From 648bed40d3ab2bd7a666efc8ef745857b06e6445 Mon Sep 17 00:00:00 2001
From: Zhongyang Wu <zhongyang.wu@outlook.com>
Date: Mon, 4 Nov 2019 23:43:39 -0500
Subject: [PATCH] expression: implement vectorized evaluation for
 `builtinCRC32Sig` (#13126)

---
 expression/builtin_math_vec.go      | 22 ++++++++++++++++++++--
 expression/builtin_math_vec_test.go |  3 +++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/expression/builtin_math_vec.go b/expression/builtin_math_vec.go
index 571df82255..def5de04b6 100644
--- a/expression/builtin_math_vec.go
+++ b/expression/builtin_math_vec.go
@@ -15,6 +15,7 @@ package expression
 
 import (
 	"fmt"
+	"hash/crc32"
 	"math"
 	"strconv"
 
@@ -658,11 +659,28 @@ func (b *builtinRoundWithFracIntSig) vectorized() bool {
 	return true
 }
 func (b *builtinCRC32Sig) vectorized() bool {
-	return false
+	return true
 }
 
 func (b *builtinCRC32Sig) vecEvalInt(input *chunk.Chunk, result *chunk.Column) error {
-	return errors.Errorf("not implemented")
+	n := input.NumRows()
+	buf, err := b.bufAllocator.get(types.ETString, n)
+	if err != nil {
+		return err
+	}
+	defer b.bufAllocator.put(buf)
+	if err := b.args[0].VecEvalString(b.ctx, input, buf); err != nil {
+		return err
+	}
+	result.ResizeInt64(n, false)
+	i64s := result.Int64s()
+	result.MergeNulls(buf)
+	for i := range i64s {
+		if !buf.IsNull(i) {
+			i64s[i] = int64(crc32.ChecksumIEEE(buf.GetBytes(i)))
+		}
+	}
+	return nil
 }
 
 func (b *builtinPISig) vectorized() bool {
diff --git a/expression/builtin_math_vec_test.go b/expression/builtin_math_vec_test.go
index 5a90a0f031..230372109d 100644
--- a/expression/builtin_math_vec_test.go
+++ b/expression/builtin_math_vec_test.go
@@ -110,6 +110,9 @@ var vecBuiltinMathCases = map[string][]vecExprBenchCase{
 		{retEvalType: types.ETInt, childrenTypes: []types.EvalType{types.ETInt, types.ETInt}, geners: []dataGenerator{nil, &rangeInt64Gener{-10, 10}}},
 		{retEvalType: types.ETInt, childrenTypes: []types.EvalType{types.ETInt, types.ETInt}, childrenFieldTypes: []*types.FieldType{{Tp: mysql.TypeInt24, Flag: mysql.UnsignedFlag}}, geners: []dataGenerator{nil, &rangeInt64Gener{-10, 10}}},
 	},
+	ast.CRC32: {
+		{retEvalType: types.ETInt, childrenTypes: []types.EvalType{types.ETString}},
+	},
 }
 
 func (s *testEvaluatorSuite) TestVectorizedBuiltinMathEvalOneVec(c *C) {