SBCL中的大增殖

Question

昨天，我试着在我的SBCL盒(v.1.3.2 (x64)，Windows 10，Dell Core i5 8GB内存)上计算出新的Mersenne (X64)的大小，几乎一个小时后我放弃并中断了计算。在生成的屏幕下面：

This is SBCL 1.3.2, an implementation of ANSI Common Lisp.
More information about SBCL is available at <http://www.sbcl.org/>.

SBCL is free software, provided as is, with absolutely no warranty.
It is mostly in the public domain; some portions are provided under
BSD-style licenses.  See the CREDITS and COPYING files in the
distribution for more information.

WARNING: the Windows port is fragile, particularly for multithreaded
code.  Unfortunately, the development team currently lacks the time
and resources this platform demands.
* (- (expt 2 74207281) 1)


debugger invoked on a SB-SYS:INTERACTIVE-INTERRUPT in thread
 '#<THREAD "main thread" RUNNING {1002A9BD03}>:'
  Interactive interrupt at #x100008BD9E.

Type HELP for debugger help, or (SB-EXT:EXIT) to exit from SBCL.

restarts (invokable by number or by possibly-abbreviated name):

  0: [CONTINUE] Return from SB-WIN32::SIGINT.

  1: [ABORT   ] Exit debugger, returning to top level.
1

(SB-BIGNUM:MULTIPLY-BIGNUMS #<unavailable argument> #<unavailable argument>)
0] 1

对我来说，这很有趣，因为我在球拍6.4上，在同一台机器上尝试了同样的表达式，并且(相对地)只用了1m08s就开始吐痰了。在Haskell，又在同一台机器上

GHCi, version 7.10.3: http://www.haskell.org/ghc/  :? for help

Prelude> 2^74207281 - 1

数字展览只花了8s就开始了。

尽管它可能是一个bug，但有人知道SBCL是如何做大乘法的吗？它的做法是否可能造成延误？

提前感谢！

*编辑

在西尔维斯特的评论之后，也许正确的问题是:是什么阻止了大数字被展示出来？是的，它确实很大(Racket和Haskell版本把它写到了一个21 MB的文本文件中)，但是它的大小似乎是阻止任务完成的因素。

Answer 1

实际计算在我的机器上相当快，实际上还不到一秒钟。

(defun make-prime ()
  (declare (optimize (safety 0)(debug 0)(speed 3)))
  (time (- (expt 2 74207281) 1)))

(defparameter *prime* (make-prime))

;Evaluation took:
;  0.000 seconds of real time
;  0.000017 seconds of total run time (0.000015 user, 0.000002 system)
;  100.00% CPU
;  1,292 processor cycles
;  0 bytes consed
; ==> *PRIME*

然而，打印这个数字完全是另一回事。