#include <cfloat>
#include <map>
#include <string>
+#include "log.h"
+#include <fenv.h>
+
+#define PARANOID_DIGIT_T float // we could theoretically replace this with a template
+ // but let's not do that...
namespace IPDF
{
+ typedef enum {ADD, SUBTRACT, MULTIPLY, DIVIDE} Optype;
+
+ /** Performs an operation, returning if the result was exact **/
+ // NOTE: DIFFERENT to ParanoidOp (although that wraps to this...)
+ template <class T> bool TrustingOp(T & a, const T & b, Optype op);
+
+ /** Performs an operation _only_ if the result would be exact **/
+ template <class T> bool ParanoidOp(T & a, const T & b, Optype op)
+ {
+ T cpy(a);
+ if (TrustingOp<T>(cpy, b, op))
+ {
+ a = cpy;
+ return true;
+ }
+ 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;
+ }
+
class ParanoidNumber
{
+
public:
- typedef enum {ADD, SUBTRACT, MULTIPLY, DIVIDE} Optype;
-
- ParanoidNumber(float value=0, Optype type = ADD) : m_value(value), m_op(type), m_next(NULL)
+ 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)
{
-
+ Construct();
}
- ParanoidNumber(const ParanoidNumber & cpy) : m_value(cpy.m_value), m_op(cpy.m_op), m_next(NULL)
+ ParanoidNumber(const ParanoidNumber & cpy) : m_value(cpy.m_value), m_op(cpy.m_op), m_next_term(NULL), m_next_factor(NULL)
{
- if (cpy.m_next != NULL)
+ if (cpy.m_next_term != NULL)
+ {
+ m_next_term = new ParanoidNumber(*(cpy.m_next_term));
+ }
+ if (cpy.m_next_factor != NULL)
{
- m_next = new ParanoidNumber(*(cpy.m_next));
+ m_next_factor = new ParanoidNumber(*(cpy.m_next_factor));
}
+ Construct();
}
ParanoidNumber(const ParanoidNumber & cpy, Optype type) : ParanoidNumber(cpy)
}
ParanoidNumber(const char * str);
+ ParanoidNumber(const std::string & str) : ParanoidNumber(str.c_str()) {Construct();}
virtual ~ParanoidNumber()
{
- if (m_next != NULL)
- delete m_next;
+ if (m_next_term != NULL)
+ delete m_next_term;
+ if (m_next_factor != NULL)
+ delete m_next_factor;
+ g_count--;
}
+ inline void Construct() {g_count++;}
+
- double ToDouble() const;
+ 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);}
+
+
+
+
+ double ToDouble() const {return Convert<double>();}
+ float ToFloat() const {return Convert<float>();}
+ digit_t Digit() const {return Convert<digit_t>();}
+
+ bool Floating() const {return (m_next_term == NULL && m_next_factor == NULL);}
+ bool Sunken() const {return !Floating();} // I could not resist...
ParanoidNumber & operator+=(const ParanoidNumber & a);
ParanoidNumber & operator-=(const ParanoidNumber & a);
}
std::string Str() const;
+ static char OpChar(Optype op)
+ {
+ static char opch[] = {'+','-','*','/'};
+ return opch[(int)op];
+ }
+
+ static int64_t Paranoia() {return g_count;}
private:
+ static int64_t g_count;
void Simplify();
- ParanoidNumber * InsertAfter(ParanoidNumber * insert);
- ParanoidNumber * InsertAfter(float value, Optype op);
+ void SimplifyTerms();
+ void SimplifyFactors();
+
- float m_value;
+ digit_t m_value;
Optype m_op;
- ParanoidNumber * m_next;
+ ParanoidNumber * m_next_term;
+ ParanoidNumber * m_next_factor;
+ };
-
-
+template <class T>
+T ParanoidNumber::AddTerms() const
+{
+ T value(0);
+ for (ParanoidNumber * a = m_next_term; a != NULL; a = a->m_next_term)
+ {
+ value += a->Head<T>() * a->MultiplyFactors<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)
+ {
+ if (a->m_op == DIVIDE)
+ value /= (a->Head<T>() + a->AddTerms<T>());
+ else
+ value *= (a->Head<T>() + a->AddTerms<T>());
+ }
+ return value;
+}
+
+
+
+template <class T>
+T ParanoidNumber::Convert() const
+{
+ return Head<T>() * MultiplyFactors<T>() + AddTerms<T>();
+}
- };
}
git.ucc.asn.au / ipdf / code.git / blobdiff
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