code review 5502079: strconv: faster FormatFloat(x, *, -1, 64) using Grisu3 ...

src/pkg/strconv/ftoa_test.go

 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 package strconv_test
 
 import (
         "math"
         "math/rand"
         . "strconv"
@@ skipping 106 matching lines @@
         {0.05, 'f', 1, "0.1"},
         {0.05, 'f', 0, "0"},
         {0.5, 'f', 1, "0.5"},
         {0.5, 'f', 0, "0"},
         {1.5, 'f', 0, "2"},
 
         // http://www.exploringbinary.com/java-hangs-when-converting-2-2250738585072012e-308/
         {2.2250738585072012e-308, 'g', -1, "2.2250738585072014e-308"},
         // http://www.exploringbinary.com/php-hangs-on-numeric-value-2-2250738585072011e-308/
         {2.2250738585072011e-308, 'g', -1, "2.225073858507201e-308"},
+
+        // Issue 2625.
+        {383260575764816448, 'f', 0, "383260575764816448"},
+        {383260575764816448, 'g', -1, "3.8326057576481645e+17"},
 }
 
 func TestFtoa(t *testing.T) {
         for i := 0; i < len(ftoatests); i++ {
                 test := &ftoatests[i]
                 s := FormatFloat(test.f, test.fmt, test.prec, 64)
                 if s != test.s {
                         t.Error("testN=64", test.f, string(test.fmt), test.prec, "want", test.s, "got", s)
                 }
                 x := AppendFloat([]byte("abc"), test.f, test.fmt, test.prec, 64)
@@ skipping 106 matching lines @@
                 AppendFloat(dst, -5.11e-95, 'g', -1, 64)
         }
 }
 
 func BenchmarkAppendFloatBig(b *testing.B) {
         dst := make([]byte, 0, 30)
         for i := 0; i < b.N; i++ {
                 AppendFloat(dst, 123456789123456789123456789, 'g', -1, 64)
         }
 }