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-rw-r--r--src/math/big/natconv_test.go463
1 files changed, 463 insertions, 0 deletions
diff --git a/src/math/big/natconv_test.go b/src/math/big/natconv_test.go
new file mode 100644
index 0000000..d390272
--- /dev/null
+++ b/src/math/big/natconv_test.go
@@ -0,0 +1,463 @@
+// 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"
+ "io"
+ "math/bits"
+ "strings"
+ "testing"
+)
+
+func TestMaxBase(t *testing.T) {
+ if MaxBase != len(digits) {
+ t.Fatalf("%d != %d", MaxBase, len(digits))
+ }
+}
+
+// log2 computes the integer binary logarithm of x.
+// The result is the integer n for which 2^n <= x < 2^(n+1).
+// If x == 0, the result is -1.
+func log2(x Word) int {
+ return bits.Len(uint(x)) - 1
+}
+
+func itoa(x nat, base int) []byte {
+ // special cases
+ switch {
+ case base < 2:
+ panic("illegal base")
+ case len(x) == 0:
+ return []byte("0")
+ }
+
+ // allocate buffer for conversion
+ i := x.bitLen()/log2(Word(base)) + 1 // +1: round up
+ s := make([]byte, i)
+
+ // don't destroy x
+ q := nat(nil).set(x)
+
+ // convert
+ for len(q) > 0 {
+ i--
+ var r Word
+ q, r = q.divW(q, Word(base))
+ s[i] = digits[r]
+ }
+
+ return s[i:]
+}
+
+var strTests = []struct {
+ x nat // nat value to be converted
+ b int // conversion base
+ s string // expected result
+}{
+ {nil, 2, "0"},
+ {nat{1}, 2, "1"},
+ {nat{0xc5}, 2, "11000101"},
+ {nat{03271}, 8, "3271"},
+ {nat{10}, 10, "10"},
+ {nat{1234567890}, 10, "1234567890"},
+ {nat{0xdeadbeef}, 16, "deadbeef"},
+ {nat{0x229be7}, 17, "1a2b3c"},
+ {nat{0x309663e6}, 32, "o9cov6"},
+ {nat{0x309663e6}, 62, "TakXI"},
+}
+
+func TestString(t *testing.T) {
+ // test invalid base explicitly
+ var panicStr string
+ func() {
+ defer func() {
+ panicStr = recover().(string)
+ }()
+ natOne.utoa(1)
+ }()
+ if panicStr != "invalid base" {
+ t.Errorf("expected panic for invalid base")
+ }
+
+ for _, a := range strTests {
+ s := string(a.x.utoa(a.b))
+ if s != a.s {
+ t.Errorf("string%+v\n\tgot s = %s; want %s", a, s, a.s)
+ }
+
+ x, b, _, err := nat(nil).scan(strings.NewReader(a.s), a.b, false)
+ if x.cmp(a.x) != 0 {
+ t.Errorf("scan%+v\n\tgot z = %v; want %v", a, x, a.x)
+ }
+ if b != a.b {
+ t.Errorf("scan%+v\n\tgot b = %d; want %d", a, b, a.b)
+ }
+ if err != nil {
+ t.Errorf("scan%+v\n\tgot error = %s", a, err)
+ }
+ }
+}
+
+var natScanTests = []struct {
+ s string // string to be scanned
+ base int // input base
+ frac bool // fraction ok
+ x nat // expected nat
+ b int // expected base
+ count int // expected digit count
+ err error // expected error
+ next rune // next character (or 0, if at EOF)
+}{
+ // invalid: no digits
+ {"", 0, false, nil, 10, 0, errNoDigits, 0},
+ {"_", 0, false, nil, 10, 0, errNoDigits, 0},
+ {"?", 0, false, nil, 10, 0, errNoDigits, '?'},
+ {"?", 10, false, nil, 10, 0, errNoDigits, '?'},
+ {"", 10, false, nil, 10, 0, errNoDigits, 0},
+ {"", 36, false, nil, 36, 0, errNoDigits, 0},
+ {"", 62, false, nil, 62, 0, errNoDigits, 0},
+ {"0b", 0, false, nil, 2, 0, errNoDigits, 0},
+ {"0o", 0, false, nil, 8, 0, errNoDigits, 0},
+ {"0x", 0, false, nil, 16, 0, errNoDigits, 0},
+ {"0x_", 0, false, nil, 16, 0, errNoDigits, 0},
+ {"0b2", 0, false, nil, 2, 0, errNoDigits, '2'},
+ {"0B2", 0, false, nil, 2, 0, errNoDigits, '2'},
+ {"0o8", 0, false, nil, 8, 0, errNoDigits, '8'},
+ {"0O8", 0, false, nil, 8, 0, errNoDigits, '8'},
+ {"0xg", 0, false, nil, 16, 0, errNoDigits, 'g'},
+ {"0Xg", 0, false, nil, 16, 0, errNoDigits, 'g'},
+ {"345", 2, false, nil, 2, 0, errNoDigits, '3'},
+
+ // invalid: incorrect use of decimal point
+ {"._", 0, true, nil, 10, 0, errNoDigits, 0},
+ {".0", 0, false, nil, 10, 0, errNoDigits, '.'},
+ {".0", 10, false, nil, 10, 0, errNoDigits, '.'},
+ {".", 0, true, nil, 10, 0, errNoDigits, 0},
+ {"0x.", 0, true, nil, 16, 0, errNoDigits, 0},
+ {"0x.g", 0, true, nil, 16, 0, errNoDigits, 'g'},
+ {"0x.0", 0, false, nil, 16, 0, errNoDigits, '.'},
+
+ // invalid: incorrect use of separators
+ {"_0", 0, false, nil, 10, 1, errInvalSep, 0},
+ {"0_", 0, false, nil, 10, 1, errInvalSep, 0},
+ {"0__0", 0, false, nil, 8, 1, errInvalSep, 0},
+ {"0x___0", 0, false, nil, 16, 1, errInvalSep, 0},
+ {"0_x", 0, false, nil, 10, 1, errInvalSep, 'x'},
+ {"0_8", 0, false, nil, 10, 1, errInvalSep, '8'},
+ {"123_.", 0, true, nat{123}, 10, 0, errInvalSep, 0},
+ {"._123", 0, true, nat{123}, 10, -3, errInvalSep, 0},
+ {"0b__1000", 0, false, nat{0x8}, 2, 4, errInvalSep, 0},
+ {"0o60___0", 0, false, nat{0600}, 8, 3, errInvalSep, 0},
+ {"0466_", 0, false, nat{0466}, 8, 3, errInvalSep, 0},
+ {"01234567_8", 0, false, nat{01234567}, 8, 7, errInvalSep, '8'},
+ {"1_.", 0, true, nat{1}, 10, 0, errInvalSep, 0},
+ {"0._1", 0, true, nat{1}, 10, -1, errInvalSep, 0},
+ {"2.7_", 0, true, nat{27}, 10, -1, errInvalSep, 0},
+ {"0x1.0_", 0, true, nat{0x10}, 16, -1, errInvalSep, 0},
+
+ // valid: separators are not accepted for base != 0
+ {"0_", 10, false, nil, 10, 1, nil, '_'},
+ {"1__0", 10, false, nat{1}, 10, 1, nil, '_'},
+ {"0__8", 10, false, nil, 10, 1, nil, '_'},
+ {"xy_z_", 36, false, nat{33*36 + 34}, 36, 2, nil, '_'},
+
+ // valid, no decimal point
+ {"0", 0, false, nil, 10, 1, nil, 0},
+ {"0", 36, false, nil, 36, 1, nil, 0},
+ {"0", 62, false, nil, 62, 1, nil, 0},
+ {"1", 0, false, nat{1}, 10, 1, nil, 0},
+ {"1", 10, false, nat{1}, 10, 1, nil, 0},
+ {"0 ", 0, false, nil, 10, 1, nil, ' '},
+ {"00 ", 0, false, nil, 8, 1, nil, ' '}, // octal 0
+ {"0b1", 0, false, nat{1}, 2, 1, nil, 0},
+ {"0B11000101", 0, false, nat{0xc5}, 2, 8, nil, 0},
+ {"0B110001012", 0, false, nat{0xc5}, 2, 8, nil, '2'},
+ {"07", 0, false, nat{7}, 8, 1, nil, 0},
+ {"08", 0, false, nil, 10, 1, nil, '8'},
+ {"08", 10, false, nat{8}, 10, 2, nil, 0},
+ {"018", 0, false, nat{1}, 8, 1, nil, '8'},
+ {"0o7", 0, false, nat{7}, 8, 1, nil, 0},
+ {"0o18", 0, false, nat{1}, 8, 1, nil, '8'},
+ {"0O17", 0, false, nat{017}, 8, 2, nil, 0},
+ {"03271", 0, false, nat{03271}, 8, 4, nil, 0},
+ {"10ab", 0, false, nat{10}, 10, 2, nil, 'a'},
+ {"1234567890", 0, false, nat{1234567890}, 10, 10, nil, 0},
+ {"A", 36, false, nat{10}, 36, 1, nil, 0},
+ {"A", 37, false, nat{36}, 37, 1, nil, 0},
+ {"xyz", 36, false, nat{(33*36+34)*36 + 35}, 36, 3, nil, 0},
+ {"XYZ?", 36, false, nat{(33*36+34)*36 + 35}, 36, 3, nil, '?'},
+ {"XYZ?", 62, false, nat{(59*62+60)*62 + 61}, 62, 3, nil, '?'},
+ {"0x", 16, false, nil, 16, 1, nil, 'x'},
+ {"0xdeadbeef", 0, false, nat{0xdeadbeef}, 16, 8, nil, 0},
+ {"0XDEADBEEF", 0, false, nat{0xdeadbeef}, 16, 8, nil, 0},
+
+ // valid, with decimal point
+ {"0.", 0, false, nil, 10, 1, nil, '.'},
+ {"0.", 10, true, nil, 10, 0, nil, 0},
+ {"0.1.2", 10, true, nat{1}, 10, -1, nil, '.'},
+ {".000", 10, true, nil, 10, -3, nil, 0},
+ {"12.3", 10, true, nat{123}, 10, -1, nil, 0},
+ {"012.345", 10, true, nat{12345}, 10, -3, nil, 0},
+ {"0.1", 0, true, nat{1}, 10, -1, nil, 0},
+ {"0.1", 2, true, nat{1}, 2, -1, nil, 0},
+ {"0.12", 2, true, nat{1}, 2, -1, nil, '2'},
+ {"0b0.1", 0, true, nat{1}, 2, -1, nil, 0},
+ {"0B0.12", 0, true, nat{1}, 2, -1, nil, '2'},
+ {"0o0.7", 0, true, nat{7}, 8, -1, nil, 0},
+ {"0O0.78", 0, true, nat{7}, 8, -1, nil, '8'},
+ {"0xdead.beef", 0, true, nat{0xdeadbeef}, 16, -4, nil, 0},
+
+ // valid, with separators
+ {"1_000", 0, false, nat{1000}, 10, 4, nil, 0},
+ {"0_466", 0, false, nat{0466}, 8, 3, nil, 0},
+ {"0o_600", 0, false, nat{0600}, 8, 3, nil, 0},
+ {"0x_f0_0d", 0, false, nat{0xf00d}, 16, 4, nil, 0},
+ {"0b1000_0001", 0, false, nat{0x81}, 2, 8, nil, 0},
+ {"1_000.000_1", 0, true, nat{10000001}, 10, -4, nil, 0},
+ {"0x_f00d.1e", 0, true, nat{0xf00d1e}, 16, -2, nil, 0},
+ {"0x_f00d.1E2", 0, true, nat{0xf00d1e2}, 16, -3, nil, 0},
+ {"0x_f00d.1eg", 0, true, nat{0xf00d1e}, 16, -2, nil, 'g'},
+}
+
+func TestScanBase(t *testing.T) {
+ for _, a := range natScanTests {
+ r := strings.NewReader(a.s)
+ x, b, count, err := nat(nil).scan(r, a.base, a.frac)
+ if err != a.err {
+ t.Errorf("scan%+v\n\tgot error = %v; want %v", a, err, a.err)
+ }
+ if x.cmp(a.x) != 0 {
+ t.Errorf("scan%+v\n\tgot z = %v; want %v", a, x, a.x)
+ }
+ if b != a.b {
+ t.Errorf("scan%+v\n\tgot b = %d; want %d", a, b, a.base)
+ }
+ if count != a.count {
+ t.Errorf("scan%+v\n\tgot count = %d; want %d", a, count, a.count)
+ }
+ next, _, err := r.ReadRune()
+ if err == io.EOF {
+ next = 0
+ err = nil
+ }
+ if err == nil && next != a.next {
+ t.Errorf("scan%+v\n\tgot next = %q; want %q", a, next, a.next)
+ }
+ }
+}
+
+var pi = "3" +
+ "14159265358979323846264338327950288419716939937510582097494459230781640628620899862803482534211706798214808651" +
+ "32823066470938446095505822317253594081284811174502841027019385211055596446229489549303819644288109756659334461" +
+ "28475648233786783165271201909145648566923460348610454326648213393607260249141273724587006606315588174881520920" +
+ "96282925409171536436789259036001133053054882046652138414695194151160943305727036575959195309218611738193261179" +
+ "31051185480744623799627495673518857527248912279381830119491298336733624406566430860213949463952247371907021798" +
+ "60943702770539217176293176752384674818467669405132000568127145263560827785771342757789609173637178721468440901" +
+ "22495343014654958537105079227968925892354201995611212902196086403441815981362977477130996051870721134999999837" +
+ "29780499510597317328160963185950244594553469083026425223082533446850352619311881710100031378387528865875332083" +
+ "81420617177669147303598253490428755468731159562863882353787593751957781857780532171226806613001927876611195909" +
+ "21642019893809525720106548586327886593615338182796823030195203530185296899577362259941389124972177528347913151" +
+ "55748572424541506959508295331168617278558890750983817546374649393192550604009277016711390098488240128583616035" +
+ "63707660104710181942955596198946767837449448255379774726847104047534646208046684259069491293313677028989152104" +
+ "75216205696602405803815019351125338243003558764024749647326391419927260426992279678235478163600934172164121992" +
+ "45863150302861829745557067498385054945885869269956909272107975093029553211653449872027559602364806654991198818" +
+ "34797753566369807426542527862551818417574672890977772793800081647060016145249192173217214772350141441973568548" +
+ "16136115735255213347574184946843852332390739414333454776241686251898356948556209921922218427255025425688767179" +
+ "04946016534668049886272327917860857843838279679766814541009538837863609506800642251252051173929848960841284886" +
+ "26945604241965285022210661186306744278622039194945047123713786960956364371917287467764657573962413890865832645" +
+ "99581339047802759009946576407895126946839835259570982582262052248940772671947826848260147699090264013639443745" +
+ "53050682034962524517493996514314298091906592509372216964615157098583874105978859597729754989301617539284681382" +
+ "68683868942774155991855925245953959431049972524680845987273644695848653836736222626099124608051243884390451244" +
+ "13654976278079771569143599770012961608944169486855584840635342207222582848864815845602850601684273945226746767" +
+ "88952521385225499546667278239864565961163548862305774564980355936345681743241125150760694794510965960940252288" +
+ "79710893145669136867228748940560101503308617928680920874760917824938589009714909675985261365549781893129784821" +
+ "68299894872265880485756401427047755513237964145152374623436454285844479526586782105114135473573952311342716610" +
+ "21359695362314429524849371871101457654035902799344037420073105785390621983874478084784896833214457138687519435" +
+ "06430218453191048481005370614680674919278191197939952061419663428754440643745123718192179998391015919561814675" +
+ "14269123974894090718649423196156794520809514655022523160388193014209376213785595663893778708303906979207734672" +
+ "21825625996615014215030680384477345492026054146659252014974428507325186660021324340881907104863317346496514539" +
+ "05796268561005508106658796998163574736384052571459102897064140110971206280439039759515677157700420337869936007" +
+ "23055876317635942187312514712053292819182618612586732157919841484882916447060957527069572209175671167229109816" +
+ "90915280173506712748583222871835209353965725121083579151369882091444210067510334671103141267111369908658516398" +
+ "31501970165151168517143765761835155650884909989859982387345528331635507647918535893226185489632132933089857064" +
+ "20467525907091548141654985946163718027098199430992448895757128289059232332609729971208443357326548938239119325" +
+ "97463667305836041428138830320382490375898524374417029132765618093773444030707469211201913020330380197621101100" +
+ "44929321516084244485963766983895228684783123552658213144957685726243344189303968642624341077322697802807318915" +
+ "44110104468232527162010526522721116603966655730925471105578537634668206531098965269186205647693125705863566201" +
+ "85581007293606598764861179104533488503461136576867532494416680396265797877185560845529654126654085306143444318" +
+ "58676975145661406800700237877659134401712749470420562230538994561314071127000407854733269939081454664645880797" +
+ "27082668306343285878569830523580893306575740679545716377525420211495576158140025012622859413021647155097925923" +
+ "09907965473761255176567513575178296664547791745011299614890304639947132962107340437518957359614589019389713111" +
+ "79042978285647503203198691514028708085990480109412147221317947647772622414254854540332157185306142288137585043" +
+ "06332175182979866223717215916077166925474873898665494945011465406284336639379003976926567214638530673609657120" +
+ "91807638327166416274888800786925602902284721040317211860820419000422966171196377921337575114959501566049631862" +
+ "94726547364252308177036751590673502350728354056704038674351362222477158915049530984448933309634087807693259939" +
+ "78054193414473774418426312986080998886874132604721569516239658645730216315981931951673538129741677294786724229" +
+ "24654366800980676928238280689964004824354037014163149658979409243237896907069779422362508221688957383798623001" +
+ "59377647165122893578601588161755782973523344604281512627203734314653197777416031990665541876397929334419521541" +
+ "34189948544473456738316249934191318148092777710386387734317720754565453220777092120190516609628049092636019759" +
+ "88281613323166636528619326686336062735676303544776280350450777235547105859548702790814356240145171806246436267" +
+ "94561275318134078330336254232783944975382437205835311477119926063813346776879695970309833913077109870408591337"
+
+// Test case for BenchmarkScanPi.
+func TestScanPi(t *testing.T) {
+ var x nat
+ z, _, _, err := x.scan(strings.NewReader(pi), 10, false)
+ if err != nil {
+ t.Errorf("scanning pi: %s", err)
+ }
+ if s := string(z.utoa(10)); s != pi {
+ t.Errorf("scanning pi: got %s", s)
+ }
+}
+
+func TestScanPiParallel(t *testing.T) {
+ const n = 2
+ c := make(chan int)
+ for i := 0; i < n; i++ {
+ go func() {
+ TestScanPi(t)
+ c <- 0
+ }()
+ }
+ for i := 0; i < n; i++ {
+ <-c
+ }
+}
+
+func BenchmarkScanPi(b *testing.B) {
+ for i := 0; i < b.N; i++ {
+ var x nat
+ x.scan(strings.NewReader(pi), 10, false)
+ }
+}
+
+func BenchmarkStringPiParallel(b *testing.B) {
+ var x nat
+ x, _, _, _ = x.scan(strings.NewReader(pi), 0, false)
+ if string(x.utoa(10)) != pi {
+ panic("benchmark incorrect: conversion failed")
+ }
+ b.RunParallel(func(pb *testing.PB) {
+ for pb.Next() {
+ x.utoa(10)
+ }
+ })
+}
+
+func BenchmarkScan(b *testing.B) {
+ const x = 10
+ for _, base := range []int{2, 8, 10, 16} {
+ for _, y := range []Word{10, 100, 1000, 10000, 100000} {
+ if isRaceBuilder && y > 1000 {
+ continue
+ }
+ b.Run(fmt.Sprintf("%d/Base%d", y, base), func(b *testing.B) {
+ b.StopTimer()
+ var z nat
+ z = z.expWW(x, y)
+
+ s := z.utoa(base)
+ if t := itoa(z, base); !bytes.Equal(s, t) {
+ b.Fatalf("scanning: got %s; want %s", s, t)
+ }
+ b.StartTimer()
+
+ for i := 0; i < b.N; i++ {
+ z.scan(bytes.NewReader(s), base, false)
+ }
+ })
+ }
+ }
+}
+
+func BenchmarkString(b *testing.B) {
+ const x = 10
+ for _, base := range []int{2, 8, 10, 16} {
+ for _, y := range []Word{10, 100, 1000, 10000, 100000} {
+ if isRaceBuilder && y > 1000 {
+ continue
+ }
+ b.Run(fmt.Sprintf("%d/Base%d", y, base), func(b *testing.B) {
+ b.StopTimer()
+ var z nat
+ z = z.expWW(x, y)
+ z.utoa(base) // warm divisor cache
+ b.StartTimer()
+
+ for i := 0; i < b.N; i++ {
+ _ = z.utoa(base)
+ }
+ })
+ }
+ }
+}
+
+func BenchmarkLeafSize(b *testing.B) {
+ for n := 0; n <= 16; n++ {
+ b.Run(fmt.Sprint(n), func(b *testing.B) { LeafSizeHelper(b, 10, n) })
+ }
+ // Try some large lengths
+ for _, n := range []int{32, 64} {
+ b.Run(fmt.Sprint(n), func(b *testing.B) { LeafSizeHelper(b, 10, n) })
+ }
+}
+
+func LeafSizeHelper(b *testing.B, base, size int) {
+ b.StopTimer()
+ originalLeafSize := leafSize
+ resetTable(cacheBase10.table[:])
+ leafSize = size
+ b.StartTimer()
+
+ for d := 1; d <= 10000; d *= 10 {
+ b.StopTimer()
+ var z nat
+ z = z.expWW(Word(base), Word(d)) // build target number
+ _ = z.utoa(base) // warm divisor cache
+ b.StartTimer()
+
+ for i := 0; i < b.N; i++ {
+ _ = z.utoa(base)
+ }
+ }
+
+ b.StopTimer()
+ resetTable(cacheBase10.table[:])
+ leafSize = originalLeafSize
+ b.StartTimer()
+}
+
+func resetTable(table []divisor) {
+ if table != nil && table[0].bbb != nil {
+ for i := 0; i < len(table); i++ {
+ table[i].bbb = nil
+ table[i].nbits = 0
+ table[i].ndigits = 0
+ }
+ }
+}
+
+func TestStringPowers(t *testing.T) {
+ var p Word
+ for b := 2; b <= 16; b++ {
+ for p = 0; p <= 512; p++ {
+ if testing.Short() && p > 10 {
+ break
+ }
+ x := nat(nil).expWW(Word(b), p)
+ xs := x.utoa(b)
+ xs2 := itoa(x, b)
+ if !bytes.Equal(xs, xs2) {
+ t.Errorf("failed at %d ** %d in base %d: %s != %s", b, p, b, xs, xs2)
+ }
+ }
+ if b >= 3 && testing.Short() {
+ break
+ }
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-12 17:25:52 +0000