-fregs-graph: GraphOps.coalesceNodes: can't coalesce the same node.

If -fregs-graph is used then the build fails when compiling PrimOps.cmm:

$ /home/ian/ghc/darcs/ghc/ghc/stage1-inplace/ghc  -Werror -H64m -O0 -fasm -optc-O2 -I../includes -I. -Iparallel -Ism -Ieventlog -DCOMPILING_RTS -package-name rts -static  -I../gmp/gmpbuild -I../libffi/build/include -I. -dcmm-lint     -c PrimOps.cmm -o PrimOps.o -fregs-graph
ghc: panic! (the 'impossible' happened)
  (GHC version 6.11.20090409 for x86_64-unknown-linux):
        GraphOps.coalesceNodes: can't coalesce the same node.

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

This blocks #2790 (closed).

Trac metadata

Trac field	Value
Version	6.10.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	high
Resolution	Unresolved
Component	Compiler
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