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Editing: atof_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" "reflect" . "strconv" "strings" "sync" "testing" ) type atofTest struct { in string out string err error } var atoftests = []atofTest{ {"", "0", ErrSyntax}, {"1", "1", nil}, {"+1", "1", nil}, {"1x", "0", ErrSyntax}, {"1.1.", "0", ErrSyntax}, {"1e23", "1e+23", nil}, {"1E23", "1e+23", nil}, {"100000000000000000000000", "1e+23", nil}, {"1e-100", "1e-100", nil}, {"123456700", "1.234567e+08", nil}, {"99999999999999974834176", "9.999999999999997e+22", nil}, {"100000000000000000000001", "1.0000000000000001e+23", nil}, {"100000000000000008388608", "1.0000000000000001e+23", nil}, {"100000000000000016777215", "1.0000000000000001e+23", nil}, {"100000000000000016777216", "1.0000000000000003e+23", nil}, {"-1", "-1", nil}, {"-0.1", "-0.1", nil}, {"-0", "-0", nil}, {"1e-20", "1e-20", nil}, {"625e-3", "0.625", nil}, // Hexadecimal floating-point. {"0x1p0", "1", nil}, {"0x1p1", "2", nil}, {"0x1p-1", "0.5", nil}, {"0x1ep-1", "15", nil}, {"-0x1ep-1", "-15", nil}, {"-0x1_ep-1", "-15", nil}, {"0x1p-200", "6.223015277861142e-61", nil}, {"0x1p200", "1.6069380442589903e+60", nil}, {"0x1fFe2.p0", "131042", nil}, {"0x1fFe2.P0", "131042", nil}, {"-0x2p3", "-16", nil}, {"0x0.fp4", "15", nil}, {"0x0.fp0", "0.9375", nil}, {"0x1e2", "0", ErrSyntax}, {"1p2", "0", ErrSyntax}, // zeros {"0", "0", nil}, {"0e0", "0", nil}, {"-0e0", "-0", nil}, {"+0e0", "0", nil}, {"0e-0", "0", nil}, {"-0e-0", "-0", nil}, {"+0e-0", "0", nil}, {"0e+0", "0", nil}, {"-0e+0", "-0", nil}, {"+0e+0", "0", nil}, {"0e+01234567890123456789", "0", nil}, {"0.00e-01234567890123456789", "0", nil}, {"-0e+01234567890123456789", "-0", nil}, {"-0.00e-01234567890123456789", "-0", nil}, {"0x0p+01234567890123456789", "0", nil}, {"0x0.00p-01234567890123456789", "0", nil}, {"-0x0p+01234567890123456789", "-0", nil}, {"-0x0.00p-01234567890123456789", "-0", nil}, {"0e291", "0", nil}, // issue 15364 {"0e292", "0", nil}, // issue 15364 {"0e347", "0", nil}, // issue 15364 {"0e348", "0", nil}, // issue 15364 {"-0e291", "-0", nil}, {"-0e292", "-0", nil}, {"-0e347", "-0", nil}, {"-0e348", "-0", nil}, {"0x0p126", "0", nil}, {"0x0p127", "0", nil}, {"0x0p128", "0", nil}, {"0x0p129", "0", nil}, {"0x0p130", "0", nil}, {"0x0p1022", "0", nil}, {"0x0p1023", "0", nil}, {"0x0p1024", "0", nil}, {"0x0p1025", "0", nil}, {"0x0p1026", "0", nil}, {"-0x0p126", "-0", nil}, {"-0x0p127", "-0", nil}, {"-0x0p128", "-0", nil}, {"-0x0p129", "-0", nil}, {"-0x0p130", "-0", nil}, {"-0x0p1022", "-0", nil}, {"-0x0p1023", "-0", nil}, {"-0x0p1024", "-0", nil}, {"-0x0p1025", "-0", nil}, {"-0x0p1026", "-0", nil}, // NaNs {"nan", "NaN", nil}, {"NaN", "NaN", nil}, {"NAN", "NaN", nil}, // Infs {"inf", "+Inf", nil}, {"-Inf", "-Inf", nil}, {"+INF", "+Inf", nil}, {"-Infinity", "-Inf", nil}, {"+INFINITY", "+Inf", nil}, {"Infinity", "+Inf", nil}, // largest float64 {"1.7976931348623157e308", "1.7976931348623157e+308", nil}, {"-1.7976931348623157e308", "-1.7976931348623157e+308", nil}, {"0x1.fffffffffffffp1023", "1.7976931348623157e+308", nil}, {"-0x1.fffffffffffffp1023", "-1.7976931348623157e+308", nil}, {"0x1fffffffffffffp+971", "1.7976931348623157e+308", nil}, {"-0x1fffffffffffffp+971", "-1.7976931348623157e+308", nil}, {"0x.1fffffffffffffp1027", "1.7976931348623157e+308", nil}, {"-0x.1fffffffffffffp1027", "-1.7976931348623157e+308", nil}, // next float64 - too large {"1.7976931348623159e308", "+Inf", ErrRange}, {"-1.7976931348623159e308", "-Inf", ErrRange}, {"0x1p1024", "+Inf", ErrRange}, {"-0x1p1024", "-Inf", ErrRange}, {"0x2p1023", "+Inf", ErrRange}, {"-0x2p1023", "-Inf", ErrRange}, {"0x.1p1028", "+Inf", ErrRange}, {"-0x.1p1028", "-Inf", ErrRange}, {"0x.2p1027", "+Inf", ErrRange}, {"-0x.2p1027", "-Inf", ErrRange}, // the border is ...158079 // borderline - okay {"1.7976931348623158e308", "1.7976931348623157e+308", nil}, {"-1.7976931348623158e308", "-1.7976931348623157e+308", nil}, {"0x1.fffffffffffff7fffp1023", "1.7976931348623157e+308", nil}, {"-0x1.fffffffffffff7fffp1023", "-1.7976931348623157e+308", nil}, // borderline - too large {"1.797693134862315808e308", "+Inf", ErrRange}, {"-1.797693134862315808e308", "-Inf", ErrRange}, {"0x1.fffffffffffff8p1023", "+Inf", ErrRange}, {"-0x1.fffffffffffff8p1023", "-Inf", ErrRange}, {"0x1fffffffffffff.8p+971", "+Inf", ErrRange}, {"-0x1fffffffffffff8p+967", "-Inf", ErrRange}, {"0x.1fffffffffffff8p1027", "+Inf", ErrRange}, {"-0x.1fffffffffffff9p1027", "-Inf", ErrRange}, // a little too large {"1e308", "1e+308", nil}, {"2e308", "+Inf", ErrRange}, {"1e309", "+Inf", ErrRange}, {"0x1p1025", "+Inf", ErrRange}, // way too large {"1e310", "+Inf", ErrRange}, {"-1e310", "-Inf", ErrRange}, {"1e400", "+Inf", ErrRange}, {"-1e400", "-Inf", ErrRange}, {"1e400000", "+Inf", ErrRange}, {"-1e400000", "-Inf", ErrRange}, {"0x1p1030", "+Inf", ErrRange}, {"0x1p2000", "+Inf", ErrRange}, {"0x1p2000000000", "+Inf", ErrRange}, {"-0x1p1030", "-Inf", ErrRange}, {"-0x1p2000", "-Inf", ErrRange}, {"-0x1p2000000000", "-Inf", ErrRange}, // denormalized {"1e-305", "1e-305", nil}, {"1e-306", "1e-306", nil}, {"1e-307", "1e-307", nil}, {"1e-308", "1e-308", nil}, {"1e-309", "1e-309", nil}, {"1e-310", "1e-310", nil}, {"1e-322", "1e-322", nil}, // smallest denormal {"5e-324", "5e-324", nil}, {"4e-324", "5e-324", nil}, {"3e-324", "5e-324", nil}, // too small {"2e-324", "0", nil}, // way too small {"1e-350", "0", nil}, {"1e-400000", "0", nil}, // Near denormals and denormals. {"0x2.00000000000000p-1010", "1.8227805048890994e-304", nil}, // 0x00e0000000000000 {"0x1.fffffffffffff0p-1010", "1.8227805048890992e-304", nil}, // 0x00dfffffffffffff {"0x1.fffffffffffff7p-1010", "1.8227805048890992e-304", nil}, // rounded down {"0x1.fffffffffffff8p-1010", "1.8227805048890994e-304", nil}, // rounded up {"0x1.fffffffffffff9p-1010", "1.8227805048890994e-304", nil}, // rounded up {"0x2.00000000000000p-1022", "4.450147717014403e-308", nil}, // 0x0020000000000000 {"0x1.fffffffffffff0p-1022", "4.4501477170144023e-308", nil}, // 0x001fffffffffffff {"0x1.fffffffffffff7p-1022", "4.4501477170144023e-308", nil}, // rounded down {"0x1.fffffffffffff8p-1022", "4.450147717014403e-308", nil}, // rounded up {"0x1.fffffffffffff9p-1022", "4.450147717014403e-308", nil}, // rounded up {"0x1.00000000000000p-1022", "2.2250738585072014e-308", nil}, // 0x0010000000000000 {"0x0.fffffffffffff0p-1022", "2.225073858507201e-308", nil}, // 0x000fffffffffffff {"0x0.ffffffffffffe0p-1022", "2.2250738585072004e-308", nil}, // 0x000ffffffffffffe {"0x0.ffffffffffffe7p-1022", "2.2250738585072004e-308", nil}, // rounded down {"0x1.ffffffffffffe8p-1023", "2.225073858507201e-308", nil}, // rounded up {"0x1.ffffffffffffe9p-1023", "2.225073858507201e-308", nil}, // rounded up {"0x0.00000003fffff0p-1022", "2.072261e-317", nil}, // 0x00000000003fffff {"0x0.00000003456780p-1022", "1.694649e-317", nil}, // 0x0000000000345678 {"0x0.00000003456787p-1022", "1.694649e-317", nil}, // rounded down {"0x0.00000003456788p-1022", "1.694649e-317", nil}, // rounded down (half to even) {"0x0.00000003456790p-1022", "1.6946496e-317", nil}, // 0x0000000000345679 {"0x0.00000003456789p-1022", "1.6946496e-317", nil}, // rounded up {"0x0.0000000345678800000000000000000000000001p-1022", "1.6946496e-317", nil}, // rounded up {"0x0.000000000000f0p-1022", "7.4e-323", nil}, // 0x000000000000000f {"0x0.00000000000060p-1022", "3e-323", nil}, // 0x0000000000000006 {"0x0.00000000000058p-1022", "3e-323", nil}, // rounded up {"0x0.00000000000057p-1022", "2.5e-323", nil}, // rounded down {"0x0.00000000000050p-1022", "2.5e-323", nil}, // 0x0000000000000005 {"0x0.00000000000010p-1022", "5e-324", nil}, // 0x0000000000000001 {"0x0.000000000000081p-1022", "5e-324", nil}, // rounded up {"0x0.00000000000008p-1022", "0", nil}, // rounded down {"0x0.00000000000007fp-1022", "0", nil}, // rounded down // try to overflow exponent {"1e-4294967296", "0", nil}, {"1e+4294967296", "+Inf", ErrRange}, {"1e-18446744073709551616", "0", nil}, {"1e+18446744073709551616", "+Inf", ErrRange}, {"0x1p-4294967296", "0", nil}, {"0x1p+4294967296", "+Inf", ErrRange}, {"0x1p-18446744073709551616", "0", nil}, {"0x1p+18446744073709551616", "+Inf", ErrRange}, // Parse errors {"1e", "0", ErrSyntax}, {"1e-", "0", ErrSyntax}, {".e-1", "0", ErrSyntax}, {"1\x00.2", "0", ErrSyntax}, {"0x", "0", ErrSyntax}, {"0x.", "0", ErrSyntax}, {"0x1", "0", ErrSyntax}, {"0x.1", "0", ErrSyntax}, {"0x1p", "0", ErrSyntax}, {"0x.1p", "0", ErrSyntax}, {"0x1p+", "0", ErrSyntax}, {"0x.1p+", "0", ErrSyntax}, {"0x1p-", "0", ErrSyntax}, {"0x.1p-", "0", ErrSyntax}, {"0x1p+2", "4", nil}, {"0x.1p+2", "0.25", nil}, {"0x1p-2", "0.25", nil}, {"0x.1p-2", "0.015625", nil}, // https://www.exploringbinary.com/java-hangs-when-converting-2-2250738585072012e-308/ {"2.2250738585072012e-308", "2.2250738585072014e-308", nil}, // https://www.exploringbinary.com/php-hangs-on-numeric-value-2-2250738585072011e-308/ {"2.2250738585072011e-308", "2.225073858507201e-308", nil}, // A very large number (initially wrongly parsed by the fast algorithm). {"4.630813248087435e+307", "4.630813248087435e+307", nil}, // A different kind of very large number. {"22.222222222222222", "22.22222222222222", nil}, {"2." + strings.Repeat("2", 4000) + "e+1", "22.22222222222222", nil}, {"0x1.1111111111111p222", "7.18931911124017e+66", nil}, {"0x2.2222222222222p221", "7.18931911124017e+66", nil}, {"0x2." + strings.Repeat("2", 4000) + "p221", "7.18931911124017e+66", nil}, // Exactly halfway between 1 and math.Nextafter(1, 2). // Round to even (down). {"1.00000000000000011102230246251565404236316680908203125", "1", nil}, {"0x1.00000000000008p0", "1", nil}, // Slightly lower; still round down. {"1.00000000000000011102230246251565404236316680908203124", "1", nil}, {"0x1.00000000000007Fp0", "1", nil}, // Slightly higher; round up. {"1.00000000000000011102230246251565404236316680908203126", "1.0000000000000002", nil}, {"0x1.000000000000081p0", "1.0000000000000002", nil}, {"0x1.00000000000009p0", "1.0000000000000002", nil}, // Slightly higher, but you have to read all the way to the end. {"1.00000000000000011102230246251565404236316680908203125" + strings.Repeat("0", 10000) + "1", "1.0000000000000002", nil}, {"0x1.00000000000008" + strings.Repeat("0", 10000) + "1p0", "1.0000000000000002", nil}, // Halfway between x := math.Nextafter(1, 2) and math.Nextafter(x, 2) // Round to even (up). {"1.00000000000000033306690738754696212708950042724609375", "1.0000000000000004", nil}, {"0x1.00000000000018p0", "1.0000000000000004", nil}, // Halfway between 1090544144181609278303144771584 and 1090544144181609419040633126912 // (15497564393479157p+46, should round to even 15497564393479156p+46, issue 36657) {"1090544144181609348671888949248", "1.0905441441816093e+30", nil}, // slightly above, rounds up {"1090544144181609348835077142190", "1.0905441441816094e+30", nil}, // Underscores. {"1_23.50_0_0e+1_2", "1.235e+14", nil}, {"-_123.5e+12", "0", ErrSyntax}, {"+_123.5e+12", "0", ErrSyntax}, {"_123.5e+12", "0", ErrSyntax}, {"1__23.5e+12", "0", ErrSyntax}, {"123_.5e+12", "0", ErrSyntax}, {"123._5e+12", "0", ErrSyntax}, {"123.5_e+12", "0", ErrSyntax}, {"123.5__0e+12", "0", ErrSyntax}, {"123.5e_+12", "0", ErrSyntax}, {"123.5e+_12", "0", ErrSyntax}, {"123.5e_-12", "0", ErrSyntax}, {"123.5e-_12", "0", ErrSyntax}, {"123.5e+1__2", "0", ErrSyntax}, {"123.5e+12_", "0", ErrSyntax}, {"0x_1_2.3_4_5p+1_2", "74565", nil}, {"-_0x12.345p+12", "0", ErrSyntax}, {"+_0x12.345p+12", "0", ErrSyntax}, {"_0x12.345p+12", "0", ErrSyntax}, {"0x__12.345p+12", "0", ErrSyntax}, {"0x1__2.345p+12", "0", ErrSyntax}, {"0x12_.345p+12", "0", ErrSyntax}, {"0x12._345p+12", "0", ErrSyntax}, {"0x12.3__45p+12", "0", ErrSyntax}, {"0x12.345_p+12", "0", ErrSyntax}, {"0x12.345p_+12", "0", ErrSyntax}, {"0x12.345p+_12", "0", ErrSyntax}, {"0x12.345p_-12", "0", ErrSyntax}, {"0x12.345p-_12", "0", ErrSyntax}, {"0x12.345p+1__2", "0", ErrSyntax}, {"0x12.345p+12_", "0", ErrSyntax}, {"1e100x", "0", ErrSyntax}, {"1e1000x", "0", ErrSyntax}, } var atof32tests = []atofTest{ // Hex {"0x1p-100", "7.888609e-31", nil}, {"0x1p100", "1.2676506e+30", nil}, // Exactly halfway between 1 and the next float32. // Round to even (down). {"1.000000059604644775390625", "1", nil}, {"0x1.000001p0", "1", nil}, // Slightly lower. {"1.000000059604644775390624", "1", nil}, {"0x1.0000008p0", "1", nil}, {"0x1.000000fp0", "1", nil}, // Slightly higher. {"1.000000059604644775390626", "1.0000001", nil}, {"0x1.000002p0", "1.0000001", nil}, {"0x1.0000018p0", "1.0000001", nil}, {"0x1.0000011p0", "1.0000001", nil}, // Slightly higher, but you have to read all the way to the end. {"1.000000059604644775390625" + strings.Repeat("0", 10000) + "1", "1.0000001", nil}, {"0x1.000001" + strings.Repeat("0", 10000) + "1p0", "1.0000001", nil}, // largest float32: (1<<128) * (1 - 2^-24) {"340282346638528859811704183484516925440", "3.4028235e+38", nil}, {"-340282346638528859811704183484516925440", "-3.4028235e+38", nil}, {"0x.ffffffp128", "3.4028235e+38", nil}, {"-340282346638528859811704183484516925440", "-3.4028235e+38", nil}, {"-0x.ffffffp128", "-3.4028235e+38", nil}, // next float32 - too large {"3.4028236e38", "+Inf", ErrRange}, {"-3.4028236e38", "-Inf", ErrRange}, {"0x1.0p128", "+Inf", ErrRange}, {"-0x1.0p128", "-Inf", ErrRange}, // the border is 3.40282356779...e+38 // borderline - okay {"3.402823567e38", "3.4028235e+38", nil}, {"-3.402823567e38", "-3.4028235e+38", nil}, {"0x.ffffff7fp128", "3.4028235e+38", nil}, {"-0x.ffffff7fp128", "-3.4028235e+38", nil}, // borderline - too large {"3.4028235678e38", "+Inf", ErrRange}, {"-3.4028235678e38", "-Inf", ErrRange}, {"0x.ffffff8p128", "+Inf", ErrRange}, {"-0x.ffffff8p128", "-Inf", ErrRange}, // Denormals: less than 2^-126 {"1e-38", "1e-38", nil}, {"1e-39", "1e-39", nil}, {"1e-40", "1e-40", nil}, {"1e-41", "1e-41", nil}, {"1e-42", "1e-42", nil}, {"1e-43", "1e-43", nil}, {"1e-44", "1e-44", nil}, {"6e-45", "6e-45", nil}, // 4p-149 = 5.6e-45 {"5e-45", "6e-45", nil}, // Smallest denormal {"1e-45", "1e-45", nil}, // 1p-149 = 1.4e-45 {"2e-45", "1e-45", nil}, {"3e-45", "3e-45", nil}, // Near denormals and denormals. {"0x0.89aBcDp-125", "1.2643093e-38", nil}, // 0x0089abcd {"0x0.8000000p-125", "1.1754944e-38", nil}, // 0x00800000 {"0x0.1234560p-125", "1.671814e-39", nil}, // 0x00123456 {"0x0.1234567p-125", "1.671814e-39", nil}, // rounded down {"0x0.1234568p-125", "1.671814e-39", nil}, // rounded down {"0x0.1234569p-125", "1.671815e-39", nil}, // rounded up {"0x0.1234570p-125", "1.671815e-39", nil}, // 0x00123457 {"0x0.0000010p-125", "1e-45", nil}, // 0x00000001 {"0x0.00000081p-125", "1e-45", nil}, // rounded up {"0x0.0000008p-125", "0", nil}, // rounded down {"0x0.0000007p-125", "0", nil}, // rounded down // 2^92 = 8388608p+69 = 4951760157141521099596496896 (4.9517602e27) // is an exact power of two that needs 8 decimal digits to be correctly // parsed back. // The float32 before is 16777215p+68 = 4.95175986e+27 // The halfway is 4.951760009. A bad algorithm that thinks the previous // float32 is 8388607p+69 will shorten incorrectly to 4.95176e+27. {"4951760157141521099596496896", "4.9517602e+27", nil}, } type atofSimpleTest struct { x float64 s string } var ( atofOnce sync.Once atofRandomTests []atofSimpleTest benchmarksRandomBits [1024]string benchmarksRandomNormal [1024]string ) func initAtof() { atofOnce.Do(initAtofOnce) } func initAtofOnce() { // The atof routines return NumErrors wrapping // the error and the string. Convert the table above. for i := range atoftests { test := &atoftests[i] if test.err != nil { test.err = &NumError{"ParseFloat", test.in, test.err} } } for i := range atof32tests { test := &atof32tests[i] if test.err != nil { test.err = &NumError{"ParseFloat", test.in, test.err} } } // Generate random inputs for tests and benchmarks if testing.Short() { atofRandomTests = make([]atofSimpleTest, 100) } else { atofRandomTests = make([]atofSimpleTest, 10000) } for i := range atofRandomTests { n := uint64(rand.Uint32())<<32 | uint64(rand.Uint32()) x := math.Float64frombits(n) s := FormatFloat(x, 'g', -1, 64) atofRandomTests[i] = atofSimpleTest{x, s} } for i := range benchmarksRandomBits { bits := uint64(rand.Uint32())<<32 | uint64(rand.Uint32()) x := math.Float64frombits(bits) benchmarksRandomBits[i] = FormatFloat(x, 'g', -1, 64) } for i := range benchmarksRandomNormal { x := rand.NormFloat64() benchmarksRandomNormal[i] = FormatFloat(x, 'g', -1, 64) } } func TestParseFloatPrefix(t *testing.T) { for i := range atoftests { test := &atoftests[i] if test.err != nil { continue } // Adding characters that do not extend a number should not invalidate it. // Test a few. The "i" and "init" cases test that we accept "infi", "infinit" // correctly as "inf" with suffix. for _, suffix := range []string{" ", "q", "+", "-", "<", "=", ">", "(", ")", "i", "init"} { in := test.in + suffix _, n, err := ParseFloatPrefix(in, 64) if err != nil { t.Errorf("ParseFloatPrefix(%q, 64): err = %v; want no error", in, err) } if n != len(test.in) { t.Errorf("ParseFloatPrefix(%q, 64): n = %d; want %d", in, n, len(test.in)) } } } } func testAtof(t *testing.T, opt bool) { initAtof() oldopt := SetOptimize(opt) for i := 0; i < len(atoftests); i++ { test := &atoftests[i] out, err := ParseFloat(test.in, 64) outs := FormatFloat(out, 'g', -1, 64) if outs != test.out || !reflect.DeepEqual(err, test.err) { t.Errorf("ParseFloat(%v, 64) = %v, %v want %v, %v", test.in, out, err, test.out, test.err) } if float64(float32(out)) == out { out, err := ParseFloat(test.in, 32) out32 := float32(out) if float64(out32) != out { t.Errorf("ParseFloat(%v, 32) = %v, not a float32 (closest is %v)", test.in, out, float64(out32)) continue } outs := FormatFloat(float64(out32), 'g', -1, 32) if outs != test.out || !reflect.DeepEqual(err, test.err) { t.Errorf("ParseFloat(%v, 32) = %v, %v want %v, %v # %v", test.in, out32, err, test.out, test.err, out) } } } for _, test := range atof32tests { out, err := ParseFloat(test.in, 32) out32 := float32(out) if float64(out32) != out { t.Errorf("ParseFloat(%v, 32) = %v, not a float32 (closest is %v)", test.in, out, float64(out32)) continue } outs := FormatFloat(float64(out32), 'g', -1, 32) if outs != test.out || !reflect.DeepEqual(err, test.err) { t.Errorf("ParseFloat(%v, 32) = %v, %v want %v, %v # %v", test.in, out32, err, test.out, test.err, out) } } SetOptimize(oldopt) } func TestAtof(t *testing.T) { testAtof(t, true) } func TestAtofSlow(t *testing.T) { testAtof(t, false) } func TestAtofRandom(t *testing.T) { initAtof() for _, test := range atofRandomTests { x, _ := ParseFloat(test.s, 64) switch { default: t.Errorf("number %s badly parsed as %b (expected %b)", test.s, x, test.x) case x == test.x: case math.IsNaN(test.x) && math.IsNaN(x): } } t.Logf("tested %d random numbers", len(atofRandomTests)) } var roundTripCases = []struct { f float64 s string }{ // Issue 2917. // This test will break the optimized conversion if the // FPU is using 80-bit registers instead of 64-bit registers, // usually because the operating system initialized the // thread with 80-bit precision and the Go runtime didn't // fix the FP control word. {8865794286000691 << 39, "4.87402195346389e+27"}, {8865794286000692 << 39, "4.8740219534638903e+27"}, } func TestRoundTrip(t *testing.T) { for _, tt := range roundTripCases { old := SetOptimize(false) s := FormatFloat(tt.f, 'g', -1, 64) if s != tt.s { t.Errorf("no-opt FormatFloat(%b) = %s, want %s", tt.f, s, tt.s) } f, err := ParseFloat(tt.s, 64) if f != tt.f || err != nil { t.Errorf("no-opt ParseFloat(%s) = %b, %v want %b, nil", tt.s, f, err, tt.f) } SetOptimize(true) s = FormatFloat(tt.f, 'g', -1, 64) if s != tt.s { t.Errorf("opt FormatFloat(%b) = %s, want %s", tt.f, s, tt.s) } f, err = ParseFloat(tt.s, 64) if f != tt.f || err != nil { t.Errorf("opt ParseFloat(%s) = %b, %v want %b, nil", tt.s, f, err, tt.f) } SetOptimize(old) } } // TestRoundTrip32 tries a fraction of all finite positive float32 values. func TestRoundTrip32(t *testing.T) { step := uint32(997) if testing.Short() { step = 99991 } count := 0 for i := uint32(0); i < 0xff<<23; i += step { f := math.Float32frombits(i) if i&1 == 1 { f = -f // negative } s := FormatFloat(float64(f), 'g', -1, 32) parsed, err := ParseFloat(s, 32) parsed32 := float32(parsed) switch { case err != nil: t.Errorf("ParseFloat(%q, 32) gave error %s", s, err) case float64(parsed32) != parsed: t.Errorf("ParseFloat(%q, 32) = %v, not a float32 (nearest is %v)", s, parsed, parsed32) case parsed32 != f: t.Errorf("ParseFloat(%q, 32) = %b (expected %b)", s, parsed32, f) } count++ } t.Logf("tested %d float32's", count) } // Issue 42297: a lot of code in the wild accidentally calls ParseFloat(s, 10) // or ParseFloat(s, 0), so allow bitSize values other than 32 and 64. func TestParseFloatIncorrectBitSize(t *testing.T) { const s = "1.5e308" const want = 1.5e308 for _, bitSize := range []int{0, 10, 100, 128} { f, err := ParseFloat(s, bitSize) if err != nil { t.Fatalf("ParseFloat(%q, %d) gave error %s", s, bitSize, err) } if f != want { t.Fatalf("ParseFloat(%q, %d) = %g (expected %g)", s, bitSize, f, want) } } } func BenchmarkAtof64Decimal(b *testing.B) { for i := 0; i < b.N; i++ { ParseFloat("33909", 64) } } func BenchmarkAtof64Float(b *testing.B) { for i := 0; i < b.N; i++ { ParseFloat("339.7784", 64) } } func BenchmarkAtof64FloatExp(b *testing.B) { for i := 0; i < b.N; i++ { ParseFloat("-5.09e75", 64) } } func BenchmarkAtof64Big(b *testing.B) { for i := 0; i < b.N; i++ { ParseFloat("123456789123456789123456789", 64) } } func BenchmarkAtof64RandomBits(b *testing.B) { initAtof() b.ResetTimer() for i := 0; i < b.N; i++ { ParseFloat(benchmarksRandomBits[i%1024], 64) } } func BenchmarkAtof64RandomFloats(b *testing.B) { initAtof() b.ResetTimer() for i := 0; i < b.N; i++ { ParseFloat(benchmarksRandomNormal[i%1024], 64) } } func BenchmarkAtof64RandomLongFloats(b *testing.B) { initAtof() samples := make([]string, len(atofRandomTests)) for i, t := range atofRandomTests { samples[i] = FormatFloat(t.x, 'g', 20, 64) } b.ResetTimer() idx := 0 for i := 0; i < b.N; i++ { ParseFloat(samples[idx], 64) idx++ if idx == len(samples) { idx = 0 } } } func BenchmarkAtof32Decimal(b *testing.B) { for i := 0; i < b.N; i++ { ParseFloat("33909", 32) } } func BenchmarkAtof32Float(b *testing.B) { for i := 0; i < b.N; i++ { ParseFloat("339.778", 32) } } func BenchmarkAtof32FloatExp(b *testing.B) { for i := 0; i < b.N; i++ { ParseFloat("12.3456e32", 32) } } func BenchmarkAtof32Random(b *testing.B) { n := uint32(997) var float32strings [4096]string for i := range float32strings { n = (99991*n + 42) % (0xff << 23) float32strings[i] = FormatFloat(float64(math.Float32frombits(n)), 'g', -1, 32) } b.ResetTimer() for i := 0; i < b.N; i++ { ParseFloat(float32strings[i%4096], 32) } } func BenchmarkAtof32RandomLong(b *testing.B) { n := uint32(997) var float32strings [4096]string for i := range float32strings { n = (99991*n + 42) % (0xff << 23) float32strings[i] = FormatFloat(float64(math.Float32frombits(n)), 'g', 20, 32) } b.ResetTimer() for i := 0; i < b.N; i++ { ParseFloat(float32strings[i%4096], 32) } }
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