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decimal_test.go
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// Copyright 2020 Denis Bernard <[email protected]>. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package decimal
import (
"encoding"
"encoding/gob"
"fmt"
"math"
"math/rand"
"strings"
"testing"
)
func BenchmarkDecimal_dnorm(b *testing.B) {
d := dec(nil).make(1000)
for i := range d {
d[i] = Word(rand.Uint64()) % _DB
}
for i := 0; i < b.N; i++ {
d[0] = Word(rand.Uint64()) % _DB
d[len(d)-1] = Word(rand.Uint64()) % _DB
_ = uint(dnorm(d))
}
}
func BenchmarkDecimal_Sqrt(b *testing.B) {
x := new(Decimal).SetUint64(2)
z := new(Decimal).SetPrec(34)
for i := 0; i < b.N; i++ {
z.Sqrt(x)
}
}
func BenchmarkDecimal_Float(b *testing.B) {
d := new(Decimal).SetPrec(100).SetUint64(2)
d.Sqrt(d)
f := d.Float(nil)
for i := 0; i < b.N; i++ {
d.Float(f)
}
}
func TestDecimal_FMA(t *testing.T) {
x := NewDecimal(123, -2).SetPrec(3)
y := NewDecimal(227, -2).SetPrec(3)
u := NewDecimal(3, -3).SetPrec(3)
z := new(Decimal).SetPrec(3).Mul(x, y) // == 2.7921
z.Add(z, u)
if s := z.String(); s != "2.79" {
t.Fatalf("Precision 3, 2.79 + 0.003 = %s, want 2.79", s)
}
z = z.FMA(x, y, u)
if s := z.String(); s != "2.8" {
t.Fatalf("Precision 3, %v * %v + 0.003 = %s, want 2.8", x, y, s)
}
// test aliasing z and u
u.FMA(x, y, u)
if s := z.String(); s != "2.8" {
t.Fatalf("Aliasing z & u, %v * %v + 0.003 = %s, want 2.8", x, y, s)
}
}
var decimalZero Decimal
var (
// required implemented interfaces
_ fmt.Stringer = &decimalZero
_ fmt.Scanner = &decimalZero
_ fmt.Formatter = &decimalZero
_ encoding.TextMarshaler = &decimalZero
_ encoding.TextUnmarshaler = &decimalZero
_ gob.GobEncoder = &decimalZero
_ gob.GobDecoder = &decimalZero
)
// Verify that ErrNaN implements the error interface.
var _ error = ErrNaN{}
func (x *Decimal) uint64() uint64 {
u, acc := x.Uint64()
if acc != Exact {
panic(fmt.Sprintf("%s is not a uint64", x.Text('g', 10)))
}
return u
}
func (x *Decimal) int64() int64 {
i, acc := x.Int64()
if acc != Exact {
panic(fmt.Sprintf("%s is not an int64", x.Text('g', 10)))
}
return i
}
func TestDecimalZeroValue(t *testing.T) {
// zero (uninitialized) value is a ready-to-use 0.0
var x Decimal
if s := x.Text('f', 1); s != "0.0" {
t.Errorf("zero value = %s; want 0.0", s)
}
// zero value has precision 0
if prec := x.Prec(); prec != 0 {
t.Errorf("prec = %d; want 0", prec)
}
// zero value can be used in any and all positions of binary operations
make := func(x int) *Decimal {
var f Decimal
if x != 0 {
f.SetInt64(int64(x))
}
// x == 0 translates into the zero value
return &f
}
for _, test := range []struct {
z, x, y, want int
opname rune
op func(z, x, y *Decimal) *Decimal
}{
{0, 0, 0, 0, '+', (*Decimal).Add},
{0, 1, 2, 3, '+', (*Decimal).Add},
{1, 2, 0, 2, '+', (*Decimal).Add},
{2, 0, 1, 1, '+', (*Decimal).Add},
{0, 0, 0, 0, '-', (*Decimal).Sub},
{0, 1, 2, -1, '-', (*Decimal).Sub},
{1, 2, 0, 2, '-', (*Decimal).Sub},
{2, 0, 1, -1, '-', (*Decimal).Sub},
{0, 0, 0, 0, '*', (*Decimal).Mul},
{0, 1, 2, 2, '*', (*Decimal).Mul},
{1, 2, 0, 0, '*', (*Decimal).Mul},
{2, 0, 1, 0, '*', (*Decimal).Mul},
// {0, 0, 0, 0, '/', (*Decimal).Quo}, // panics
{0, 2, 1, 2, '/', (*Decimal).Quo},
{1, 2, 0, 0, '/', (*Decimal).Quo}, // = +Inf
{2, 0, 1, 0, '/', (*Decimal).Quo},
} {
z := make(test.z)
test.op(z, make(test.x), make(test.y))
got := 0
if !z.IsInf() {
got = int(z.int64())
}
if got != test.want {
t.Errorf("%d %c %d = %d; want %d", test.x, test.opname, test.y, got, test.want)
}
}
// TODO(db47h) test how precision is set for zero value results
}
func makeDecimal(s string) *Decimal {
x, _, err := ParseDecimal(s, 0, 350, ToNearestEven)
if err != nil {
panic(err)
}
return x
}
func TestDecimalSetPrec(t *testing.T) {
for _, test := range []struct {
x string
prec uint
want string
acc Accuracy
}{
// prec 0
{"0", 0, "0", Exact},
{"-0", 0, "-0", Exact},
{"-Inf", 0, "-Inf", Exact},
{"+Inf", 0, "+Inf", Exact},
{"123", 0, "0", Below},
{"-123", 0, "-0", Above},
// prec at upper limit
{"0", MaxPrec, "0", Exact},
{"-0", MaxPrec, "-0", Exact},
{"-Inf", MaxPrec, "-Inf", Exact},
{"+Inf", MaxPrec, "+Inf", Exact},
// just a few regular cases - general rounding is tested elsewhere
{"1.5", 1, "2", Above},
{"-1.5", 1, "-2", Below},
{"123", 1e6, "123", Exact},
{"-123", 1e6, "-123", Exact},
} {
x := makeDecimal(test.x).SetPrec(test.prec)
prec := test.prec
if prec > MaxPrec {
prec = MaxPrec
}
if got := x.Prec(); got != prec {
t.Errorf("%s.SetPrec(%d).Prec() == %d; want %d", test.x, test.prec, got, prec)
}
if got, acc := x.String(), x.Acc(); got != test.want || acc != test.acc {
t.Errorf("%s.SetPrec(%d) = %s (%s); want %s (%s)", test.x, test.prec, got, acc, test.want, test.acc)
}
}
}
func TestDecimalMinPrec(t *testing.T) {
const max = 30
for _, test := range []struct {
x string
want uint
}{
{"0", 0},
{"-0", 0},
{"+Inf", 0},
{"-Inf", 0},
{"1", 1},
{"9", 1},
{"999", 3},
{"123456", 6},
{"123456e-1000", 6},
{"123456e+1000", 6},
// {"0.1", max},
} {
x := makeDecimal(test.x).SetPrec(max)
if got := x.MinPrec(); got != test.want {
t.Errorf("%s.MinPrec() = %d; want %d", test.x, got, test.want)
}
}
}
func TestDecimalSign(t *testing.T) {
for _, test := range []struct {
x string
s int
}{
{"-Inf", -1},
{"-1", -1},
{"-0", 0},
{"+0", 0},
{"+1", +1},
{"+Inf", +1},
} {
x := makeDecimal(test.x)
s := x.Sign()
if s != test.s {
t.Errorf("%s.Sign() = %d; want %d", test.x, s, test.s)
}
}
}
// alike(x, y) is like x.Cmp(y) == 0 but also considers the sign of 0 (0 != -0).
func alike(x, y *Decimal) bool {
return x.Cmp(y) == 0 && x.Signbit() == y.Signbit()
}
func alike32(x, y float32) bool {
// we can ignore NaNs
return x == y && math.Signbit(float64(x)) == math.Signbit(float64(y))
}
func alike64(x, y float64) bool {
// we can ignore NaNs
return x == y && math.Signbit(x) == math.Signbit(y)
}
func TestDecimalMantExp(t *testing.T) {
for _, test := range []struct {
x string
mant string
exp int
}{
{"0", "0", 0},
{"+0", "0", 0},
{"-0", "-0", 0},
{"Inf", "+Inf", 0},
{"+Inf", "+Inf", 0},
{"-Inf", "-Inf", 0},
{"1.5", "0.15", 1},
{"1.024e3", "0.1024", 4},
{"-0.00125", "-0.125", -2},
} {
x := makeDecimal(test.x)
mant := makeDecimal(test.mant)
m := new(Decimal)
e := x.MantExp(m)
if !alike(m, mant) || e != test.exp {
t.Errorf("%s.MantExp() = %s, %d; want %s, %d", test.x, m.Text('g', 10), e, test.mant, test.exp)
}
}
}
func TestDecimalMantExpAliasing(t *testing.T) {
x := makeDecimal("0.5e10")
if e := x.MantExp(x); e != 10 {
t.Fatalf("Decimal.MantExp aliasing error: got %d; want 10", e)
}
if want := makeDecimal("0.5"); !alike(x, want) {
t.Fatalf("Decimal.MantExp aliasing error: got %s; want %s", x.Text('g', 10), want.Text('g', 10))
}
}
func TestDecimalSetMantExp(t *testing.T) {
for _, test := range []struct {
frac string
exp int
z string
}{
{"0", 0, "0"},
{"+0", 0, "0"},
{"-0", 0, "-0"},
{"Inf", 1234, "+Inf"},
{"+Inf", -1234, "+Inf"},
{"-Inf", -1234, "-Inf"},
{"0", MinExp, "0"},
{"0.01", MinExp, "+0"}, // exponent underflow
{"-0.01", MinExp, "-0"}, // exponent underflow
{"1", MaxExp, "+Inf"}, // exponent overflow
{"10", MaxExp - 1, "+Inf"}, // exponent overflow
{"1", MaxExp - 1, "1e2147483646"},
{"0.75", 1, "7.5"},
{"0.5", 4, "5000"},
{"-0.5", -2, "-0.005"},
{"32", 2, "3200"},
{"1024", -5, "0.01024"},
} {
frac := makeDecimal(test.frac)
want := makeDecimal(test.z)
var z Decimal
z.SetMantExp(frac, test.exp)
if !alike(&z, want) {
t.Errorf("SetMantExp(%s, %d) = %s; want %s", test.frac, test.exp, z.Text('g', 10), test.z)
}
// test inverse property
mant := new(Decimal)
if z.SetMantExp(mant, want.MantExp(mant)).Cmp(want) != 0 {
t.Errorf("Inverse property not satisfied: got %s; want %s", z.Text('g', 10), test.z)
}
}
}
func TestDecimalPredicates(t *testing.T) {
for _, test := range []struct {
x string
sign int
signbit, inf bool
}{
{x: "-Inf", sign: -1, signbit: true, inf: true},
{x: "-1", sign: -1, signbit: true},
{x: "-0", signbit: true},
{x: "0"},
{x: "1", sign: 1},
{x: "+Inf", sign: 1, inf: true},
} {
x := makeDecimal(test.x)
if got := x.Signbit(); got != test.signbit {
t.Errorf("(%s).Signbit() = %v; want %v", test.x, got, test.signbit)
}
if got := x.Sign(); got != test.sign {
t.Errorf("(%s).Sign() = %d; want %d", test.x, got, test.sign)
}
if got := x.IsInf(); got != test.inf {
t.Errorf("(%s).IsInf() = %v; want %v", test.x, got, test.inf)
}
}
}
func TestDecimalIsInt(t *testing.T) {
for _, test := range []string{
"0 int",
"-0 int",
"1 int",
"-1 int",
"0.5",
"1.23",
"1.23e1",
"1.23e2 int",
"0.000000001e+8",
"0.000000001e+9 int",
"1.2345e200 int",
"Inf",
"+Inf",
"-Inf",
} {
s := strings.TrimSuffix(test, " int")
want := s != test
if got := makeDecimal(s).IsInt(); got != want {
t.Errorf("%s.IsInt() == %t", s, got)
}
}
}
// func fromBinary(s string) int64 {
// x, err := strconv.ParseInt(s, 2, 64)
// if err != nil {
// panic(err)
// }
// return x
// }
// func toBinary(x int64) string {
// return strconv.FormatInt(x, 2)
// }
// func testFloatRound(t *testing.T, x, r int64, prec uint, mode RoundingMode) {
// // verify test data
// var ok bool
// switch mode {
// case ToNearestEven, ToNearestAway:
// ok = true // nothing to do for now
// case ToZero:
// if x < 0 {
// ok = r >= x
// } else {
// ok = r <= x
// }
// case AwayFromZero:
// if x < 0 {
// ok = r <= x
// } else {
// ok = r >= x
// }
// case ToNegativeInf:
// ok = r <= x
// case ToPositiveInf:
// ok = r >= x
// default:
// panic("unreachable")
// }
// if !ok {
// t.Fatalf("incorrect test data for prec = %d, %s: x = %s, r = %s", prec, mode, toBinary(x), toBinary(r))
// }
// // compute expected accuracy
// a := Exact
// switch {
// case r < x:
// a = Below
// case r > x:
// a = Above
// }
// // round
// f := new(Float).SetMode(mode).SetInt64(x).SetPrec(prec)
// // check result
// r1 := f.int64()
// p1 := f.Prec()
// a1 := f.Acc()
// if r1 != r || p1 != prec || a1 != a {
// t.Errorf("round %s (%d bits, %s) incorrect: got %s (%d bits, %s); want %s (%d bits, %s)",
// toBinary(x), prec, mode,
// toBinary(r1), p1, a1,
// toBinary(r), prec, a)
// return
// }
// // g and f should be the same
// // (rounding by SetPrec after SetInt64 using default precision
// // should be the same as rounding by SetInt64 after setting the
// // precision)
// g := new(Float).SetMode(mode).SetPrec(prec).SetInt64(x)
// if !alike(g, f) {
// t.Errorf("round %s (%d bits, %s) not symmetric: got %s and %s; want %s",
// toBinary(x), prec, mode,
// toBinary(g.int64()),
// toBinary(r1),
// toBinary(r),
// )
// return
// }
// // h and f should be the same
// // (repeated rounding should be idempotent)
// h := new(Float).SetMode(mode).SetPrec(prec).Set(f)
// if !alike(h, f) {
// t.Errorf("round %s (%d bits, %s) not idempotent: got %s and %s; want %s",
// toBinary(x), prec, mode,
// toBinary(h.int64()),
// toBinary(r1),
// toBinary(r),
// )
// return
// }
// }
// // TestFloatRound tests basic rounding.
// func TestFloatRound(t *testing.T) {
// for _, test := range []struct {
// prec uint
// x, zero, neven, naway, away string // input, results rounded to prec bits
// }{
// {5, "1000", "1000", "1000", "1000", "1000"},
// {5, "1001", "1001", "1001", "1001", "1001"},
// {5, "1010", "1010", "1010", "1010", "1010"},
// {5, "1011", "1011", "1011", "1011", "1011"},
// {5, "1100", "1100", "1100", "1100", "1100"},
// {5, "1101", "1101", "1101", "1101", "1101"},
// {5, "1110", "1110", "1110", "1110", "1110"},
// {5, "1111", "1111", "1111", "1111", "1111"},
// {4, "1000", "1000", "1000", "1000", "1000"},
// {4, "1001", "1001", "1001", "1001", "1001"},
// {4, "1010", "1010", "1010", "1010", "1010"},
// {4, "1011", "1011", "1011", "1011", "1011"},
// {4, "1100", "1100", "1100", "1100", "1100"},
// {4, "1101", "1101", "1101", "1101", "1101"},
// {4, "1110", "1110", "1110", "1110", "1110"},
// {4, "1111", "1111", "1111", "1111", "1111"},
// {3, "1000", "1000", "1000", "1000", "1000"},
// {3, "1001", "1000", "1000", "1010", "1010"},
// {3, "1010", "1010", "1010", "1010", "1010"},
// {3, "1011", "1010", "1100", "1100", "1100"},
// {3, "1100", "1100", "1100", "1100", "1100"},
// {3, "1101", "1100", "1100", "1110", "1110"},
// {3, "1110", "1110", "1110", "1110", "1110"},
// {3, "1111", "1110", "10000", "10000", "10000"},
// {3, "1000001", "1000000", "1000000", "1000000", "1010000"},
// {3, "1001001", "1000000", "1010000", "1010000", "1010000"},
// {3, "1010001", "1010000", "1010000", "1010000", "1100000"},
// {3, "1011001", "1010000", "1100000", "1100000", "1100000"},
// {3, "1100001", "1100000", "1100000", "1100000", "1110000"},
// {3, "1101001", "1100000", "1110000", "1110000", "1110000"},
// {3, "1110001", "1110000", "1110000", "1110000", "10000000"},
// {3, "1111001", "1110000", "10000000", "10000000", "10000000"},
// {2, "1000", "1000", "1000", "1000", "1000"},
// {2, "1001", "1000", "1000", "1000", "1100"},
// {2, "1010", "1000", "1000", "1100", "1100"},
// {2, "1011", "1000", "1100", "1100", "1100"},
// {2, "1100", "1100", "1100", "1100", "1100"},
// {2, "1101", "1100", "1100", "1100", "10000"},
// {2, "1110", "1100", "10000", "10000", "10000"},
// {2, "1111", "1100", "10000", "10000", "10000"},
// {2, "1000001", "1000000", "1000000", "1000000", "1100000"},
// {2, "1001001", "1000000", "1000000", "1000000", "1100000"},
// {2, "1010001", "1000000", "1100000", "1100000", "1100000"},
// {2, "1011001", "1000000", "1100000", "1100000", "1100000"},
// {2, "1100001", "1100000", "1100000", "1100000", "10000000"},
// {2, "1101001", "1100000", "1100000", "1100000", "10000000"},
// {2, "1110001", "1100000", "10000000", "10000000", "10000000"},
// {2, "1111001", "1100000", "10000000", "10000000", "10000000"},
// {1, "1000", "1000", "1000", "1000", "1000"},
// {1, "1001", "1000", "1000", "1000", "10000"},
// {1, "1010", "1000", "1000", "1000", "10000"},
// {1, "1011", "1000", "1000", "1000", "10000"},
// {1, "1100", "1000", "10000", "10000", "10000"},
// {1, "1101", "1000", "10000", "10000", "10000"},
// {1, "1110", "1000", "10000", "10000", "10000"},
// {1, "1111", "1000", "10000", "10000", "10000"},
// {1, "1000001", "1000000", "1000000", "1000000", "10000000"},
// {1, "1001001", "1000000", "1000000", "1000000", "10000000"},
// {1, "1010001", "1000000", "1000000", "1000000", "10000000"},
// {1, "1011001", "1000000", "1000000", "1000000", "10000000"},
// {1, "1100001", "1000000", "10000000", "10000000", "10000000"},
// {1, "1101001", "1000000", "10000000", "10000000", "10000000"},
// {1, "1110001", "1000000", "10000000", "10000000", "10000000"},
// {1, "1111001", "1000000", "10000000", "10000000", "10000000"},
// } {
// x := fromBinary(test.x)
// z := fromBinary(test.zero)
// e := fromBinary(test.neven)
// n := fromBinary(test.naway)
// a := fromBinary(test.away)
// prec := test.prec
// testFloatRound(t, x, z, prec, ToZero)
// testFloatRound(t, x, e, prec, ToNearestEven)
// testFloatRound(t, x, n, prec, ToNearestAway)
// testFloatRound(t, x, a, prec, AwayFromZero)
// testFloatRound(t, x, z, prec, ToNegativeInf)
// testFloatRound(t, x, a, prec, ToPositiveInf)
// testFloatRound(t, -x, -a, prec, ToNegativeInf)
// testFloatRound(t, -x, -z, prec, ToPositiveInf)
// }
// }
// // TestFloatRound24 tests that rounding a float64 to 24 bits
// // matches IEEE-754 rounding to nearest when converting a
// // float64 to a float32 (excluding denormal numbers).
// func TestFloatRound24(t *testing.T) {
// const x0 = 1<<26 - 0x10 // 11...110000 (26 bits)
// for d := 0; d <= 0x10; d++ {
// x := float64(x0 + d)
// f := new(Float).SetPrec(24).SetFloat64(x)
// got, _ := f.Float32()
// want := float32(x)
// if got != want {
// t.Errorf("Round(%g, 24) = %g; want %g", x, got, want)
// }
// }
// }
// func TestFloatSetUint64(t *testing.T) {
// for _, want := range []uint64{
// 0,
// 1,
// 2,
// 10,
// 100,
// 1<<32 - 1,
// 1 << 32,
// 1<<64 - 1,
// } {
// var f Float
// f.SetUint64(want)
// if got := f.uint64(); got != want {
// t.Errorf("got %#x (%s); want %#x", got, f.Text('p', 0), want)
// }
// }
// // test basic rounding behavior (exhaustive rounding testing is done elsewhere)
// const x uint64 = 0x8765432187654321 // 64 bits needed
// for prec := uint(1); prec <= 64; prec++ {
// f := new(Float).SetPrec(prec).SetMode(ToZero).SetUint64(x)
// got := f.uint64()
// want := x &^ (1<<(64-prec) - 1) // cut off (round to zero) low 64-prec bits
// if got != want {
// t.Errorf("got %#x (%s); want %#x", got, f.Text('p', 0), want)
// }
// }
// }
// func TestFloatSetInt64(t *testing.T) {
// for _, want := range []int64{
// 0,
// 1,
// 2,
// 10,
// 100,
// 1<<32 - 1,
// 1 << 32,
// 1<<63 - 1,
// } {
// for i := range [2]int{} {
// if i&1 != 0 {
// want = -want
// }
// var f Float
// f.SetInt64(want)
// if got := f.int64(); got != want {
// t.Errorf("got %#x (%s); want %#x", got, f.Text('p', 0), want)
// }
// }
// }
// // test basic rounding behavior (exhaustive rounding testing is done elsewhere)
// const x int64 = 0x7654321076543210 // 63 bits needed
// for prec := uint(1); prec <= 63; prec++ {
// f := new(Float).SetPrec(prec).SetMode(ToZero).SetInt64(x)
// got := f.int64()
// want := x &^ (1<<(63-prec) - 1) // cut off (round to zero) low 63-prec bits
// if got != want {
// t.Errorf("got %#x (%s); want %#x", got, f.Text('p', 0), want)
// }
// }
// }
// func TestFloatSetFloat64(t *testing.T) {
// for _, want := range []float64{
// 0,
// 1,
// 2,
// 12345,
// 1e10,
// 1e100,
// 3.14159265e10,
// 2.718281828e-123,
// 1.0 / 3,
// math.MaxFloat32,
// math.MaxFloat64,
// math.SmallestNonzeroFloat32,
// math.SmallestNonzeroFloat64,
// math.Inf(-1),
// math.Inf(0),
// -math.Inf(1),
// } {
// for i := range [2]int{} {
// if i&1 != 0 {
// want = -want
// }
// var f Float
// f.SetFloat64(want)
// if got, acc := f.Float64(); got != want || acc != Exact {
// t.Errorf("got %g (%s, %s); want %g (Exact)", got, f.Text('p', 0), acc, want)
// }
// }
// }
// // test basic rounding behavior (exhaustive rounding testing is done elsewhere)
// const x uint64 = 0x8765432143218 // 53 bits needed
// for prec := uint(1); prec <= 52; prec++ {
// f := new(Float).SetPrec(prec).SetMode(ToZero).SetFloat64(float64(x))
// got, _ := f.Float64()
// want := float64(x &^ (1<<(52-prec) - 1)) // cut off (round to zero) low 53-prec bits
// if got != want {
// t.Errorf("got %g (%s); want %g", got, f.Text('p', 0), want)
// }
// }
// // test NaN
// defer func() {
// if p, ok := recover().(ErrNaN); !ok {
// t.Errorf("got %v; want ErrNaN panic", p)
// }
// }()
// var f Float
// f.SetFloat64(math.NaN())
// // should not reach here
// t.Errorf("got %s; want ErrNaN panic", f.Text('p', 0))
// }
// func TestFloatSetInt(t *testing.T) {
// for _, want := range []string{
// "0",
// "1",
// "-1",
// "1234567890",
// "123456789012345678901234567890",
// "123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890",
// } {
// var x Int
// _, ok := x.SetString(want, 0)
// if !ok {
// t.Errorf("invalid integer %s", want)
// continue
// }
// n := x.BitLen()
// var f Float
// f.SetInt(&x)
// // check precision
// if n < 64 {
// n = 64
// }
// if prec := f.Prec(); prec != uint(n) {
// t.Errorf("got prec = %d; want %d", prec, n)
// }
// // check value
// got := f.Text('g', 100)
// if got != want {
// t.Errorf("got %s (%s); want %s", got, f.Text('p', 0), want)
// }
// }
// // TODO(gri) test basic rounding behavior
// }
// func TestFloatSetRat(t *testing.T) {
// for _, want := range []string{
// "0",
// "1",
// "-1",
// "1234567890",
// "123456789012345678901234567890",
// "123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890",
// "1.2",
// "3.14159265",
// // TODO(gri) expand
// } {
// var x Rat
// _, ok := x.SetString(want)
// if !ok {
// t.Errorf("invalid fraction %s", want)
// continue
// }
// n := max(x.Num().BitLen(), x.Denom().BitLen())
// var f1, f2 Float
// f2.SetPrec(1000)
// f1.SetRat(&x)
// f2.SetRat(&x)
// // check precision when set automatically
// if n < 64 {
// n = 64
// }
// if prec := f1.Prec(); prec != uint(n) {
// t.Errorf("got prec = %d; want %d", prec, n)
// }
// got := f2.Text('g', 100)
// if got != want {
// t.Errorf("got %s (%s); want %s", got, f2.Text('p', 0), want)
// }
// }
// }
// func TestFloatSetInf(t *testing.T) {
// var f Float
// for _, test := range []struct {
// signbit bool
// prec uint
// want string
// }{
// {false, 0, "+Inf"},
// {true, 0, "-Inf"},
// {false, 10, "+Inf"},
// {true, 30, "-Inf"},
// } {
// x := f.SetPrec(test.prec).SetInf(test.signbit)
// if got := x.String(); got != test.want || x.Prec() != test.prec {
// t.Errorf("SetInf(%v) = %s (prec = %d); want %s (prec = %d)", test.signbit, got, x.Prec(), test.want, test.prec)
// }
// }
// }
// func TestFloatUint64(t *testing.T) {
// for _, test := range []struct {
// x string
// out uint64
// acc Accuracy
// }{
// {"-Inf", 0, Above},
// {"-1", 0, Above},
// {"-1e-1000", 0, Above},
// {"-0", 0, Exact},
// {"0", 0, Exact},
// {"1e-1000", 0, Below},
// {"1", 1, Exact},
// {"1.000000000000000000001", 1, Below},
// {"12345.0", 12345, Exact},
// {"12345.000000000000000000001", 12345, Below},
// {"18446744073709551615", 18446744073709551615, Exact},
// {"18446744073709551615.000000000000000000001", math.MaxUint64, Below},
// {"18446744073709551616", math.MaxUint64, Below},
// {"1e10000", math.MaxUint64, Below},
// {"+Inf", math.MaxUint64, Below},
// } {
// x := makeFloat(test.x)
// out, acc := x.Uint64()
// if out != test.out || acc != test.acc {
// t.Errorf("%s: got %d (%s); want %d (%s)", test.x, out, acc, test.out, test.acc)
// }
// }
// }
// func TestFloatInt64(t *testing.T) {
// for _, test := range []struct {
// x string
// out int64
// acc Accuracy
// }{
// {"-Inf", math.MinInt64, Above},
// {"-1e10000", math.MinInt64, Above},
// {"-9223372036854775809", math.MinInt64, Above},
// {"-9223372036854775808.000000000000000000001", math.MinInt64, Above},
// {"-9223372036854775808", -9223372036854775808, Exact},
// {"-9223372036854775807.000000000000000000001", -9223372036854775807, Above},
// {"-9223372036854775807", -9223372036854775807, Exact},
// {"-12345.000000000000000000001", -12345, Above},
// {"-12345.0", -12345, Exact},
// {"-1.000000000000000000001", -1, Above},
// {"-1.5", -1, Above},
// {"-1", -1, Exact},
// {"-1e-1000", 0, Above},
// {"0", 0, Exact},
// {"1e-1000", 0, Below},
// {"1", 1, Exact},
// {"1.000000000000000000001", 1, Below},
// {"1.5", 1, Below},
// {"12345.0", 12345, Exact},
// {"12345.000000000000000000001", 12345, Below},
// {"9223372036854775807", 9223372036854775807, Exact},
// {"9223372036854775807.000000000000000000001", math.MaxInt64, Below},
// {"9223372036854775808", math.MaxInt64, Below},
// {"1e10000", math.MaxInt64, Below},
// {"+Inf", math.MaxInt64, Below},
// } {
// x := makeFloat(test.x)
// out, acc := x.Int64()
// if out != test.out || acc != test.acc {
// t.Errorf("%s: got %d (%s); want %d (%s)", test.x, out, acc, test.out, test.acc)
// }
// }
// }
// func TestFloatFloat32(t *testing.T) {
// for _, test := range []struct {
// x string
// out float32
// acc Accuracy
// }{
// {"0", 0, Exact},
// // underflow to zero
// {"1e-1000", 0, Below},
// {"0x0.000002p-127", 0, Below},
// {"0x.0000010p-126", 0, Below},
// // denormals
// {"1.401298464e-45", math.SmallestNonzeroFloat32, Above}, // rounded up to smallest denormal
// {"0x.ffffff8p-149", math.SmallestNonzeroFloat32, Above}, // rounded up to smallest denormal
// {"0x.0000018p-126", math.SmallestNonzeroFloat32, Above}, // rounded up to smallest denormal
// {"0x.0000020p-126", math.SmallestNonzeroFloat32, Exact},
// {"0x.8p-148", math.SmallestNonzeroFloat32, Exact},
// {"1p-149", math.SmallestNonzeroFloat32, Exact},
// {"0x.fffffep-126", math.Float32frombits(0x7fffff), Exact}, // largest denormal
// // special denormal cases (see issues 14553, 14651)
// {"0x0.0000001p-126", math.Float32frombits(0x00000000), Below}, // underflow to zero
// {"0x0.0000008p-126", math.Float32frombits(0x00000000), Below}, // underflow to zero
// {"0x0.0000010p-126", math.Float32frombits(0x00000000), Below}, // rounded down to even
// {"0x0.0000011p-126", math.Float32frombits(0x00000001), Above}, // rounded up to smallest denormal
// {"0x0.0000018p-126", math.Float32frombits(0x00000001), Above}, // rounded up to smallest denormal
// {"0x1.0000000p-149", math.Float32frombits(0x00000001), Exact}, // smallest denormal
// {"0x0.0000020p-126", math.Float32frombits(0x00000001), Exact}, // smallest denormal
// {"0x0.fffffe0p-126", math.Float32frombits(0x007fffff), Exact}, // largest denormal
// {"0x1.0000000p-126", math.Float32frombits(0x00800000), Exact}, // smallest normal
// {"0x0.8p-149", math.Float32frombits(0x000000000), Below}, // rounded down to even
// {"0x0.9p-149", math.Float32frombits(0x000000001), Above}, // rounded up to smallest denormal
// {"0x0.ap-149", math.Float32frombits(0x000000001), Above}, // rounded up to smallest denormal
// {"0x0.bp-149", math.Float32frombits(0x000000001), Above}, // rounded up to smallest denormal
// {"0x0.cp-149", math.Float32frombits(0x000000001), Above}, // rounded up to smallest denormal
// {"0x1.0p-149", math.Float32frombits(0x000000001), Exact}, // smallest denormal
// {"0x1.7p-149", math.Float32frombits(0x000000001), Below},
// {"0x1.8p-149", math.Float32frombits(0x000000002), Above},
// {"0x1.9p-149", math.Float32frombits(0x000000002), Above},
// {"0x2.0p-149", math.Float32frombits(0x000000002), Exact},
// {"0x2.8p-149", math.Float32frombits(0x000000002), Below}, // rounded down to even
// {"0x2.9p-149", math.Float32frombits(0x000000003), Above},
// {"0x3.0p-149", math.Float32frombits(0x000000003), Exact},
// {"0x3.7p-149", math.Float32frombits(0x000000003), Below},
// {"0x3.8p-149", math.Float32frombits(0x000000004), Above}, // rounded up to even
// {"0x4.0p-149", math.Float32frombits(0x000000004), Exact},
// {"0x4.8p-149", math.Float32frombits(0x000000004), Below}, // rounded down to even
// {"0x4.9p-149", math.Float32frombits(0x000000005), Above},
// // specific case from issue 14553
// {"0x7.7p-149", math.Float32frombits(0x000000007), Below},
// {"0x7.8p-149", math.Float32frombits(0x000000008), Above},
// {"0x7.9p-149", math.Float32frombits(0x000000008), Above},
// // normals
// {"0x.ffffffp-126", math.Float32frombits(0x00800000), Above}, // rounded up to smallest normal
// {"1p-126", math.Float32frombits(0x00800000), Exact}, // smallest normal
// {"0x1.fffffep-126", math.Float32frombits(0x00ffffff), Exact},
// {"0x1.ffffffp-126", math.Float32frombits(0x01000000), Above}, // rounded up
// {"1", 1, Exact},
// {"1.000000000000000000001", 1, Below},
// {"12345.0", 12345, Exact},
// {"12345.000000000000000000001", 12345, Below},
// {"0x1.fffffe0p127", math.MaxFloat32, Exact},
// {"0x1.fffffe8p127", math.MaxFloat32, Below},
// // overflow
// {"0x1.ffffff0p127", float32(math.Inf(+1)), Above},
// {"0x1p128", float32(math.Inf(+1)), Above},
// {"1e10000", float32(math.Inf(+1)), Above},
// {"0x1.ffffff0p2147483646", float32(math.Inf(+1)), Above}, // overflow in rounding
// // inf
// {"Inf", float32(math.Inf(+1)), Exact},
// } {
// for i := 0; i < 2; i++ {
// // test both signs
// tx, tout, tacc := test.x, test.out, test.acc
// if i != 0 {
// tx = "-" + tx
// tout = -tout
// tacc = -tacc
// }
// // conversion should match strconv where syntax is agreeable
// if f, err := strconv.ParseFloat(tx, 32); err == nil && !alike32(float32(f), tout) {
// t.Errorf("%s: got %g; want %g (incorrect test data)", tx, f, tout)
// }
// x := makeFloat(tx)
// out, acc := x.Float32()
// if !alike32(out, tout) || acc != tacc {
// t.Errorf("%s: got %g (%#08x, %s); want %g (%#08x, %s)", tx, out, math.Float32bits(out), acc, test.out, math.Float32bits(test.out), tacc)
// }
// // test that x.SetFloat64(float64(f)).Float32() == f
// var x2 Float
// out2, acc2 := x2.SetFloat64(float64(out)).Float32()
// if !alike32(out2, out) || acc2 != Exact {
// t.Errorf("idempotency test: got %g (%s); want %g (Exact)", out2, acc2, out)
// }
// }
// }
// }