HAWQ-1767. refactor decimalToFloat and floatToDecimal function
diff --git a/depends/dbcommon/src/dbcommon/function/typecast-func.cc b/depends/dbcommon/src/dbcommon/function/typecast-func.cc
index e49a206..958f13d 100644
--- a/depends/dbcommon/src/dbcommon/function/typecast-func.cc
+++ b/depends/dbcommon/src/dbcommon/function/typecast-func.cc
@@ -18,6 +18,7 @@
*/
#include <cmath>
+#include <fstream>
//#include <boost/lexical_cast.hpp>
#include <boost/multiprecision/cpp_int.hpp>
@@ -317,6 +318,24 @@
}
template <typename TP>
+inline DecimalVar floatToDecimal(TP in) {
+ int64_t scale = 0;
+ while (true) {
+ if (scale >= 13) {
+ break;
+ }
+ if (abs(in - static_cast<int64_t>(in)) > 1e-8) {
+ in *= 10.0;
+ ++scale;
+ } else {
+ break;
+ }
+ }
+ Int128 int128 = static_cast<int64_t>(in);
+ return DecimalVar(int128.getHighBits(), int128.getLowBits(), scale);
+}
+
+template <typename TP>
Datum TypeCast::castFloatTypeToDecimal(Datum *params, uint64_t size) {
assert(size == 2 && "invalid input");
Object *para = DatumGetValue<Object *>(params[1]);
@@ -332,7 +351,7 @@
DecimalVar *ret = retScalar->allocateValue<DecimalVar>();
TP val = DatumGetValue<TP>(srcScalar->value);
- *ret = DecimalType::fromString(boost::lexical_cast<std::string>(val));
+ *ret = floatToDecimal(val);
}
return CreateDatum(retScalar);
} else {
@@ -351,12 +370,57 @@
return false;
}
+template <int64_t n>
+constexpr uint64_t res2() {
+ return 2 * res2<n - 1>();
+}
+
+template <>
+constexpr uint64_t res2<1>() {
+ return 2;
+}
+
+template <typename TR>
+inline TR decimalToFloat(int64_t highbits, uint64_t lowbits, int64_t scale) {
+ TR exp[] = {
+ 1.0,
+ 10.0,
+ 100.0,
+ 1000.0,
+ 10000.0,
+ 100000.0,
+ 1000000.0,
+ 10000000.0,
+ 100000000.0,
+ 1000000000.0,
+ 10000000000.0,
+ 100000000000.0,
+ 1000000000000.0,
+ 10000000000000.0,
+ 100000000000000.0,
+ 1000000000000000.0,
+ 10000000000000000.0,
+ 100000000000000000.0,
+ 1000000000000000000.0,
+ 10000000000000000000.0,
+ 100000000000000000000.0,
+ };
+ Int128 int128(highbits, lowbits);
+ int128.abs();
+ TR fval =
+ static_cast<TR>(int128.getHighBits()) * static_cast<TR>(res2<64>()) +
+ static_cast<TR>(int128.getLowBits());
+ if (scale <= 20)
+ fval /= exp[scale];
+ else
+ for (int32_t i = 0; i < scale; ++i) fval /= 10.0;
+ return highbits < 0 ? -fval : fval;
+}
+
template <typename TR>
Datum TypeCast::valCastDecimalToFloatType(DecimalVar *param) {
- std::string strVal = dbcommon::DecimalType::toString(
- param->highbits, param->lowbits, param->scale);
- double fval = stod(strVal);
- return CreateDatum(static_cast<TR>(fval));
+ return CreateDatum(static_cast<TR>(
+ decimalToFloat<TR>(param->highbits, param->lowbits, param->scale)));
}
template <typename TR>
@@ -393,19 +457,15 @@
if (rnull[index]) {
rdata[index] = 0;
} else {
- std::string strVecVal =
- DecimalType::toString(hval[index], lval[index], sval[index]);
- double fval = stod(strVecVal);
- rdata[index] = static_cast<TR>(fval);
+ rdata[index] =
+ decimalToFloat<TR>(hval[index], lval[index], sval[index]);
}
}
} else {
for (uint64_t i = 0; i < sz; ++i) {
auto index = (*sel)[i];
- std::string strVecVal =
- DecimalType::toString(hval[index], lval[index], sval[index]);
- double fval = stod(strVecVal);
- rdata[index] = static_cast<TR>(fval);
+ rdata[index] =
+ decimalToFloat<TR>(hval[index], lval[index], sval[index]);
}
}
} else {
@@ -416,18 +476,12 @@
if (rnull[i]) {
rdata[i] = 0;
} else {
- std::string strVecVal =
- DecimalType::toString(hval[i], lval[i], sval[i]);
- double fval = stod(strVecVal);
- rdata[i] = static_cast<TR>(fval);
+ rdata[i] = decimalToFloat<TR>(hval[i], lval[i], sval[i]);
}
}
} else {
for (uint64_t i = 0; i < sz; ++i) {
- std::string strVecVal =
- DecimalType::toString(hval[i], lval[i], sval[i]);
- double fval = stod(strVecVal);
- rdata[i] = static_cast<TR>(fval);
+ rdata[i] = decimalToFloat<TR>(hval[i], lval[i], sval[i]);
}
}
}
@@ -472,21 +526,19 @@
auto index = (*sel)[i];
rnull[index] = nulls[index];
if (!rnull[index]) {
- snprintf(buffer, sizeof(buffer), "%.*g", DBL_DIG, v[index]);
- DecimalVar decVal = DecimalType::fromString(buffer);
- rLowbit[index] = decVal.lowbits;
- rHighbit[index] = decVal.highbits;
- rScales[index] = decVal.scale;
+ DecimalVar decValtmp = floatToDecimal(v[index]);
+ rLowbit[index] = decValtmp.lowbits;
+ rHighbit[index] = decValtmp.highbits;
+ rScales[index] = decValtmp.scale;
}
}
} else {
for (uint64_t i = 0; i < sz; ++i) {
auto index = (*sel)[i];
- snprintf(buffer, sizeof(buffer), "%.*g", DBL_DIG, v[index]);
- DecimalVar decVal = DecimalType::fromString(buffer);
- rLowbit[index] = decVal.lowbits;
- rHighbit[index] = decVal.highbits;
- rScales[index] = decVal.scale;
+ DecimalVar decValtmp = floatToDecimal(v[index]);
+ rLowbit[index] = decValtmp.lowbits;
+ rHighbit[index] = decValtmp.highbits;
+ rScales[index] = decValtmp.scale;
}
}
} else {
@@ -495,20 +547,18 @@
for (uint64_t i = 0; i < sz; ++i) {
rnull[i] = nulls[i];
if (!rnull[i]) {
- snprintf(buffer, sizeof(buffer), "%.*g", DBL_DIG, v[i]);
- DecimalVar decVal = DecimalType::fromString(buffer);
- rLowbit[i] = decVal.lowbits;
- rHighbit[i] = decVal.highbits;
- rScales[i] = decVal.scale;
+ DecimalVar decValtmp = floatToDecimal(v[i]);
+ rLowbit[i] = decValtmp.lowbits;
+ rHighbit[i] = decValtmp.highbits;
+ rScales[i] = decValtmp.scale;
}
}
} else {
for (uint64_t i = 0; i < sz; ++i) {
- snprintf(buffer, sizeof(buffer), "%.*g", DBL_DIG, v[i]);
- DecimalVar decVal = DecimalType::fromString(buffer);
- rLowbit[i] = decVal.lowbits;
- rHighbit[i] = decVal.highbits;
- rScales[i] = decVal.scale;
+ DecimalVar decValtmp = floatToDecimal(v[i]);
+ rLowbit[i] = decValtmp.lowbits;
+ rHighbit[i] = decValtmp.highbits;
+ rScales[i] = decValtmp.scale;
}
}
}
