1 files changed, 82 insertions, 40 deletions
diff --git a/libgo/go/testing/benchmark_test.go b/libgo/go/testing/benchmark_test.go
index 431bb53..1434c26 100644
--- a/libgo/go/testing/benchmark_test.go
+++ b/libgo/go/testing/benchmark_test.go
@@ -7,63 +7,70 @@ package testing_test
 import (
 	"bytes"
 	"runtime"
+	"sort"
+	"strings"
 	"sync/atomic"
 	"testing"
 	"text/template"
+	"time"
 )
 
-var roundDownTests = []struct {
-	v, expected int
+var prettyPrintTests = []struct {
+	v        float64
+	expected string
 }{
-	{1, 1},
-	{9, 1},
-	{10, 10},
-	{11, 10},
-	{100, 100},
-	{101, 100},
-	{999, 100},
-	{1000, 1000},
-	{1001, 1000},
+	{0, "         0 x"},
+	{1234.1, "      1234 x"},
+	{-1234.1, "     -1234 x"},
+	{99.950001, "       100 x"},
+	{99.949999, "        99.9 x"},
+	{9.9950001, "        10.0 x"},
+	{9.9949999, "         9.99 x"},
+	{-9.9949999, "        -9.99 x"},
+	{0.0099950001, "         0.0100 x"},
+	{0.0099949999, "         0.00999 x"},
 }
 
-func TestRoundDown10(t *testing.T) {
-	for _, tt := range roundDownTests {
-		actual := testing.RoundDown10(tt.v)
-		if tt.expected != actual {
-			t.Errorf("roundDown10(%d): expected %d, actual %d", tt.v, tt.expected, actual)
+func TestPrettyPrint(t *testing.T) {
+	for _, tt := range prettyPrintTests {
+		buf := new(strings.Builder)
+		testing.PrettyPrint(buf, tt.v, "x")
+		if tt.expected != buf.String() {
+			t.Errorf("prettyPrint(%v): expected %q, actual %q", tt.v, tt.expected, buf.String())
 		}
 	}
 }
 
-var roundUpTests = []struct {
-	v, expected int
-}{
-	{0, 1},
-	{1, 1},
-	{2, 2},
-	{3, 3},
-	{5, 5},
-	{9, 10},
-	{999, 1000},
-	{1000, 1000},
-	{1400, 2000},
-	{1700, 2000},
-	{2700, 3000},
-	{4999, 5000},
-	{5000, 5000},
-	{5001, 10000},
-}
+func TestResultString(t *testing.T) {
+	// Test fractional ns/op handling
+	r := testing.BenchmarkResult{
+		N: 100,
+		T: 240 * time.Nanosecond,
+	}
+	if r.NsPerOp() != 2 {
+		t.Errorf("NsPerOp: expected 2, actual %v", r.NsPerOp())
+	}
+	if want, got := "     100\t         2.40 ns/op", r.String(); want != got {
+		t.Errorf("String: expected %q, actual %q", want, got)
+	}
 
-func TestRoundUp(t *testing.T) {
-	for _, tt := range roundUpTests {
-		actual := testing.RoundUp(tt.v)
-		if tt.expected != actual {
-			t.Errorf("roundUp(%d): expected %d, actual %d", tt.v, tt.expected, actual)
-		}
+	// Test sub-1 ns/op (issue #31005)
+	r.T = 40 * time.Nanosecond
+	if want, got := "     100\t         0.400 ns/op", r.String(); want != got {
+		t.Errorf("String: expected %q, actual %q", want, got)
+	}
+
+	// Test 0 ns/op
+	r.T = 0
+	if want, got := "     100", r.String(); want != got {
+		t.Errorf("String: expected %q, actual %q", want, got)
 	}
 }
 
 func TestRunParallel(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping in short mode")
+	}
 	testing.Benchmark(func(b *testing.B) {
 		procs := uint32(0)
 		iters := uint64(0)
@@ -111,3 +118,38 @@ func ExampleB_RunParallel() {
 		})
 	})
 }
+
+func TestReportMetric(t *testing.T) {
+	res := testing.Benchmark(func(b *testing.B) {
+		b.ReportMetric(12345, "ns/op")
+		b.ReportMetric(0.2, "frobs/op")
+	})
+	// Test built-in overriding.
+	if res.NsPerOp() != 12345 {
+		t.Errorf("NsPerOp: expected %v, actual %v", 12345, res.NsPerOp())
+	}
+	// Test stringing.
+	res.N = 1 // Make the output stable
+	want := "       1\t     12345 ns/op\t         0.200 frobs/op"
+	if want != res.String() {
+		t.Errorf("expected %q, actual %q", want, res.String())
+	}
+}
+
+func ExampleB_ReportMetric() {
+	// This reports a custom benchmark metric relevant to a
+	// specific algorithm (in this case, sorting).
+	testing.Benchmark(func(b *testing.B) {
+		var compares int64
+		for i := 0; i < b.N; i++ {
+			s := []int{5, 4, 3, 2, 1}
+			sort.Slice(s, func(i, j int) bool {
+				compares++
+				return s[i] < s[j]
+			})
+		}
+		// This metric is per-operation, so divide by b.N and
+		// report it as a "/op" unit.
+		b.ReportMetric(float64(compares)/float64(b.N), "compares/op")
+	})
+}