buf.WriteRune(r)
		}
	}
}

// From Issue 5154.
func BenchmarkBufferNotEmptyWriteRead(b *testing.B) {
	buf := make([]byte, 1024)
	for i := 0; i < b.N; i++ {
		var b Buffer
		b.Write(buf[0:1])
		for i := 0; i < 5<<10; i++ {
			b.Write(buf)
			b.Read(buf)
		}
	}
}

// Check that we don't compact too often. From Issue 5154.
func BenchmarkBufferFullSmallReads(b *testing.B) {

	tests := []struct {
		name     string
		r        io.Reader
		bufSize  int // 0 means 16
		peekSize int

		n int // input to Discard

		want    int   // from Discard
		wantErr error // from Discard

		wantBuffered int
	}{
		{
			name:         "normal case",
			r:            strings.NewReader("abcdefghijklmnopqrstuvwxyz"),
			peekSize:     16,
			n:            6,

		nproc = 7
	}
	if setNproc {
		var rlim syscall.Rlimit
		if syscall.Getrlimit(nproc, &rlim) == nil {
			max := int(rlim.Cur) / (threads + 5)
			if attempts > max {
				t.Logf("lowering attempts from %d to %d for RLIMIT_NPROC", attempts, max)
				attempts = max
			}
		}
	}

	if os.Getenv("test18146") == "exec" {
		runtime.GOMAXPROCS(1)
		for n := threads; n > 0; n-- {
			go func() {
				for {

	// Deprecated: use B.
	A         = 1
	a         = 11
	A64 int64 = 1

	AIsLowerA = a // previously declared
)

const (
	ConversionConst = MyInt(5)
)

// Variables from function calls.
var (
	V = ptwo.F()
	// Deprecated: use WError.
	VError = BarE()
	V1     = Bar1(1, 2, 3)
	V2     = ptwo.G()
)

// Variables with conversions:
var (
	StrConv  = string("foo")

			// ADR label, R. Label is in From.
			target = &a[0]
			prog.To = a[1]
			targetAddr = &prog.From
		} else {
			target = &a[1]
			prog.From = a[0]
		}
	case 3:
		if p.arch.Family == sys.PPC64 {
			// Special 3-operand jumps.
			// a[1] is a register number expressed as a constant or register value
			target = &a[2]
			prog.From = a[0]
			if a[0].Type != obj.TYPE_CONST {

		case "linux":
			// Copied from golang.org/x/sys/unix/dev_linux.go.
			major := uint32((dev & 0x00000000000fff00) >> 8)
			major |= uint32((dev & 0xfffff00000000000) >> 32)
			minor := uint32((dev & 0x00000000000000ff) >> 0)
			minor |= uint32((dev & 0x00000ffffff00000) >> 12)
			h.Devmajor, h.Devminor = int64(major), int64(minor)
		case "darwin", "ios":
			// Copied from golang.org/x/sys/unix/dev_darwin.go.

		if i == 0 {
			return 0
		}
		return i + f(i-1)
	}
	r = C.int(f(128))
	return
}

// Test that C can pass in a Go string from a string constant.
func testCallGoWithString(t *testing.T) {
	C.callGoWithString()
	want := "string passed from C to Go"
	if stringFromGo != want {
		t.Errorf("string passed through C is %s, want %s", stringFromGo, want)
	}
}

var stringFromGo string

// The Compressor itself must be safe to invoke from multiple goroutines
// simultaneously, but each returned writer will be used only by
// one goroutine at a time.
type Compressor func(w io.Writer) (io.WriteCloser, error)

// A Decompressor returns a new decompressing reader, reading from r.
// The [io.ReadCloser]'s Close method must be used to release associated resources.

	return mode
}

func (fi headerFileInfo) String() string {
	return fs.FormatFileInfo(fi)
}

// sysStat, if non-nil, populates h from system-dependent fields of fi.
var sysStat func(fi fs.FileInfo, h *Header, doNameLookups bool) error

const (
	// Mode constants from the USTAR spec:
	// See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13_06
	c_ISUID = 04000 // Set uid

)

// ErrTooLarge is passed to panic if memory cannot be allocated to store data in a buffer.
var ErrTooLarge = errors.New("bytes.Buffer: too large")
var errNegativeRead = errors.New("bytes.Buffer: reader returned negative count from Read")

const maxInt = int(^uint(0) >> 1)

// Bytes returns a slice of length b.Len() holding the unread portion of the buffer.
// The slice is valid for use only until the next buffer modification (that is,