expression: implement vectorized evaluation for builtinLastDaySig

expression/builtin_time.go

@@ -6532,8 +6532,8 @@ func (b *builtinLastDaySig) evalTime(row chunk.Row) (types.Time, bool, error) {
 		return types.Time{}, true, handleInvalidTimeError(b.ctx, err)
 	}
 	tm := arg.Time
-	year, month, day := tm.Year(), tm.Month(), tm.Day()
-	if month == 0 || day == 0 {
+	year, month := tm.Year(), tm.Month()
+	if arg.InvalidZero() {
 		return types.Time{}, true, handleInvalidTimeError(b.ctx, types.ErrIncorrectDatetimeValue.GenWithStackByArgs(arg.String()))
 	}
 	lastDay := types.GetLastDay(year, month)

expression/builtin_time_vec.go

@@ -716,11 +716,36 @@ func (b *builtinGetFormatSig) getFormat(format, location string) string {
 }
 
 func (b *builtinLastDaySig) vectorized() bool {
-	return false
+	return true
 }
 
 func (b *builtinLastDaySig) vecEvalTime(input *chunk.Chunk, result *chunk.Column) error {
-	return errors.Errorf("not implemented")
+	n := input.NumRows()
+	if err := b.args[0].VecEvalTime(b.ctx, input, result); err != nil {
+		return err
+	}
+	times := result.Times()
+	for i := 0; i < n; i++ {
+		if result.IsNull(i) {
+			continue
+		}
+		if times[i].InvalidZero() {
+			if err := handleInvalidTimeError(b.ctx, types.ErrIncorrectDatetimeValue.GenWithStackByArgs(times[i].String())); err != nil {
+				return err
+			}
+			result.SetNull(i, true)
+			continue
+		}
+		tm := times[i].Time
+		year, month := tm.Year(), tm.Month()
+		lastDay := types.GetLastDay(year, month)
+		times[i] = types.Time{
+			Time: types.FromDate(year, month, lastDay, 0, 0, 0, 0),
+			Type: mysql.TypeDate,
+			Fsp:  types.DefaultFsp,
+		}
+	}
+	return nil
 }
 
 func (b *builtinAddDateStringDecimalSig) vectorized() bool {

expression/builtin_time_vec_test.go

@@ -259,6 +259,9 @@ var vecBuiltinTimeCases = map[string][]vecExprBenchCase{
 		// {retEvalType: types.ETDatetime, childrenTypes: []types.EvalType{types.ETInt},
 		// 	geners: []dataGenerator{&rangeInt64Gener{begin: 0, end: 7}}},
 	},
+	ast.LastDay: {
+		{retEvalType: types.ETDatetime, childrenTypes: []types.EvalType{types.ETDatetime}},
+	},
 }
 
 func (s *testEvaluatorSuite) TestVectorizedBuiltinTimeEvalOneVec(c *C) {