#8905: Function arguments are always spilled/reloaded if scrutinee is already in WHNF --------------------------------------------+------------------------------ Reporter: tibbe | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.9 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime performance bug | Unknown/Multiple Test Case: | Difficulty: Unknown Blocking: | Blocked By: | Related Tickets: --------------------------------------------+------------------------------ Comment (by tibbe): Here are the nofib results on my machine {{{ $ nofib-analyse/nofib-analyse spill.log no-spill.log | head -n 150 NoFib Results -------------------------------------------------------------------------------- Program Size Allocs Runtime Elapsed TotalMem -------------------------------------------------------------------------------- anna +2.2% 0.0% 0.07 0.08 0.0% ansi 0.0% 0.0% 0.00 0.00 0.0% atom 0.0% 0.0% +7.9% +6.1% 0.0% awards 0.0% 0.0% 0.00 0.00 0.0% banner 0.0% 0.0% 0.00 0.00 0.0% bernouilli 0.0% 0.0% 0.11 0.12 0.0% binary-trees 0.0% 0.0% -14.8% -15.1% 0.0% boyer 0.0% 0.0% 0.02 0.03 0.0% boyer2 +0.2% 0.0% 0.00 0.00 0.0% bspt +1.7% 0.0% 0.00 0.01 0.0% cacheprof +0.5% -0.0% +11.8% +12.7% +5.5% calendar +0.1% 0.0% 0.00 0.00 0.0% cichelli +0.1% 0.0% 0.05 0.05 0.0% circsim +0.2% 0.0% +15.0% +15.8% 0.0% clausify 0.0% 0.0% 0.02 0.03 0.0% comp_lab_zift +0.2% 0.0% 0.12 0.13 0.0% compress +0.1% 0.0% 0.11 0.12 0.0% compress2 +0.6% 0.0% 0.10 0.12 0.0% constraints +0.1% 0.0% +9.4% +9.4% 0.0% cryptarithm1 0.0% 0.0% +19.2% +18.4% 0.0% cryptarithm2 +0.1% 0.0% 0.00 0.01 0.0% cse 0.0% 0.0% 0.00 0.00 0.0% eliza 0.0% 0.0% 0.00 0.00 0.0% event +0.1% 0.0% 0.09 0.10 0.0% exp3_8 0.0% 0.0% 0.15 0.16 0.0% expert +0.2% 0.0% 0.00 0.00 0.0% fannkuch-redux +0.1% 0.0% -7.6% -7.3% 0.0% fasta 0.0% 0.0% -4.5% -4.2% 0.0% fem +1.0% 0.0% 0.01 0.02 0.0% fft +0.1% 0.0% 0.02 0.03 0.0% fft2 +0.1% 0.0% 0.03 0.03 0.0% fibheaps +0.2% 0.0% 0.02 0.02 0.0% fish +0.1% 0.0% 0.01 0.01 0.0% fluid +2.5% 0.0% 0.00 0.01 0.0% fulsom +0.8% 0.0% 0.16 0.18 0.0% gamteb +0.3% 0.0% 0.02 0.03 0.0% gcd 0.0% 0.0% 0.02 0.02 0.0% gen_regexps 0.0% 0.0% 0.00 0.00 0.0% genfft 0.0% 0.0% 0.02 0.02 0.0% gg +0.5% 0.0% 0.00 0.01 0.0% grep +0.3% 0.0% 0.00 0.00 0.0% hidden +0.5% 0.0% +1.0% -0.0% 0.0% hpg +0.3% 0.0% 0.04 0.11 0.0% ida +0.2% 0.0% 0.06 0.06 0.0% infer +0.2% 0.0% 0.03 0.04 0.0% integer 0.0% 0.0% +5.6% +5.7% 0.0% integrate 0.0% 0.0% 0.06 0.09 0.0% k-nucleotide +0.2% 0.0% -4.6% -4.8% 0.0% kahan 0.0% 0.0% 0.17 0.18 0.0% knights +0.3% 0.0% 0.00 0.00 0.0% lcss 0.0% -0.0% +2.9% +2.6% 0.0% life 0.0% 0.0% 0.17 0.17 0.0% lift +0.3% 0.0% 0.00 0.00 0.0% listcompr 0.0% 0.0% 0.04 0.05 0.0% listcopy 0.0% 0.0% 0.05 0.06 0.0% maillist 0.0% +0.0% 0.03 0.17 +2.2% mandel 0.0% 0.0% 0.03 0.04 0.0% mandel2 +0.1% 0.0% 0.00 0.00 0.0% minimax +0.1% 0.0% 0.00 0.00 0.0% mkhprog +0.1% 0.0% 0.00 0.00 0.0% multiplier +0.1% 0.0% 0.07 0.08 0.0% n-body 0.0% 0.0% -6.3% -6.2% 0.0% nucleic2 +1.8% 0.0% 0.04 0.05 0.0% para +0.5% 0.0% 0.20 0.22 0.0% paraffins +0.1% 0.0% 0.07 0.09 0.0% parser +1.0% 0.0% 0.02 0.02 0.0% parstof +0.4% 0.0% 0.00 0.01 0.0% pic +0.5% 0.0% 0.00 0.01 0.0% pidigits 0.0% 0.0% -6.3% -5.5% 0.0% power +0.1% 0.0% +7.7% +7.4% +1.8% pretty 0.0% 0.0% 0.00 0.00 0.0% primes 0.0% 0.0% 0.04 0.04 0.0% primetest 0.0% 0.0% 0.06 0.07 0.0% prolog +0.2% 0.0% 0.00 0.00 0.0% puzzle +0.3% 0.0% 0.09 0.13 0.0% queens 0.0% 0.0% 0.01 0.01 0.0% reptile +0.5% 0.0% 0.00 0.01 0.0% reverse-complem +0.1% 0.0% 0.05 0.08 0.0% rewrite +0.2% 0.0% 0.01 0.01 0.0% rfib 0.0% 0.0% 0.01 0.01 0.0% rsa 0.0% 0.0% 0.01 0.01 0.0% scc 0.0% 0.0% 0.00 0.00 0.0% sched +0.1% 0.0% 0.01 0.01 0.0% scs +1.8% 0.0% -10.4% -13.1% 0.0% simple +2.9% 0.0% 0.15 0.17 0.0% solid +0.1% 0.0% 0.09 0.11 0.0% sorting +0.1% 0.0% 0.00 0.00 0.0% spectral-norm 0.0% 0.0% +3.5% +3.1% 0.0% sphere +0.6% 0.0% 0.02 0.03 0.0% symalg +0.2% 0.0% 0.00 0.00 0.0% tak 0.0% 0.0% 0.01 0.01 0.0% transform +0.4% 0.0% 0.22 +12.6% 0.0% treejoin +0.1% 0.0% 0.09 0.11 0.0% typecheck +0.1% 0.0% 0.14 0.15 0.0% veritas +1.9% 0.0% 0.00 0.01 0.0% wang +0.1% 0.0% 0.07 0.09 0.0% wave4main +0.1% 0.0% 0.14 0.16 0.0% wheel-sieve1 +0.1% 0.0% +3.8% +4.5% 0.0% wheel-sieve2 0.0% 0.0% 0.12 0.14 0.0% x2n1 0.0% 0.0% 0.00 0.00 0.0% -------------------------------------------------------------------------------- Min 0.0% -0.0% -14.8% -15.1% 0.0% Max +2.9% +0.0% +19.2% +18.4% +5.5% Geometric Mean +0.3% -0.0% +1.5% +1.8% +0.1% }}} A more detailed analysis of the results would be interesting. For example, I note that programs that are already heavily tuned (from the shootout suite) get faster, while some more "traditional" benchmarks get slower. However, given that it's a slight regressions on average on nofib, I think this isn't something we should go ahead with without further investigation. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8905#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler