Repository : ssh://darcs.haskell.org//srv/darcs/ghc On branch : master
http://hackage.haskell.org/trac/ghc/changeset/9ea2b6666cb6684279a120c688e8557bcef3dc73 >--------------------------------------------------------------- commit 9ea2b6666cb6684279a120c688e8557bcef3dc73 Author: Simon Peyton Jones <simo...@microsoft.com> Date: Mon Dec 24 11:34:51 2012 +0000 Simplify the binder-swap transformation The occurrence analyser implements the "binder-swap" transformation, described in Note [Binder swap] in OccAnal. For some reason I had implemeted an extremely complicated version, I believe intended to get as much as possible done in single simplifier pass. But it turned out (Trac #7258) that the 'getProxies' bit of this complicated code scaled rather non-linearly, and all by itself could consume half of the entire compile time. The patch dramatically simplifies the transformation, so that we simply swizzle case x of y { I# v -> e } to case x of y { I# v -> let x = y in e } I can't see any reason not to do this * Compiler allocation for #7258 with 200 fields goes down by 25% and compile time by 20% * The nofib figures do not budge * Quite a bit of complicated code goes away compiler/simplCore/OccurAnal.lhs | 255 +++++++------------------------------- 1 files changed, 46 insertions(+), 209 deletions(-) Diff suppressed because of size. To see it, use: git show 9ea2b6666cb6684279a120c688e8557bcef3dc73 _______________________________________________ Cvs-ghc mailing list Cvs-ghc@haskell.org http://www.haskell.org/mailman/listinfo/cvs-ghc
