Refactor name and remove old 128 bit implementation

cppalliance · Jul 2, 2024 · 50393e8 · 50393e8
1 parent 76dafa5
commit 50393e8
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Showing 3 changed files with 7 additions and 79 deletions.
diff --git a/include/boost/decimal/decimal128.hpp b/include/boost/decimal/decimal128.hpp
@@ -1602,7 +1602,7 @@ constexpr auto operator-(decimal128 lhs, decimal128 rhs) noexcept -> decimal128
     auto exp_rhs {rhs.biased_exponent()};
     detail::normalize<decimal128>(sig_rhs, exp_rhs);
 
-    return detail::new_d128_sub_impl<decimal128>(
+    return detail::d128_sub_impl<decimal128>(
             sig_lhs, exp_lhs, lhs.isneg(),
             sig_rhs, exp_rhs, rhs.isneg(),
             abs(lhs) > abs(rhs));
@@ -1631,7 +1631,7 @@ constexpr auto operator-(decimal128 lhs, Integer rhs) noexcept
     exp_type exp_rhs {0};
     detail::normalize<decimal128>(sig_rhs, exp_rhs);
 
-    return detail::new_d128_sub_impl<decimal128>(
+    return detail::d128_sub_impl<decimal128>(
             sig_lhs, exp_lhs, lhs.isneg(),
             sig_rhs, exp_rhs, (rhs < 0),
             abs_lhs_bigger);
@@ -1660,7 +1660,7 @@ constexpr auto operator-(Integer lhs, decimal128 rhs) noexcept
     auto exp_rhs {rhs.biased_exponent()};
     detail::normalize<decimal128>(sig_rhs, exp_rhs);
 
-    return detail::new_d128_sub_impl<decimal128>(
+    return detail::d128_sub_impl<decimal128>(
             sig_lhs, exp_lhs, (lhs < 0),
             sig_rhs, exp_rhs, rhs.isneg(),
             abs_lhs_bigger);

diff --git a/include/boost/decimal/decimal128_fast.hpp b/include/boost/decimal/decimal128_fast.hpp
@@ -826,7 +826,7 @@ constexpr auto operator-(decimal128_fast lhs, decimal128_fast rhs) noexcept -> d
     }
     #endif
 
-    return detail::new_d128_sub_impl<decimal128_fast>(
+    return detail::d128_sub_impl<decimal128_fast>(
             lhs.significand_, lhs.biased_exponent(), lhs.sign_,
             rhs.significand_, rhs.biased_exponent(), rhs.sign_,
             abs(lhs) > abs(rhs));
@@ -851,7 +851,7 @@ constexpr auto operator-(decimal128_fast lhs, Integer rhs) noexcept
     exp_type exp_rhs {0};
     detail::normalize<decimal128>(sig_rhs, exp_rhs);
 
-    return detail::new_d128_sub_impl<decimal128_fast>(
+    return detail::d128_sub_impl<decimal128_fast>(
             lhs.significand_, lhs.biased_exponent(), lhs.sign_,
             sig_rhs, exp_rhs, (rhs < 0),
             abs_lhs_bigger);
@@ -876,7 +876,7 @@ constexpr auto operator-(Integer lhs, decimal128_fast rhs) noexcept
     exp_type exp_lhs {0};
     detail::normalize<decimal128>(sig_lhs, exp_lhs);
 
-    return detail::new_d128_sub_impl<decimal128_fast>(
+    return detail::d128_sub_impl<decimal128_fast>(
             sig_lhs, exp_lhs, (lhs < 0),
             rhs.significand_, rhs.biased_exponent(), rhs.sign_,
             abs_lhs_bigger);

diff --git a/include/boost/decimal/detail/sub_impl.hpp b/include/boost/decimal/detail/sub_impl.hpp
@@ -150,7 +150,7 @@ constexpr auto d64_sub_impl(T lhs_sig, U lhs_exp, bool lhs_sign,
 }
 
 template <typename ReturnType, BOOST_DECIMAL_INTEGRAL T, BOOST_DECIMAL_INTEGRAL U>
-constexpr auto new_d128_sub_impl(T lhs_sig, U lhs_exp, bool lhs_sign,
+constexpr auto d128_sub_impl(T lhs_sig, U lhs_exp, bool lhs_sign,
                              T rhs_sig, U rhs_exp, bool rhs_sign,
                              bool abs_lhs_bigger) noexcept -> ReturnType
 {
@@ -220,78 +220,6 @@ constexpr auto new_d128_sub_impl(T lhs_sig, U lhs_exp, bool lhs_sign,
     return {res_sig, new_exp, new_sign};
 }
 
-template <typename ReturnType, BOOST_DECIMAL_INTEGRAL T1, BOOST_DECIMAL_INTEGRAL U1,
-                               BOOST_DECIMAL_INTEGRAL T2, BOOST_DECIMAL_INTEGRAL U2>
-constexpr auto d128_sub_impl(T1 lhs_sig, U1 lhs_exp, bool lhs_sign,
-                             T2 rhs_sig, U2 rhs_exp, bool rhs_sign,
-                             bool abs_lhs_bigger) noexcept -> ReturnType
-{
-    #if defined(BOOST_DECIMAL_HAS_INT128) && (!defined(__clang_major__) || __clang_major__ > 13)
-    using sub_type = detail::int128_t;
-    #else
-    using sub_type = detail::int128;
-    #endif
-
-    using unsigned_sub_type = detail::make_unsigned_t<sub_type>;
-
-    auto delta_exp {lhs_exp > rhs_exp ? lhs_exp - rhs_exp : rhs_exp - lhs_exp};
-
-    if (delta_exp > detail::precision_v<decimal128> + 1)
-    {
-        // If the difference in exponents is more than the digits of accuracy
-        // we return the larger of the two
-        //
-        // e.g. 1e20 - 1e-20 = 1e20
-        return abs_lhs_bigger ? ReturnType{detail::shrink_significand<detail::uint128>(lhs_sig, lhs_exp), lhs_exp, false} :
-                                ReturnType{detail::shrink_significand<detail::uint128>(rhs_sig, rhs_exp), rhs_exp, true};
-    }
-
-    // The two numbers can be subtracted together without special handling
-
-    auto& sig_bigger {abs_lhs_bigger ? lhs_sig : rhs_sig};
-    auto& exp_bigger {abs_lhs_bigger ? lhs_exp : rhs_exp};
-    auto& sig_smaller {abs_lhs_bigger ? rhs_sig : lhs_sig};
-    auto& smaller_sign {abs_lhs_bigger ? rhs_sign : lhs_sign};
-
-    if (delta_exp == 1)
-    {
-        sig_bigger *= 10;
-        --delta_exp;
-        --exp_bigger;
-    }
-    else
-    {
-        if (delta_exp >= 2)
-        {
-            sig_bigger *= 100;
-            delta_exp -= 2;
-            exp_bigger -= 2;
-        }
-
-        if (delta_exp > 1)
-        {
-            sig_smaller /= pow10<std::remove_reference_t<decltype(sig_smaller)>>(delta_exp - 1);
-            delta_exp = 1;
-        }
-
-        if (delta_exp == 1)
-        {
-            detail::fenv_round<decimal128>(sig_smaller, smaller_sign);
-        }
-    }
-
-    const auto signed_sig_lhs {detail::make_signed_value(static_cast<unsigned_sub_type>(lhs_sig), lhs_sign)};
-    const auto signed_sig_rhs {detail::make_signed_value(static_cast<unsigned_sub_type>(rhs_sig), rhs_sign)};
-
-    const auto new_sig {rhs_sign && !lhs_sign ? signed_sig_lhs + signed_sig_rhs : signed_sig_lhs - signed_sig_rhs};
-
-    const auto new_exp {abs_lhs_bigger ? lhs_exp : rhs_exp};
-    const auto new_sign {new_sig < 0};
-    const auto res_sig {detail::make_positive_unsigned(new_sig)};
-
-    return {res_sig, new_exp, new_sign};
-}
-
 } // namespace detail
 } // namespace decimal
 } // namespace boost