Panic when using lots of registers in cmm code

If I try to compile (using ghc -c) the following code:

test
{
  foreign "C" f(R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11);
}

I get:

ghc: panic! (the 'impossible' happened)
  (GHC version 7.2.1 for x86_64-apple-darwin):
	baseRegOffset:other

Trac metadata

Trac field	Value
Version	7.2.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
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