expression: implement vectorized evaluation for builtinNowWithArgSig (p…

…ingcap#13372)

expression/builtin_time_vec.go

@@ -563,11 +563,48 @@ func (b *builtinTimeTimeTimeDiffSig) vecEvalDuration(input *chunk.Chunk, result
 }
 
 func (b *builtinNowWithArgSig) vectorized() bool {
-	return false
+	return true
 }
 
 func (b *builtinNowWithArgSig) vecEvalTime(input *chunk.Chunk, result *chunk.Column) error {
-	return errors.Errorf("not implemented")
+	n := input.NumRows()
+	bufFsp, err := b.bufAllocator.get(types.ETInt, n)
+	if err != nil {
+		return err
+	}
+	defer b.bufAllocator.put(bufFsp)
+	if err = b.args[0].VecEvalInt(b.ctx, input, bufFsp); err != nil {
+		return err
+	}
+
+	result.ResizeTime(n, false)
+	times := result.Times()
+	fsps := bufFsp.Int64s()
+
+	for i := 0; i < n; i++ {
+		fsp := int8(0)
+		if !bufFsp.IsNull(i) {
+			if fsps[i] > int64(types.MaxFsp) {
+				return errors.Errorf("Too-big precision %v specified for 'now'. Maximum is %v.", fsps[i], types.MaxFsp)
+			}
+			if fsps[i] < int64(types.MinFsp) {
+				return errors.Errorf("Invalid negative %d specified, must in [0, 6].", fsps[i])
+			}
+			fsp = int8(fsps[i])
+		}
+
+		t, isNull, err := evalNowWithFsp(b.ctx, fsp)
+		if err != nil {
+			return err
+		}
+		if isNull {
+			result.SetNull(i, true)
+			continue
+		}
+
+		times[i] = t
+	}
+	return nil
 }
 
 func (b *builtinSubDateStringRealSig) vectorized() bool {

expression/builtin_time_vec_test.go

@@ -71,6 +71,9 @@ var vecBuiltinTimeCases = map[string][]vecExprBenchCase{
 	ast.MicroSecond: {},
 	ast.Now: {
 		{retEvalType: types.ETDatetime},
+		{retEvalType: types.ETDatetime, childrenTypes: []types.EvalType{types.ETInt},
+			geners: []dataGenerator{&rangeInt64Gener{0, 7}},
+		},
 	},
 	ast.DayOfWeek: {
 		{retEvalType: types.ETInt, childrenTypes: []types.EvalType{types.ETDatetime}},