Optimize bit reverse and unary minus oparations

Author: devatrun

include/slimcpplib/long_math.h

@@ -119,6 +119,13 @@ using half_t = typename half_type<type_t>::type;
 // standalone routines
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
+// make array from specified array
+
+template<typename type_t, uint_t size, typename func_t>
+constexpr std::array<type_t, size> make_array(const std::array<type_t, size>& arr, const func_t& func);
+template<typename type_t, uint_t size, typename func_t, uint_t... idx>
+constexpr std::array<type_t, size> make_array(const std::array<type_t, size>& arr, const func_t& func, std::integer_sequence<uint_t, idx...>);
+
 // extract low half of unsigned integer
 
 template<typename type_t, std::enable_if_t<is_unsigned_v<type_t>, int> = 0>
@@ -183,6 +190,24 @@ constexpr type_t divr2(type_t value1_hi, type_t value1_lo, type_t value2, std::o
 // standalone routines
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
+template<typename type_t, uint_t size, typename func_t>
+constexpr std::array<type_t, size> make_array(const std::array<type_t, size>& arr, const func_t& func)
+{
+    return make_array(arr, func, std::make_integer_sequence<uint_t, size>{});
+}
+
+
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+template<typename type_t, uint_t size, typename func_t, uint_t... idx>
+constexpr std::array<type_t, size> make_array(const std::array<type_t, size>& arr, const func_t& func, std::integer_sequence<uint_t, idx...>)
+{
+    return std::array<type_t, size>{ (func(idx, arr[idx]))... };
+}
+
+
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
 template<typename type_t, std::enable_if_t<is_unsigned_v<type_t>, int>>
 constexpr type_t half_lo(type_t value) noexcept
 {

include/slimcpplib/long_uint.h

@@ -336,14 +336,9 @@ constexpr bool long_uint_t<native_t, size>::operator>=(const long_uint_t& that)
 template<typename native_t, uint_t size>
 constexpr long_uint_t<native_t, size> long_uint_t<native_t, size>::operator~() const noexcept
 {
-    long_uint_t result;
-
-    result.digits[0] = ~digits[0];
-
-    for (uint_t n = 1; n < std::size(digits); ++n)
-        result.digits[n] = ~digits[n];
-
-    return result;
+    return make_array(digits, [](uint_t /*idx*/, native_t value) {
+        return ~value;
+    });
 }
 
 
@@ -579,17 +574,11 @@ constexpr long_uint_t<native_t, size> long_uint_t<native_t, size>::operator--(in
 template<typename native_t, uint_t size>
 constexpr long_uint_t<native_t, size> long_uint_t<native_t, size>::operator-() const noexcept
 {
-    long_uint_t negative = *this;
-    
     bool borrow = true;
 
-    for (uint_t n = 0; n < std::size(negative.digits); ++n)
-        negative.digits[n] = subb<native_t>(negative.digits[n], 0, borrow);
-
-    for (uint_t n = 0; n < std::size(negative.digits); ++n)
-        negative.digits[n] = ~negative.digits[n];
-
-    return negative;
+    return make_array(digits, [&borrow](uint_t /*idx*/, native_t value) {
+        return ~subb<native_t>(value, 0, borrow);
+    });
 }