Hello everyone,
Apologies in advance if I'm asking an incredibly simple question, but
I'm using GHC 6.4 on Windows XP SP2. I was recently playing with
implementing the Kocher attack on RSA in Haskell, and along the way I
needed a reasonable way to time operations -- the built-in Windows
functions don't do such a good job. I wrote a very simple function
that uses the rdtsc instruction:
--- begin: AccuTime.c
#include
__declspec(dllexport) ULONGLONG accuticks() {
LARGE_INTEGER i;
ULONG lo, hi;
__asm {
rdtsc
mov hi, edx
mov lo, eax
}
i.HighPart = hi;
i.LowPart = lo;
return i.QuadPart;
}
--- end
--- begin: AccuTime.h
#ifndef __accutime_h
#define __acutime_h
#include
ULONGLONG accuticks();
#endif /* __accutime_h */
--- end
and compiled it to AccuTime.dll. I then attempted to piece together
the file I'd need to import this function into Haskell:
--- begin: AccuTime.hs
module AccuTime where
import Foreign.C.Types
foreign import stdcall unsafe "accutime.h accuticks" c_accuticks :: IO CULLong
accuticks :: IO Integer
accuticks = do ull <- c_accuticks
return (fromIntegral ull)
--- end
And then, after passing the correct -L and -l flags to ghci, attempted
to load that module. Unfortunately, I got:
___ ___ _
/ _ \ /\ /\/ __(_)
/ /_\// /_/ / / | | GHC Interactive, version 6.4, for Haskell 98.
/ /_\\/ __ / /___| | http://www.haskell.org/ghc/
\____/\/ /_/\____/|_| Type :? for help.
Loading package base-1.0 ... linking ... done.
Loading object (dynamic) AccuTime ... done
final link ... done
Prelude> :l AccuTime.hs
Compiling AccuTime ( AccuTime.hs, interpreted )
ghc.exe: panic! (the `impossible' happened, GHC version 6.4):
ByteCodeFFI.mkMarshalCode_wrk(x86) L_
Please report it as a compiler bug to glasgow-haskell-bugs@haskell.org,
or http://sourceforge.net/projects/ghc/.
At this point, I'm quite confused. Does anyone else know what I'm
doing to cause this panic?
Thanks,
/g
