June 2015 - ghc-tickets

[GHC] #10409: Binary compiled with ghc-7.10 amd64/linux to aarch64/linux cross compiler segfaults.
by GHC 22 Oct '15

22 Oct '15

#10409: Binary compiled with ghc-7.10 amd64/linux to aarch64/linux cross compiler segfaults. -------------------------------------+------------------------------------- Reporter: erikd | Owner: erikd Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.1 Keywords: cross- | Operating System: Linux compiling | Type of failure: Runtime crash Architecture: aarch64 | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Compiling a simple "hello-world" program with an amd64/linux to aarch64/linux cross compiler built from the current `ghc-7.10` branch results in a binary that segfaults as soon as it is run. A cross compiler build from the master branch works and I thought it also worked for `ghc-7.10`. A native aarch64/linux compiler built from the `ghc-7.10` branch works correctly. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10409> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10549: floatExpr tick break<2>
by GHC 22 Oct '15

22 Oct '15

#10549: floatExpr tick break<2> -------------------------------------+------------------------------------- Reporter: | Owner: NeilMitchell | Status: new Type: bug | Milestone: Priority: normal | Version: 7.11 Component: Compiler | Operating System: Unknown/Multiple Keywords: | Type of failure: None/Unknown Architecture: | Blocked By: Unknown/Multiple | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- When running the Shake test suite against GHC HEAD I get: {{{ ghc: panic! (the 'impossible' happened) (GHC version 7.11.20150615 for x86_64-unknown-linux): floatExpr tick break<2>() }}} Full log at https://travis-ci.org/ndmitchell/shake/jobs/67636563. The command line that produced it is: {{{ runhaskell -ignore-package=hashmap -ioutput/docs/ -isrc output/docs/Main.hs }}} If this seems like a legitimate bug that you don't already know about and are interested in tracking down, I'll try and grab the output/docs directory (it's on a remote machine I don't have access to on a different OS with a compiler I don't have installed, so it's not trivial to find it, but should be possible). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10549> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10493: Inaccessible code might be accessible with newtypes and Coercible
by GHC 22 Oct '15

22 Oct '15

#10493: Inaccessible code might be accessible with newtypes and Coercible -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- If I say {{{ module A (Age, ageCo) where import Data.Type.Coercion newtype Age = MkAge Int ageCo :: Coercion Age Int ageCo = Coercion }}} {{{ {-# LANGUAGE FlexibleContexts #-} module B where import Data.Coerce import A foo :: Coercible Age Int => () foo = () }}} I get {{{ B.hs:8:8: error: Couldn't match representation of type ‘Age’ with that of ‘Int’ Inaccessible code in the type signature for: foo :: Coercible Age Int => () In the ambiguity check for the type signature for ‘foo’: foo :: Coercible Age Int => () To defer the ambiguity check to use sites, enable AllowAmbiguousTypes In the type signature for ‘foo’: foo :: Coercible Age Int => () }}} I agree that module `B` can't directly prove `Coercible Age Int`. But `ageCo` is in scope which proves exactly this! So it is provable, albeit directly. GHC should not claim that the code is inaccessible. Proposed fix: in `canDecomposableTyConApp`, only call `canEqHardFailure` for a representational equality when both tycons involved say `True` to `isDistinctTyCon`. I'm happy to put the fix in, once someone seconds this idea. Getting this right has proved harder than I thought! -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10493> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9297: Packages linked against certain Windows .dll files give warnings at runtime
by GHC 22 Oct '15

22 Oct '15

#9297: Packages linked against certain Windows .dll files give warnings at runtime ----------------------------------+--------------------------------- Reporter: RyanGlScott | Owner: simonmar Type: bug | Status: new Priority: normal | Milestone: Component: Runtime System | Version: 7.8.2 Keywords: | Operating System: Windows Architecture: x86_64 (amd64) | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------------+--------------------------------- I am using GHC 7.8.3 on Windows 7, x86_64. When GHC loads certain packages at runtime, it gives some interesting warnings: {{{ > ghci -package haskeline GHCi, version 7.8.3: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Loading package array-0.5.0.0 ... linking ... done. Loading package deepseq-1.3.0.2 ... linking ... done. Loading package bytestring-0.10.4.0 ... linking ... done. Loading package Win32-2.3.0.2 ... linking ... done. Loading package containers-0.5.5.1 ... linking ... done. Loading package filepath-1.3.0.2 ... linking ... done. Loading package old-locale-1.0.0.6 ... linking ... done. Loading package time-1.4.2 ... linking ... done. Loading package directory-1.2.1.0 ... linking ... done. Loading package transformers-0.3.0.0 ... linking ... done. Loading package haskeline-0.7.1.2 ... linking ... ghc.exe: warning: SetConsoleCursorPosition from kernel32 is linked instead of __imp_SetConsoleCursorPosition ghc.exe: warning: FillConsoleOutputCharacterA from kernel32 is linked instead of __imp_FillConsoleOutputCharacterA ghc.exe: warning: FillConsoleOutputAttribute from kernel32 is linked instead of __imp_FillConsoleOutputAttribute done. Prelude> }}} Besides {{{haskeline}}}, other packages with similar problems include {{{unix-compat}}}, {{{network}}}, and {{{regex-posix}}}. To see them all at once, you can run the [{{{hermit-web}}} https://github.com/ku-fpg /hermit-web] executable: {{{ > hermit-web Last.hs [starting HERMIT-Web v0.1.0.0 on Last.hs] [starting HERMIT v0.5.0.0 on Last.hs] % ghc Last.hs -fforce-recomp -O2 -dcore-lint -fsimple-list-literals -fexpose-all-unfoldings -fplugin=HERMIT.Web -fplugin-opt=HERMIT.Web:*: [1 of 1] Compiling Main ( Last.hs, Last.o ) Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Loading package array-0.5.0.0 ... linking ... done. Loading package deepseq-1.3.0.2 ... linking ... done. Loading package bytestring-0.10.4.0 ... linking ... done. Loading package containers-0.5.5.1 ... linking ... done. Loading package Win32-2.3.0.2 ... linking ... done. Loading package filepath-1.3.0.2 ... linking ... done. Loading package old-locale-1.0.0.6 ... linking ... done. Loading package time-1.4.2 ... linking ... done. Loading package directory-1.2.1.0 ... linking ... done. Loading package pretty-1.1.1.1 ... linking ... done. Loading package process-1.2.0.0 ... linking ... done. Loading package Cabal-1.18.1.3 ... linking ... done. Loading package binary-0.7.1.0 ... linking ... done. Loading package bin-package-db-0.0.0.0 ... linking ... done. Loading package hoopl-3.10.0.1 ... linking ... done. Loading package hpc-0.6.0.1 ... linking ... done. Loading package template-haskell ... linking ... done. Loading package transformers-0.3.0.0 ... linking ... done. Loading package ghc-7.8.3 ... linking ... done. Loading package haskeline-0.7.1.2 ... linking ... ghc: warning: SetConsoleCursorPosition from kernel32 is linked instead of __imp_SetConsoleCursorPosition ghc: warning: FillConsoleOutputCharacterA from kernel32 is linked instead of __imp_FillConsoleOutputCharacterA ghc: warning: FillConsoleOutputAttribute from kernel32 is linked instead of __imp_FillConsoleOutputAttribute done. Loading package text-1.1.1.3 ... linking ... done. Loading package hashable-1.2.2.0 ... linking ... done. Loading package scientific-0.3.2.2 ... linking ... done. Loading package attoparsec-0.12.1.0 ... linking ... done. Loading package dlist-0.7.1 ... linking ... done. Loading package mtl-2.1.3.1 ... linking ... done. Loading package syb-0.4.2 ... linking ... done. Loading package unordered-containers-0.2.5.0 ... linking ... done. Loading package primitive-0.5.3.0 ... linking ... done. Loading package vector-0.10.11.0 ... linking ... done. Loading package aeson-0.7.0.6 ... linking ... done. Loading package blaze-builder-0.3.3.2 ... linking ... done. Loading package data-default-class-0.0.1 ... linking ... done. Loading package data-default-instances-base-0.0.1 ... linking ... done. Loading package data-default-instances-containers-0.0.1 ... linking ... done. Loading package data-default-instances-dlist-0.0.1 ... linking ... done. Loading package data-default-instances-old-locale-0.0.1 ... linking ... done. Loading package data-default-0.5.3 ... linking ... done. Loading package ansi-terminal-0.6.1.1 ... linking ... done. Loading package kure-2.16.2 ... linking ... done. Loading package marked-pretty-0.1 ... linking ... done. Loading package random-1.0.1.1 ... linking ... done. Loading package operational-0.2.3.2 ... linking ... done. Loading package stm-2.4.3 ... linking ... done. Loading package exceptions-0.6.1 ... linking ... done. Loading package temporary-1.2.0.3 ... linking ... done. Loading package hermit-0.5.0.0 ... linking ... done. Loading package case-insensitive-1.2.0.0 ... linking ... done. Loading package http-types-0.8.5 ... linking ... done. Loading package transformers-base-0.4.2 ... linking ... done. Loading package monad-control-0.3.3.0 ... linking ... done. Loading package lifted-base-0.2.3.0 ... linking ... done. Loading package mmorph-1.0.3 ... linking ... done. Loading package resourcet-1.1.2.2 ... linking ... done. Loading package nats-0.2 ... linking ... done. Loading package semigroups-0.15.1 ... linking ... done. Loading package void-0.6.1 ... linking ... done. Loading package conduit-1.1.6 ... linking ... done. Loading package regex-base-0.93.2 ... linking ... done. Loading package regex-posix-0.95.2 ... linking ... ghc: warning: isupper from msvcrt is linked instead of __imp_isupper ghc: warning: toupper from msvcrt is linked instead of __imp_toupper ghc: warning: tolower from msvcrt is linked instead of __imp_tolower ghc: warning: isalpha from msvcrt is linked instead of __imp_isalpha ghc: warning: isalpha from msvcrt is linked instead of __imp_isalpha ghc: warning: isalpha from msvcrt is linked instead of __imp_isalpha ghc: warning: iscntrl from msvcrt is linked instead of __imp_iscntrl ghc: warning: isupper from msvcrt is linked instead of __imp_isupper ghc: warning: isgraph from msvcrt is linked instead of __imp_isgraph ghc: warning: isprint from msvcrt is linked instead of __imp_isprint ghc: warning: ispunct from msvcrt is linked instead of __imp_ispunct ghc: warning: isalnum from msvcrt is linked instead of __imp_isalnum ghc: warning: isalpha from msvcrt is linked instead of __imp_isalpha ghc: warning: isalnum from msvcrt is linked instead of __imp_isalnum ghc: warning: isalnum from msvcrt is linked instead of __imp_isalnum ghc: warning: isalnum from msvcrt is linked instead of __imp_isalnum ghc: warning: isalnum from msvcrt is linked instead of __imp_isalnum ghc: warning: isalnum from msvcrt is linked instead of __imp_isalnum ghc: warning: isalnum from msvcrt is linked instead of __imp_isalnum ghc: warning: isalnum from msvcrt is linked instead of __imp_isalnum ghc: warning: isalnum from msvcrt is linked instead of __imp_isalnum ghc: warning: isalnum from msvcrt is linked instead of __imp_isalnum ghc: warning: isalnum from msvcrt is linked instead of __imp_isalnum ghc: warning: isalnum from msvcrt is linked instead of __imp_isalnum ghc: warning: isalnum from msvcrt is linked instead of __imp_isalnum done. Loading package regex-compat-0.95.1 ... linking ... done. Loading package parsec-3.1.5 ... linking ... done. Loading package network-2.5.0.0 ... linking ... ghc: warning: WSACleanup from ws2_32 is linked instead of __imp_WSACleanup ghc: warning: WSAStartup from ws2_32 is linked instead of __imp_WSAStartup ghc: warning: WSACleanup from ws2_32 is linked instead of __imp_WSACleanup ghc: warning: accept from ws2_32 is linked instead of __imp_accept ghc: warning: inet_ntoa from ws2_32 is linked instead of __imp_inet_ntoa ghc: warning: getnameinfo from ws2_32 is linked instead of __imp_getnameinfo ghc: warning: getaddrinfo from ws2_32 is linked instead of __imp_getaddrinfo ghc: warning: freeaddrinfo from ws2_32 is linked instead of __imp_freeaddrinfo done. Loading package vault-0.3.0.3 ... linking ... done. Loading package wai-3.0.0.2 ... linking ... done. Loading package base64-bytestring-1.0.0.1 ... linking ... done. Loading package fast-logger-2.1.5 ... linking ... done. Loading package zlib-0.5.4.1 ... linking ... done. Loading package streaming-commons-0.1.3.1 ... linking ... done. Loading package stringsearch-0.3.6.5 ... linking ... done. Loading package byteorder-1.0.4 ... linking ... done. Loading package wai-logger-2.1.1 ... linking ... done. Loading package word8-0.0.4 ... linking ... done. Loading package wai-extra-3.0.1 ... linking ... done. Loading package conduit-extra-1.1.1 ... linking ... done. Loading package simple-sendfile-0.2.15 ... linking ... done. Loading package unix-compat-0.4.1.3 ... linking ... ghc: warning: GetVersionExA from kernel32 is linked instead of __imp_GetVersionExA ghc: warning: GetModuleHandleA from kernel32 is linked instead of __imp_GetModuleHandleA ghc: warning: GetProcAddress from kernel32 is linked instead of __imp_GetProcAddress ghc: warning: _snprintf from msvcrt is linked instead of __imp__snprintf ghc: warning: GetSystemInfo from kernel32 is linked instead of __imp_GetSystemInfo ghc: warning: GetSystemMetrics from user32 is linked instead of __imp_GetSystemMetrics ghc: warning: GetVersionExA from kernel32 is linked instead of __imp_GetVersionExA ghc: warning: _snprintf from msvcrt is linked instead of __imp__snprintf ghc: warning: GetSystemInfo from kernel32 is linked instead of __imp_GetSystemInfo ghc: warning: GetComputerNameA from kernel32 is linked instead of __imp_GetComputerNameA ghc: warning: CryptAcquireContextA from advapi32 is linked instead of __imp_CryptAcquireContextA ghc: warning: CryptGenRandom from advapi32 is linked instead of __imp_CryptGenRandom ghc: warning: _stat64 from msvcrt is linked instead of __imp__stat64 ghc: warning: _open from msvcrt is linked instead of __imp__open ghc: warning: _stat64 from msvcrt is linked instead of __imp__stat64 done. Loading package warp-3.0.0.4 ... linking ... done. Loading package scotty-0.8.1 ... linking ... done. Loading package hermit-web-0.1.0.0 ... linking ... done. Setting phasers to stun... (port 3000) (ctrl-c to quit) }}} These warnings seem to be related to Windows-specific {{{.dll}}} files, including {{{kernel32.dll}}}, {{{user32.dll}}}, {{{msvcrt.dll}}}, {{{advapi32.dll}}}, and {{{ws2_32.dll}}}. As far as I can tell, there are no problems other than the warnings themselves, but I can't be sure. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9297> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9878: Static pointers in GHCi cause panic
by GHC 22 Oct '15

22 Oct '15

#9878: Static pointers in GHCi cause panic -------------------------------------+------------------------------------- Reporter: monoidal | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.9 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: GHCi crash Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- I load this module into ghci {{{#!hs {-# LANGUAGE StaticPointers #-} module Static where import GHC.StaticPtr f = deRefStaticPtr (static True) }}} and get a panic upon evaluating `f` {{{ > f ghc: panic! (the 'impossible' happened) (GHC version 7.9.20141210 for x86_64-unknown-linux): Loading temp shared object failed: /tmp/ghc30486_0/ghc30486_5.so: undefined symbol: Static_sptEntryZC0_closure Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} Am I doing static pointers right? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9878> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10149: The argument of mask does not always restore the masking state
by GHC 22 Oct '15

22 Oct '15

#10149: The argument of mask does not always restore the masking state -------------------------------------+------------------------------------- Reporter: | Owner: facundo.dominguez | Status: new Type: bug | Milestone: Priority: normal | Version: 7.8.4 Component: | Operating System: Unknown/Multiple libraries/base | Type of failure: None/Unknown Keywords: | Blocked By: Architecture: | Related Tickets: Unknown/Multiple | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- In the documentation of `mask` and `uninterruptibleMask` it is claimed that the `restore` argument restores the masking state. However this is not true in the following programs: {{{#!hs mask_ $ -- start with exceptions masked mask $ \restore -> forkIOWithUnmask $ \unmask -> unmask $ restore $ getMaskingState >>= print }}} {{{#!hs uninterruptibleMask_ $ -- start with exceptions uninterruptibly masked uninterruptibleMask $ \restore -> forkIOWithUnmask $ \unmask -> unmask $ restore $ getMaskingState >>= print }}} The expected state is that `getMaskingState` would produce `MaskedInterruptible` and `MaskedUninterruptible`, however, in both cases it gives Unmasked. Either the documentation needs to be changed, or the implementation must really restore the masking state in these cases. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10149> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10498: "if ... then \case -> else ..." causes a "missing else clause" error
by GHC 22 Oct '15

22 Oct '15

#10498: "if ... then \case -> else ..." causes a "missing else clause" error -------------------------------------+------------------------------------- Reporter: | Owner: dramforever | Status: new Type: bug | Milestone: Priority: normal | Version: 7.10.1 Component: Compiler | Operating System: Unknown/Multiple (Parser) | Type of failure: Other Keywords: | Blocked By: Architecture: | Related Tickets: Unknown/Multiple | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- The following program: {{{#!hs {-# LANGUAGE LambdaCase #-} foo = if True then \case -> 1 -> 2 else id }}} Produces this message: {{{ problem.hs:4:5: parse error in if statement: missing required else clause }}} The problem in the code is that there's a -> after the \case. I don't know if a better error message can be generated, but this one is really unhelpful. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10498> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10375: arm: ghci.debugger tests hit illegal instruction
by GHC 22 Oct '15

22 Oct '15

#10375: arm: ghci.debugger tests hit illegal instruction ---------------------------------+------------------------------------- Reporter: erikd | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.12.1 Component: GHCi | Version: 7.11 Keywords: | Operating System: Unknown/Multiple Architecture: arm | Type of failure: GHCi crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | ---------------------------------+------------------------------------- Some GHCi tests on arm/linux ie: {{{ (cd testsuite ; make TEST="print018 print020 print021 print022 print025") }}} fail, all with the same error: {{{ Stderr: Illegal instruction }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10375> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10469: ghc crash on arm with -j2: internal error: scavenge: unimplemented/strange closure type
by GHC 22 Oct '15

22 Oct '15

#10469: ghc crash on arm with -j2: internal error: scavenge: unimplemented/strange closure type -----------------------------------+--------------------------------------- Reporter: joeyhess | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.1 Keywords: | Operating System: Linux Architecture: arm | Type of failure: Compile-time crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -----------------------------------+--------------------------------------- ghc: internal error: scavenge: unimplemented/strange closure type 0 @ 0xac103240 (GHC version 7.10.1 for arm_unknown_linux) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug Aborted I can consistently get either this crash, or a segfault from ghc, building git-annex on an arm system. Seems about 50/50. In either case, it crashes either before ghc has printed out any "Compiling" lines, or within the first 1 or 2 files compiled. I got lucky and found out a way to avoid the crash.. cabal was passing -j2 to ghc. If I remove the -j2, the build proceeds without a crash. The hardware is a CubieTruck arm board, with 2 gb of ram, and 1 cpu core, running Debian armel unstable, with kernel 3.4.103. I was able to use cabal to install the entire dependencies of git-annex, all the way up to yesod, which takes hours on this hardware, and all that built ok.. so I think the hardware is pretty stable, but still cannot really rule out a hardware problem. Happy to debug further, although this machine is a bit resource constrained to do things like building ghc on it. ghc 7.8.4 and 7.10.1 both crash the same way. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10469> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10014: Data.Array.Base.elems needlessly calls bounds.
by GHC 21 Oct '15

21 Oct '15

#10014: Data.Array.Base.elems needlessly calls bounds. -------------------------------------+------------------------------------- Reporter: ekmett | Owner: ekmett Type: feature | Status: new request | Milestone: Priority: normal | Version: 7.8.4 Component: Core | Operating System: Unknown/Multiple Libraries | Type of failure: Runtime Keywords: | performance bug Architecture: | Blocked By: Unknown/Multiple | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- {{{ elems arr = case bounds arr of (_l, _u) -> [unsafeAt arr i | i <- [0 .. numElements arr - 1]] }}} It never uses the result. I'd propose simplifying it to {{{ elems arr = [unsafeAt arr i | i <- [0 .. numElements arr - 1]] }}} It appears at some point someone optimized it to use the `unsafeAt`, but never removed the bounds check. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10014> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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