1 files changed, 27 insertions, 43 deletions

diff --git a/src/pkg/strconv/ftoa_test.go b/src/pkg/strconv/ftoa_test.go
index 7d8617a85..39b861547 100644
--- a/src/pkg/strconv/ftoa_test.go
+++ b/src/pkg/strconv/ftoa_test.go
@@ -163,6 +163,7 @@ func TestFtoaRandom(t *testing.T) {
 	for i := 0; i < N; i++ {
 		bits := uint64(rand.Uint32())<<32 | uint64(rand.Uint32())
 		x := math.Float64frombits(bits)
+
 		shortFast := FormatFloat(x, 'g', -1, 64)
 		SetOptimize(false)
 		shortSlow := FormatFloat(x, 'g', -1, 64)
@@ -170,23 +171,15 @@ func TestFtoaRandom(t *testing.T) {
 		if shortSlow != shortFast {
 			t.Errorf("%b printed as %s, want %s", x, shortFast, shortSlow)
 		}
-	}
-}
 
-func TestAppendFloatDoesntAllocate(t *testing.T) {
-	n := numAllocations(func() {
-		var buf [64]byte
-		AppendFloat(buf[:0], 1.23, 'g', 5, 64)
-	})
-	want := 1 // TODO(bradfitz): this might be 0, once escape analysis is better
-	if n != want {
-		t.Errorf("with local buffer, did %d allocations, want %d", n, want)
-	}
-	n = numAllocations(func() {
-		AppendFloat(globalBuf[:0], 1.23, 'g', 5, 64)
-	})
-	if n != 0 {
-		t.Errorf("with reused buffer, did %d allocations, want 0", n)
+		prec := rand.Intn(12) + 5
+		shortFast = FormatFloat(x, 'e', prec, 64)
+		SetOptimize(false)
+		shortSlow = FormatFloat(x, 'e', prec, 64)
+		SetOptimize(true)
+		if shortSlow != shortFast {
+			t.Errorf("%b printed as %s, want %s", x, shortFast, shortSlow)
+		}
 	}
 }
 
@@ -220,37 +213,28 @@ func BenchmarkFormatFloatBig(b *testing.B) {
 	}
 }
 
-func BenchmarkAppendFloatDecimal(b *testing.B) {
-	dst := make([]byte, 0, 30)
+func benchmarkAppendFloat(b *testing.B, f float64, fmt byte, prec, bitSize int) {
+	dst := make([]byte, 30)
 	for i := 0; i < b.N; i++ {
-		AppendFloat(dst, 33909, 'g', -1, 64)
+		AppendFloat(dst[:0], f, fmt, prec, bitSize)
 	}
 }
 
-func BenchmarkAppendFloat(b *testing.B) {
-	dst := make([]byte, 0, 30)
-	for i := 0; i < b.N; i++ {
-		AppendFloat(dst, 339.7784, 'g', -1, 64)
-	}
-}
-
-func BenchmarkAppendFloatExp(b *testing.B) {
-	dst := make([]byte, 0, 30)
-	for i := 0; i < b.N; i++ {
-		AppendFloat(dst, -5.09e75, 'g', -1, 64)
-	}
+func BenchmarkAppendFloatDecimal(b *testing.B) { benchmarkAppendFloat(b, 33909, 'g', -1, 64) }
+func BenchmarkAppendFloat(b *testing.B)        { benchmarkAppendFloat(b, 339.7784, 'g', -1, 64) }
+func BenchmarkAppendFloatExp(b *testing.B)     { benchmarkAppendFloat(b, -5.09e75, 'g', -1, 64) }
+func BenchmarkAppendFloatNegExp(b *testing.B)  { benchmarkAppendFloat(b, -5.11e-95, 'g', -1, 64) }
+func BenchmarkAppendFloatBig(b *testing.B) {
+	benchmarkAppendFloat(b, 123456789123456789123456789, 'g', -1, 64)
 }
 
-func BenchmarkAppendFloatNegExp(b *testing.B) {
-	dst := make([]byte, 0, 30)
-	for i := 0; i < b.N; i++ {
-		AppendFloat(dst, -5.11e-95, 'g', -1, 64)
-	}
-}
+func BenchmarkAppendFloat32Integer(b *testing.B)       { benchmarkAppendFloat(b, 33909, 'g', -1, 32) }
+func BenchmarkAppendFloat32ExactFraction(b *testing.B) { benchmarkAppendFloat(b, 3.375, 'g', -1, 32) }
+func BenchmarkAppendFloat32Point(b *testing.B)         { benchmarkAppendFloat(b, 339.7784, 'g', -1, 32) }
+func BenchmarkAppendFloat32Exp(b *testing.B)           { benchmarkAppendFloat(b, -5.09e25, 'g', -1, 32) }
+func BenchmarkAppendFloat32NegExp(b *testing.B)        { benchmarkAppendFloat(b, -5.11e-25, 'g', -1, 32) }
 
-func BenchmarkAppendFloatBig(b *testing.B) {
-	dst := make([]byte, 0, 30)
-	for i := 0; i < b.N; i++ {
-		AppendFloat(dst, 123456789123456789123456789, 'g', -1, 64)
-	}
-}
+func BenchmarkAppendFloat64Fixed1(b *testing.B) { benchmarkAppendFloat(b, 123456, 'e', 3, 64) }
+func BenchmarkAppendFloat64Fixed2(b *testing.B) { benchmarkAppendFloat(b, 123.456, 'e', 3, 64) }
+func BenchmarkAppendFloat64Fixed3(b *testing.B) { benchmarkAppendFloat(b, 1.23456e+78, 'e', 3, 64) }
+func BenchmarkAppendFloat64Fixed4(b *testing.B) { benchmarkAppendFloat(b, 1.23456e-78, 'e', 3, 64) }