221 lines
		
	
	
		
			6.4 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			221 lines
		
	
	
		
			6.4 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| // Copyright 2017 The go-ethereum Authors
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| // This file is part of the go-ethereum library.
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| //
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| // The go-ethereum library is free software: you can redistribute it and/or modify
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| // it under the terms of the GNU Lesser General Public License as published by
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| // the Free Software Foundation, either version 3 of the License, or
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| // (at your option) any later version.
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| //
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| // The go-ethereum library is distributed in the hope that it will be useful,
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| // but WITHOUT ANY WARRANTY; without even the implied warranty of
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| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| // GNU Lesser General Public License for more details.
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| //
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| // You should have received a copy of the GNU Lesser General Public License
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| // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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| 
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| package math
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| 
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| import (
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| 	"bytes"
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| 	"encoding/hex"
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| 	"math/big"
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| 	"testing"
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| )
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| 
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| func TestHexOrDecimal256(t *testing.T) {
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| 	tests := []struct {
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| 		input string
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| 		num   *big.Int
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| 		ok    bool
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| 	}{
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| 		{"", big.NewInt(0), true},
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| 		{"0", big.NewInt(0), true},
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| 		{"0x0", big.NewInt(0), true},
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| 		{"12345678", big.NewInt(12345678), true},
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| 		{"0x12345678", big.NewInt(0x12345678), true},
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| 		{"0X12345678", big.NewInt(0x12345678), true},
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| 		// Tests for leading zero behaviour:
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| 		{"0123456789", big.NewInt(123456789), true}, // note: not octal
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| 		{"00", big.NewInt(0), true},
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| 		{"0x00", big.NewInt(0), true},
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| 		{"0x012345678abc", big.NewInt(0x12345678abc), true},
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| 		// Invalid syntax:
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| 		{"abcdef", nil, false},
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| 		{"0xgg", nil, false},
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| 		// Larger than 256 bits:
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| 		{"115792089237316195423570985008687907853269984665640564039457584007913129639936", nil, false},
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| 	}
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| 	for _, test := range tests {
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| 		var num HexOrDecimal256
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| 		err := num.UnmarshalText([]byte(test.input))
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| 		if (err == nil) != test.ok {
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| 			t.Errorf("ParseBig(%q) -> (err == nil) == %t, want %t", test.input, err == nil, test.ok)
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| 			continue
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| 		}
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| 		if test.num != nil && (*big.Int)(&num).Cmp(test.num) != 0 {
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| 			t.Errorf("ParseBig(%q) -> %d, want %d", test.input, (*big.Int)(&num), test.num)
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| 		}
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| 	}
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| }
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| 
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| func TestMustParseBig256(t *testing.T) {
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| 	defer func() {
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| 		if recover() == nil {
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| 			t.Error("MustParseBig should've panicked")
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| 		}
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| 	}()
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| 	MustParseBig256("ggg")
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| }
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| 
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| func TestBigMax(t *testing.T) {
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| 	a := big.NewInt(10)
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| 	b := big.NewInt(5)
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| 
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| 	max1 := BigMax(a, b)
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| 	if max1 != a {
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| 		t.Errorf("Expected %d got %d", a, max1)
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| 	}
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| 
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| 	max2 := BigMax(b, a)
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| 	if max2 != a {
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| 		t.Errorf("Expected %d got %d", a, max2)
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| 	}
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| }
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| 
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| func TestBigMin(t *testing.T) {
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| 	a := big.NewInt(10)
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| 	b := big.NewInt(5)
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| 
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| 	min1 := BigMin(a, b)
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| 	if min1 != b {
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| 		t.Errorf("Expected %d got %d", b, min1)
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| 	}
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| 
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| 	min2 := BigMin(b, a)
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| 	if min2 != b {
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| 		t.Errorf("Expected %d got %d", b, min2)
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| 	}
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| }
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| 
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| func TestFirstBigSet(t *testing.T) {
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| 	tests := []struct {
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| 		num *big.Int
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| 		ix  int
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| 	}{
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| 		{big.NewInt(0), 0},
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| 		{big.NewInt(1), 0},
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| 		{big.NewInt(2), 1},
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| 		{big.NewInt(0x100), 8},
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| 	}
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| 	for _, test := range tests {
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| 		if ix := FirstBitSet(test.num); ix != test.ix {
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| 			t.Errorf("FirstBitSet(b%b) = %d, want %d", test.num, ix, test.ix)
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| 		}
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| 	}
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| }
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| 
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| func TestPaddedBigBytes(t *testing.T) {
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| 	tests := []struct {
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| 		num    *big.Int
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| 		n      int
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| 		result []byte
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| 	}{
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| 		{num: big.NewInt(0), n: 4, result: []byte{0, 0, 0, 0}},
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| 		{num: big.NewInt(1), n: 4, result: []byte{0, 0, 0, 1}},
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| 		{num: big.NewInt(512), n: 4, result: []byte{0, 0, 2, 0}},
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| 		{num: BigPow(2, 32), n: 4, result: []byte{1, 0, 0, 0, 0}},
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| 	}
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| 	for _, test := range tests {
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| 		if result := PaddedBigBytes(test.num, test.n); !bytes.Equal(result, test.result) {
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| 			t.Errorf("PaddedBigBytes(%d, %d) = %v, want %v", test.num, test.n, result, test.result)
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| 		}
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| 	}
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| }
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| 
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| func BenchmarkPaddedBigBytes(b *testing.B) {
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| 	bigint := MustParseBig256("123456789123456789123456789123456789")
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| 	for i := 0; i < b.N; i++ {
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| 		PaddedBigBytes(bigint, 32)
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| 	}
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| }
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| 
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| func TestReadBits(t *testing.T) {
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| 	check := func(input string) {
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| 		want, _ := hex.DecodeString(input)
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| 		int, _ := new(big.Int).SetString(input, 16)
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| 		buf := make([]byte, len(want))
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| 		ReadBits(int, buf)
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| 		if !bytes.Equal(buf, want) {
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| 			t.Errorf("have: %x\nwant: %x", buf, want)
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| 		}
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| 	}
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| 	check("000000000000000000000000000000000000000000000000000000FEFCF3F8F0")
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| 	check("0000000000012345000000000000000000000000000000000000FEFCF3F8F0")
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| 	check("18F8F8F1000111000110011100222004330052300000000000000000FEFCF3F8F0")
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| }
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| 
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| func TestU256(t *testing.T) {
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| 	tests := []struct{ x, y *big.Int }{
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| 		{x: big.NewInt(0), y: big.NewInt(0)},
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| 		{x: big.NewInt(1), y: big.NewInt(1)},
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| 		{x: BigPow(2, 255), y: BigPow(2, 255)},
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| 		{x: BigPow(2, 256), y: big.NewInt(0)},
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| 		{x: new(big.Int).Add(BigPow(2, 256), big.NewInt(1)), y: big.NewInt(1)},
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| 		// negative values
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| 		{x: big.NewInt(-1), y: new(big.Int).Sub(BigPow(2, 256), big.NewInt(1))},
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| 		{x: big.NewInt(-2), y: new(big.Int).Sub(BigPow(2, 256), big.NewInt(2))},
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| 		{x: BigPow(2, -255), y: big.NewInt(1)},
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| 	}
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| 	for _, test := range tests {
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| 		if y := U256(new(big.Int).Set(test.x)); y.Cmp(test.y) != 0 {
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| 			t.Errorf("U256(%x) = %x, want %x", test.x, y, test.y)
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| 		}
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| 	}
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| }
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| 
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| func TestS256(t *testing.T) {
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| 	tests := []struct{ x, y *big.Int }{
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| 		{x: big.NewInt(0), y: big.NewInt(0)},
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| 		{x: big.NewInt(1), y: big.NewInt(1)},
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| 		{x: big.NewInt(2), y: big.NewInt(2)},
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| 		{
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| 			x: new(big.Int).Sub(BigPow(2, 255), big.NewInt(1)),
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| 			y: new(big.Int).Sub(BigPow(2, 255), big.NewInt(1)),
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| 		},
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| 		{
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| 			x: BigPow(2, 255),
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| 			y: new(big.Int).Neg(BigPow(2, 255)),
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| 		},
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| 		{
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| 			x: new(big.Int).Sub(BigPow(2, 256), big.NewInt(1)),
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| 			y: big.NewInt(-1),
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| 		},
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| 		{
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| 			x: new(big.Int).Sub(BigPow(2, 256), big.NewInt(2)),
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| 			y: big.NewInt(-2),
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| 		},
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| 	}
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| 	for _, test := range tests {
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| 		if y := S256(test.x); y.Cmp(test.y) != 0 {
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| 			t.Errorf("S256(%x) = %x, want %x", test.x, y, test.y)
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| 		}
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| 	}
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| }
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| 
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| func TestExp(t *testing.T) {
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| 	tests := []struct{ base, exponent, result *big.Int }{
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| 		{base: big.NewInt(0), exponent: big.NewInt(0), result: big.NewInt(1)},
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| 		{base: big.NewInt(1), exponent: big.NewInt(0), result: big.NewInt(1)},
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| 		{base: big.NewInt(1), exponent: big.NewInt(1), result: big.NewInt(1)},
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| 		{base: big.NewInt(1), exponent: big.NewInt(2), result: big.NewInt(1)},
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| 		{base: big.NewInt(3), exponent: big.NewInt(144), result: MustParseBig256("507528786056415600719754159741696356908742250191663887263627442114881")},
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| 		{base: big.NewInt(2), exponent: big.NewInt(255), result: MustParseBig256("57896044618658097711785492504343953926634992332820282019728792003956564819968")},
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| 	}
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| 	for _, test := range tests {
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| 		if result := Exp(test.base, test.exponent); result.Cmp(test.result) != 0 {
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| 			t.Errorf("Exp(%d, %d) = %d, want %d", test.base, test.exponent, result, test.result)
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| 		}
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| 	}
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| }
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