[FOLD] Merge with the latest Number

Author: HowardHinnant

src/ripple/basics/IOUAmount.h

@@ -186,10 +186,6 @@ mulRatio(
     std::uint32_t den,
     bool roundUp);
 
-// Since IOUAmount and STAmount do not have access to a ledger, this
-// is needed to put low-level routines on an amendment switch. Only
-// transactions need to use this switchover. Outside of a transaction
-// it's safe to unconditionally use the new behavior.
 extern LocalValue<bool> stNumberSwitchover;
 
 /** RAII class to set and restore the Number switchover.

src/ripple/basics/Number.h

@@ -22,6 +22,7 @@
 
 #include <ripple/basics/XRPAmount.h>
 #include <cstdint>
+#include <limits>
 #include <ostream>
 #include <string>
 
@@ -336,6 +337,24 @@ squelch(Number const& x, Number const& limit) noexcept
     return x;
 }
 
+class saveNumberRoundMode
+{
+    Number::rounding_mode mode_;
+
+public:
+    ~saveNumberRoundMode()
+    {
+        Number::setround(mode_);
+    }
+    explicit saveNumberRoundMode(Number::rounding_mode mode) noexcept
+        : mode_{mode}
+    {
+    }
+    saveNumberRoundMode(saveNumberRoundMode const&) = delete;
+    saveNumberRoundMode&
+    operator=(saveNumberRoundMode const&) = delete;
+};
+
 }  // namespace ripple
 
 #endif  // RIPPLE_BASICS_NUMBER_H_INCLUDED

src/ripple/basics/impl/IOUAmount.cpp

@@ -45,6 +45,12 @@ IOUAmount::minPositiveAmount()
 void
 IOUAmount::normalize()
 {
+    if (mantissa_ == 0)
+    {
+        *this = beast::zero;
+        return;
+    }
+
     if (*stNumberSwitchover)
     {
         Number v{mantissa_, exponent_};
@@ -56,11 +62,6 @@ IOUAmount::normalize()
             *this = beast::zero;
         return;
     }
-    if (mantissa_ == 0)
-    {
-        *this = beast::zero;
-        return;
-    }
 
     bool const negative = (mantissa_ < 0);
 
@@ -107,48 +108,46 @@ IOUAmount::IOUAmount(Number const& other)
 IOUAmount&
 IOUAmount::operator+=(IOUAmount const& other)
 {
+    if (other == beast::zero)
+        return *this;
+
+    if (*this == beast::zero)
+    {
+        *this = other;
+        return *this;
+    }
+
     if (*stNumberSwitchover)
     {
         *this = IOUAmount{Number{*this} + Number{other}};
+        return *this;
     }
-    else
-    {
-        if (other == beast::zero)
-            return *this;
-
-        if (*this == beast::zero)
-        {
-            *this = other;
-            return *this;
-        }
+    auto m = other.mantissa_;
+    auto e = other.exponent_;
 
-        auto m = other.mantissa_;
-        auto e = other.exponent_;
-
-        while (exponent_ < e)
-        {
-            mantissa_ /= 10;
-            ++exponent_;
-        }
-
-        while (e < exponent_)
-        {
-            m /= 10;
-            ++e;
-        }
+    while (exponent_ < e)
+    {
+        mantissa_ /= 10;
+        ++exponent_;
+    }
 
-        // This addition cannot overflow an std::int64_t but we may throw from
-        // normalize if the result isn't representable.
-        mantissa_ += m;
+    while (e < exponent_)
+    {
+        m /= 10;
+        ++e;
+    }
 
-        if (mantissa_ >= -10 && mantissa_ <= 10)
-        {
-            *this = beast::zero;
-            return *this;
-        }
+    // This addition cannot overflow an std::int64_t but we may throw from
+    // normalize if the result isn't representable.
+    mantissa_ += m;
 
-        normalize();
+    if (mantissa_ >= -10 && mantissa_ <= 10)
+    {
+        *this = beast::zero;
+        return *this;
     }
+
+    normalize();
     return *this;
 }
 

src/ripple/basics/impl/Number.cpp

@@ -25,7 +25,7 @@
 #include <type_traits>
 #include <utility>
 
-#ifdef _MSVC_LANG
+#ifdef BOOST_COMP_MSVC
 #include <boost/multiprecision/cpp_int.hpp>
 using uint128_t = boost::multiprecision::uint128_t;
 #else   // !defined(_MSVC_LANG)
@@ -130,32 +130,37 @@ int
 Number::Guard::round() noexcept
 {
     auto mode = Number::getround();
-    switch (mode)
+
+    if (mode == towards_zero)
+        return -1;
+
+    if (mode == downward)
     {
-        case to_nearest:
-            if (digits_ > 0x5000'0000'0000'0000)
-                return 1;
-            if (digits_ < 0x5000'0000'0000'0000)
-                return -1;
-            if (xbit_)
-                return 1;
-            return 0;
-        case towards_zero:
-            return -1;
-        case downward:
-            if (sbit_)
-            {
-                if (digits_ > 0 || xbit_)
-                    return 1;
-            }
-            return -1;
-        case upward:
-            if (sbit_)
-                return -1;
+        if (sbit_)
+        {
             if (digits_ > 0 || xbit_)
                 return 1;
+        }
+        return -1;
+    }
+
+    if (mode == upward)
+    {
+        if (sbit_)
             return -1;
+        if (digits_ > 0 || xbit_)
+            return 1;
+        return -1;
     }
+
+    // assume round to nearest if mode is not one of the predefined values
+    if (digits_ > 0x5000'0000'0000'0000)
+        return 1;
+    if (digits_ < 0x5000'0000'0000'0000)
+        return -1;
+    if (xbit_)
+        return 1;
+    return 0;
 }
 
 // Number
@@ -171,9 +176,9 @@ Number::normalize()
         return;
     }
     bool const negative = (mantissa_ < 0);
-    if (negative)
-        mantissa_ = -mantissa_;
     auto m = static_cast<std::make_unsigned_t<rep>>(mantissa_);
+    if (negative)
+        m = -m;
     while ((m < minMantissa) && (exponent_ > minExponent))
     {
         m *= 10;
@@ -506,8 +511,8 @@ to_string(Number const& amount)
 
     assert(exponent + 43 > 0);
 
-    size_t const pad_prefix = 27;
-    size_t const pad_suffix = 23;
+    ptrdiff_t const pad_prefix = 27;
+    ptrdiff_t const pad_suffix = 23;
 
     std::string const raw_value(std::to_string(mantissa));
     std::string val;
@@ -517,7 +522,7 @@ to_string(Number const& amount)
     val.append(raw_value);
     val.append(pad_suffix, '0');
 
-    size_t const offset(exponent + 43);
+    ptrdiff_t const offset(exponent + 43);
 
     auto pre_from(val.begin());
     auto const pre_to(val.begin() + offset);

src/ripple/protocol/impl/STAmount.cpp

@@ -725,24 +725,36 @@ STAmount::canonicalize()
                     "Native currency amount out of range");
         }
 
-        while (mOffset < 0)
+        if (*stNumberSwitchover && *stAmountCanonicalizeSwitchover)
         {
-            mValue /= 10;
-            ++mOffset;
+            Number num(
+                mIsNegative ? -mValue : mValue, mOffset, Number::unchecked{});
+            XRPAmount xrp{num};
+            mIsNegative = xrp.drops() < 0;
+            mValue = mIsNegative ? -xrp.drops() : xrp.drops();
+            mOffset = 0;
         }
-
-        while (mOffset > 0)
+        else
         {
-            if (*stAmountCanonicalizeSwitchover)
+            while (mOffset < 0)
+            {
+                mValue /= 10;
+                ++mOffset;
+            }
+
+            while (mOffset > 0)
             {
-                // N.B. do not move the overflow check to after the
-                // multiplication
-                if (mValue > cMaxNativeN)
-                    Throw<std::runtime_error>(
-                        "Native currency amount out of range");
+                if (*stAmountCanonicalizeSwitchover)
+                {
+                    // N.B. do not move the overflow check to after the
+                    // multiplication
+                    if (mValue > cMaxNativeN)
+                        Throw<std::runtime_error>(
+                            "Native currency amount out of range");
+                }
+                mValue *= 10;
+                --mOffset;
             }
-            mValue *= 10;
-            --mOffset;
         }
 
         if (mValue > cMaxNativeN)

src/test/app/NFToken_test.cpp

@@ -2335,7 +2335,13 @@ class NFToken_test : public beast::unit_test::suite
 
         // See the impact of rounding when the nft is sold for small amounts
         // of drops.
+        for (auto NumberSwitchOver : {true})
         {
+            if (NumberSwitchOver)
+                env.enableFeature(fixUniversalNumber);
+            else
+                env.disableFeature(fixUniversalNumber);
+
             // An nft with a transfer fee of 1 basis point.
             uint256 const nftID =
                 token::getNextID(env, alice, 0u, tfTransferable, 1);
@@ -2360,16 +2366,16 @@ class NFToken_test : public beast::unit_test::suite
 
             // minter sells to carol.  The payment is just small enough that
             // alice does not get any transfer fee.
+            auto pmt = NumberSwitchOver ? drops(50000) : drops(99999);
             STAmount carolBalance = env.balance(carol);
             uint256 const minterSellOfferIndex =
                 keylet::nftoffer(minter, env.seq(minter)).key;
-            env(token::createOffer(minter, nftID, drops(99999)),
-                txflags(tfSellNFToken));
+            env(token::createOffer(minter, nftID, pmt), txflags(tfSellNFToken));
             env.close();
             env(token::acceptSellOffer(carol, minterSellOfferIndex));
             env.close();
-            minterBalance += drops(99999) - fee;
-            carolBalance -= drops(99999) + fee;
+            minterBalance += pmt - fee;
+            carolBalance -= pmt + fee;
             BEAST_EXPECT(env.balance(alice) == aliceBalance);
             BEAST_EXPECT(env.balance(minter) == minterBalance);
             BEAST_EXPECT(env.balance(carol) == carolBalance);
@@ -2379,13 +2385,13 @@ class NFToken_test : public beast::unit_test::suite
             STAmount beckyBalance = env.balance(becky);
             uint256 const beckyBuyOfferIndex =
                 keylet::nftoffer(becky, env.seq(becky)).key;
-            env(token::createOffer(becky, nftID, drops(100000)),
-                token::owner(carol));
+            pmt = NumberSwitchOver ? drops(50001) : drops(100000);
+            env(token::createOffer(becky, nftID, pmt), token::owner(carol));
             env.close();
             env(token::acceptBuyOffer(carol, beckyBuyOfferIndex));
             env.close();
-            carolBalance += drops(99999) - fee;
-            beckyBalance -= drops(100000) + fee;
+            carolBalance += pmt - drops(1) - fee;
+            beckyBalance -= pmt + fee;
             aliceBalance += drops(1);
 
             BEAST_EXPECT(env.balance(alice) == aliceBalance);