exec: overflow handling for vectorized arithmetic

The overflow checks are done as part of the code generation in
overloads.go. The checks are done inline, rather than calling the
functions in the arith package for performance reasons.

The checks are only done for integer math. float math is already
well-defined since overflow will result in +Inf and -Inf as necessary.

The operations that these checks are relevant for are the SUM_INT
aggregator and projection. In the future, AVG will also benefit from
these overflow checks.

This changes the error message produced by overflows in the
non-vectorized SUM_INT aggregator so that the messages are consistent.
This should be fine in terms of postgres-compatibility since SUM_INT is
unique to CRDB and eventually we will get rid of it anyway.

resolves #38775

Release note: None

Makefile

@@ -802,7 +802,8 @@ EXECGEN_TARGETS = \
   pkg/sql/exec/vec_comparators.eg.go \
   pkg/sql/exec/vecbuiltins/rank.eg.go \
   pkg/sql/exec/vecbuiltins/row_number.eg.go \
-  pkg/sql/exec/zerocolumns.eg.go
+  pkg/sql/exec/zerocolumns.eg.go \
+  pkg/sql/exec/overloads_test_utils.eg.go
 
 execgen-exclusions = $(addprefix -not -path ,$(EXECGEN_TARGETS))
 

pkg/sql/exec/.gitignore

@@ -19,3 +19,4 @@ vec_comparators.eg.go
 vecbuiltins/rank.eg.go
 vecbuiltins/row_number.eg.go
 zerocolumns.eg.go
+overloads_test_utils.eg.go

pkg/sql/exec/execgen/cmd/execgen/overloads.go

@@ -14,6 +14,8 @@ import (
 	"errors"
 	"fmt"
 	"regexp"
+	"strings"
+	"text/template"
 
 	"github.com/cockroachdb/cockroach/pkg/sql/exec/types"
 	"github.com/cockroachdb/cockroach/pkg/sql/sem/tree"
@@ -103,7 +105,7 @@ var hashOverloads []*overload
 // Assign produces a Go source string that assigns the "target" variable to the
 // result of applying the overload to the two inputs, l and r.
 //
-// For example, an overload that implemented the int64 plus operation, when fed
+// For example, an overload that implemented the float64 plus operation, when fed
 // the inputs "x", "a", "b", would produce the string "x = a + b".
 func (o overload) Assign(target, l, r string) string {
 	if o.AssignFunc != nil {
@@ -349,6 +351,120 @@ func (c intCustomizer) getHashAssignFunc() assignFunc {
 	}
 }
 
+func (c intCustomizer) getBinOpAssignFunc() assignFunc {
+	return func(op overload, target, l, r string) string {
+		args := map[string]string{"Target": target, "Left": l, "Right": r}
+		buf := strings.Builder{}
+		var t *template.Template
+
+		switch op.BinOp {
+
+		case tree.Plus:
+			t = template.Must(template.New("").Parse(`
+				{
+					result := {{.Left}} + {{.Right}}
+					if (result < {{.Left}}) != ({{.Right}} < 0) {
+						panic(tree.ErrIntOutOfRange)
+					}
+					{{.Target}} = result
+				}
+			`))
+
+		case tree.Minus:
+			t = template.Must(template.New("").Parse(`
+				{
+					result := {{.Left}} - {{.Right}}
+					if (result < {{.Left}}) != ({{.Right}} > 0) {
+						panic(tree.ErrIntOutOfRange)
+					}
+					{{.Target}} = result
+				}
+			`))
+
+		case tree.Mult:
+			// If the inputs are small enough, then we don't have to do any further
+			// checks. For the sake of legibility, upperBound and lowerBound are both
+			// not set to their maximal/minimal values. An even more advanced check
+			// (for positive values) might involve adding together the highest bit
+			// positions of the inputs, and checking if the sum is less than the
+			// integer width.
+			var upperBound, lowerBound string
+			switch c.width {
+			case 8:
+				upperBound = "10"
+				lowerBound = "-10"
+			case 16:
+				upperBound = "math.MaxInt8"
+				lowerBound = "math.MinInt8"
+			case 32:
+				upperBound = "math.MaxInt16"
+				lowerBound = "math.MinInt16"
+			case 64:
+				upperBound = "math.MaxInt32"
+				lowerBound = "math.MinInt32"
+			default:
+				panic(fmt.Sprintf("unhandled integer width %d", c.width))
+			}
+
+			args["UpperBound"] = upperBound
+			args["LowerBound"] = lowerBound
+			t = template.Must(template.New("").Parse(`
+				{
+					result := {{.Left}} * {{.Right}}
+					if {{.Left}} > {{.UpperBound}} || {{.Left}} < {{.LowerBound}} || {{.Right}} > {{.UpperBound}} || {{.Right}} < {{.LowerBound}} {
+						if {{.Left}} != 0 && {{.Right}} != 0 {
+							sameSign := ({{.Left}} < 0) == ({{.Right}} < 0)
+							if (result < 0) == sameSign {
+								panic(tree.ErrIntOutOfRange)
+							} else if result/{{.Right}} != {{.Left}} {
+								panic(tree.ErrIntOutOfRange)
+							}
+						}
+					}
+					{{.Target}} = result
+				}
+			`))
+
+		case tree.Div:
+			var minInt string
+			switch c.width {
+			case 8:
+				minInt = "math.MinInt8"
+			case 16:
+				minInt = "math.MinInt16"
+			case 32:
+				minInt = "math.MinInt32"
+			case 64:
+				minInt = "math.MinInt64"
+			default:
+				panic(fmt.Sprintf("unhandled integer width %d", c.width))
+			}
+
+			args["MinInt"] = minInt
+			t = template.Must(template.New("").Parse(`
+				{
+					if {{.Right}} == 0 {
+						panic(tree.ErrDivByZero)
+					}
+					result := {{.Left}} / {{.Right}}
+					if {{.Left}} == {{.MinInt}} && {{.Right}} == -1 {
+						panic(tree.ErrIntOutOfRange)
+					}
+					{{.Target}} = result
+				}
+			`))
+
+		default:
+			panic(fmt.Sprintf("unhandled binary operator %s", op.BinOp.String()))
+		}
+
+		if err := t.Execute(&buf, args); err != nil {
+			panic(err)
+		}
+		return buf.String()
+	}
+}
+
 func registerTypeCustomizers() {
 	typeCustomizers = make(map[types.T]typeCustomizer)
 	registerTypeCustomizer(types.Bool, boolCustomizer{})

pkg/sql/exec/execgen/cmd/execgen/overloads_test_utils_gen.go

@@ -0,0 +1,65 @@
+// Copyright 2019 The Cockroach Authors.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+package main
+
+import (
+	"io"
+	"text/template"
+
+	"github.com/cockroachdb/cockroach/pkg/sql/exec/types"
+)
+
+const overloadsTestUtilsTemplate = `
+package exec
+
+import (
+  "math"
+
+	"github.com/cockroachdb/apd"
+	"github.com/cockroachdb/cockroach/pkg/sql/sem/tree"
+)
+
+{{define "opName"}}perform{{.Name}}{{.LTyp}}{{end}}
+
+{{/* The outer range is a types.T, and the inner is the overloads associated
+     with that type. */}}
+{{range .}}
+{{range .}}
+
+func {{template "opName" .}}(a, b {{.LTyp.GoTypeName}}) {{.RetTyp.GoTypeName}} {
+	{{(.Assign "a" "a" "b")}}
+	return a
+}
+
+{{end}}
+{{end}}
+`
+
+// genOverloadsTestUtils creates a file that has a function for each overload
+// defined in overloads.go. This is so that we can more easily test each
+// overload.
+func genOverloadsTestUtils(wr io.Writer) error {
+	tmpl, err := template.New("overloads_test_utils").Parse(overloadsTestUtilsTemplate)
+	if err != nil {
+		return err
+	}
+
+	typToOverloads := make(map[types.T][]*overload)
+	for _, overload := range binaryOpOverloads {
+		typ := overload.LTyp
+		typToOverloads[typ] = append(typToOverloads[typ], overload)
+	}
+	return tmpl.Execute(wr, typToOverloads)
+}
+
+func init() {
+	registerGenerator(genOverloadsTestUtils, "overloads_test_utils.eg.go")
+}

pkg/sql/exec/execgen/cmd/execgen/projection_ops_gen.go

@@ -23,6 +23,7 @@ package exec
 import (
 	"bytes"
   "context"
+  "math"
 
 	"github.com/cockroachdb/apd"
 	"github.com/cockroachdb/cockroach/pkg/sql/exec/coldata"

pkg/sql/exec/overloads_test.go

@@ -0,0 +1,121 @@
+// Copyright 2019 The Cockroach Authors.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+package exec
+
+import (
+	"math"
+	"testing"
+
+	"github.com/cockroachdb/cockroach/pkg/sql/sem/tree"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIntegerAddition(t *testing.T) {
+	// The addition overload is the same for all integer widths, so we only test
+	// one of them.
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performPlusInt16(1, math.MaxInt16) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performPlusInt16(-1, math.MinInt16) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performPlusInt16(math.MaxInt16, 1) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performPlusInt16(math.MinInt16, -1) })
+
+	assert.Equal(t, int16(math.MaxInt16), performPlusInt16(1, math.MaxInt16-1))
+	assert.Equal(t, int16(math.MinInt16), performPlusInt16(-1, math.MinInt16+1))
+	assert.Equal(t, int16(math.MaxInt16-1), performPlusInt16(-1, math.MaxInt16))
+	assert.Equal(t, int16(math.MinInt16+1), performPlusInt16(1, math.MinInt16))
+
+	assert.Equal(t, int16(22), performPlusInt16(10, 12))
+	assert.Equal(t, int16(-22), performPlusInt16(-10, -12))
+	assert.Equal(t, int16(2), performPlusInt16(-10, 12))
+	assert.Equal(t, int16(-2), performPlusInt16(10, -12))
+}
+
+func TestIntegerSubtraction(t *testing.T) {
+	// The subtraction overload is the same for all integer widths, so we only
+	// test one of them.
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMinusInt16(1, -math.MaxInt16) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMinusInt16(-2, math.MaxInt16) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMinusInt16(math.MaxInt16, -1) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMinusInt16(math.MinInt16, 1) })
+
+	assert.Equal(t, int16(math.MaxInt16), performMinusInt16(1, -math.MaxInt16+1))
+	assert.Equal(t, int16(math.MinInt16), performMinusInt16(-1, math.MaxInt16))
+	assert.Equal(t, int16(math.MaxInt16-1), performMinusInt16(-1, -math.MaxInt16))
+	assert.Equal(t, int16(math.MinInt16+1), performMinusInt16(0, math.MaxInt16))
+
+	assert.Equal(t, int16(-2), performMinusInt16(10, 12))
+	assert.Equal(t, int16(2), performMinusInt16(-10, -12))
+	assert.Equal(t, int16(-22), performMinusInt16(-10, 12))
+	assert.Equal(t, int16(22), performMinusInt16(10, -12))
+}
+
+func TestIntegerDivision(t *testing.T) {
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performDivInt8(math.MinInt8, -1) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performDivInt16(math.MinInt16, -1) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performDivInt32(math.MinInt32, -1) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performDivInt64(math.MinInt64, -1) })
+
+	assert.PanicsWithValue(t, tree.ErrDivByZero, func() { performDivInt8(10, 0) })
+	assert.PanicsWithValue(t, tree.ErrDivByZero, func() { performDivInt16(10, 0) })
+	assert.PanicsWithValue(t, tree.ErrDivByZero, func() { performDivInt32(10, 0) })
+	assert.PanicsWithValue(t, tree.ErrDivByZero, func() { performDivInt64(10, 0) })
+
+	assert.Equal(t, int8(-math.MaxInt8), performDivInt8(math.MaxInt8, -1))
+	assert.Equal(t, int16(-math.MaxInt16), performDivInt16(math.MaxInt16, -1))
+	assert.Equal(t, int32(-math.MaxInt32), performDivInt32(math.MaxInt32, -1))
+	assert.Equal(t, int64(-math.MaxInt64), performDivInt64(math.MaxInt64, -1))
+
+	assert.Equal(t, int16(0), performDivInt16(10, 12))
+	assert.Equal(t, int16(0), performDivInt16(-10, -12))
+	assert.Equal(t, int16(-1), performDivInt16(-12, 10))
+	assert.Equal(t, int16(-1), performDivInt16(12, -10))
+}
+
+func TestIntegerMultiplication(t *testing.T) {
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt8(math.MaxInt8-1, 100) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt8(math.MaxInt8-1, 3) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt8(math.MinInt8+1, 3) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt8(math.MinInt8+1, 100) })
+
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt16(math.MaxInt16-1, 100) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt16(math.MaxInt16-1, 3) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt16(math.MinInt16+1, 3) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt16(math.MinInt16+1, 100) })
+
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt32(math.MaxInt32-1, 100) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt32(math.MaxInt32-1, 3) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt32(math.MinInt32+1, 3) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt32(math.MinInt32+1, 100) })
+
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt64(math.MaxInt64-1, 100) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt64(math.MaxInt64-1, 3) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt64(math.MinInt64+1, 3) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt64(math.MinInt64+1, 100) })
+
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt8(math.MinInt8, -1) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt16(math.MinInt16, -1) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt32(math.MinInt32, -1) })
+	assert.PanicsWithValue(t, tree.ErrIntOutOfRange, func() { performMultInt64(math.MinInt64, -1) })
+
+	assert.Equal(t, int8(-math.MaxInt8), performMultInt8(math.MaxInt8, -1))
+	assert.Equal(t, int16(-math.MaxInt16), performMultInt16(math.MaxInt16, -1))
+	assert.Equal(t, int32(-math.MaxInt32), performMultInt32(math.MaxInt32, -1))
+	assert.Equal(t, int64(-math.MaxInt64), performMultInt64(math.MaxInt64, -1))
+
+	assert.Equal(t, int8(0), performMultInt8(math.MinInt8, 0))
+	assert.Equal(t, int16(0), performMultInt16(math.MinInt16, 0))
+	assert.Equal(t, int32(0), performMultInt32(math.MinInt32, 0))
+	assert.Equal(t, int64(0), performMultInt64(math.MinInt64, 0))
+
+	assert.Equal(t, int8(120), performMultInt8(10, 12))
+	assert.Equal(t, int16(120), performMultInt16(-10, -12))
+	assert.Equal(t, int32(-120), performMultInt32(-12, 10))
+	assert.Equal(t, int64(-120), performMultInt64(12, -10))
+}

pkg/sql/logictest/testdata/logic_test/edge

@@ -195,7 +195,7 @@ WHERE
 ----
 131068  8589934588
 
-statement error sum exceeded int range
+statement error integer out of range
 SELECT sum_int(t._int8) FROM t, t AS u WHERE t.key = 'max'
 
 query RRRRRRRRRR
@@ -227,7 +227,7 @@ WHERE
 ----
 -131072  -8589934592
 
-statement error sum exceeded int range
+statement error integer out of range
 SELECT sum_int(t._int8) FROM t, t AS u WHERE t.key = 'min'
 
 query RRRRRRRRRR

pkg/sql/logictest/testdata/logic_test/overflow

@@ -0,0 +1,21 @@
+# LogicTest: local-vec local-opt fakedist fakedist-opt fakedist-metadata
+
+# Test for overflow handling in sum aggregate.
+
+statement ok
+CREATE TABLE large_numbers (a INT8)
+
+statement ok
+INSERT INTO large_numbers VALUES (9223372036854775807),(1)
+
+statement error integer out of range
+SELECT sum_int(a) FROM large_numbers
+
+statement ok
+DELETE FROM large_numbers
+
+statement ok
+INSERT INTO large_numbers VALUES (-9223372036854775808),(-1)
+
+statement error integer out of range
+SELECT sum_int(a) FROM large_numbers