Calling a function which takes SIMD vectors causes a segfault

The following program which uses SIMD vectors reliably segfaults. (Currently the only backend that supports SIMD is the LLVM backend, but it segfaults with the native backend I am adding to GHC as well.)

{-# LANGUAGE Haskell2010 #-}
{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE MagicHash #-}
{-# LANGUAGE UnboxedTuples #-}

module Main where

import GHC.Exts

main :: IO ()
main =
  case foo ( \ x y -> plusDoubleX2# x y ) of
    v -> case unpackDoubleX2# v of
      (# d1, d2 #) ->
        print [ D# d1, D# d2 ]

{-# NOINLINE foo #-}
foo :: ( DoubleX2# -> DoubleX2# -> DoubleX2# ) -> DoubleX2#
foo f =
  case packDoubleX2# (# 10.01##, 20.02## #) of
    !x -> f x x

To reproduce, compile this file and run it. For instance, with the LLVM backend, ghc Main.hs -fllvm. This will segfault somewhere inside stg_ap_v16_fast.

Looking at the assembly, the code before the jump to stg_ap_v16_fast seem correct to me, so I currently suspect that stg_ap_v16_fast is at fault (I may be wrong).