with a template
+#define PARANOID_DIGIT_T double // we could theoretically replace this with a template
// but let's not do that...
+
+
+//#define PARANOID_CACHE_RESULTS
+
+//#define PARANOID_USE_ARENA
+#define PARANOID_SIZE_LIMIT 4
+
+
+// Define to compare all ops against double ops and check within epsilon
+//#define PARANOID_COMPARE_EPSILON 1e-6
+#ifdef PARANOID_COMPARE_EPSILON
+#define CompareForSanity(...) ParanoidNumber::CompareForSanityEx(__func__, __FILE__, __LINE__, __VA_ARGS__)
+#endif
namespace IPDF
{
- typedef enum {ADD, SUBTRACT, MULTIPLY, DIVIDE} Optype;
+ typedef enum {ADD, SUBTRACT, MULTIPLY, DIVIDE, NOP} Optype;
+ inline Optype InverseOp(Optype op)
+ {
+ return ((op == ADD) ? SUBTRACT :
+ (op == SUBTRACT) ? ADD :
+ (op == MULTIPLY) ? DIVIDE :
+ (op == DIVIDE) ? MULTIPLY :
+ (op == NOP) ? NOP : NOP);
+ }
+
+
+ inline char OpChar(int op)
+ {
+ static char opch[] = {'+','-','*','/'};
+ return (op < NOP && op >= 0) ? opch[op] : '?';
+ }
+
/** Performs an operation, returning if the result was exact **/
// NOTE: DIFFERENT to ParanoidOp (although that wraps to this...)
}
return false;
}
-
-
template <> bool TrustingOp<float>(float & a, const float & b, Optype op);
template <> bool TrustingOp<double>(double & a, const double & b, Optype op);
template <> bool TrustingOp<int8_t>(int8_t & a, const int8_t & b, Optype op);
- // Attempt to comine two terms: a*b + c*d or a/b + c/d
- template <class T> bool CombineTerms(T & aa, Optype aop, T & bb, T & cc, Optype cop, T & dd)
- {
- T a(aa); T b(bb); T c(cc); T d(dd);
- if (aop == MULTIPLY && cop == MULTIPLY) // a*b + c*d
- {
- if ((ParanoidOp<T>(c, b, DIVIDE) || ParanoidOp(d, b, DIVIDE))
- && TrustingOp<T>(c, d, MULTIPLY) && TrustingOp<T>(a,c,ADD)
- && TrustingOp<T>(a, b, MULTIPLY)) // (a + (cd)/b) * b
- {
- aa = a;
- bb = 1;
- cc = 1;
- dd = 1;
- return true;
- }
- if ((ParanoidOp<T>(a, d, DIVIDE) || ParanoidOp(b, d, DIVIDE))
- && TrustingOp<T>(a, b, MULTIPLY) && TrustingOp<T>(a,c,ADD)
- && TrustingOp<T>(a, d, MULTIPLY)) // ((ab)/d + c)*d
- {
- aa = a;
- bb = 1;
- cc = 1;
- dd = 1;
- return true;
- }
- return false;
- }
- else if (aop == DIVIDE && cop == DIVIDE)
- {
- if (TrustingOp<T>(a, d, MULTIPLY) && TrustingOp<T>(c, b, MULTIPLY)
- && TrustingOp<T>(a, c, ADD) && TrustingOp<T>(b, d, MULTIPLY))
- {
- cc = 1;
- dd = 1;
- if (ParanoidOp<T>(a, b, DIVIDE))
- {
- aa = a;
- bb = 1;
- return true;
- }
- aa = a;
- bb = b;
- return true;
- }
- return false;
- }
- return false;
- }
-
+ /**
+ * A ParanoidNumber
+ * Idea: Perform regular floating point arithmetic but rearrange operations to only ever use exact results
+ * Memory Usage: O(all of it)
+ * CPU Usage: O(all of it)
+ * Accuracy: O(gives better result for 0.3+0.3+0.3, gives same result for everything else, or worse result)
+ *
+ * The ParanoidNumber basically stores 4 linked lists which can be split into two "dimensions"
+ * 1. Terms to ADD and terms to SUBTRACT
+ * 2. Factors to MULTIPLY and DIVIDE
+ * Because ADD and SUBTRACT are inverse operations and MULTIPLY and DIVIDE are inverse operations
+ * See paranoidnumber.cpp and the ParanoidNumber::Operation function
+ */
class ParanoidNumber
{
public:
typedef PARANOID_DIGIT_T digit_t;
- ParanoidNumber(digit_t value=0, Optype type = ADD) : m_value(value), m_op(type), m_next_term(NULL), m_next_factor(NULL)
+ ParanoidNumber(PARANOID_DIGIT_T value=0) : m_value(value), m_next()
{
- Construct();
+ #ifdef PARANOID_SIZE_LIMIT
+ m_size = 1;
+ #endif
+ #ifdef PARANOID_CACHE_RESULTS
+ m_cached_result = value;
+ m_cache_valid = true;
+ #endif
}
- ParanoidNumber(const ParanoidNumber & cpy) : m_value(cpy.m_value), m_op(cpy.m_op), m_next_term(NULL), m_next_factor(NULL)
+ ParanoidNumber(const ParanoidNumber & cpy) : m_value(cpy.m_value), m_next()
{
- if (cpy.m_next_term != NULL)
+
+ #ifdef PARANOID_SIZE_LIMIT
+ m_size = cpy.m_size;
+ #endif
+ #ifdef PARANOID_CACHE_RESULTS
+ m_cached_result = cpy.m_cached_result;
+ m_cache_valid = cpy.m_cache_valid;
+ #endif
+ for (int i = 0; i < NOP; ++i)
{
- m_next_term = new ParanoidNumber(*(cpy.m_next_term));
+ for (auto next : cpy.m_next[i])
+ {
+ if (next != NULL) // why would this ever be null
+ m_next[i].push_back(new ParanoidNumber(*next)); // famous last words...
+ }
}
- if (cpy.m_next_factor != NULL)
- {
- m_next_factor = new ParanoidNumber(*(cpy.m_next_factor));
- }
- Construct();
+ #ifdef PARANOID_COMPARE_EPSILON
+ CompareForSanity(cpy.Digit(), cpy.Digit());
+ #endif
+ //assert(SanityCheck());
}
- ParanoidNumber(const ParanoidNumber & cpy, Optype type) : ParanoidNumber(cpy)
- {
- m_op = type;
- }
+ //ParanoidNumber(const char * str);
+ ParanoidNumber(const std::string & str);// : ParanoidNumber(str.c_str()) {}
- ParanoidNumber(const char * str);
- ParanoidNumber(const std::string & str) : ParanoidNumber(str.c_str()) {Construct();}
+ virtual ~ParanoidNumber();
+
- virtual ~ParanoidNumber()
+ bool SanityCheck(std::set<ParanoidNumber*> & visited) const;
+ bool SanityCheck() const
{
- if (m_next_term != NULL)
- delete m_next_term;
- if (m_next_factor != NULL)
- delete m_next_factor;
- g_count--;
+ std::set<ParanoidNumber*> s;
+ return SanityCheck(s);
}
- inline void Construct() {g_count++;}
-
-
template <class T> T Convert() const;
- template <class T> T AddTerms() const;
- template <class T> T MultiplyFactors() const;
- template <class T> T Head() const {return (m_op == SUBTRACT) ? T(-m_value) : T(m_value);}
-
-
+ digit_t GetFactors() const;
+ digit_t GetTerms() const;
+
+ // This function is declared const purely to trick the compiler.
+ // It is not actually const, and therefore, none of the other functions that call it are const either.
+ digit_t Digit() const;
+ // Like this one. It isn't const.
+ double ToDouble() const {return (double)Digit();}
- double ToDouble() const {return Convert<double>();}
- float ToFloat() const {return Convert<float>();}
- digit_t Digit() const {return Convert<digit_t>();}
+ operator double() const {return ToDouble();}
- bool Floating() const {return (m_next_term == NULL && m_next_factor == NULL);}
+ // This one is probably const.
+ bool Floating() const
+ {
+ return NoFactors() && NoTerms();
+ }
bool Sunken() const {return !Floating();} // I could not resist...
+ bool NoFactors() const {return (m_next[MULTIPLY].size() == 0 && m_next[DIVIDE].size() == 0);}
+ bool NoTerms() const {return (m_next[ADD].size() == 0 && m_next[SUBTRACT].size() == 0);}
+
+
ParanoidNumber & operator+=(const ParanoidNumber & a);
ParanoidNumber & operator-=(const ParanoidNumber & a);
ParanoidNumber & operator*=(const ParanoidNumber & a);
ParanoidNumber & operator/=(const ParanoidNumber & a);
ParanoidNumber & operator=(const ParanoidNumber & a);
+ ParanoidNumber & operator+=(const digit_t & a);
+ ParanoidNumber & operator-=(const digit_t & a);
+ ParanoidNumber & operator*=(const digit_t & a);
+ ParanoidNumber & operator/=(const digit_t & a);
+ ParanoidNumber & operator=(const digit_t & a);
+
+
+ ParanoidNumber * OperationTerm(ParanoidNumber * b, Optype op, ParanoidNumber ** merge_point = NULL, Optype * mop = NULL);
+ ParanoidNumber * OperationFactor(ParanoidNumber * b, Optype op, ParanoidNumber ** merge_point = NULL, Optype * mop = NULL);
+ ParanoidNumber * TrivialOp(ParanoidNumber * b, Optype op);
+ ParanoidNumber * Operation(ParanoidNumber * b, Optype op, ParanoidNumber ** merge_point = NULL, Optype * mop = NULL);
+ bool Simplify(Optype op);
+ bool FullSimplify();
+
+
+ // None of these are actually const
+ bool operator<(const ParanoidNumber & a) const {return Digit() < a.Digit();}
+ bool operator<=(const ParanoidNumber & a) const {return Digit() <= a.Digit();}
+ bool operator>(const ParanoidNumber & a) const {return Digit() > a.Digit();}
+ bool operator>=(const ParanoidNumber & a) const {return Digit() >= a.Digit();}
+ bool operator==(const ParanoidNumber & a) const {return Digit() == a.Digit();}
+ bool operator!=(const ParanoidNumber & a) const {return Digit() != a.Digit();}
+
+ ParanoidNumber operator-() const
+ {
+ ParanoidNumber neg(*this);
+ neg.Negate();
+ #ifdef PARANOID_COMPARE_EPSILON
+ neg.CompareForSanity(-Digit(), Digit());
+ #endif
+ return neg;
+ }
+
+ void Negate();
- bool operator<(const ParanoidNumber & a) const {return ToDouble() < a.ToDouble();}
- bool operator<=(const ParanoidNumber & a) const {return this->operator<(a) || this->operator==(a);}
- bool operator>(const ParanoidNumber & a) const {return !(this->operator<=(a));}
- bool operator>=(const ParanoidNumber & a) const {return !(this->operator<(a));}
- bool operator==(const ParanoidNumber & a) const {return ToDouble() == a.ToDouble();}
- bool operator!=(const ParanoidNumber & a) const {return !(this->operator==(a));}
ParanoidNumber operator+(const ParanoidNumber & a) const
{
ParanoidNumber result(*this);
result += a;
+ #ifdef PARANOID_COMPARE_EPSILON
+ result.CompareForSanity(Digit()+a.Digit(), a.Digit());
+ #endif
return result;
}
ParanoidNumber operator-(const ParanoidNumber & a) const
{
ParanoidNumber result(*this);
result -= a;
+ #ifdef PARANOID_COMPARE_EPSILON
+ result.CompareForSanity(Digit()-a.Digit(), a.Digit());
+ #endif
return result;
}
ParanoidNumber operator*(const ParanoidNumber & a) const
{
ParanoidNumber result(*this);
result *= a;
+ #ifdef PARANOID_COMPARE_EPSILON
+ result.CompareForSanity(Digit()*a.Digit(), a.Digit());
+ #endif
return result;
}
ParanoidNumber operator/(const ParanoidNumber & a) const
{
ParanoidNumber result(*this);
result /= a;
+ #ifdef PARANOID_COMPARE_EPSILON
+ result.CompareForSanity(Digit()/a.Digit(), a.Digit());
+ #endif
return result;
}
std::string Str() const;
- static char OpChar(Optype op)
+
+ #ifdef PARANOID_COMPARE_EPSILON
+ inline void CompareForSanityEx(const char * func, const char * file, int line, const digit_t & compare, const digit_t & arg, const digit_t & eps = PARANOID_COMPARE_EPSILON)
{
- static char opch[] = {'+','-','*','/'};
- return opch[(int)op];
+ if (!SanityCheck())
+ Fatal("This is insane!");
+ if (fabs(Digit() - compare) > eps)
+ {
+ Error("Called via %s(%lf) (%s:%d)", func, arg, file, line);
+ Error("Failed: %s", Str().c_str());
+ Fatal("This: %.30lf vs Expected: %.30lf", Digit(), compare);
+ }
}
-
- static int64_t Paranoia() {return g_count;}
+ #endif
+
+ std::string PStr() const;
+
+ #ifdef PARANOID_USE_ARENA
+ void * operator new(size_t byes);
+ void operator delete(void * p);
+ #endif //PARANOID_USE_ARENA
private:
- static int64_t g_count;
+
void Simplify();
void SimplifyTerms();
void SimplifyFactors();
+ digit_t m_value;
+ #ifdef PARANOID_CACHE_RESULTS
+ digit_t m_cached_result;
+ bool m_cache_valid;
+ #endif
+ std::vector<ParanoidNumber*> m_next[4];
+ #ifdef PARANOID_SIZE_LIMIT
+ int64_t m_size;
+ #endif //PARANOID_SIZE_LIMIT
+
+ #ifdef PARANOID_USE_ARENA
+ class Arena
+ {
+ public:
+ Arena(int64_t block_size = 10000);
+ ~Arena();
+
+ void * allocate(size_t bytes);
+ void deallocate(void * p);
+
+ private:
+ struct Block
+ {
+ void * memory;
+ int64_t used;
+ };
+
+ std::vector<Block> m_blocks;
+ int64_t m_block_size;
+
+ void * m_spare;
+
+ };
- digit_t m_value;
- Optype m_op;
- ParanoidNumber * m_next_term;
- ParanoidNumber * m_next_factor;
+ static Arena g_arena;
+ #endif //PARANOID_USE_ARENA
+
+
};
+
+
+
template <class T>
-T ParanoidNumber::AddTerms() const
+T ParanoidNumber::Convert() const
{
- T value(0);
- for (ParanoidNumber * a = m_next_term; a != NULL; a = a->m_next_term)
+ #ifdef PARANOID_CACHE_RESULTS
+ if (m_cache_valid)
+ return (T)m_cached_result;
+ #endif
+ T value(m_value);
+ for (auto mul : m_next[MULTIPLY])
{
- value += a->Head<T>() * a->MultiplyFactors<T>();
+ value *= mul->Convert<T>();
}
- return value;
-}
-
-template <class T>
-T ParanoidNumber::MultiplyFactors() const
-{
- T value(1);
- for (ParanoidNumber * a = m_next_factor; a != NULL; a = a->m_next_factor)
+ for (auto div : m_next[DIVIDE])
{
- if (a->m_op == DIVIDE)
- value /= (a->Head<T>() + a->AddTerms<T>());
- else
- value *= (a->Head<T>() + a->AddTerms<T>());
+ value /= div->Convert<T>();
}
+ for (auto add : m_next[ADD])
+ value += add->Convert<T>();
+ for (auto sub : m_next[SUBTRACT])
+ value -= sub->Convert<T>();
return value;
}
-template <class T>
-T ParanoidNumber::Convert() const
-{
- return Head<T>() * MultiplyFactors<T>() + AddTerms<T>();
-}
-
}