1 files changed, 74 insertions, 4 deletions

diff --git a/libgo/go/strconv/itoa_test.go b/libgo/go/strconv/itoa_test.go
index 48dc03e8390..89c2de6941a 100644
--- a/libgo/go/strconv/itoa_test.go
+++ b/libgo/go/strconv/itoa_test.go
@@ -126,10 +126,46 @@ func TestUitoa(t *testing.T) {
 	}
 }
 
+var varlenUints = []struct {
+	in  uint64
+	out string
+}{
+	{1, "1"},
+	{12, "12"},
+	{123, "123"},
+	{1234, "1234"},
+	{12345, "12345"},
+	{123456, "123456"},
+	{1234567, "1234567"},
+	{12345678, "12345678"},
+	{123456789, "123456789"},
+	{1234567890, "1234567890"},
+	{12345678901, "12345678901"},
+	{123456789012, "123456789012"},
+	{1234567890123, "1234567890123"},
+	{12345678901234, "12345678901234"},
+	{123456789012345, "123456789012345"},
+	{1234567890123456, "1234567890123456"},
+	{12345678901234567, "12345678901234567"},
+	{123456789012345678, "123456789012345678"},
+	{1234567890123456789, "1234567890123456789"},
+	{12345678901234567890, "12345678901234567890"},
+}
+
+func TestFormatUintVarlen(t *testing.T) {
+	for _, test := range varlenUints {
+		s := FormatUint(test.in, 10)
+		if s != test.out {
+			t.Errorf("FormatUint(%v, 10) = %v want %v", test.in, s, test.out)
+		}
+	}
+}
+
 func BenchmarkFormatInt(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		for _, test := range itob64tests {
-			FormatInt(test.in, test.base)
+			s := FormatInt(test.in, test.base)
+			BenchSink += len(s)
 		}
 	}
 }
@@ -138,7 +174,8 @@ func BenchmarkAppendInt(b *testing.B) {
 	dst := make([]byte, 0, 30)
 	for i := 0; i < b.N; i++ {
 		for _, test := range itob64tests {
-			AppendInt(dst, test.in, test.base)
+			dst = AppendInt(dst[:0], test.in, test.base)
+			BenchSink += len(dst)
 		}
 	}
 }
@@ -146,7 +183,8 @@ func BenchmarkAppendInt(b *testing.B) {
 func BenchmarkFormatUint(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		for _, test := range uitob64tests {
-			FormatUint(test.in, test.base)
+			s := FormatUint(test.in, test.base)
+			BenchSink += len(s)
 		}
 	}
 }
@@ -155,7 +193,39 @@ func BenchmarkAppendUint(b *testing.B) {
 	dst := make([]byte, 0, 30)
 	for i := 0; i < b.N; i++ {
 		for _, test := range uitob64tests {
-			AppendUint(dst, test.in, test.base)
+			dst = AppendUint(dst[:0], test.in, test.base)
+			BenchSink += len(dst)
 		}
 	}
 }
+
+func BenchmarkFormatIntSmall(b *testing.B) {
+	const smallInt = 42
+	for i := 0; i < b.N; i++ {
+		s := FormatInt(smallInt, 10)
+		BenchSink += len(s)
+	}
+}
+
+func BenchmarkAppendIntSmall(b *testing.B) {
+	dst := make([]byte, 0, 30)
+	const smallInt = 42
+	for i := 0; i < b.N; i++ {
+		dst = AppendInt(dst[:0], smallInt, 10)
+		BenchSink += len(dst)
+	}
+}
+
+func BenchmarkAppendUintVarlen(b *testing.B) {
+	for _, test := range varlenUints {
+		b.Run(test.out, func(b *testing.B) {
+			dst := make([]byte, 0, 30)
+			for j := 0; j < b.N; j++ {
+				dst = AppendUint(dst[:0], test.in, 10)
+				BenchSink += len(dst)
+			}
+		})
+	}
+}
+
+var BenchSink int // make sure compiler cannot optimize away benchmarks