Skip to content

[fix](decimal256) fix unstable overflow error when casting decimal256 to float #56848

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
yiguolei merged 2 commits into from
Oct 13, 2025
Merged

[fix](decimal256) fix unstable overflow error when casting decimal256 to float #56848

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
fc9d263
[fix](decimal256) fix unstable overflow error when casting decimal256…
jacktengg Oct 11, 2025
14dd300
fix be ut
jacktengg Oct 12, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 2 additions & 7 deletions be/src/vec/functions/cast/cast_to_basic_number_common.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -328,13 +328,8 @@ struct CastToFloat {
static inline bool _from_decimalv3(const FromCppT& from, UInt32 from_scale, ToCppT& to,
const typename FromCppT::NativeType& scale_multiplier,
CastParameters& params) {
if constexpr (IsDecimal256<FromCppT>) {
to = static_cast<ToCppT>(static_cast<long double>(from.value) /
static_cast<long double>(scale_multiplier));
} else {
to = static_cast<ToCppT>(static_cast<double>(from.value) /
static_cast<double>(scale_multiplier));
}
to = static_cast<ToCppT>(static_cast<double>(from.value) /
static_cast<double>(scale_multiplier));
return true;
}
// cast from date and datetime to float/double, will not overflow
Expand Down
57 changes: 12 additions & 45 deletions be/test/vec/function/cast/cast_to_float_double.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -892,14 +892,8 @@ struct FunctionCastToFloatTest : public FunctionCastTest {
auto decimal_num = decimal_ctor(i, 0, FromScale);
auto num_str = dt_from.to_string(decimal_num);
// auto float_v = static_cast<FloatType>(i);
FloatType float_v;
if constexpr (IsDecimal256<FromT>) {
float_v = static_cast<long double>(decimal_num.value) /
static_cast<long double>(scale_multiplier);
} else {
float_v = static_cast<double>(decimal_num.value) /
static_cast<double>(scale_multiplier);
}
FloatType float_v = static_cast<double>(decimal_num.value) /
static_cast<double>(scale_multiplier);
if (std::isinf(float_v)) {
// std::cout << fmt::format("cast {}({}, {}) value {} to float_v result is inf\n",
// type_to_string(FromT::PType), FromPrecision, FromScale,
Expand All @@ -912,13 +906,8 @@ struct FunctionCastToFloatTest : public FunctionCastTest {

decimal_num = decimal_ctor(-i, 0, FromScale);
num_str = dt_from.to_string(decimal_num);
if constexpr (IsDecimal256<FromT>) {
float_v = static_cast<long double>(decimal_num.value) /
static_cast<long double>(scale_multiplier);
} else {
float_v = static_cast<double>(decimal_num.value) /
static_cast<double>(scale_multiplier);
}
float_v = static_cast<double>(decimal_num.value) /
static_cast<double>(scale_multiplier);
if (std::isinf(float_v)) {
// std::cout << fmt::format("cast {}({}, {}) value {} to float_v result is inf\n",
// type_to_string(FromT::PType), FromPrecision, FromScale,
Expand All @@ -940,27 +929,16 @@ struct FunctionCastToFloatTest : public FunctionCastTest {
for (const auto& f : fractional_part) {
auto decimal_num = decimal_ctor(0, f, FromScale);
auto num_str = dt_from.to_string(decimal_num);
FloatType float_v;
if constexpr (IsDecimal256<FromT>) {
float_v = static_cast<long double>(decimal_num.value) /
static_cast<long double>(scale_multiplier);
} else {
float_v = static_cast<double>(decimal_num.value) /
static_cast<double>(scale_multiplier);
}
FloatType float_v = static_cast<double>(decimal_num.value) /
static_cast<double>(scale_multiplier);
// dbg_str += fmt::format("({}, {})|", dt.to_string(decimal_num), float_v);
data_set.push_back({{decimal_num}, float_v});
test_data_set.emplace_back(num_str, float_v);

decimal_num = decimal_ctor(0, -f, FromScale);
num_str = dt_from.to_string(decimal_num);
if constexpr (IsDecimal256<FromT>) {
float_v = static_cast<long double>(decimal_num.value) /
static_cast<long double>(scale_multiplier);
} else {
float_v = static_cast<double>(decimal_num.value) /
static_cast<double>(scale_multiplier);
}
float_v = static_cast<double>(decimal_num.value) /
static_cast<double>(scale_multiplier);
// dbg_str += fmt::format("({}, {})|", dt.to_string(decimal_num), float_v);
data_set.push_back({{decimal_num}, float_v});
test_data_set.emplace_back(num_str, float_v);
Expand All @@ -977,14 +955,8 @@ struct FunctionCastToFloatTest : public FunctionCastTest {
for (const auto& f : fractional_part) {
auto decimal_num = decimal_ctor(i, f, FromScale);
auto num_str = dt_from.to_string(decimal_num);
FloatType float_v;
if constexpr (IsDecimal256<FromT>) {
float_v = static_cast<long double>(decimal_num.value) /
static_cast<long double>(scale_multiplier);
} else {
float_v = static_cast<double>(decimal_num.value) /
static_cast<double>(scale_multiplier);
}
FloatType float_v = static_cast<double>(decimal_num.value) /
static_cast<double>(scale_multiplier);
if (std::isinf(float_v)) {
// std::cout << fmt::format("cast {}({}, {}) value {} to float_v result is inf\n",
// type_to_string(FromT::PType), FromPrecision, FromScale,
Expand All @@ -997,13 +969,8 @@ struct FunctionCastToFloatTest : public FunctionCastTest {

decimal_num = decimal_ctor(-i, -f, FromScale);
num_str = dt_from.to_string(decimal_num);
if constexpr (IsDecimal256<FromT>) {
float_v = static_cast<long double>(decimal_num.value) /
static_cast<long double>(scale_multiplier);
} else {
float_v = static_cast<double>(decimal_num.value) /
static_cast<double>(scale_multiplier);
}
float_v = static_cast<double>(decimal_num.value) /
static_cast<double>(scale_multiplier);
if (std::isinf(float_v)) {
// std::cout << fmt::format("cast {}({}, {}) value {} to float_v result is inf\n",
// type_to_string(FromT::PType), FromPrecision, FromScale,
Expand Down
Loading