sbcl windows can't load a dll

[Richard Fateman]

See transcript below. FWIW, the same dll loads into Allegro CL, provides linkable entry points etc.
The mpfr.dll is a multi-precision floating-point / with rounding/ library.

If this doesn't provide enough info, I can post the 219kb file somewhere.

why do I care? Lots of similar libraries for numeric stuff potentially
useful for Maxima. None of them load. See nemocas.org for nice stuff.

Thanks for any hints!
Richard Fateman

..................

Microsoft Windows [Version 10.0.10586]
(c) 2015 Microsoft Corporation. All rights reserved.

c:\Users\fateman\Desktop>sbcl.exe
sbcl.exe
This is SBCL 1.2.7, 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.
* t

T
* (load "c:/lisp/generic/mpfr.dll")

debugger invoked on a SB-C::INPUT-ERROR-IN-LOAD in thread
#<THREAD "main thread" RUNNING {2426EA61}>:
  READ error during LOAD:

    :CP1252 stream decoding error on
    #<SB-SYS:FD-STREAM for "file c:\\lisp\\generic\\mpfr.dll" {2427D5C9}>:
      the octet sequence #(144) cannot be decoded.

    (in form starting at line: 1, column: 0, file-position: 0)

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

restarts (invokable by number or by possibly-abbreviated name):
  0: [ABORT] Abort loading file "c:\\lisp\\generic\\mpfr.dll".
  1: Exit debugger, returning to top level.

(SB-C:COMPILER-ERROR SB-C::INPUT-ERROR-IN-LOAD :CONDITION #<SB-INT:STREAM-DECODING-ERROR {2427F571}> :POSITION 0 :STREAM #<SB-SYS:FD-STREAM for "file c:\\lisp\\generic\\mpfr.dll" {2427D5C9}>)
0]

[PuercoPop (pirata)]

load is for lisp files. If you want to make avaiable a c library there you'd have to write a foreign function interface, as described in the manual[0]. Fortunately SBCL already comes with an interface for mpfr. All you have to do is require it, (require 'sb-mpfr) in the REPL to make it available.

[0]: http://www.sbcl.org/manual/#Foreign-Function-Interface