Again: Uniques in GHC

Joachim Breitner mail at
Mon Oct 6 10:36:56 UTC 2014


Am Montag, den 06.10.2014, 09:58 +0000 schrieb
p.k.f.holzenspies at
> - The implementation is based on FastInts, which, on most machines
> nowadays, is a 64-bit thing. The serialisation in BinIface is
> explicitly based on Word32s. Aside from the obvious potential (albeit
> with a low probability) for errors, this lead me to wonder about
> 32/64-bitness. Is there a reason for 64-bit versions of GHC to write
> Word32s, or is this a historic thing? Must the interface-files be
> bit-compatible between different versions (32/64-bits) of the
> compiler? Lastly, is the choice of whether "this" is a 32 or 64-bit
> version completely determined by WORD_SIZE_IN_BITS (MachDeps.h)?
A while ago we had problems with haddock in Debian when the
serialization became bit-dependent.¹ I suggest to keep the specification
of any on-disk format independent of architecture specifics.



Joachim “nomeata” Breitner
  mail at joachim-breitner.de
  Jabber: nomeata at  • GPG-Key: 0xF0FBF51F
  Debian Developer: nomeata at

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