Too many specialisations in SpecConstr
Ben reports that SpecConstr
can loop:
{-# LANGUAGE PArr #-}
{-# OPTIONS -fvectorise #-}
module Loop where
import Data.Array.Parallel.Prelude
import Data.Array.Parallel.Prelude.Double
import qualified Prelude
loop :: [:Double:] -> [:Double:]
loop xs
| 0 == 0 = xs
| otherwise = ([::] !: 0) +:+ [::] +:+ ([::] !: 0)
Compile with
~/devel/ghc/ghc-head-incoming/inplace/bin/ghc-stage2 -c -Odph -fdph-seq -package dph-seq -package dph-prim-seq -c Loop.hs
(You need to build the DPH libraries first, of course.) This causes SpecConstr
to loop for at least 5 mins on my machine. Removing the middle [::]
in the last line gets it though SpecConstr, but the result size is 1501143 and it then runs out of memory in the simplifier.
Building with -dph-par
runs fine.
This is probably also why the dph-words
benchmark in the testsuite is failing due to using too much memory during compilation.
Trac metadata
Trac field | Value |
---|---|
Version | 7.0.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |