#2130: Mulitple comparisons on Word types produce redundant comparisons
-------------------------------+--------------------------------------------
Reporter: dons | Owner: igloo
Type: merge | Status: new
Priority: normal | Milestone:
Component: Compiler | Version: 6.8.2
Severity: normal | Resolution:
Keywords: performance, Word | Difficulty: Unknown
Testcase: | Architecture: x86
Os: Linux |
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Changes (by simonpj):
* owner: => igloo
* difficulty: => Unknown
* type: run-time performance bug => merge
Comment:
Excellent point, thanks. It's actually not at all easy to optimise the
generation of `Ord` instances perfectly; see `Note [Comparision of
primitive types]` in `TcGenDeriv.hs`. But I have improved matters a bit,
by making a special case for data types that are wrappers for primitive
types.
{{{
Thu Feb 28 12:11:06 GMT 2008 [EMAIL PROTECTED]
* Fix Trac #2130: improve derived Ord for primmitive types
}}}
That still leaves room for improvement: I've opened a new ticket for that
#2132. But it does completely fix the `Word` type and its friends.
Simon
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/2130#comment:3>
GHC <http://www.haskell.org/ghc/>
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