minor fix

rui-mo · Feb 23, 2024 · 74d0c45 · 74d0c45
1 parent aa18b28
commit 74d0c45
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Showing 2 changed files with 22 additions and 22 deletions.
diff --git a/velox/expression/tests/CastExprTest.cpp b/velox/expression/tests/CastExprTest.cpp
@@ -2086,12 +2086,12 @@ TEST_F(CastExprTest, doubleToDecimal) {
       DOUBLE(),
       DECIMAL(38, 2),
       {std::numeric_limits<double>::max()},
-      "Cannot cast DOUBLE '1.7976931348623157E308' to DECIMAL(38, 2). Result overflows.");
+      "Result overflows.");
   testThrow<double>(
       DOUBLE(),
       DECIMAL(38, 2),
       {std::numeric_limits<double>::lowest()},
-      "Cannot cast DOUBLE '-1.7976931348623157E308' to DECIMAL(38, 2). Result overflows.");
+      "Result overflows.");
   testCast(
       makeConstant<double>(std::numeric_limits<double>::min(), 1),
       makeConstant<int128_t>(0, 1, DECIMAL(38, 2)));
@@ -2169,10 +2169,7 @@ TEST_F(CastExprTest, realToDecimal) {
           DECIMAL(38, 18)));
 
   testThrow<float>(
-      REAL(),
-      DECIMAL(10, 2),
-      {9999999999999999999999.99},
-      "Cannot cast REAL '9.999999778196308E21' to DECIMAL(10, 2). Result overflows.");
+      REAL(), DECIMAL(10, 2), {9999999999999999999999.99}, "Result overflows.");
   testThrow<float>(
       REAL(),
       DECIMAL(10, 2),
@@ -2189,22 +2186,22 @@ TEST_F(CastExprTest, realToDecimal) {
       REAL(),
       DECIMAL(20, 2),
       {static_cast<float>(DecimalUtil::kLongDecimalMax)},
-      "Cannot cast REAL '9.999999680285692E37' to DECIMAL(20, 2). Result overflows.");
+      "Result overflows.");
   testThrow<float>(
       REAL(),
       DECIMAL(20, 2),
       {static_cast<float>(DecimalUtil::kLongDecimalMin)},
-      "Cannot cast REAL '-9.999999680285692E37' to DECIMAL(20, 2). Result overflows.");
+      "Result overflows.");
   testThrow<float>(
       REAL(),
       DECIMAL(38, 2),
       {std::numeric_limits<float>::max()},
-      "Cannot cast REAL '3.4028234663852886E38' to DECIMAL(38, 2). Result overflows.");
+      "Result overflows.");
   testThrow<float>(
       REAL(),
       DECIMAL(38, 2),
       {std::numeric_limits<float>::lowest()},
-      "Cannot cast REAL '-3.4028234663852886E38' to DECIMAL(38, 2). Result overflows.");
+      "Result overflows.");
   testCast(
       makeConstant<float>(std::numeric_limits<float>::min(), 1),
       makeConstant<int128_t>(0, 1, DECIMAL(38, 2)));

diff --git a/velox/type/DecimalUtil.h b/velox/type/DecimalUtil.h
@@ -233,26 +233,29 @@ class DecimalUtil {
     }
 
     // Calculate the precise fractional digits.
-    const auto integralValue =
-        static_cast<uint128_t>(value > 0 ? value : -value);
-    const auto integralDigits =
-        integralValue == 0 ? 0 : countDigits(integralValue);
-    const auto fractionDigits = digits - integralDigits;
+    // const auto integralValue =
+    //     static_cast<uint128_t>(value > 0 ? value : -value);
+    // const auto integralDigits =
+    //     integralValue == 0 ? 0 : countDigits(integralValue);
+
+    // const auto fractionDigits = std::max(digits - integralDigits, 0);
+
     /// Scales up the input value to keep all the precise fractional digits
     /// before rounding. Convert value to long double type, as double * int128_t
     /// returns int128_t and fractional digits are lost. No need to consider
     /// 'toValue' becoming infinite as DOUBLE_MAX * 10^38 < LONG_DOUBLE_MAX.
-    const auto scaledValue =
-        (long double)value * DecimalUtil::kPowersOfTen[fractionDigits];
+    // const auto scaledValue =
+    //     (long double)value * DecimalUtil::kPowersOfTen[digits];
 
     long double rounded;
-    if (scale > fractionDigits) {
-      rounded = std::round(scaledValue) *
-          DecimalUtil::kPowersOfTen[scale - fractionDigits];
+    if (scale < digits) {
+      rounded = std::round(
+          std::round((long double)value * DecimalUtil::kPowersOfTen[digits]) /
+          DecimalUtil::kPowersOfTen[digits - scale]);
     } else {
       rounded = std::round(
-          std::round(scaledValue) /
-          DecimalUtil::kPowersOfTen[fractionDigits - scale]);
+          std::round((long double)value * DecimalUtil::kPowersOfTen[digits]) *
+          DecimalUtil::kPowersOfTen[scale - digits]);
     }
 
     const auto result = folly::tryTo<TOutput>(rounded);