srcBuf := bytes.NewBuffer(make([]byte, 8192))
	src := NewReader(onlyReader{srcBuf})
	dstBuf := new(bytes.Buffer)
	dst := onlyWriter{dstBuf}
	for i := 0; i < b.N; i++ {
		srcBuf.Reset()
		src.Reset(onlyReader{srcBuf})
		dstBuf.Reset()
		io.Copy(dst, src)
	}
}

func BenchmarkReaderCopyNoWriteTo(b *testing.B) {
	srcBuf := bytes.NewBuffer(make([]byte, 8192))

(MOVOstore [dstOff] {dstSym} ptr (MOVOload [srcOff] {srcSym} (SB) _) mem) && symIsRO(srcSym) =>
  (MOVQstore [dstOff+8] {dstSym} ptr (MOVQconst [int64(read64(srcSym, int64(srcOff)+8, config.ctxt.Arch.ByteOrder))])
    (MOVQstore [dstOff] {dstSym} ptr (MOVQconst [int64(read64(srcSym, int64(srcOff), config.ctxt.Arch.ByteOrder))]) mem))

// Arch-specific inlining for small or disjoint runtime.memmove

		// Check it here to be sure.
		if lib.Fingerprint.IsZero() { // Not yet imported. Update its fingerprint.
			lib.Fingerprint = fingerprint
		}
		checkFingerprint(lib, fingerprint, lib.Srcref, lib.Fingerprint)
	}

	addImports(ctxt, lib, pn)
	return nil
}

// symbolsAreUnresolved scans through the loader's list of unresolved