math/big: cut 2 minutes off race tests

No need to test so many sizes in race mode, especially for a package
which doesn't use goroutines.

Reduces test time from 2.5 minutes to 25 seconds.

Updates #17104

Change-Id: I7065b39273f82edece385c0d67b3f2d83d4934b8
Reviewed-on: https://go-review.googlesource.com/29163
Reviewed-by: David Crawshaw <crawshaw@golang.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/math/big/arith_test.go b/src/math/big/arith_test.go
index 75862b4951..f2b3083000 100644
--- a/src/math/big/arith_test.go
+++ b/src/math/big/arith_test.go
@@ -6,10 +6,14 @@ package big
 
 import (
 	"fmt"
+	"internal/testenv"
 	"math/rand"
+	"strings"
 	"testing"
 )
 
+var isRaceBuilder = strings.HasSuffix(testenv.Builder(), "-race")
+
 type funWW func(x, y, c Word) (z1, z0 Word)
 type argWW struct {
 	x, y, c, z1, z0 Word
@@ -123,6 +127,9 @@ var benchSizes = []int{1, 2, 3, 4, 5, 1e1, 1e2, 1e3, 1e4, 1e5}
 
 func BenchmarkAddVV(b *testing.B) {
 	for _, n := range benchSizes {
+		if isRaceBuilder && n > 1e3 {
+			continue
+		}
 		x := rndV(n)
 		y := rndV(n)
 		z := make([]Word, n)
@@ -233,6 +240,9 @@ func TestFunVW(t *testing.T) {
 
 func BenchmarkAddVW(b *testing.B) {
 	for _, n := range benchSizes {
+		if isRaceBuilder && n > 1e3 {
+			continue
+		}
 		x := rndV(n)
 		y := rndW()
 		z := make([]Word, n)
@@ -371,6 +381,9 @@ func TestMulAddWWW(t *testing.T) {
 
 func BenchmarkAddMulVVW(b *testing.B) {
 	for _, n := range benchSizes {
+		if isRaceBuilder && n > 1e3 {
+			continue
+		}
 		x := rndV(n)
 		y := rndW()
 		z := make([]Word, n)