#1600: Optimisation: CPR the results of IO -------------------------------------+------------------------------------- Reporter: simonmar | Owner: nomeata Type: task | Status: new Priority: lowest | Milestone: 7.6.2 Component: Compiler | Version: 6.6.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: Runtime | Difficulty: Moderate (less performance bug | than a day) Test Case: | Blocked By: Blocking: | Related Tickets: #8598 -------------------------------------+------------------------------------- Comment (by nomeata): Fixed the `transform` issue (when analysing a complex case expression where we do the scrunitee first to feed nested CPR information into the pattern match variable, I was not making sure that the case binder gets at least a flat CPR property, even if the scrunitee has none), and we are finally where Simon expected nested CPR to be: No increased allocations any more (or at least none that are not surpassed by the gains). Still a very small effect, though. {{{ -------------------------------------------------------------------------------- Program Size Allocs Runtime Elapsed TotalMem -------------------------------------------------------------------------------- ansi +0.3% -0.1% 0.00 0.00 +0.0% awards +0.3% -0.1% 0.00 0.00 +0.0% compress2 +0.6% -0.8% 0.11 0.11 -8.0% fibheaps +0.3% -0.3% 0.03 0.03 +0.0% gamteb +0.4% -0.2% 0.04 0.04 +0.0% grep +0.3% -0.1% 0.00 0.00 +0.0% hpg +0.4% -3.0% 0.13 0.13 +0.0% infer +0.3% -1.2% 0.03 0.03 +0.0% k-nucleotide +0.2% -6.9% -0.7% -0.5% +0.0% maillist +0.4% -0.8% 0.04 0.04 -4.2% mkhprog +0.4% -0.3% 0.00 0.00 +0.0% pic +0.3% -0.7% 0.00 0.00 +0.0% pretty +0.4% -0.1% 0.00 0.00 +0.0% rfib +0.3% -0.2% 0.01 0.01 +0.0% scc +0.3% -0.1% 0.00 0.00 +0.0% spectral-norm +0.4% -0.1% +0.0% +0.0% +0.0% sphere +0.4% -4.7% 0.04 0.04 +0.0% symalg +0.3% -0.1% 0.01 0.01 +0.0% tak +0.3% -0.3% 0.01 0.01 +0.0% -------------------------------------------------------------------------------- Min +0.2% -6.9% -5.3% -27.3% -8.0% Max +0.7% +0.0% +1.4% +1.4% +50.0% Geometric Mean +0.3% -0.2% -0.7% -2.3% +0.2% }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/1600#comment:38 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler