#9155: O2: allocateRegsAndSpill: Cannot read from uninitialized register %vI_s154O (GHC version 7.8.2 for x86_64-unknown-linux) -------------------------------------+------------------------------------ Reporter: slyfox | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by slyfox): -HEAD has the same disease: {{{ [sf] ~/dev/git/ghc:inplace/bin/ghc-stage2 --make -O2 /tmp/M.hs [1 of 1] Compiling M ( /tmp/M.hs, /tmp/M.o ) ghc-stage2: panic! (the 'impossible' happened) (GHC version 7.9.20140531 for x86_64-unknown-linux): RegAlloc.Liveness.computeLivenss SCCs aren't in reverse dependent order bad blockId c1cG ... }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9155#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler