Handle Octeon 3 not supporting MIPS paired-single instructions.

[official-gcc.git] / libgo / go / math / big / ratconv_test.go

// Copyright 2015 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 big

import (
        "bytes"
        "fmt"
        "math"
        "strconv"
        "strings"
        "testing"
)

type StringTest struct {
        in, out string
        ok      bool
}

var setStringTests = []StringTest{
        {"0", "0", true},
        {"-0", "0", true},
        {"1", "1", true},
        {"-1", "-1", true},
        {"1.", "1", true},
        {"1e0", "1", true},
        {"1.e1", "10", true},
        {in: "1e"},
        {in: "1.e"},
        {in: "1e+14e-5"},
        {in: "1e4.5"},
        {in: "r"},
        {in: "a/b"},
        {in: "a.b"},
        {"-0.1", "-1/10", true},
        {"-.1", "-1/10", true},
        {"2/4", "1/2", true},
        {".25", "1/4", true},
        {"-1/5", "-1/5", true},
        {"8129567.7690E14", "812956776900000000000", true},
        {"78189e+4", "781890000", true},
        {"553019.8935e+8", "55301989350000", true},
        {"98765432109876543210987654321e-10", "98765432109876543210987654321/10000000000", true},
        {"9877861857500000E-7", "3951144743/4", true},
        {"2169378.417e-3", "2169378417/1000000", true},
        {"884243222337379604041632732738665534", "884243222337379604041632732738665534", true},
        {"53/70893980658822810696", "53/70893980658822810696", true},
        {"106/141787961317645621392", "53/70893980658822810696", true},
        {"204211327800791583.81095", "4084226556015831676219/20000", true},
        {in: "1/0"},
}

// These are not supported by fmt.Fscanf.
var setStringTests2 = []StringTest{
        {"0x10", "16", true},
        {"-010/1", "-8", true}, // TODO(gri) should we even permit octal here?
        {"-010.", "-10", true},
        {"0x10/0x20", "1/2", true},
        {"0b1000/3", "8/3", true},
        // TODO(gri) add more tests
}

func TestRatSetString(t *testing.T) {
        var tests []StringTest
        tests = append(tests, setStringTests...)
        tests = append(tests, setStringTests2...)

        for i, test := range tests {
                x, ok := new(Rat).SetString(test.in)

                if ok {
                        if !test.ok {
                                t.Errorf("#%d SetString(%q) expected failure", i, test.in)
                        } else if x.RatString() != test.out {
                                t.Errorf("#%d SetString(%q) got %s want %s", i, test.in, x.RatString(), test.out)
                        }
                } else if x != nil {
                        t.Errorf("#%d SetString(%q) got %p want nil", i, test.in, x)
                }
        }
}

func TestRatScan(t *testing.T) {
        var buf bytes.Buffer
        for i, test := range setStringTests {
                x := new(Rat)
                buf.Reset()
                buf.WriteString(test.in)

                _, err := fmt.Fscanf(&buf, "%v", x)
                if err == nil != test.ok {
                        if test.ok {
                                t.Errorf("#%d (%s) error: %s", i, test.in, err)
                        } else {
                                t.Errorf("#%d (%s) expected error", i, test.in)
                        }
                        continue
                }
                if err == nil && x.RatString() != test.out {
                        t.Errorf("#%d got %s want %s", i, x.RatString(), test.out)
                }
        }
}

var floatStringTests = []struct {
        in   string
        prec int
        out  string
}{
        {"0", 0, "0"},
        {"0", 4, "0.0000"},
        {"1", 0, "1"},
        {"1", 2, "1.00"},
        {"-1", 0, "-1"},
        {"0.05", 1, "0.1"},
        {"-0.05", 1, "-0.1"},
        {".25", 2, "0.25"},
        {".25", 1, "0.3"},
        {".25", 3, "0.250"},
        {"-1/3", 3, "-0.333"},
        {"-2/3", 4, "-0.6667"},
        {"0.96", 1, "1.0"},
        {"0.999", 2, "1.00"},
        {"0.9", 0, "1"},
        {".25", -1, "0"},
        {".55", -1, "1"},
}

func TestFloatString(t *testing.T) {
        for i, test := range floatStringTests {
                x, _ := new(Rat).SetString(test.in)

                if x.FloatString(test.prec) != test.out {
                        t.Errorf("#%d got %s want %s", i, x.FloatString(test.prec), test.out)
                }
        }
}

// Test inputs to Rat.SetString.  The prefix "long:" causes the test
// to be skipped in --test.short mode.  (The threshold is about 500us.)
var float64inputs = []string{
        // Constants plundered from strconv/testfp.txt.

        // Table 1: Stress Inputs for Conversion to 53-bit Binary, < 1/2 ULP
        "5e+125",
        "69e+267",
        "999e-026",
        "7861e-034",
        "75569e-254",
        "928609e-261",
        "9210917e+080",
        "84863171e+114",
        "653777767e+273",
        "5232604057e-298",
        "27235667517e-109",
        "653532977297e-123",
        "3142213164987e-294",
        "46202199371337e-072",
        "231010996856685e-073",
        "9324754620109615e+212",
        "78459735791271921e+049",
        "272104041512242479e+200",
        "6802601037806061975e+198",
        "20505426358836677347e-221",
        "836168422905420598437e-234",
        "4891559871276714924261e+222",

        // Table 2: Stress Inputs for Conversion to 53-bit Binary, > 1/2 ULP
        "9e-265",
        "85e-037",
        "623e+100",
        "3571e+263",
        "81661e+153",
        "920657e-023",
        "4603285e-024",
        "87575437e-309",
        "245540327e+122",
        "6138508175e+120",
        "83356057653e+193",
        "619534293513e+124",
        "2335141086879e+218",
        "36167929443327e-159",
        "609610927149051e-255",
        "3743626360493413e-165",
        "94080055902682397e-242",
        "899810892172646163e+283",
        "7120190517612959703e+120",
        "25188282901709339043e-252",
        "308984926168550152811e-052",
        "6372891218502368041059e+064",

        // Table 14: Stress Inputs for Conversion to 24-bit Binary, <1/2 ULP
        "5e-20",
        "67e+14",
        "985e+15",
        "7693e-42",
        "55895e-16",
        "996622e-44",
        "7038531e-32",
        "60419369e-46",
        "702990899e-20",
        "6930161142e-48",
        "25933168707e+13",
        "596428896559e+20",

        // Table 15: Stress Inputs for Conversion to 24-bit Binary, >1/2 ULP
        "3e-23",
        "57e+18",
        "789e-35",
        "2539e-18",
        "76173e+28",
        "887745e-11",
        "5382571e-37",
        "82381273e-35",
        "750486563e-38",
        "3752432815e-39",
        "75224575729e-45",
        "459926601011e+15",

        // Constants plundered from strconv/atof_test.go.

        "0",
        "1",
        "+1",
        "1e23",
        "1E23",
        "100000000000000000000000",
        "1e-100",
        "123456700",
        "99999999999999974834176",
        "100000000000000000000001",
        "100000000000000008388608",
        "100000000000000016777215",
        "100000000000000016777216",
        "-1",
        "-0.1",
        "-0", // NB: exception made for this input
        "1e-20",
        "625e-3",

        // largest float64
        "1.7976931348623157e308",
        "-1.7976931348623157e308",
        // next float64 - too large
        "1.7976931348623159e308",
        "-1.7976931348623159e308",
        // the border is ...158079
        // borderline - okay
        "1.7976931348623158e308",
        "-1.7976931348623158e308",
        // borderline - too large
        "1.797693134862315808e308",
        "-1.797693134862315808e308",

        // a little too large
        "1e308",
        "2e308",
        "1e309",

        // way too large
        "1e310",
        "-1e310",
        "1e400",
        "-1e400",
        "long:1e400000",
        "long:-1e400000",

        // denormalized
        "1e-305",
        "1e-306",
        "1e-307",
        "1e-308",
        "1e-309",
        "1e-310",
        "1e-322",
        // smallest denormal
        "5e-324",
        "4e-324",
        "3e-324",
        // too small
        "2e-324",
        // way too small
        "1e-350",
        "long:1e-400000",
        // way too small, negative
        "-1e-350",
        "long:-1e-400000",

        // try to overflow exponent
        // [Disabled: too slow and memory-hungry with rationals.]
        // "1e-4294967296",
        // "1e+4294967296",
        // "1e-18446744073709551616",
        // "1e+18446744073709551616",

        // http://www.exploringbinary.com/java-hangs-when-converting-2-2250738585072012e-308/
        "2.2250738585072012e-308",
        // http://www.exploringbinary.com/php-hangs-on-numeric-value-2-2250738585072011e-308/
        "2.2250738585072011e-308",

        // A very large number (initially wrongly parsed by the fast algorithm).
        "4.630813248087435e+307",

        // A different kind of very large number.
        "22.222222222222222",
        "long:2." + strings.Repeat("2", 4000) + "e+1",

        // Exactly halfway between 1 and math.Nextafter(1, 2).
        // Round to even (down).
        "1.00000000000000011102230246251565404236316680908203125",
        // Slightly lower; still round down.
        "1.00000000000000011102230246251565404236316680908203124",
        // Slightly higher; round up.
        "1.00000000000000011102230246251565404236316680908203126",
        // Slightly higher, but you have to read all the way to the end.
        "long:1.00000000000000011102230246251565404236316680908203125" + strings.Repeat("0", 10000) + "1",

        // Smallest denormal, 2^(-1022-52)
        "4.940656458412465441765687928682213723651e-324",
        // Half of smallest denormal, 2^(-1022-53)
        "2.470328229206232720882843964341106861825e-324",
        // A little more than the exact half of smallest denormal
        // 2^-1075 + 2^-1100.  (Rounds to 1p-1074.)
        "2.470328302827751011111470718709768633275e-324",
        // The exact halfway between smallest normal and largest denormal:
        // 2^-1022 - 2^-1075.  (Rounds to 2^-1022.)
        "2.225073858507201136057409796709131975935e-308",

        "1152921504606846975",  //   1<<60 - 1
        "-1152921504606846975", // -(1<<60 - 1)
        "1152921504606846977",  //   1<<60 + 1
        "-1152921504606846977", // -(1<<60 + 1)

        "1/3",
}

// isFinite reports whether f represents a finite rational value.
// It is equivalent to !math.IsNan(f) && !math.IsInf(f, 0).
func isFinite(f float64) bool {
        return math.Abs(f) <= math.MaxFloat64
}

func TestFloat32SpecialCases(t *testing.T) {
        for _, input := range float64inputs {
                if strings.HasPrefix(input, "long:") {
                        if testing.Short() {
                                continue
                        }
                        input = input[len("long:"):]
                }

                r, ok := new(Rat).SetString(input)
                if !ok {
                        t.Errorf("Rat.SetString(%q) failed", input)
                        continue
                }
                f, exact := r.Float32()

                // 1. Check string -> Rat -> float32 conversions are
                // consistent with strconv.ParseFloat.
                // Skip this check if the input uses "a/b" rational syntax.
                if !strings.Contains(input, "/") {
                        e64, _ := strconv.ParseFloat(input, 32)
                        e := float32(e64)

                        // Careful: negative Rats too small for
                        // float64 become -0, but Rat obviously cannot
                        // preserve the sign from SetString("-0").
                        switch {
                        case math.Float32bits(e) == math.Float32bits(f):
                                // Ok: bitwise equal.
                        case f == 0 && r.Num().BitLen() == 0:
                                // Ok: Rat(0) is equivalent to both +/- float64(0).
                        default:
                                t.Errorf("strconv.ParseFloat(%q) = %g (%b), want %g (%b); delta = %g", input, e, e, f, f, f-e)
                        }
                }

                if !isFinite(float64(f)) {
                        continue
                }

                // 2. Check f is best approximation to r.
                if !checkIsBestApprox32(t, f, r) {
                        // Append context information.
                        t.Errorf("(input was %q)", input)
                }

                // 3. Check f->R->f roundtrip is non-lossy.
                checkNonLossyRoundtrip32(t, f)

                // 4. Check exactness using slow algorithm.
                if wasExact := new(Rat).SetFloat64(float64(f)).Cmp(r) == 0; wasExact != exact {
                        t.Errorf("Rat.SetString(%q).Float32().exact = %t, want %t", input, exact, wasExact)
                }
        }
}

func TestFloat64SpecialCases(t *testing.T) {
        for _, input := range float64inputs {
                if strings.HasPrefix(input, "long:") {
                        if testing.Short() {
                                continue
                        }
                        input = input[len("long:"):]
                }

                r, ok := new(Rat).SetString(input)
                if !ok {
                        t.Errorf("Rat.SetString(%q) failed", input)
                        continue
                }
                f, exact := r.Float64()

                // 1. Check string -> Rat -> float64 conversions are
                // consistent with strconv.ParseFloat.
                // Skip this check if the input uses "a/b" rational syntax.
                if !strings.Contains(input, "/") {
                        e, _ := strconv.ParseFloat(input, 64)

                        // Careful: negative Rats too small for
                        // float64 become -0, but Rat obviously cannot
                        // preserve the sign from SetString("-0").
                        switch {
                        case math.Float64bits(e) == math.Float64bits(f):
                                // Ok: bitwise equal.
                        case f == 0 && r.Num().BitLen() == 0:
                                // Ok: Rat(0) is equivalent to both +/- float64(0).
                        default:
                                t.Errorf("strconv.ParseFloat(%q) = %g (%b), want %g (%b); delta = %g", input, e, e, f, f, f-e)
                        }
                }

                if !isFinite(f) {
                        continue
                }

                // 2. Check f is best approximation to r.
                if !checkIsBestApprox64(t, f, r) {
                        // Append context information.
                        t.Errorf("(input was %q)", input)
                }

                // 3. Check f->R->f roundtrip is non-lossy.
                checkNonLossyRoundtrip64(t, f)

                // 4. Check exactness using slow algorithm.
                if wasExact := new(Rat).SetFloat64(f).Cmp(r) == 0; wasExact != exact {
                        t.Errorf("Rat.SetString(%q).Float64().exact = %t, want %t", input, exact, wasExact)
                }
        }
}