Бобрик Вячеслав ФТ-404

.gitignore

@@ -2,3 +2,4 @@ build/
 .cache/
 compile_commands.json
 crash-*
+.vs

real48.cpp

@@ -0,0 +1,231 @@
+#include <cstdint>
+#include <stdexcept>
+#include <cstring>
+#include "real48.hpp"
+
+namespace math
+{
+Real48::Real48(const float number)
+{
+    uint32_t bits = 0;
+    std::memcpy(&bits, &number, sizeof(bits));
+
+    const uint64_t sFloat = (bits >> 31) & 1u;
+    const uint64_t eFloat = (bits >> 23) & 0xFFu;
+    const uint64_t fFloat = bits & ((1u << 23) - 1u);
+
+    if (eFloat == 0) {
+        std::memset(real48, 0, 6);
+        return;
+    }
+
+    if (eFloat == 0xFF) {
+        throw std::overflow_error("float inf/nan");
+    }
+
+    const uint64_t e_ = eFloat + 2;
+    if (e_ > 255) {
+        throw std::overflow_error("float exponent out of range");
+    }
+
+    const uint64_t f_ = (uint64_t(fFloat) << 16) & ((1ULL << 39) - 1);
+
+    const uint64_t v48 = (sFloat << 47) | (f_ << 8) | (e_ & 0xFFULL);
+
+    real48[0] = (v48 >> 40) & 0xFF;
+    real48[1] = (v48 >> 32) & 0xFF;
+    real48[2] = (v48 >> 24) & 0xFF;
+    real48[3] = (v48 >> 16) & 0xFF;
+    real48[4] = (v48 >>  8) & 0xFF;
+    real48[5] = (v48 >>  0) & 0xFF;
+}
+
+Real48::Real48(const double number)
+{
+    uint64_t bits = 0;
+    std::memcpy(&bits, &number, sizeof(bits));
+
+    const uint64_t sDouble = (bits >> 63) & 1ULL;
+    const uint64_t eDouble = (bits >> 52) & 0x7FFULL;
+    const uint64_t fDouble = bits & ((1ULL << 52) - 1ULL);
+
+    if (eDouble == 0) {
+        std::memset(real48, 0, 6);
+        return;
+    }
+
+    if (eDouble == 0x7FF) {
+        throw std::overflow_error("double inf/nan");
+    }
+
+    const uint64_t e_ = eDouble - 894;
+
+    if (e_ < 1 || e_ > 255) {
+        throw std::overflow_error("double exponent out of range");
+    }
+
+    const uint64_t f_ = (fDouble >> 13) & ((1ULL << 39) - 1ULL);
+
+    const uint64_t v48 = (sDouble << 47) | (f_ << 8) | (e_ & 0xFFULL);
+
+    real48[0] = (v48 >> 40) & 0xFF;
+    real48[1] = (v48 >> 32) & 0xFF;
+    real48[2] = (v48 >> 24) & 0xFF;
+    real48[3] = (v48 >> 16) & 0xFF;
+    real48[4] = (v48 >>  8) & 0xFF;
+    real48[5] = (v48 >>  0) & 0xFF;
+}
+
+// conversion operators
+Real48::operator float() const
+{
+    auto s_ = s();
+    auto e_ = e();
+    auto f_ = f();
+
+    if (e_ == 0)
+    {
+        return 0;
+    }
+
+    if (e_ <= 1)
+    {
+        throw std::runtime_error("e_ <= 1");
+    }
+
+    uint64_t result = 0;
+    result |= (s_ << 31);
+    result |= ((e_ - 2) << 23);
+    result |= (f_ >> 16);
+
+    float resultFloat;
+    std::memcpy(&resultFloat, &result, sizeof(float));
+    return resultFloat;
+}
+
+Real48::operator double() const noexcept
+{
+    auto s_ = s();
+    auto e_ = e();
+    auto f_ = f();
+
+    if (e_ == 0)
+    {
+        return 0;
+    }
+
+    uint64_t result = 0;
+    result |= (uint64_t(s_) << 63);
+    result |= ((uint64_t(e_) + 894) << 52);
+    result |= (f_ << 13);
+
+    double resultDouble;
+    std::memcpy(&resultDouble, &result, sizeof(double));
+    return resultDouble;
+}
+
+// assignment operators
+Real48& Real48::operator+=(const Real48& b)
+{
+    auto doubleResult = static_cast<double>(*this) + static_cast<double>(b);
+    *this = Real48(doubleResult);
+    return *this;
+}
+
+Real48& Real48::operator-=(const Real48& b)
+{
+    auto doubleResult = static_cast<double>(*this) - static_cast<double>(b);
+    *this = Real48(doubleResult);
+    return *this;
+}
+
+Real48& Real48::operator*=(const Real48& b)
+{
+    auto doubleResult = static_cast<double>(*this) * static_cast<double>(b);
+    *this = Real48(doubleResult);
+    return *this;
+}
+
+Real48& Real48::operator/=(const Real48& b)
+{
+    auto doubleResult = static_cast<double>(*this) / static_cast<double>(b);
+    *this = Real48(doubleResult);
+    return *this;
+}
+
+// arithmetic operators
+Real48 Real48::operator+() const noexcept
+{
+    return *this;
+}
+
+Real48 Real48::operator-() const noexcept
+{
+    Real48 result{*this};
+    result.real48[0] ^= 0x80;
+    return result;
+}
+
+Real48 Real48::operator+(const Real48& o) const
+{
+    auto doubleResult = static_cast<double>(*this) + static_cast<double>(o);
+    return Real48(doubleResult);
+}
+
+Real48 Real48::operator-(const Real48& o) const
+{
+    auto doubleResult = static_cast<double>(*this) - static_cast<double>(o);
+    return Real48(doubleResult);
+}
+
+Real48 Real48::operator*(const Real48& o) const
+{
+    auto doubleResult = static_cast<double>(*this) * static_cast<double>(o);
+    return Real48(doubleResult);
+}
+
+Real48 Real48::operator/(const Real48& o) const
+{
+    auto doubleResult = static_cast<double>(*this) / static_cast<double>(o);
+    return Real48(doubleResult);
+}
+
+// comparison operators
+bool Real48::operator>(const Real48& o) const noexcept
+{
+    return (static_cast<double>(*this) > static_cast<double>(o));
+}
+
+bool Real48::operator<(const Real48& o) const noexcept
+{
+    return (static_cast<double>(*this) < static_cast<double>(o));
+}
+
+Real48::Class Real48::Classify() const noexcept
+{
+    if (e() == 0)
+    {
+        return Class::ZERO;
+    }
+    return Class::NORMAL;
+}
+
+bool Real48::s() const
+    {
+        return (real48[0] >> 7) & 1;
+    }
+
+    uint8_t Real48::e() const
+    {
+        return static_cast<uint8_t>(real48[5]);
+    }
+
+    uint64_t Real48::f() const
+    {
+        uint64_t f_ = 0;
+        for (int i = 0; i < 6; ++i)
+            f_ = (f_ << 8) | real48[i];
+
+        return (f_ >> 8) & ((1ULL << 39) - 1);
+    }
+} // namespace math

real48.hpp

@@ -1,13 +1,18 @@
+#pragma once
+#include <cstdint>
+#include <cstring>
+#include <stdexcept>
+
 namespace math
 {
 
 class Real48
 {
 public:
     // constructors
-    constexpr Real48(); // TODO: add definition
-    Real48(const float number);
-    Real48(const double number);
+    constexpr Real48(): real48{} {};
+    explicit Real48(const float number);
+    explicit Real48(const double number);
     constexpr Real48(const Real48& o) = default;
 
     // conversion operators
@@ -42,12 +47,40 @@ class Real48
     Class Classify() const noexcept;
 
     // limits
-    consteval static Real48 min();     // TODO: add definition
-    consteval static Real48 max();     // TODO: add definition
-    consteval static Real48 epsilon(); // TODO: add definition
+    consteval static Real48 min()
+    {
+        Real48 m{};
+        m.real48[5] = 1;
+        return m;
+    }
+
+    consteval static Real48 max()
+    {
+        Real48 m{};
+        m.real48[0] = 0x7F;
+        m.real48[1] = 0xFF;
+        m.real48[2] = 0xFF;
+        m.real48[3] = 0xFF;
+        m.real48[4] = 0xFF;
+        m.real48[5] = 0xFF;
+        return m;
+    }
+
+    consteval static Real48 epsilon()
+    {
+        Real48 eps;
+        eps.real48[5] = 90;
+        return eps;
+    }
 
 private:
-    // TODO: add members
+    unsigned char real48[6];
+
+    bool s() const;
+
+    uint8_t e() const;
+
+    uint64_t f() const;
 };
 
 } // namespace math