#14962: "ghc: Out of memory" upon compiling combination of map/foldl/setBit -------------------------------------+------------------------------------- Reporter: martijnbastiaan | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Resolution: | Keywords: Operating System: Linux | Architecture: x86_64 Type of failure: Compile-time | (amd64) crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Description changed by martijnbastiaan: Old description:
The following code snippet:
{{{#!hs module Test where
import Data.Bits (setBit) import Data.List
f :: Integer f = foldl setBit 0 toSet where toSet = [n | (n, _) <- zip [0..] [1]] }}}
Fails to compile, yielding:
{{{ martijn@qbltop:~/code/scratch$ ghc Test.hs -O1 [1 of 1] Compiling Test ( Test.hs, Test.o ) ghc: Out of memory }}}
A few observations:
- Compiling with no optimizations (-O0) works fine - I have not found a function other than setBit which triggers this behavior - Changing foldl to its strict brother foldl' does not help - Changing the type signature of "f" from "Integer" to "Int" causes the code to compile just fine
I have been unable to reduce this example any further. I am using GHC 8.2.1.
New description: The following code snippet: {{{#!hs module Test where import Data.Bits (setBit) f :: Integer f = foldl setBit 0 toSet where toSet = [n | (n, _) <- zip [0..] [1]] }}} Fails to compile, yielding: {{{ martijn@qbltop:~/code/scratch$ ghc Test.hs -O1 [1 of 1] Compiling Test ( Test.hs, Test.o ) ghc: Out of memory }}} A few observations: - Compiling with no optimizations (-O0) works fine - I have not found a function other than setBit which triggers this behavior - Changing foldl to its strict brother foldl' does not help - Changing the type signature of "f" from "Integer" to "Int" causes the code to compile just fine - Changing [0..] to something silly like [0..2^1024] does not trigger the bug I have been unable to reduce this example any further. I am using GHC 8.2.1. -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14962#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler