expression: implement vectorized evaluation for builtinRoundWithFracI…

…ntSig (pingcap#12103)

expression/builtin_math_vec.go

@@ -431,3 +431,34 @@ func (b *builtinAbsIntSig) vecEvalInt(input *chunk.Chunk, result *chunk.Column)
 func (b *builtinAbsIntSig) vectorized() bool {
 	return true
 }
+
+func (b *builtinRoundWithFracIntSig) vecEvalInt(input *chunk.Chunk, result *chunk.Column) error {
+	if err := b.args[0].VecEvalInt(b.ctx, input, result); err != nil {
+		return err
+	}
+
+	n := input.NumRows()
+	buf, err := b.bufAllocator.get(types.ETInt, n)
+	if err != nil {
+		return err
+	}
+	defer b.bufAllocator.put(buf)
+	if err := b.args[1].VecEvalInt(b.ctx, input, buf); err != nil {
+		return err
+	}
+
+	i64s := result.Int64s()
+	frac := buf.Int64s()
+	result.MergeNulls(buf)
+	for i := 0; i < n; i++ {
+		if result.IsNull(i) {
+			continue
+		}
+		i64s[i] = int64(types.Round(float64(i64s[i]), int(frac[i])))
+	}
+	return nil
+}
+
+func (b *builtinRoundWithFracIntSig) vectorized() bool {
+	return true
+}

expression/builtin_math_vec_test.go

@@ -70,6 +70,7 @@ var vecBuiltinMathCases = map[string][]vecExprBenchCase{
 	},
 	ast.Round: {
 		{types.ETDecimal, []types.EvalType{types.ETDecimal}, nil},
+		{types.ETInt, []types.EvalType{types.ETInt, types.ETInt}, []dataGenerator{nil, &rangeInt64Gener{-100, 100}}},
 	},
 	ast.Pow: {
 		{types.ETReal, []types.EvalType{types.ETReal, types.ETReal}, []dataGenerator{&rangeRealGener{0, 10, 0.5}, &rangeRealGener{0, 100, 0.5}}},