#849: Offer control over branch prediction
---------------------------------+------------------------------------------
Reporter: simonpj | Owner:
Type: feature request | Status: new
Priority: normal | Milestone: 6.10 branch
Component: Compiler | Version: 6.4.2
Severity: normal | Resolution:
Keywords: | Difficulty: Unknown
Testcase: N/A | Os: Unknown/Multiple
Architecture: Unknown/Multiple |
---------------------------------+------------------------------------------
Changes (by claus):
* cc: claus (added)
Comment:
GHC actually ignores any expected-frequency information that programmers
might try to encode in the ordering of pattern-match/conditional clauses,
sorting them by data type definition order instead. If GHC would respect
the source ordering of branches, programmers would have a chance to
express expected frequency information without pragmas (assuming that
successful match would correspond to fall-through, no jump). See this
thread
[http://www.haskell.org/pipermail/glasgow-haskell-
users/2009-March/016907.html compilation of pattern-matching?]
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/849#comment:8>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
_______________________________________________
Glasgow-haskell-bugs mailing list
Glasgow-haskell-bugs@haskell.org
http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
