ARCHIVE/rippled
1
0
Fork 0
mirror of https://github.com/XRPLF/rippled.git synced 2026-06-03 00:36:48 +00:00
Code Issues Packages Projects Releases Wiki Activity

Update the testUpwardRoundsDown test to run under all scales

Browse Source 
- Demonstrates the incorrect "before" behavior
This commit is contained in:
Ed Hennis
2026-05-28 19:58:52 -04:00
parent 2fdfd2b420
commit cd21d74538
1 changed files with 59 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

73
src/test/basics/Number_test.cpp
View File

@@ -1626,10 +1626,11 @@ public:
void
testUpwardRoundsDown()
{
auto const scale = Number::getMantissaScale();
{
testcase << "upward rounding produces a value below exact at kMaxRep cusp";
testcase << "upward rounding produces a value below exact at kMaxRep cusp "
<< to_string(scale);
NumberMantissaScaleGuard const mg{MantissaRange::MantissaScale::Large};
NumberRoundModeGuard const rg{Number::RoundingMode::Upward};
constexpr std::int64_t kAValue = 1'000'000'000'000'049'863LL;
@@ -1655,13 +1656,41 @@ public:
<< " exact a*b = " << fmt(exactProduct) << "\n"
<< " stored = " << fmt(storedValue) << "\n"
<< " stored - exact = " << fmt(signedDifference) << "\n"
<< " upward = " << (signedDifference >= 0 ? "held" : "VIOLATED") << "\n";
BEAST_EXPECT(signedDifference >= 0);
BEAST_EXPECT(signedDifference < pow10<BigInt>(product.exponent()));
BEAST_EXPECT(product.mantissa() == (std::numeric_limits<std::int64_t>::max() / 10) + 1);
BEAST_EXPECT(product.exponent() == 19);
<< " upward = " << (signedDifference >= 0 ? "held" : "VIOLATED") << "\n"
<< " stored.mantissa = " << product.mantissa() << "\n"
<< " stored.exponent = " << product.exponent() << "\n";
log.flush();
switch (scale)
{
case MantissaRange::MantissaScale::Large:
BEAST_EXPECT(signedDifference >= 0);
BEAST_EXPECT(signedDifference < pow10<BigInt>(product.exponent()));
BEAST_EXPECT(
product.mantissa() == (std::numeric_limits<std::int64_t>::max() / 10) + 1);
BEAST_EXPECT(product.exponent() == 19);
break;
case MantissaRange::MantissaScale::LargeLegacy:
BEAST_EXPECT(signedDifference < 0);
BEAST_EXPECT(
product.mantissa() ==
(std::numeric_limits<std::int64_t>::max() / 100) * 100);
BEAST_EXPECT(product.exponent() == 18);
break;
case MantissaRange::MantissaScale::Small:
// The seemingly weird rounding here is because
// a & b are both normalized, and both round up when
// being converted to Number, so you're really
// getting 1_000_000_000_000_050 * 9_223_372_036_854_316
BEAST_EXPECT(signedDifference >= 0);
BEAST_EXPECT(
product.mantissa() ==
(std::numeric_limits<std::int64_t>::max() / 1000) + 3);
BEAST_EXPECT(product.exponent() == 21);
break;
}
}
{
@@ -1687,9 +1716,8 @@ public:
* 4. Under Upward + positive, `round()` returns -1 (no round-up), and
* the algorithm returns the truncated zm
*/
testcase << "operator/= Upward on Large returns value < truth ";
testcase << "operator/= Upward on Large returns value < truth " << to_string(scale);
NumberMantissaScaleGuard const scaleGuard{MantissaRange::MantissaScale::Large};
NumberRoundModeGuard const roundGuard{Number::RoundingMode::Upward};
constexpr std::int64_t aValue = 2LL;
@@ -1713,10 +1741,27 @@ public:
<< " (negative => Upward gave value BELOW truth)\n"
<< " quotient.mantissa = " << quotient.mantissa() << "\n"
<< " quotient.exponent = " << quotient.exponent() << "\n";
log.flush();
// Upward invariant: stored >= exact. Bug: stored < exact.
BEAST_EXPECT(stored >= exact);
BEAST_EXPECT(diff < pow10(quotient.exponent()));
switch (scale)
{
case MantissaRange::MantissaScale::Large:
BEAST_EXPECT(stored >= exact);
BEAST_EXPECT(diff < pow10(quotient.exponent()));
break;
case MantissaRange::MantissaScale::LargeLegacy:
BEAST_EXPECT(stored < exact);
BEAST_EXPECT(diff >= -pow10(quotient.exponent()));
break;
case MantissaRange::MantissaScale::Small:
// Small mantissa doesn't have the correction for
// dropped remainders
BEAST_EXPECT(stored < exact);
break;
}
}
}
@@ -1747,9 +1792,9 @@ public:
testTruncate();
testRounding();
testInt64();
testUpwardRoundsDown();
}
// This test sets its own number range
testUpwardRoundsDown();
}
};