pcg_test.go

     1  // Copyright 2023 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package rand_test
     6  
     7  import (
     8  	. "math/rand/v2"
     9  	"testing"
    10  )
    11  
    12  func BenchmarkPCG_DXSM(b *testing.B) {
    13  	var p PCG
    14  	var t uint64
    15  	for n := b.N; n > 0; n-- {
    16  		t += p.Uint64()
    17  	}
    18  	Sink = t
    19  }
    20  
    21  func TestPCGMarshal(t *testing.T) {
    22  	var p PCG
    23  	const (
    24  		seed1      = 0x123456789abcdef0
    25  		seed2      = 0xfedcba9876543210
    26  		want       = "pcg:\x12\x34\x56\x78\x9a\xbc\xde\xf0\xfe\xdc\xba\x98\x76\x54\x32\x10"
    27  		wantAppend = "\x00\x00\x00\x00" + want
    28  	)
    29  	p.Seed(seed1, seed2)
    30  	data, err := p.MarshalBinary()
    31  	if string(data) != want || err != nil {
    32  		t.Errorf("MarshalBinary() = %q, %v, want %q, nil", data, err, want)
    33  	}
    34  
    35  	dataAppend := make([]byte, 4, 32)
    36  	dataAppend, err = p.AppendBinary(dataAppend)
    37  	if string(dataAppend) != wantAppend || err != nil {
    38  		t.Errorf("AppendBinary() = %q, %v, want %q, nil", dataAppend, err, wantAppend)
    39  	}
    40  
    41  	q := PCG{}
    42  	if err := q.UnmarshalBinary([]byte(want)); err != nil {
    43  		t.Fatalf("UnmarshalBinary(): %v", err)
    44  	}
    45  	if q != p {
    46  		t.Fatalf("after round trip, q = %#x, but p = %#x", q, p)
    47  	}
    48  
    49  	qu := q.Uint64()
    50  	pu := p.Uint64()
    51  	if qu != pu {
    52  		t.Errorf("after round trip, q.Uint64() = %#x, but p.Uint64() = %#x", qu, pu)
    53  	}
    54  }
    55  
    56  func TestPCG(t *testing.T) {
    57  	p := NewPCG(1, 2)
    58  	want := []uint64{
    59  		0xc4f5a58656eef510,
    60  		0x9dcec3ad077dec6c,
    61  		0xc8d04605312f8088,
    62  		0xcbedc0dcb63ac19a,
    63  		0x3bf98798cae97950,
    64  		0xa8c6d7f8d485abc,
    65  		0x7ffa3780429cd279,
    66  		0x730ad2626b1c2f8e,
    67  		0x21ff2330f4a0ad99,
    68  		0x2f0901a1947094b0,
    69  		0xa9735a3cfbe36cef,
    70  		0x71ddb0a01a12c84a,
    71  		0xf0e53e77a78453bb,
    72  		0x1f173e9663be1e9d,
    73  		0x657651da3ac4115e,
    74  		0xc8987376b65a157b,
    75  		0xbb17008f5fca28e7,
    76  		0x8232bd645f29ed22,
    77  		0x12be8f07ad14c539,
    78  		0x54908a48e8e4736e,
    79  	}
    80  
    81  	for i, x := range want {
    82  		if u := p.Uint64(); u != x {
    83  			t.Errorf("PCG #%d = %#x, want %#x", i, u, x)
    84  		}
    85  	}
    86  }
    87
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