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Created by Sergei Trofimovich@trofiReporter

O2: allocateRegsAndSpill: Cannot read from uninitialized register %vI_s154O (GHC version 7.8.2 for x86_64-unknown-linux)

When building all world with -O2 I've stuck on wxhaskell (all versions):

[11 of 16] Compiling Graphics.UI.WX.Controls ( src/Graphics/UI/WX/Controls.hs, dist/build/Graphics/UI/WX/Controls.o )

<no location info>:
    ghc: panic! (the 'impossible' happened)
  (GHC version 7.8.2 for x86_64-unknown-linux):
        allocateRegsAndSpill: Cannot read from uninitialized register
    %vI_s154O

I've stripped it down to minimal complete example (but it significantly changed error message)

ghc: panic! (the 'impossible' happened)
  (GHC version 7.8.2 for x86_64-unknown-linux):
        RegAlloc.Liveness.computeLivenss
    SCCs aren't in reverse dependent order
    bad blockId c1tU
    [NONREC
        c1uc:
                movq $-8,%rbx
                andq $main:M.AlignLeft{v rb}_closure+1,%rbx
                addq $8,%rbp
                jmp *(%rbx),
     NONREC
...
Trac metadata
Trac field Value
Version 7.8.2
Type Bug
TypeOfFailure OtherFailure
Priority normal
Resolution Unresolved
Component Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture Unknown/Multiple
Edited by Sergei Trofimovich